blood research article

Submission guidelines

Article types, manuscript submission, artwork and illustrations guidelines, supplementary information (si), after acceptance, research data policy and data availability statements, terminology, ethical responsibilities of authors, competing interests, research involving human participants, their data or biological material, authorship principles, research involving human embryos, gametes and stem cells, editorial procedure, editing services, open access publishing.

• Mistakes to avoid during manuscript preparation

Instructions for Authors

Blood Research accepts submissions of the following article types:

Is a manuscript containing results of clinical, laboratory, or experimental investigations. The article should be organized in the order of Title page, Abstract, Introduction, Materials and Methods, Discussion, Acknowledgments, References, Tables and Figures. Length is limited to 3500 words of body text and 30 references.

Is usually solicited by the Editor-in-Chief. Authors who wish to submit an unsolicited review should contact the Editor-in- Chief. Topics of scientific consensus or remaining controversial may be dealt with in the review. It is organized as Title page, Abstract, Introduction, body text, Conclusion, Acknowledgments, References, Tables and Figures. Length is limited to 250 words of unstructured abstracts, 5000 words of body text, and 150 references.

Is usually written by Editorial Board members. It focuses on the recent hot issues or deals with the articles in the corresponding issue. It may include up to 1200 words and 10 references.

Article covers a wide variety of topics of current hematology- related issues. It may include up to 1200 words, one figure, 2 tables and 10 references.

Contains brief communications on interesting topics in hematology may be considered for publication. Comments that concern previously published articles may also be considered, and if necessary, responses by the author of the subject paper may be provided. Letters may be edited by the Editorial Board. The maximum length of a Letter is 1,500 words. Letters should have no more than 6 authors, 2 tables, 2 figures with legends, and 15 references.

Is intended to share an interesting and impressive hematology-related image that has not been submitted or published elsewhere. The title should contain no more than 10 words and the legend should contain no more than 200 words.

Submission of a manuscript implies: that the work described has not been published before; that it is not under consideration for publication anywhere else; that its publication has been approved by all co-authors, if any, as well as by the responsible authorities – tacitly or explicitly – at the institute where the work has been carried out. The publisher will not be held legally responsible should there be any claims for compensation.

Permissions

Authors wishing to include figures, tables, or text passages that have already been published elsewhere are required to obtain permission from the copyright owner(s) for both the print and online format and to include evidence that such permission has been granted when submitting their papers. Any material received without such evidence will be assumed to originate from the authors.

Online Submission

Please follow the hyperlink “Submit manuscript” and upload all of your manuscript files following the instructions given on the screen.

Source Files

Please ensure you provide all relevant editable source files at every submission and revision. Failing to submit a complete set of editable source files will result in your article not being considered for review. For your manuscript text please always submit in common word processing formats such as .docx or LaTeX.

Please make sure your title page contains the following information.

The title should be concise and informative.

Author information

• The name(s) of the author(s)
• The affiliation(s) of the author(s), i.e. institution, (department), city, (state), country
• A clear indication and an active e-mail address of the corresponding author
• If available, the 16-digit ORCID of the author(s)

If address information is provided with the affiliation(s) it will also be published.

For authors that are (temporarily) unaffiliated we will only capture their city and country of residence, not their e-mail address unless specifically requested.

Large Language Models (LLMs), such as ChatGPT , do not currently satisfy our authorship criteria . Notably an attribution of authorship carries with it accountability for the work, which cannot be effectively applied to LLMs. Use of an LLM should be properly documented in the Methods section (and if a Methods section is not available, in a suitable alternative part) of the manuscript.

Please provide a structured abstract of 150 to 250 words which should be divided into the following sections:

• Purpose (stating the main purposes and research question)

For life science journals only (when applicable)

• Trial registration number and date of registration for prospectively registered trials
• Trial registration number and date of registration followed by “retrospectively registered”, for retrospectively registered trials

Please provide 4 to 6 keywords which can be used for indexing purposes.

Statements and Declarations

The following statements should be included under the heading "Statements and Declarations" for inclusion in the published paper. Please note that submissions that do not include relevant declarations will be returned as incomplete.

• Competing Interests: Authors are required to disclose financial or non-financial interests that are directly or indirectly related to the work submitted for publication. Please refer to “Competing Interests and Funding” below for more information on how to complete this section.

Please see the relevant sections in the submission guidelines for further information as well as various examples of wording. Please revise/customize the sample statements according to your own needs.

Text Formatting

Manuscripts should be submitted in Word.

• Use a normal, plain font (e.g., 10-point Times Roman) for text.
• Use italics for emphasis.
• Use the automatic page numbering function to number the pages.
• Do not use field functions.
• Use tab stops or other commands for indents, not the space bar.
• Use the table function, not spreadsheets, to make tables.
• Use the equation editor or MathType for equations.
• Save your file in docx format (Word 2007 or higher) or doc format (older Word versions).

Manuscripts with mathematical content can also be submitted in LaTeX. We recommend using Springer Nature’s LaTeX template .

Please use no more than three levels of displayed headings.

Abbreviations

Abbreviations should be defined at first mention and used consistently thereafter.

Footnotes can be used to give additional information, which may include the citation of a reference included in the reference list. They should not consist solely of a reference citation, and they should never include the bibliographic details of a reference. They should also not contain any figures or tables.

Footnotes to the text are numbered consecutively; those to tables should be indicated by superscript lower-case letters (or asterisks for significance values and other statistical data). Footnotes to the title or the authors of the article are not given reference symbols.

Always use footnotes instead of endnotes.

Acknowledgments

Acknowledgments of people, grants, funds, etc. should be placed in a separate section on the title page. The names of funding organizations should be written in full.

Reference citations in the text should be identified by numbers in square brackets. Some examples:

1. Negotiation research spans many disciplines [3].

2. This result was later contradicted by Becker and Seligman [5].

3. This effect has been widely studied [1-3, 7].

Reference list

The list of references should only include works that are cited in the text and that have been published or accepted for publication. Personal communications and unpublished works should only be mentioned in the text.

The entries in the list should be numbered consecutively.

If available, please always include DOIs as full DOI links in your reference list (e.g. “https://doi.org/abc”).

Smith JJ. The world of science. Am J Sci. 1999;36:234–5.

Slifka MK, Whitton JL. Clinical implications of dysregulated cytokine production. J Mol Med. 2000; https://doi.org/10.1007/s001090000086

Blenkinsopp A, Paxton P. Symptoms in the pharmacy: a guide to the management of common illness. 3rd ed. Oxford: Blackwell Science; 1998.

Wyllie AH, Kerr JFR, Currie AR. Cell death: the significance of apoptosis. In: Bourne GH, Danielli JF, Jeon KW, editors. International review of cytology. London: Academic; 1980. pp. 251–306.

Doe J. Title of subordinate document. In: The dictionary of substances and their effects. Royal Society of Chemistry. 1999. http://www.rsc.org/dose/title of subordinate document. Accessed 15 Jan 1999.

Always use the standard abbreviation of a journal’s name according to the ISSN List of Title Word Abbreviations, see

ISSN.org LTWA

If you are unsure, please use the full journal title.

• All tables are to be numbered using Arabic numerals.
• Tables should always be cited in text in consecutive numerical order.
• For each table, please supply a table caption (title) explaining the components of the table.
• Identify any previously published material by giving the original source in the form of a reference at the end of the table caption.
• Footnotes to tables should be indicated by superscript lower-case letters (or asterisks for significance values and other statistical data) and included beneath the table body.

Electronic Figure Submission

• Supply all figures electronically.
• Indicate what graphics program was used to create the artwork.
• For vector graphics, the preferred format is EPS; for halftones, please use TIFF format. MSOffice files are also acceptable.
• Vector graphics containing fonts must have the fonts embedded in the files.
• Name your figure files with "Fig" and the figure number, e.g., Fig1.eps.
• Definition: Black and white graphic with no shading.
• Do not use faint lines and/or lettering and check that all lines and lettering within the figures are legible at final size.
• All lines should be at least 0.1 mm (0.3 pt) wide.
• Scanned line drawings and line drawings in bitmap format should have a minimum resolution of 1200 dpi.

Halftone Art

• Definition: Photographs, drawings, or paintings with fine shading, etc.
• If any magnification is used in the photographs, indicate this by using scale bars within the figures themselves.
• Halftones should have a minimum resolution of 300 dpi.

Combination Art

• Definition: a combination of halftone and line art, e.g., halftones containing line drawing, extensive lettering, color diagrams, etc.
• Combination artwork should have a minimum resolution of 600 dpi.
• Color illustrations should be submitted as RGB (8 bits per channel).

Figure Lettering

• To add lettering, it is best to use Helvetica or Arial (sans serif fonts).
• Keep lettering consistently sized throughout your final-sized artwork, usually about 2–3 mm (8–12 pt).
• Variance of type size within an illustration should be minimal, e.g., do not use 8-pt type on an axis and 20-pt type for the axis label.
• Avoid effects such as shading, outline letters, etc.
• Do not include titles or captions within your illustrations.

Figure Numbering

• All figures are to be numbered using Arabic numerals.
• Figures should always be cited in text in consecutive numerical order.
• Figure parts should be denoted by lowercase letters (a, b, c, etc.).
• If an appendix appears in your article and it contains one or more figures, continue the consecutive numbering of the main text. Do not number the appendix figures,"A1, A2, A3, etc." Figures in online appendices [Supplementary Information (SI)] should, however, be numbered separately.

Figure Captions

• Each figure should have a concise caption describing accurately what the figure depicts. Include the captions in the text file of the manuscript, not in the figure file.
• Figure captions begin with the term Fig. in bold type, followed by the figure number, also in bold type.
• No punctuation is to be included after the number, nor is any punctuation to be placed at the end of the caption.
• Identify all elements found in the figure in the figure caption; and use boxes, circles, etc., as coordinate points in graphs.
• Identify previously published material by giving the original source in the form of a reference citation at the end of the figure caption.

Figure Placement and Size

• Figures should be submitted within the body of the text. Only if the file size of the manuscript causes problems in uploading it, the large figures should be submitted separately from the text.

If you include figures that have already been published elsewhere, you must obtain permission from the copyright owner(s). Please be aware that some publishers do not grant electronic rights for free and that Springer will not be able to refund any costs that may have occurred to receive these permissions. In such cases, material from other sources should be used.

Accessibility

In order to give people of all abilities and disabilities access to the content of your figures, please make sure that

• All figures have descriptive captions (blind users could then use a text-to-speech software or a text-to-Braille hardware)
• Patterns are used instead of or in addition to colors for conveying information (colorblind users would then be able to distinguish the visual elements)
• Any figure lettering has a contrast ratio of at least 4.5:1

Generative AI Images

Please check Springer’s policy on generative AI images and make sure your work adheres to the principles described therein.

Springer accepts electronic multimedia files (animations, movies, audio, etc.) and other supplementary files to be published online along with an article or a book chapter. This feature can add dimension to the author's article, as certain information cannot be printed or is more convenient in electronic form.

Before submitting research datasets as Supplementary Information, authors should read the journal’s Research data policy. We encourage research data to be archived in data repositories wherever possible.

• Supply all supplementary material in standard file formats.
• Please include in each file the following information: article title, journal name, author names; affiliation and e-mail address of the corresponding author.
• To accommodate user downloads, please keep in mind that larger-sized files may require very long download times and that some users may experience other problems during downloading.
• High resolution (streamable quality) videos can be submitted up to a maximum of 25GB; low resolution videos should not be larger than 5GB.

Audio, Video, and Animations

• Aspect ratio: 16:9 or 4:3
• Maximum file size: 25 GB for high resolution files; 5 GB for low resolution files
• Minimum video duration: 1 sec
• Supported file formats: avi, wmv, mp4, mov, m2p, mp2, mpg, mpeg, flv, mxf, mts, m4v, 3gp

Text and Presentations

• Submit your material in PDF format; .doc or .ppt files are not suitable for long-term viability.
• A collection of figures may also be combined in a PDF file.

Spreadsheets

• Spreadsheets should be submitted as .csv or .xlsx files (MS Excel).

Specialized Formats

• Specialized format such as .pdb (chemical), .wrl (VRML), .nb (Mathematica notebook), and .tex can also be supplied.

Collecting Multiple Files

• It is possible to collect multiple files in a .zip or .gz file.
• If supplying any supplementary material, the text must make specific mention of the material as a citation, similar to that of figures and tables.
• Refer to the supplementary files as “Online Resource”, e.g., "... as shown in the animation (Online Resource 3)", “... additional data are given in Online Resource 4”.
• Name the files consecutively, e.g. “ESM_3.mpg”, “ESM_4.pdf”.
• For each supplementary material, please supply a concise caption describing the content of the file.

Processing of supplementary files

• Supplementary Information (SI) will be published as received from the author without any conversion, editing, or reformatting.

In order to give people of all abilities and disabilities access to the content of your supplementary files, please make sure that

• The manuscript contains a descriptive caption for each supplementary material
• Video files do not contain anything that flashes more than three times per second (so that users prone to seizures caused by such effects are not put at risk)

Color illustrations

Publication of color illustrations is free of charge.

Proof reading

The purpose of the proof is to check for typesetting or conversion errors and the completeness and accuracy of the text, tables and figures. Substantial changes in content, e.g., new results, corrected values, title and authorship, are not allowed without the approval of the Editor. After online publication, further changes can only be made in the form of an Erratum, which will be hyperlinked to the article.

Articles in Springer Nature open access journals do not require transfer of copyright as the copyright remains with the author. In confirming the publication of your article with open access you agree to the Creative Commons Attribution License.

Find more about the license agreement

This journal operates a type 3 research data policy . A submission to the journal implies that materials described in the manuscript, including all relevant raw data, will be freely available to any researcher wishing to use them for non-commercial purposes, without breaching participant confidentiality.

Data availability

All original research must include a data availability statement. Data availability statements should include information on where data supporting the results reported in the article can be found, if applicable. Statements should include, where applicable, hyperlinks to publicly archived datasets analysed or generated during the study. For the purposes of the data availability statement, “data” is defined as the minimal dataset that would be necessary to interpret, replicate and build upon the findings reported in the article. When it is not possible to share research data publicly, for instance when individual privacy could be compromised, data availability should still be stated in the manuscript along with any conditions for access. Data availability statements can take one of the following forms (or a combination of more than one if required for multiple datasets):

1. The datasets generated during and/or analysed during the current study are available in the [NAME] repository, [PERSISTENT WEB LINK TO DATASETS]

2. The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.

3. All data generated or analysed during this study are included in this published article [and its supplementary information files].

4. The datasets generated during and/or analysed during the current study are not publicly available due [REASON(S) WHY DATA ARE NOT PUBLIC] but are available from the corresponding author on reasonable request.].

5. Data sharing not applicable to this article as no datasets were generated or analysed during the current study.

6. The data that support the findings of this study are available from [THIRD PARTY NAME] but restrictions apply to the availability of these data, which were used under licence for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of [THIRD PARTY NAME].

More templates for data availability statements, including examples of openly available and restricted access datasets, are available here:

Data availability statements

Data repositories

This journal strongly encourages that all datasets on which the conclusions of the paper rely are available to readers. We encourage authors to ensure that their datasets are either deposited in publicly available repositories (where available and appropriate) or presented in the main manuscript or additional supporting files whenever possible. Please see Springer Nature’s information on recommended repositories.

List of Repositories

General repositories - for all types of research data - such as figshare and Dryad may be used where appropriate.

Data citation

The journal also requires that authors cite any publicly available data on which the conclusions of the paper rely. Data citations should include a persistent identifier (such as a DOI), should be included in the reference list using the minimum information recommended by DataCite, and follow journal style. Dataset identifiers including DOIs should be expressed as full URLs.

Research data and peer review

Peer reviewers are encouraged to check the manuscript’s Data availability statement, where applicable. They should consider if the authors have complied with the journal’s policy on the availability of research data, and whether reasonable effort has been made to make the data that support the findings of the study available for replication or reuse by other researchers. Peer reviewers are entitled to request access to underlying data (and code) when needed for them to perform their evaluation of a manuscript.

If the journal that you’re submitting to uses double-blind peer review and you are providing reviewers with access to your data (for example via a repository link, supplementary information or data on request), it is strongly suggested that the authorship in the data is also blinded. There are data repositories that can assist with this and/or will create a link to mask the authorship of your data.

Authors who need help understanding our data sharing policies, help finding a suitable data repository, or help organising and sharing research data can access our Author Support portal for additional guidance.

For more information:

http://www.springernature.com/gp/group/data-policy/faq

Please always use internationally accepted signs and symbols for units.

Nomenclature:

Insofar as possible, authors should use systematic names similar to those used by Chemical Abstract Service or IUPAC.

This journal is committed to upholding the integrity of the scientific record. As a member of the Committee on Publication Ethics ( COPE ) the journal will follow the COPE guidelines on how to deal with potential acts of misconduct.

Authors should refrain from misrepresenting research results which could damage the trust in the journal, the professionalism of scientific authorship, and ultimately the entire scientific endeavour. Maintaining integrity of the research and its presentation is helped by following the rules of good scientific practice, which include*:

• The manuscript should not be submitted to more than one journal for simultaneous consideration.
• The submitted work should be original and should not have been published elsewhere in any form or language (partially or in full), unless the new work concerns an expansion of previous work. (Please provide transparency on the re-use of material to avoid the concerns about text-recycling (‘self-plagiarism’).
• A single study should not be split up into several parts to increase the quantity of submissions and submitted to various journals or to one journal over time (i.e. ‘salami-slicing/publishing’).
• Concurrent or secondary publication is sometimes justifiable, provided certain conditions are met. Examples include: translations or a manuscript that is intended for a different group of readers.
• Results should be presented clearly, honestly, and without fabrication, falsification or inappropriate data manipulation (including image based manipulation). Authors should adhere to discipline-specific rules for acquiring, selecting and processing data.
• No data, text, or theories by others are presented as if they were the author’s own (‘plagiarism’). Proper acknowledgements to other works must be given (this includes material that is closely copied (near verbatim), summarized and/or paraphrased), quotation marks (to indicate words taken from another source) are used for verbatim copying of material, and permissions secured for material that is copyrighted.

Important note: the journal may use software to screen for plagiarism.

• Authors should make sure they have permissions for the use of software, questionnaires/(web) surveys and scales in their studies (if appropriate).
• Research articles and non-research articles (e.g. Opinion, Review, and Commentary articles) must cite appropriate and relevant literature in support of the claims made. Excessive and inappropriate self-citation or coordinated efforts among several authors to collectively self-cite is strongly discouraged.
• Authors should avoid untrue statements about an entity (who can be an individual person or a company) or descriptions of their behavior or actions that could potentially be seen as personal attacks or allegations about that person.
• Research that may be misapplied to pose a threat to public health or national security should be clearly identified in the manuscript (e.g. dual use of research). Examples include creation of harmful consequences of biological agents or toxins, disruption of immunity of vaccines, unusual hazards in the use of chemicals, weaponization of research/technology (amongst others).
• Authors are strongly advised to ensure the author group, the Corresponding Author, and the order of authors are all correct at submission. Adding and/or deleting authors during the revision stages is generally not permitted, but in some cases may be warranted. Reasons for changes in authorship should be explained in detail. Please note that changes to authorship cannot be made after acceptance of a manuscript.

*All of the above are guidelines and authors need to make sure to respect third parties rights such as copyright and/or moral rights.

Upon request authors should be prepared to send relevant documentation or data in order to verify the validity of the results presented. This could be in the form of raw data, samples, records, etc. Sensitive information in the form of confidential or proprietary data is excluded.

If there is suspicion of misbehavior or alleged fraud the Journal and/or Publisher will carry out an investigation following COPE guidelines. If, after investigation, there are valid concerns, the author(s) concerned will be contacted under their given e-mail address and given an opportunity to address the issue. Depending on the situation, this may result in the Journal’s and/or Publisher’s implementation of the following measures, including, but not limited to:

• If the manuscript is still under consideration, it may be rejected and returned to the author.

- an erratum/correction may be placed with the article

- an expression of concern may be placed with the article

- or in severe cases retraction of the article may occur.

The reason will be given in the published erratum/correction, expression of concern or retraction note. Please note that retraction means that the article is maintained on the platform , watermarked “retracted” and the explanation for the retraction is provided in a note linked to the watermarked article.

• The author’s institution may be informed
• A notice of suspected transgression of ethical standards in the peer review system may be included as part of the author’s and article’s bibliographic record.

Fundamental errors

Authors have an obligation to correct mistakes once they discover a significant error or inaccuracy in their published article. The author(s) is/are requested to contact the journal and explain in what sense the error is impacting the article. A decision on how to correct the literature will depend on the nature of the error. This may be a correction or retraction. The retraction note should provide transparency which parts of the article are impacted by the error.

Suggesting / excluding reviewers

Authors are welcome to suggest suitable reviewers and/or request the exclusion of certain individuals when they submit their manuscripts. When suggesting reviewers, authors should make sure they are totally independent and not connected to the work in any way. It is strongly recommended to suggest a mix of reviewers from different countries and different institutions. When suggesting reviewers, the Corresponding Author must provide an institutional email address for each suggested reviewer, or, if this is not possible to include other means of verifying the identity such as a link to a personal homepage, a link to the publication record or a researcher or author ID in the submission letter. Please note that the Journal may not use the suggestions, but suggestions are appreciated and may help facilitate the peer review process.

Authors are requested to disclose interests that are directly or indirectly related to the work submitted for publication. Interests within the last 3 years of beginning the work (conducting the research and preparing the work for submission) should be reported. Interests outside the 3-year time frame must be disclosed if they could reasonably be perceived as influencing the submitted work. Disclosure of interests provides a complete and transparent process and helps readers form their own judgments of potential bias. This is not meant to imply that a financial relationship with an organization that sponsored the research or compensation received for consultancy work is inappropriate.

Editorial Board Members and Editors are required to declare any competing interests and may be excluded from the peer review process if a competing interest exists. In addition, they should exclude themselves from handling manuscripts in cases where there is a competing interest. This may include – but is not limited to – having previously published with one or more of the authors, and sharing the same institution as one or more of the authors. Where an Editor or Editorial Board Member is on the author list we recommend they declare this in the competing interests section on the submitted manuscript. If they are an author or have any other competing interest regarding a specific manuscript, another Editor or member of the Editorial Board will be assigned to assume responsibility for overseeing peer review. These submissions are subject to the exact same review process as any other manuscript. Editorial Board Members are welcome to submit papers to the journal. These submissions are not given any priority over other manuscripts, and Editorial Board Member status has no bearing on editorial consideration.

Interests that should be considered and disclosed but are not limited to the following:

Funding: Research grants from funding agencies (please give the research funder and the grant number) and/or research support (including salaries, equipment, supplies, reimbursement for attending symposia, and other expenses) by organizations that may gain or lose financially through publication of this manuscript.

Employment: Recent (while engaged in the research project), present or anticipated employment by any organization that may gain or lose financially through publication of this manuscript. This includes multiple affiliations (if applicable).

Financial interests: Stocks or shares in companies (including holdings of spouse and/or children) that may gain or lose financially through publication of this manuscript; consultation fees or other forms of remuneration from organizations that may gain or lose financially; patents or patent applications whose value may be affected by publication of this manuscript.

It is difficult to specify a threshold at which a financial interest becomes significant, any such figure is necessarily arbitrary, so one possible practical guideline is the following: "Any undeclared financial interest that could embarrass the author were it to become publicly known after the work was published."

Non-financial interests: In addition, authors are requested to disclose interests that go beyond financial interests that could impart bias on the work submitted for publication such as professional interests, personal relationships or personal beliefs (amongst others). Examples include, but are not limited to: position on editorial board, advisory board or board of directors or other type of management relationships; writing and/or consulting for educational purposes; expert witness; mentoring relations; and so forth.

Primary research articles require a disclosure statement. Review articles present an expert synthesis of evidence and may be treated as an authoritative work on a subject. Review articles therefore require a disclosure statement. Other article types such as editorials, book reviews, comments (amongst others) may, dependent on their content, require a disclosure statement. If you are unclear whether your article type requires a disclosure statement, please contact the Editor-in-Chief.

Please note that, in addition to the above requirements, funding information (given that funding is a potential competing interest (as mentioned above)) needs to be disclosed upon submission of the manuscript in the peer review system. This information will automatically be added to the Record of CrossMark, however it is not added to the manuscript itself. Under ‘summary of requirements’ (see below) funding information should be included in the ‘ Declarations ’ section.

Summary of requirements

The above should be summarized in a statement and placed in a ‘Declarations’ section before the reference list under a heading of ‘Funding’ and/or ‘Competing interests’. Other declarations include Ethics approval, Consent, Data, Material and/or Code availability and Authors’ contribution statements.

Please see the various examples of wording below and revise/customize the sample statements according to your own needs.

When all authors have the same (or no) conflicts and/or funding it is sufficient to use one blanket statement.

Examples of statements to be used when funding has been received:

• Partial financial support was received from [...]
• The research leading to these results received funding from […] under Grant Agreement No[…].
• This study was funded by […]
• This work was supported by […] (Grant numbers […] and […]

Examples of statements to be used when there is no funding:

• The authors did not receive support from any organization for the submitted work.
• No funding was received to assist with the preparation of this manuscript.
• No funding was received for conducting this study.
• No funds, grants, or other support was received.

Examples of statements to be used when there are interests to declare:

Non-financial interests: Author C is an unpaid member of committee Z.

Non-financial interests: Author A is on the board of directors of Y and receives no compensation as member of the board of directors.

Non-financial interests: none.

Non-financial interests: Author D has served on advisory boards for Company M, Company N and Company O.

Examples of statements to be used when authors have nothing to declare:

• The authors have no relevant financial or non-financial interests to disclose.
• The authors have no competing interests to declare that are relevant to the content of this article.
• All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript.
• The authors have no financial or proprietary interests in any material discussed in this article.

Authors are responsible for correctness of the statements provided in the manuscript. See also Authorship Principles. The Editor-in-Chief reserves the right to reject submissions that do not meet the guidelines described in this section.

Ethics approval

When reporting a study that involved human participants, their data or biological material, authors should include a statement that confirms that the study was approved (or granted exemption) by the appropriate institutional and/or national research ethics committee (including the name of the ethics committee) and certify that the study was performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. If doubt exists whether the research was conducted in accordance with the 1964 Helsinki Declaration or comparable standards, the authors must explain the reasons for their approach, and demonstrate that an independent ethics committee or institutional review board explicitly approved the doubtful aspects of the study. If a study was granted exemption from requiring ethics approval, this should also be detailed in the manuscript (including the reasons for the exemption).

Retrospective ethics approval

If a study has not been granted ethics committee approval prior to commencing, retrospective ethics approval usually cannot be obtained and it may not be possible to consider the manuscript for peer review. The decision on whether to proceed to peer review in such cases is at the Editor's discretion.

Ethics approval for retrospective studies

Although retrospective studies are conducted on already available data or biological material (for which formal consent may not be needed or is difficult to obtain) ethics approval may be required dependent on the law and the national ethical guidelines of a country. Authors should check with their institution to make sure they are complying with the specific requirements of their country.

Ethics approval for case studies

Case reports require ethics approval. Most institutions will have specific policies on this subject. Authors should check with their institution to make sure they are complying with the specific requirements of their institution and seek ethics approval where needed. Authors should be aware to secure informed consent from the individual (or parent or guardian if the participant is a minor or incapable) See also section on Informed Consent .

If human cells are used, authors must declare in the manuscript: what cell lines were used by describing the source of the cell line, including when and from where it was obtained, whether the cell line has recently been authenticated and by what method. If cells were bought from a life science company the following need to be given in the manuscript: name of company (that provided the cells), cell type, number of cell line, and batch of cells.

It is recommended that authors check the NCBI database for misidentification and contamination of human cell lines. This step will alert authors to possible problems with the cell line and may save considerable time and effort.

Further information is available from the International Cell Line Authentication Committee (ICLAC).

Authors should include a statement that confirms that an institutional or independent ethics committee (including the name of the ethics committee) approved the study and that informed consent was obtained from the donor or next of kin.

Research Resource Identifiers (RRID)

Research Resource Identifiers (RRID) are persistent unique identifiers (effectively similar to a DOI) for research resources. This journal encourages authors to adopt RRIDs when reporting key biological resources (antibodies, cell lines, model organisms and tools) in their manuscripts.

Organism: Filip1 tm1a(KOMP)Wtsi RRID:MMRRC_055641-UCD

Cell Line: RST307 cell line RRID:CVCL_C321

Antibody: Luciferase antibody DSHB Cat# LUC-3, RRID:AB_2722109

Plasmid: mRuby3 plasmid RRID:Addgene_104005

Software: ImageJ Version 1.2.4 RRID:SCR_003070

RRIDs are provided by the Resource Identification Portal . Many commonly used research resources already have designated RRIDs. The portal also provides authors links so that they can quickly register a new resource and obtain an RRID.

Clinical Trial Registration

The World Health Organization (WHO) definition of a clinical trial is "any research study that prospectively assigns human participants or groups of humans to one or more health-related interventions to evaluate the effects on health outcomes". The WHO defines health interventions as “A health intervention is an act performed for, with or on behalf of a person or population whose purpose is to assess, improve, maintain, promote or modify health, functioning or health conditions” and a health-related outcome is generally defined as a change in the health of a person or population as a result of an intervention.

To ensure the integrity of the reporting of patient-centered trials, authors must register prospective clinical trials (phase II to IV trials) in suitable publicly available repositories. For example www.clinicaltrials.gov or any of the primary registries that participate in the WHO International Clinical Trials Registry Platform .

The trial registration number (TRN) and date of registration should be included as the last line of the manuscript abstract.

For clinical trials that have not been registered prospectively, authors are encouraged to register retrospectively to ensure the complete publication of all results. The trial registration number (TRN), date of registration and the words 'retrospectively registered’ should be included as the last line of the manuscript abstract.

Standards of reporting

Springer Nature advocates complete and transparent reporting of biomedical and biological research and research with biological applications. Authors are recommended to adhere to the minimum reporting guidelines hosted by the EQUATOR Network when preparing their manuscript.

Exact requirements may vary depending on the journal; please refer to the journal’s Instructions for Authors.

Checklists are available for a number of study designs, including:

Randomised trials (CONSORT) and Study protocols (SPIRIT)

Observational studies (STROBE)

Systematic reviews and meta-analyses (PRISMA) and protocols (Prisma-P)

Diagnostic/prognostic studies (STARD) and (TRIPOD)

Case reports (CARE)

Clinical practice guidelines (AGREE) and (RIGHT)

Qualitative research (SRQR) and (COREQ)

Animal pre-clinical studies (ARRIVE)

Quality improvement studies (SQUIRE)

Economic evaluations (CHEERS)

The above should be summarized in a statement and placed in a ‘Declarations’ section before the reference list under a heading of ‘Ethics approval’.

Examples of statements to be used when ethics approval has been obtained:

• All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The study was approved by the Bioethics Committee of the Medical University of A (No. ...).

• This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of University B (Date.../No. ...).

• Approval was obtained from the ethics committee of University C. The procedures used in this study adhere to the tenets of the Declaration of Helsinki.

• The questionnaire and methodology for this study was approved by the Human Research Ethics committee of the University of D (Ethics approval number: ...).

Examples of statements to be used for a retrospective study:

• Ethical approval was waived by the local Ethics Committee of University A in view of the retrospective nature of the study and all the procedures being performed were part of the routine care.

• This research study was conducted retrospectively from data obtained for clinical purposes. We consulted extensively with the IRB of XYZ who determined that our study did not need ethical approval. An IRB official waiver of ethical approval was granted from the IRB of XYZ.

• This retrospective chart review study involving human participants was in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The Human Investigation Committee (IRB) of University B approved this study.

Examples of statements to be used when no ethical approval is required/exemption granted:

• This is an observational study. The XYZ Research Ethics Committee has confirmed that no ethical approval is required.

• The data reproduced from Article X utilized human tissue that was procured via our Biobank AB, which provides de-identified samples. This study was reviewed and deemed exempt by our XYZ Institutional Review Board. The BioBank protocols are in accordance with the ethical standards of our institution and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

These guidelines describe authorship principles and good authorship practices to which prospective authors should adhere to.

Authorship clarified

The Journal and Publisher assume all authors agreed with the content and that all gave explicit consent to submit and that they obtained consent from the responsible authorities at the institute/organization where the work has been carried out, before the work is submitted.

The Publisher does not prescribe the kinds of contributions that warrant authorship. It is recommended that authors adhere to the guidelines for authorship that are applicable in their specific research field. In absence of specific guidelines it is recommended to adhere to the following guidelines*:

All authors whose names appear on the submission

1) made substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data; or the creation of new software used in the work;

2) drafted the work or revised it critically for important intellectual content;

3) approved the version to be published; and

4) agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

* Based on/adapted from:

ICMJE, Defining the Role of Authors and Contributors,

Transparency in authors’ contributions and responsibilities to promote integrity in scientific publication, McNutt at all, PNAS February 27, 2018

Disclosures and declarations

All authors are requested to include information regarding sources of funding, financial or non-financial interests, study-specific approval by the appropriate ethics committee for research involving humans and/or animals, informed consent if the research involved human participants, and a statement on welfare of animals if the research involved animals (as appropriate).

The decision whether such information should be included is not only dependent on the scope of the journal, but also the scope of the article. Work submitted for publication may have implications for public health or general welfare and in those cases it is the responsibility of all authors to include the appropriate disclosures and declarations.

Data transparency

All authors are requested to make sure that all data and materials as well as software application or custom code support their published claims and comply with field standards. Please note that journals may have individual policies on (sharing) research data in concordance with disciplinary norms and expectations.

Role of the Corresponding Author

One author is assigned as Corresponding Author and acts on behalf of all co-authors and ensures that questions related to the accuracy or integrity of any part of the work are appropriately addressed.

The Corresponding Author is responsible for the following requirements:

• ensuring that all listed authors have approved the manuscript before submission, including the names and order of authors;
• managing all communication between the Journal and all co-authors, before and after publication;*
• providing transparency on re-use of material and mention any unpublished material (for example manuscripts in press) included in the manuscript in a cover letter to the Editor;
• making sure disclosures, declarations and transparency on data statements from all authors are included in the manuscript as appropriate (see above).

* The requirement of managing all communication between the journal and all co-authors during submission and proofing may be delegated to a Contact or Submitting Author. In this case please make sure the Corresponding Author is clearly indicated in the manuscript.

Author contributions

In absence of specific instructions and in research fields where it is possible to describe discrete efforts, the Publisher recommends authors to include contribution statements in the work that specifies the contribution of every author in order to promote transparency. These contributions should be listed at the separate title page.

Examples of such statement(s) are shown below:

• Free text:

All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by [full name], [full name] and [full name]. The first draft of the manuscript was written by [full name] and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Example: CRediT taxonomy:

• Conceptualization: [full name], …; Methodology: [full name], …; Formal analysis and investigation: [full name], …; Writing - original draft preparation: [full name, …]; Writing - review and editing: [full name], …; Funding acquisition: [full name], …; Resources: [full name], …; Supervision: [full name],….

For review articles where discrete statements are less applicable a statement should be included who had the idea for the article, who performed the literature search and data analysis, and who drafted and/or critically revised the work.

For articles that are based primarily on the student’s dissertation or thesis , it is recommended that the student is usually listed as principal author:

A Graduate Student’s Guide to Determining Authorship Credit and Authorship Order, APA Science Student Council 2006

Affiliation

The primary affiliation for each author should be the institution where the majority of their work was done. If an author has subsequently moved, the current address may additionally be stated. Addresses will not be updated or changed after publication of the article.

Changes to authorship

Authors are strongly advised to ensure the correct author group, the Corresponding Author, and the order of authors at submission. Changes of authorship by adding or deleting authors, and/or changes in Corresponding Author, and/or changes in the sequence of authors are not accepted after acceptance of a manuscript.

• Please note that author names will be published exactly as they appear on the accepted submission!

Please make sure that the names of all authors are present and correctly spelled, and that addresses and affiliations are current.

Adding and/or deleting authors at revision stage are generally not permitted, but in some cases it may be warranted. Reasons for these changes in authorship should be explained. Approval of the change during revision is at the discretion of the Editor-in-Chief. Please note that journals may have individual policies on adding and/or deleting authors during revision stage.

Author identification

Authors are recommended to use their ORCID ID when submitting an article for consideration or acquire an ORCID ID via the submission process.

Deceased or incapacitated authors

For cases in which a co-author dies or is incapacitated during the writing, submission, or peer-review process, and the co-authors feel it is appropriate to include the author, co-authors should obtain approval from a (legal) representative which could be a direct relative.

Authorship issues or disputes

In the case of an authorship dispute during peer review or after acceptance and publication, the Journal will not be in a position to investigate or adjudicate. Authors will be asked to resolve the dispute themselves. If they are unable the Journal reserves the right to withdraw a manuscript from the editorial process or in case of a published paper raise the issue with the authors’ institution(s) and abide by its guidelines.

Confidentiality

Authors should treat all communication with the Journal as confidential which includes correspondence with direct representatives from the Journal such as Editors-in-Chief and/or Handling Editors and reviewers’ reports unless explicit consent has been received to share information.

Manuscripts that report experiments involving the use of human embryos and gametes, human embryonic stem cells and related materials, and clinical applications of stem cells must include confirmation that all experiments were performed in accordance with relevant guidelines and regulations (See also Research involving human participants, their data or biological material .

The manuscript should include an ethics statement identifying the institutional and/or national research ethics committee (including the name of the ethics committee) approving the experiments and describing any relevant details. Authors should confirm that informed consent (See also Informed Consent ) was obtained from all recipients and/or donors of cells or tissues, where necessary, and describe the conditions of donation of materials for research, such as human embryos or gametes. Copies of approval and redacted consent documents may be requested by the Journal.

We encourage authors to follow the principles laid out in the ISSCR Guidelines for Stem Cell Research and Clinical Translation .

In deciding whether to publish papers describing modifications of the human germline, the Journal is guided by safety considerations, compliance with applicable regulations, as well as the status of the societal debate on the implications of such modifications for future generations. In case of concerns regarding a particular type of study the Journal may seek the advice from the Springer Nature Research Integrity Group.

The decision to publish a paper is the responsibility of the Editor-in-Chief of the Journal.

Single-blind peer review

This journal follows a single-blind reviewing procedure.

How can you help improve your manuscript for publication?

Presenting your work in a well-structured manuscript and in well-written English gives it its best chance for editors and reviewers to understand it and evaluate it fairly. Many researchers find that getting some independent support helps them present their results in the best possible light. The experts at Springer Nature Author Services can help you with manuscript preparation—including English language editing, developmental comments, manuscript formatting, figure preparation, translation , and more.

Get started and save 15%

You can also use our free Grammar Check tool for an evaluation of your work.

Please note that using these tools, or any other service, is not a requirement for publication, nor does it imply or guarantee that editors will accept the article, or even select it for peer review.

Chinese (中文)

您怎么做才有助于改进您的稿件以便顺利发表？

如果在结构精巧的稿件中用精心组织的英语展示您的作品，就能最大限度地让编辑和审稿人理解并公正评估您的作品。许多研究人员发现，获得一些独立支持有助于他们以尽可能美好的方式展示他们的成果。Springer Nature Author Services 的专家可帮助您准备稿件，具体包括 润色英语表述、添加有见地的注释、为稿件排版、设计图表、翻译 等。

开始使用即可节省 15% 的费用

您还可以使用我们的 免费语法检查工具 来评估您的作品。

请注意，使用这些工具或任何其他服务不是发表前必须满足的要求，也不暗示或保证相关文章定会被编辑接受（甚至未必会被选送同行评审）。

Japanese (日本語)

発表に備えて、論文を改善するにはどうすればよいでしょうか？

内容が適切に組み立てられ、質の高い英語で書かれた論文を投稿すれば、編集者や査読者が論文を理解し、公正に評価するための最善の機会となります。多くの研究者は、個別のサポートを受けることで、研究結果を可能な限り最高の形で発表できると思っています。Springer Nature Author Servicesのエキスパートが、 英文の編集、建設的な提言、論文の書式、図の調整、翻訳 など、論文の作成をサポートいたします。

今なら15％割引でご利用いただけます

原稿の評価に、無料 の文法チェック ツールもご利用いただけます。

これらのツールや他のサービスをご利用いただくことは、論文を掲載するための要件ではありません。また、編集者が論文を受理したり、査読に選定したりすることを示唆または保証するものではないことにご注意ください。

Korean (한국어)

게재를 위해 원고를 개선하려면 어떻게 해야 할까요?

여러분의 작품을 체계적인 원고로 발표하는 것은 편집자와 심사자가 여러분의 연구를 이해하고 공정하게 평가할 수 있는 최선의 기회를 제공합니다. 많은 연구자들은 어느 정도 독립적인 지원을 받는 것이 가능한 한 최선의 방법으로 자신의 결과를 발표하는 데 도움이 된다고 합니다. Springer Nature Author Services 전문가들은 영어 편집, 발전적인 논평, 원고 서식 지정, 그림 준비, 번역 등과 같은 원고 준비를 도와드릴 수 있습니다.

지금 시작하면 15% 할인됩니다.

또한 당사의 무료 문법 검사 도구를 사용하여 여러분의 연구를 평가할 수 있습니다.

이러한 도구 또는 기타 서비스를 사용하는 것은 게재를 위한 필수 요구사항이 아니며, 편집자가 해당 논문을 수락하거나 피어 리뷰에 해당 논문을 선택한다는 것을 암시하거나 보장하지는 않습니다.

To find out more about publishing your work Open Access in Blood Research , including information on fees, funding and licenses, visit our Open access publishing page .

• Find a journal
• Publish with us
• Track your research

Find anything you save across the site in your account

The History of Blood

By Jerome Groopman

During my training as a hematologist at U.C.L.A., forty years ago, a senior faculty member introduced the program of study by citing a verse from Leviticus: “The life of the flesh is in the blood.” For the assembled young physicians, this was a biological truth. Red cells carry oxygen, required for our heart to beat and our brain to function. White cells defend us against invasion by lethal pathogens. Platelets and proteins in plasma form clots that can prevent fatal hemorrhages. Blood is constantly being renewed by stem cells in our bone marrow: red cells turn over every few months, platelets and most white cells every few days. Since marrow stem cells spawn every kind of blood cell, they can, when transplanted, restore life to a dying host.

In a wide-ranging and energetic new book, “ Nine Pints ” (Metropolitan), the British journalist Rose George examines not only the unique biology of this substance but also the lore and tradition surrounding it, and even its connections to the origins of the earth and of life itself. “The iron in our blood comes from the death of supernovas, like all iron on our planet,” she writes. “This bright red liquid . . . contains salt and water, like the sea we possibly came from.” George charts the distance that our blood (as her title suggests, we contain, on average, between nine and eleven pints of it) travels in the body every day: some twelve thousand miles, “three times the distance from my front door to Novosibirsk.” Our network of veins, arteries, and capillaries is about sixty thousand miles long—“twice the circumference of the earth and more.”

Ancient peoples knew none of this biology, but they were certain of blood’s importance and fascinated by its mystery. For them, blood was something hidden—visible only when flowing from a wound, or during childbirth, miscarriage, and menstruation—so it became a symbol both of life and of death. George returns often to this dichotomy, which she terms the “two-faced nature of blood” and sees as embodied in the figure of the Gorgon Medusa. In addition to her famous serpentine coiffure, Medusa was said to have two kinds of blood coursing through her veins: on her left side, her blood was lethal; on her right side, it was life-giving. To control blood was to master mortality, so it is unsurprising that blood features prominently in many religious traditions, and that, though our understanding of its functions is more sophisticated than ever, we remain in thrall to its primal mystique. The membrane between medicine and myth is thinner than we suppose, and blood is continually circulating back and forth across it.

In some cultures, blood loss is perceived as a danger not only to the individual but also to the larger community. George journeys to a remote Hindu village in western Nepal, where she finds Radha, a sixteen-year-old chau , which means “untouchable menstruating woman” in the local dialect. During her period, Radha can’t enter her family’s house or her temple, and she can’t touch other women, lest they be polluted. If she so much as consumes buffalo milk or butter, the buffalo themselves will get sick and stop producing milk. She can be fed only boiled rice, thrown by her little sister onto a plate from a safe distance, “the way you would feed a dog.”

Customs that denigrate women during menses are widespread. George notes that our word “taboo” is believed to derive from one of two Polynesian words: tapua , which means “menstruation,” or tabu , which means “apart.” Not long ago, in America, it was thought that “the curse” could cause women to spoil meat if they came in contact with it. But menstrual blood is not always seen as harmful, and menstrual segregation at its most benevolent can take the form of communality. Some three hundred miles northwest of where Radha lives, near the border between Pakistan and Afghanistan, menstruating Kalasha women “retire to a prestigious structure called the bashali, where women hang out, have fun, and sleep entwined,” George writes. “In this reading of menstrual seclusion, the woman is prized for her blood, because it means fertility and power.”

In Wogeo, an island off the north coast of Papua New Guinea, menstrual blood is held to be both lethal and cleansing, and men emulate menstruation by cutting their penises with crab claws. In ancient Rome, too, menstrual blood was not just a curse. Pliny the Elder wrote in his “ Natural History ” that when women had their periods they could stop seeds from germinating, cause plants to wither, and make fruit fall from trees. But their destructive power had its uses. A menstruating woman was able to kill a swarm of bees or ward off hail and lightning. Wives of farmers, Pliny suggested, could even offer a sort of pesticide: “If a woman strips herself naked while she is menstruating, and walks around a field of wheat, the caterpillars, worms, beetles and other vermin will fall from off the ears of corn.”

In Islam, menstruating women are forbidden to recite certain prayers and must refrain from vaginal intercourse. In Judaism, too, menstruation can be a cause of ritual impurity, as can childbirth. According to the rabbi and theologian Shai Held, “Childbirth takes place at—and to some degree unsettles—the boundaries between life and death: A new life comes into the world, but blood, considered the seat of life, is lost in the process.”

Observant Jews and Muslims alike follow dietary laws that forbid the consumption of blood. Both kosher meat and halal meat must be drained of blood, and kosher meat is also salted, to remove any residue of the substance. A tiny blood spot in an egg renders it inedible. While believers accept these prohibitions as divine edicts to prove devotion, some scholars speculate that they developed as health measures to prevent spoilage of meat, which is accelerated through oxidation and bacterial growth. These days, even meat that is not kosher or halal is drained of blood. People who say they like their steak “bloody” are actually responding to myoglobin, a red-pigmented protein that stores oxygen in muscle and brightens when exposed to air.

Yet, despite the firm proscription against ingesting blood, one breakaway Jewish sect of the first century A.D. made the idea of doing so central to its rituals. Its leader, Jesus of Nazareth, told his disciples that the bread and the wine at the Last Supper were his body and blood, and should be consumed thereafter in memory of him. The ritual of the Eucharist became a cornerstone of early Christianity, and with it the doctrine of transubstantiation—that a literal, not just figurative, transformation occurred during the sacrament.

Link copied

Scholars have debated the reasons for this stark reversal—from forbidding the consumption of blood to sanctifying it as a bridge to the divine. Some speculate that, by the time of the Second Temple, many Jews were Hellenized, and early converts to Christianity were merely borrowing standard Dionysian rites. For instance, communal “agape feasts,” in which Christians symbolically ate their god’s flesh and drank his blood, resembled older Greek rituals.

David Biale, a professor of Jewish history at the University of California, Davis, has traced this divergence between Jewish and Christian traditions in his book “ Blood and Belief ” (2007). He cites a 1376 letter from the mystic Catherine of Siena to a disciple, in which she presciently warns of schisms within the Catholic Church and invokes the Eucharist as a symbol of unity. She argues that Christians, unlike Jews and Muslims, were “ransomed and baptized in Christ’s blood.” The notion of sacred blood as the vehicle for human salvation, Biale writes, justified the “literal interpretation of the Eucharist as dogma, popular celebrations of the Host that spread throughout Europe, and a new cult of blood relics.”

The blood of martyrs was also believed to cure disease. “ The Golden Legend ,” a thirteenth-century account of the lives of saints, attributed healing powers to the water used to wash the bloodstained clothes of Thomas à Becket, the Archbishop of Canterbury, who was murdered in 1170. The blood of St. Peter Martyr, who was killed by Cathar heretics in 1252, was also accorded medicinal properties. Blood became a central feature of Christian iconography—the stigmata, the Sacred Heart—and also a notable element in Christian anti-Semitism. In the late twelfth century, in England, a spate of pogroms occurred after Jews were accused of murdering Christian children to use their blood in the preparation of Passover matzo. It is tempting to wonder if this calumny, known as the blood libel, is connected in some way with Judaism’s highly exacting rituals designed to avoid the consumption of any kind of blood. The blood libel has proved startlingly resilient, recurring across medieval and early modern Europe, and reappearing in tsarist Russia in the early twentieth century. It has been revived as recently as last year—by Hamas, during its clashes with Israel.

For millennia, the human body was understood as a vessel for a quartet of liquids: yellow bile, black bile, white phlegm, and red blood. Each corresponded to one of the four classical elements—fire, earth, water, and air—from which it was thought everything in the cosmos was made. According to the second-century physician Galen, blood was made in the liver from food and drink carried from the digestive tract. This “natural” blood entered the veins and was transported, ebbing and flowing, to all parts of the body. Blood was believed to be constantly consumed by tissues and then replenished at each meal. The primary function of the heart was to generate heat. Galen thought that the blood in the left side of the heart came directly from the right side through pores in the septum, or through leaks from the lungs. The blood in the arteries was “vital,” its purpose to deliver spiritus vitalus to the flesh.

The key to good health was thought to be an ideal balance among the four humors. Danger arose if one predominated, so periodic voiding was crucial. For the most part, the body took care of this naturally: black bile, yellow bile, and phlegm were expelled through excrement, sweat, tears, and nasal discharge. But, other than menstruation, the body had no spontaneous way of getting rid of its blood, so, from ancient times until well into the modern era, bloodletting—using sharpened stones, fish teeth, and, later, lances and fleams—was a cornerstone of medical practice. George expounds on the work of the eleventh-century Persian scientist and philosopher Avicenna, whose “Canon of Medicine” includes an extensive guide to bloodletting treatments:

Different blood vessels served different purposes. Bleeding the veins between the eyebrows was good for long-standing headache, cutting the veins under the tongue—only lengthways, otherwise it was difficult to stanch—was useful for angina or tonsillar abscess. Opening the sciatic vein relieved podagra and elephantiasis; menstrual problems were alleviated by cutting the saphenous vein.

George becomes particularly enthralled by what she calls “an essential tool in the bloodletter’s armamentarium”—leeches. There are more than six hundred leech species: “Not all leeches suck blood and not all bloodsucking leeches seek the blood of humans,” she writes. “Many have evolved to have impressively specialized food sources: one desert variety lives in camel’s noses; another feeds on bats. Some eat hamsters and frogs.” She describes some of the earliest evidence of the human use of leeches—a painting on the wall of a three-thousand-year-old Egyptian tomb; representations of the Hindu god of healing, Dhanvantari, who is often shown holding a leech—and visits a contemporary leech-breeder, Biopharm, in Wales. The leeches raised there, destined for surgical use, are “freshwater, bloodsucking, multi-segmented annelid worms with ten stomachs, thirty-two brains, nine pairs of testicles, and several hundred teeth.” George compares the leech to an oil tanker. “The bulk of it is storage,” a Biopharm breeder tells her, with all its vital organs arranged around the periphery. He adds that, when feeding, a leech can increase its body weight fivefold—eightfold if it’s a small leech—and spend a year digesting one meal. Its bite is “spectacularly efficient,” causing far less trauma to the skin than a scalpel would, and it considerately injects its prey with anesthetic, making its feeding painless for the host.

The most common modern medical use of leeches is in plastic surgery, where they can be effective in draining swollen tissue after an operation. Hematologists employ bloodletting—therapeutic phlebotomy, as it’s now known—when treating polycythemia vera (a rare condition in which a person’s bone marrow overproduces red blood cells) and for reducing iron buildup in the body caused by a disorder called hemochromatosis. Many of the benefits that people in past eras reported after being bled can probably be chalked up to the placebo effect, but the same can be said of many sophisticated treatments today.

In pre-modern times, blood was not only a target of treatment but also a source of medicine. Richard Sugg, in his remarkable book “ Mummies, Cannibals and Vampires ” (2011), traces the belief in blood’s healing powers back to ancient Rome. Drawing on a report by Pliny the Elder, he conjures a scene at the Colosseum:

The man sprawled at such an odd angle beside the injured fighter has his face pressed against a gaping tear in the gladiator’s throat. He is drinking blood fresh from the wound. Why? . . . He suffers from epilepsy, and is using a widely known cure for his mysterious affliction.

Gladiatorial combat declined in the fourth century, with the reign of Constantine, the first Christian emperor, but the consumption of human blood continued, with supplies coming instead from criminals at executions. The ailing would swallow it “fresh and hot, seconds after a beheading,” Sugg writes, citing medieval accounts from Germany, Denmark, and Sweden. In 1483, King Louis XI of France, a paranoid religious fanatic, reportedly imbibed meals of blood collected from healthy children—a vain attempt to stave off his imminent death from leprosy. When Pope Innocent VIII was dying, in 1492, he was allegedly given the blood of three boys by a Jewish physician, in the hopes of channelling some of their youthful energy. (Medical historians doubt the veracity of the story, which may have been an anti-Semitic slander.)

Alchemists explained blood’s benefits in terms of the classical elements. It contained “air,” which, when distilled, could treat epilepsy and migraines; “water,” a tonic for cardiac and neurological disorders; and, most potent of all, “fire,” which could revive a person in the hour of death. Blood was also held to be an aphrodisiac, and alchemists prepared extracts of it, promising patients that it “maketh old age lusty, and to continue in like estate a long time.” In medieval England, friars recorded detailed alchemical methods of extracting these “elements” of blood:

Take human blood, put it in a glass phial and keep it covered in dung for forty days. Then take it out and put it inside a copper vessel and heat. . . . Let it cool for a day and night. Then scoop off what is left on the top and is clear. . . . Afterwards put what you have taken off in a glass lamp bowl and distill it through a filter. Once distilled, keep it, and mix the blood with the same quantity of ardent water (aqua ardens), then distill the mixture in an alembic. The water that remains is better than all other waters in the world for healing wounds.

Such beliefs persisted even into the early phase of the scientific revolution. The seventeenth-century British chemist Robert Boyle, who formulated the fundamental law governing the behavior of gases, also looked to alchemy to extract the “spirit of blood” as a panacea.

By then, the study of blood had begun to acquire a truly scientific basis. In 1628, Galen’s paradigm, which held that blood was produced from food, was dismantled by the publication of “An Anatomical Essay on the Motion of the Heart and Blood in Animals,” by the English physician William Harvey. Harvey’s revolutionary insight—that blood circulated from the left side of the heart through arteries and returned to the right side through veins—is often cited as the greatest single-handed discovery in medicine.

Even more remarkable is that he arrived at his discovery by empirical observation and induction—the core of the modern scientific method. Harvey drained the blood from sheep and pigs and discovered that the volume of the blood they contained was far greater than the volume of the food they had ingested. He concluded that blood was not consumed and absorbed; it must, he reasoned, circulate continuously. In a public demonstration, Harvey sliced open a live snake to show how such circulation worked. When the vein to its heart was compressed, the heart shrank in size. Afterward, when the heart was cut open, its chambers contained no blood. Using tourniquets, Harvey further showed how veins became engorged and proved that the blood in them could move in only one direction, toward the heart.

Armed with that knowledge, physicians began to consider the possibility of blood transfusions. In 1666, at the Royal Society, in London, Richard Lower presented the first scientific report on transfusion; he had transfused blood between two dogs, using a goose quill to connect an artery in the neck of one to the jugular vein in the neck of the other. A year later, French physicians introduced blood from a calf into the vein of a young man. Believing the procedure safe, they repeated the experiment, and, as the blood entered the man, his pulse rose, sweat formed on his brow, and he complained of severe back pain. These symptoms suggest that his body, having developed antibodies against the calf’s blood after the first injection, was now rejecting it. Undeterred, the French doctors administered a third transfusion, and the man died shortly thereafter.

Such early failures prompted the Royal Society, the French parliament, and the Catholic Church to suspend blood transfusions for human beings. For a hundred and fifty years, the procedure was banned from orthodox medicine. It didn’t start to become viable as a treatment until 1900, when Karl Landsteiner, a physician at the University of Vienna, made the first step toward the discovery of blood types. He tested the serum, a liquid component of blood, from six healthy men (five co-workers and himself), and found that sera from certain donors caused red blood cells in others to clump together. Landsteiner inferred that there must be different types of blood, and that they could be classified based on these observed agglutinations. Over the next few years, Landsteiner and his colleagues identified the main blood groups we know today—A, B, AB, and O—and showed that the interactions between them determined whether a transfusion would be safe. AB blood carriers were universal recipients, able to receive blood from any donor; O carriers, like Landsteiner himself, were universal donors. Now blood could be more safely administered to patients. In effect, for the first time since the days of the alchemists, blood became a medicine again.

More discoveries followed. In 1914, it was found that sodium citrate prevented blood from clotting, allowing it to be retrieved from a donor and stored until it was needed by a recipient. In the First World War, this discovery saved the lives of countless wounded soldiers. In 1937, Landsteiner and Alexander Wiener identified another essential feature of blood, the Rh factor, which explained blood incompatibilities between certain mothers and fetuses—a leading cause of stillbirths at the time.

Some of the more eye-catching and controversial experiments in recent blood research are, in a way, resurrecting the alchemists’ age-old hope—that blood might prove an elixir of youth. One such field is parabiosis—the name comes from the Greek for “next to” and “life.” By attaching two animals together, like conjoined twins, scientists have been able to observe the effects of sharing blood. Since 2013, Amy Wagers, a stem-cell researcher at Harvard, has studied parabiosis in pairs of differently aged mice. Wagers and her team have reported that when blood from a young mouse circulates through an older mouse it can reverse the deterioration of its muscles and rejuvenate its brain. These startling results have been confirmed by some outside researchers, although others have been unable to reproduce the findings.

Several companies now advertise age reversal through infusions of young blood. George’s book features one, Ambrosia, named after the food of the gods, which has clinics in San Francisco and Tampa. Its founder, Jesse Karmazin, was a doctor at Boston’s Brigham and Women’s Hospital until 2016, but he has since signed a voluntary agreement to cease practicing in Massachusetts—a tactic, as George notes, typically used by doctors who are threatened with the loss of their medical license.

Karmazin says that his company was merely conducting a clinical trial, transfusing plasma from donors under twenty-five years old. But he charged each recipient eight thousand dollars, and more than a hundred people signed up. Karmazin boasts extraordinary results: patients reported feeling younger, and at least one was allegedly cured of Alzheimer’s. Cancer, heart disease, and diabetes, Karmazin says, can all be treated with two litres of young plasma. As George writes, there’s no good reason to believe these claims, which have never been peer-reviewed. But, as in Renaissance Europe, when the nobility drank the blood of the young, there are plenty of rich people today, especially in Silicon Valley, who are happy to pay for a shot at immortality.

Bloodlines. Blood brothers. Blood feud. We still think of blood as what makes tribal identity cohere. The inquisitors in Spain defined race by blood, as did Southern slave owners and Nazi eugenicists. The current resurgence of nativism brings the jingoistic fixation on “blood and soil” to the fore, stoked by the likes of Donald Trump, Marine Le Pen, Nigel Farage, and Steve Bannon. As George puts it, “We fear blood, still, despite our science and understanding, and we look to blood to tell us who we should fear.”

Blood is figurative and emotional, too: our blood “boils” when we’re angry, “chills” when we’re afraid, “curdles” when we’re threatened. Such primitive associations appear to be impervious to advances in scientific understanding. In Japan, blood types now underpin a pseudoscientific philosophy of personality types, operating a little like astrological signs. Type A’s, George writes, are considered “perfectionist, kind, calm even in an emergency, and safe drivers; B’s are eccentric and selfish, but cheery. O’s are both vigorous and cautious while AB’s, obviously, are complicated.” Employers make hiring decisions based on blood type, and young people make dating decisions on the same basis. In 2011, when a government minister resigned after offending survivors of the Fukushima disaster, he used his blood type as an excuse. “My blood is Type B,” he announced, “which means I can be irritable and impetuous. . . . My wife called me earlier to point that out.”

When I was a medical student, the feature of blood that I came to most appreciate was that it was easy to access. A pinprick of a finger yielded a drop on a slide that, under the microscope, revealed a world of cells of different shapes, sizes, and colors. Looking at blood this way was like solving a puzzle, inspecting the configuration of the nucleus and the contents of the cytoplasm for clues on the path to a correct diagnosis.

When I was a fellow in hematology, another revolution in science transformed the art of diagnosis: recombinant-DNA technology allowed genes to be cloned and sequenced more easily. Diseases, in turn, could more readily be traced back to specific mutations in our genetic code. No longer were hematologists dependent on simply surveying cells under the microscope; instead, we were able to analyze blood on a molecular level, in order to identify the underlying abnormalities that cause leukemia, lymphoma, and other maladies. New drugs were developed that targeted such mutations and were able to achieve remission of numerous blood cancers that had been resistant to even the most intensive chemotherapy. In the past few years, gene-replacement techniques have advanced to the point where they can treat congenital blood disorders, such as hemophilia and thalassemia. And blood cells themselves have been genetically manipulated to serve as weapons against cancers: in a process called CAR T-cell therapy, the body’s own T-lymphocyte cells can be engineered to recognize and combat leukemia, lung cancer, and Hodgkin’s disease. The proteins that direct stem cells to mature into white blood cells, red blood cells, or platelets can now be mobilized to accelerate blood production in patients with low blood counts and to ameliorate the toxic effects of chemotherapy and bone-marrow transplantation, preventing fatal infections and hemorrhage.

Progress has been so fast that previous periods of my career can seem almost unimaginably primitive. Shortly after I completed my hematology training, in the early eighties, I encountered many people with hemophilia who were dying from blood transfusions they’d received. In 1985, two years after the discovery of H.I.V., tests were developed to screen blood donors and eliminate infected blood from transfusion banks. These life-saving tests, and similar ones for hepatitis B and C, are now so routine that we take them for granted.

Last month, in San Diego, the American Society of Hematology had its annual meeting. The program featured new discoveries about blood’s biology and accounts of recent advances in patient treatments—including an alternative to chemotherapy for one of the most common and incurable forms of leukemia. But, even as the field probes ever more deeply into the ways that blood serves living tissues, my colleagues and I are no closer to unravelling the oldest, most profound mystery of blood. In the verse from Leviticus, the word nefesh , translated as “life,” also means soul. ♦

Books & Fiction

By signing up, you agree to our User Agreement and Privacy Policy & Cookie Statement . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

By Amanda Schaffer

By Andrew Marantz

By Anna Wiener

Advertisement

Manuscript Submission

Author membership in the American Society of Hematology is not a prerequisite for submission or publication in Blood and is not taken into consideration during the peer review process.

• Contact information for all co-authors, including a current functioning e-mail address for each. eJournalPress requires an accurate and functional e-mail address for each author. If an author is not accessible by e-mail (e.g., deceased or out of e-mail contact), this must be discussed with the editorial office prior to submission.
• Abstract and manuscript files. Please be sure that your manuscript text document contains page numbers.
• Related manuscript ID number(s) (e.g., BLOOD/2014/123456) if this manuscript was previously submitted or if this submission is part of a companion group.
• Cover letter to the Editor-in-Chief.
• E-mail addresses of suggested reviewers, if any.
• Mechanism for payment, with all information necessary to pay the submission fee on-line. Payment is required at submission for all Regular Articles and Brief Reports.

Users are encouraged to use up-to-date browsers including Safari, Google Chrome, Mozilla Firefox or Internet Explorer 10 when submitting a manuscript through eJournalPress . Non-suggested browsers include older versions of Internet Explorer (IE 9 or less) and other out-of-date browsers as all current eJournalPress features may not be supported.

Online copyright transfer

Manuscript submission fee, affiliations.

• Current Issue
• First edition
• Collections
• Submit to Blood
• About Blood
• Subscriptions
• Public Access
• Permissions
• Blood Classifieds
• Advertising in Blood
• Terms and Conditions

American Society of Hematology

• 2021 L Street NW, Suite 900
• Washington, DC 20036
• TEL +1 202-776-0544
• FAX +1 202-776-0545

ASH Publications

• Blood Advances
• Blood Neoplasia
• Blood Vessels, Thrombosis & Hemostasis
• Hematology, ASH Education Program
• ASH Clinical News
• The Hematologist
• Publications
• Privacy Policy
• Cookie Policy
• Terms of Use

This Feature Is Available To Subscribers Only

Sign In or Create an Account

Impact Factor

• About the Journal

Aims and Scope

• Editorial Board
• Publication Charge

Current Issue

Ahead of print, review highlights.

• Instructions for Authors Instructions for Authors -->
• E-Submission
• Open Access
• Best Practice
• Similarity Check
• Advertising Policy

CYP1A1 variants on the risk of acute lymphoblastic leukemia: evidence from an updated meta-analysis'>Impact of CYP1A1 variants on the risk of acute lymphoblastic leukemia: evidence from an updated meta-analysis

Imen Frikha, Rim Frikha, Moez Medhaffer, Hanen Charfi, Fatma Turki and Moez Elloumi

Blood Res (2024) 59:9

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) gene polymorphisms in a cohort of Egyptian patients with immune thrombocytopenia (ITP)

Doaa Mohamed El Demerdash, Maha Mohamed Saber, Alia Ayad, Kareeman Gomaa and Mohamed Abdelkader Morad

Blood Res (2024) 59:8

Acute erythroid leukemia leading to the diagnosis of Schwachman-Diamond syndrome

Bernhard Strasser, Sebastian Mustafa, Josef Tomasits and Alexander Haushofer

Blood Res (2024) 59:10

Genomic testing for germline predisposition to hematologic malignancies

Sang Mee Hwang

The role of next-generation sequencing in hematologic malignancies

Young‑Uk Cho

Genomic technologies for detecting structural variations in hematologic malignancies

Practical issues in car t-cell therapy.

Ja Min Byun

Blood Res (2023) 58:10

Submit a New Manuscript!

If you want to submit your Manuscript to us, Submit at the Online System now.

FLT3 mutations in acute myeloid leukemia: a review focusing on clinically applicable drugs'> FLT3 mutations in acute myeloid leukemia: a review focusing on clinically applicable drugs

Jae-Sook Ahn, Hyeoung-Joon Kim

Blood Res 2022; 57(S1): S32-S36

Overview of inherited bone marrow failure syndromes

Meerim Park

Blood Res 2022; 57(S1): S49-S54

Management of immune thrombocytopenia: 2022 update of Korean experts recommendations

Young Hoon Park, Dae-Young Kim, Seongkoo Kim, Young Bae Choi, Dong-Yeop Shin, Jin Seok Kim, Won Sik Lee, Yeung-Chul Mun, Jun Ho Jang, Jong Wook Lee, Hoon Kook, on behalf of Korean Aplastic Anemia Working Party

Blood Res 2022; 57(1): 20-28

Human acute myeloid leukemia stem cells: evolution of concept

Dong-Yeop Shin

Blood Res 2022; 57(S1): S67-S74

Diagnosis and management of thrombocytopenia in pregnancy

Young Hoon Park

Blood Res 2022; 57(S1): S79-S85

Basic immunohistochemistry for lymphoma diagnosis

Blood Res 2022; 57(S1): S55-S61

Update on primary plasma cell leukemia

Sung-Hoon Jung, Je-Jung Lee

Blood Res 2022; 57(S1): S62-S66

Editorial Office

+82-2-516-6581

+82-2-516-6582

[email protected]

www.hematology.or.kr

Share by SNS

• Original Article
• Open access
• Published: 21 May 2021

Blood pattern analysis—a review and new findings

• Prashant Singh   ORCID: orcid.org/0000-0003-1340-1789 1 ,
• Nandini Gupta 1 &
• Ravi Rathi 2  

Egyptian Journal of Forensic Sciences volume  11 , Article number:  9 ( 2021 ) Cite this article

25k Accesses

2 Citations

1 Altmetric

Metrics details

Blood is one of the most common pieces of evidence encountered at the crime scene. Due to the viscous nature of blood, unique bloodstain patterns are formed which when studied can reveal what might have happened at the scene of the crime. Blood pattern analysis (BPA), i.e., the study of shape, size, and nature of bloodstain. The focus of this paper is to understand blood and BPA. An experimental finding to understand blood stain formation using Awlata dye was conducted within the university premises under laboratory conditions. Awlata ( Alta ), an Indian dye used for grooming of women, was used to create fake blood stains to understand the formation of bloodstains with respect to varying heights, and their relation with spines and satellite stains was determined.

When the height of dropping fake blood increased, the distance of satellite stains emerging from the fake blood stains was also increasing. From the experimental finding, it was found that satellite stains were directly proportional to height of blood stain and spines were inversely proportional.

It can be concluded that blood is a vital source of information and when interpreted correctly it can be used as a source of information that can aid in investigations. Thus, a relation between formation of blood stains with relation to height was established. This finding using fake blood stains can help in carrying out future studies.

The study aims to determine the relationship between spines and satellites stains in accordance with varying heights using Awlata dye. It involves creation of fake bloodstains using Awlata dye to determine this relation. The study also seeks to suggest the use of Awlata dye for studying bloodstains for conducting future studies.

Blood is an organic fluid circulating in our body that is essential to maintain life; it includes blood cells and plasma that accounts for approximately 8% of body weight. Blood ranges from 4–5 L (female) to 5–6 L (male). Blood has few bodily capabilities which can be required for its morphological interpretation like specific weight, viscosity, and surface tension (Peschel et al. 2011 ; Bevel and Gardner 2012 ). Viscosity in terms of blood may be described as the pressure of the flow of blood, due to shear stress or extensional stress inside the body (Bevel and Gardner 2012 ). An elastic-like property of a fluid due to cohesive forces between liquid molecules is surface tension (Larkin et al. 2012 ). Blood possesses fluid nature inside the body or when it exits from the body due to an impact/injury (James et al. 2005 ). If there were blood clots in the blood found at the crime scene, it suggests that the victim was exposed to an extended injury (Peschel et al. 2011 ; Bevel and Gardner 2012 ).

Blood can exit from the body as drip, spurt, etc., or can even ooze from wounds depending on the type of infliction/damage. BPA is a type of examination that includes the interpretation of shapes of the bloodstains (James et al. 2005 ). Blood pattern analysis aims to reveal the physical events that might have occurred at the crime scene. These bloodstains can be interpreted by their shape, size, and distribution (Brodbeck 2012 ). The facts acquired from BPA can help in crime scene reconstruction, corroborating witness statements, for the investigative procedure (James et al. 2005 ). If bloodstains at a crime scene are either dried or removed by the assailant, they can still be recovered by spraying luminol. Luminol (5-amino-2,3 dihydro-1,4-pthalazine-dione) can be used to detect the presence of minor, unnoticed, or hidden bloodstains diluted down to a level of 1:10 6 (1 μL of blood in 1 L of solution) which gives chemiluminescence or glowing effect when it reacts with dried bloodstains (Quickenden and Creamer 2001 ).

Luminol solution is usually directly sprayed in completely dark environments, and then UV (ultra violet) light visualizes the sample (blood). The fluorescence obtained is then photographed or filmed. Luminol can be used to identify minor, unnoticed, or hidden bloodstains, and it also has a high sensitivity to old blood or completely dried blood but, unfortunately, luminol can react with detergents, metals, and vegetables to give false-positive results (Barni et al. 2007 ). Sometimes, there are probabilities that the bloodstain recovered had been created using certain substances (dyes/stains) to deceive the investigators. To distinguish whether a sample is blood or not, assays like Kastle-Meyer (phenolphthalein test), Medinger reaction (Leuco malachite Green), and Tetramethylbenzidine test are used, but they cannot satisfactorily confirm blood (preliminary tests). So, for the confirmatory evaluation of blood, Teichmann and Takayama tests are performed to distinguish if the samples were blood or not (Saferstein and Hall 2020 ). It is also very important for the analyst to determine the origin of species of blood (whether human or animal) by precipitin test; this is often necessary to avoid confusion in investigative findings. There are several conditions in which the bloodstain patterns are disturbed/altered and in such cases, no useful information can be interpreted. So, DNA analysis is utilized for providing investigative leads (Saferstein and Hall 2020 ). When the bloodstains are suspected to be from multiple sources, the investigator can often rely on DNA to reveal valuable details about the crime. So, in the case of multiple victims, analysts often use DNA profiling to determine whose blood it was (James et al. 2005 ; Karger et al. 2008 ).

Bloodstain patterns distributed at the crime scene can be used for the reconstruction of an event (Comiskey et al. 2016 ). Before reconstruction, an analyst must have a comprehensive view of the overall picture and use the step-by-step approach to differentiate and analyze the bloodstain patterns and search for the informative points (James et al. 2005 ). It is also required that the investigator must create a hypothesis on the formation of blood patterns due to injuries. Reconstruction can be further improved by the contribution of case descriptions and statements (witnesses/perpetrators) that can provide insights on the sequence of events. Hence, to carry out an effective reconstruction, both casework experience combined with knowledge of injuries should be known (Karger et al. 2008 ; Kunz et al. 2013 ; Kunz et al. 2015 ).

Types of bloodstains

Passive patterns.

It is a type of bloodstain pattern formed due to gravity, patterns like drip stain, flow stain, blood pool, and serum stain are observed. A drip stain is a drop falling without any disturbance that can take a spherical shape without disintegrating into smaller droplets. Bloodstains, depending on the angle, can cause the blood drop to have a circular or slightly elongated shape; this helps in the determination of the angle of impact (Swgstain 2009 ). Sometimes, a trail can be formed due to the dripping of blood from a weapon as well as in case of blunt or trauma injuries, due to which large volume of blood can be encountered at the crime scene (James et al. 2005 ; Peschel et al. 2011 ).

Spatter patterns

These are patterns formed when hard objects are used to strike the victim (example: a pipe). Forward spatter on the other hand is a pattern formed towards the direction of damage (example: bullet creating an exit wound) (James et al. 2005 ; Peschel et al. 2011 ). Back spatter is a pattern formed by blood when damage is to a hard surface like the skull by a bullet, and the bloodstains will be pointing away from the impact. Gunfire spatter can also vary on the caliber of the weapon used, location of impact, and the location of the victim (James et al. 2005 ; Peschel et al. 2011 ).

Projected patterns are irregular patterns that are due to the motion of weapon (example: stabbing). If in case at the crime scene there was existence of droplets of blood of varied sizes, it is called a cast-off pattern (example: injuries by hammers) (James et al. 2005 ). In case of injury to the artery, the blood from the blood vessel flows like a fountain (upward to downward flow), a zig-zag pattern will be observed until the pressure of the lungs reduces. If there was injury internally, expiration from the mouth/nose releases blood that creates a pattern very small to see (fine mist-like) (James et al. 2005 ; Peschel et al. 2011 ).

Altered patterns

Bloodstain patterns that indicate that a physical change had occurred can be said as altered patterns. This change can be due to physical activity, diffusion, dilution, or insects’, which can misguide the investigators to consider them as drip patterns. In case if the body was dragged over pre-existing blood, it leaves a tangential path (James et al. 2005 ). Contact prints may also be recovered on clean surfaces at the crime scenes (bloody shoe prints, fingerprints, or the entire palm) that can help investigators in determining what might have occurred at the crime scene. This can help investigators to determine what object could have been at the crime scene (James et al. 2005 ; Peschel et al. 2011 ).

Void patterns on the other hands are formed when an object is placed between the blood source and projection area, it is likely to receive some of the stains, which consequently leads to an absence of the stains in an otherwise continuous bloodstain pattern, which can indicate that an object or person would have been a part of the pattern (like a missing object from the wall) that if recovered can help in completing the pattern (James et al. 2005 ; Peschel et al. 2011 ).

Insects that move over the blood can also create a unique pattern that can often confuse the investigators to what pattern it could be. When blood comes into contact with clothing and fabric it spreads via diffusion, often leaving an irregularly shaped pattern which is difficult to interpret, especially in that cases the surface could be collected and send for examination to forensic labs (James et al. 2005 ; Peschel et al. 2011 ).

Moreover, to reconstruct the events that caused bloodshed, the investigators use the direction and angle of the spatter to calculate the areas of convergence (it is the starting point of the bloodshed) and area of origin (point from where the blood immerged) to mark the location of the victim and perpetrator (James et al. 2005 ) (Fig. 1 ).

Fake blood stains that were made using Awlata dye

Different works have been carried in blood pattern analysis, a study showed that when determining area of origin from blood stains, larger drops which are elliptical should be given more consideration (de Bruin et al. 2011 ). In another study, the velocities of blood were considered with factors like air drag and gravity which was used to predict the back-spatter formation by carrying the experiment using a blood-soaked sponge (Comiskey et al. 2016 ).

Fluid dynamics was also given consideration in blood pattern analysis to understand how the blood behaves as a liquid when in air and the factors that are affecting the formation the blood drop (Attinger et al. 2013 ). Study of spines and satellite on basis of velocity has also depicted the formation of bloodstains (Attinger et al. 2013 ).

In a real-time setting, studying bloodstains and its patterns using real blood can be a tedious task, as it requires a large amount of blood. Moreover, in order to carry out such a study, it will require ethical clearance as well as financial support. Using Awlata dye for studying bloodstains can solve these problems because of its easy availability, low cost, and it can be made under laboratory conditions. Thus, investigators and scientists can use this for experimental purposes and to carry future studies.

Article selection criteria for review

The initial criteria for selecting literature were based on searching different keywords on Google searching engine for blood, blood pattern analysis, and blood pattern analysis in forensic science. Then, after screening of articles based on the title and abstract of papers, papers were sorted. Articles and relevant internet sources that matched the relevant criteria of the review were also selected.

Article eligibility criteria for review

Eligibility of articles was finalized by analyzing whether the papers were discussing about BPA and its related methodology or not.

On basis of analyzing existing literature, it was decided that a study needs to be conducted by creating fake bloodstains using Awlata, so as to understand the formation of stains if the angle is kept fixed and the height is varied (Buck et al. 2011 ; Attinger et al. 2013 ). An Indian dye (Awlata/Alta) was used to make fake blood stains to depict similar patterns as that of blood. Awlata (Alta) is a traditional Indian red dye used by women in the festive season and is applied to hands and feet. For the experiment Awlata dye, a Pasteur pipette and white chart papers were used. The experiment was carried within the university premises in the university laboratory.

Preparation/composition of Awlata

In cultural practices, Awlata dye was made from Betel leaves which is a vine from the family Piperaceae. Awlata is also made from the extract of lac that is a red dye obtained from the scale of an insect Laccifer Lacca. Nowadays, Awlata can be made chemically by using Vermillion (red powder) with water to make a liquid.

Source of Awlata for the experiment

For this experiment, a ready-made Awlata dye (Pari) was bought from the local market which had its composition defined and came packed in a 50-ml bottle. The reason for taking Awlata for experiment, was Awlata dries within a few minutes and its life span is about 1–2 months, after which it starts to fade. But if it is preserved and stored properly, it can stay intact for long durations.

Formation of fake bloodstains

In this experiment, we conducted different height variations to create fake bloodstains using Awlata dye (Buck et al. 2011 ; Attinger et al. 2013 ). The experiment aimed to study the shape (morphology) of these fake bloodstains at different heights (3, 4, 5, 6, and 7 feet) so that an approximate estimation of actual blood stain formation can be studied (Attinger et al. 2013 ). A Pasteur pipette was used for this experiment and about 0.5 ml of Awlata dye was taken for making a single fake blood stain.

The amount of Awlata dye that was used to make a single fake blood stain was ascertained using the indications labeled on the Pasteur pipette. Ninety-degree angle was maintained and the Awlata dye was dropped from different heights and observations were made. For each height, two stains were made and labeled drop 1 and drop 2; this was done to compare the observation and confirm the findings.

After Awlata dye was dropped from different heights to create fake blood stains, it was observed that as the height was increased, the distance of satellite stains emerging from the fake blood stains was also increasing. It can be observed that fake blood stain created from three feet has many numbers of spines and less satellite stains and they are very close to the parent stain. Similarly, as the height was increased, the numbers of spines were reduced and the number of satellite stains was increased.

The experimental observation noted was that as the height was increased, the force of gravity acting on the Awlata dye was also increasing, and hence when the Awlata dye was dropped from a height to create fake blood stains, the impact of the dye on the surface due to gravitational forces, inertial forces, and viscous forces (Attinger et al. 2013 ) could be the possible cause of formation of such stains. To ascertain the formation of these fake blood stains, we retook the height experiment and the observations were very similar to that of the first drop (see Table  1 ).

Discussions

After the experiment carried with Awlata dye, it was observed that height was directly proportional to the number of satellite stains (stains that are small droplets moving away from the parent stain, they are partially/not attached to the parent stain), i.e., more distant the satellite stains from the parent drop, more will be the height. Whereas relation of spines (these are small projections coming out from the parent stain, they remain attached to the parent stain) and height was inverse in nature, i.e., when the height was increased the number of spines reduced.

Though Awlata was used to study the formation of fake blood stains, care must be taken that this dye should be kept away from contact with moisture/water as repeated moisture/water tends to fade the dye and also wash it off. So, if Awlata dye is used for future studies, the observations made from this dye should be properly stored and preserved. This will help ensure the integrity of experimental findings is not altered.

Factors like size, age, and health of the individual should also be given consideration while studying the blood stain formation. Moreover, surface tension also plays an important role in the formation of bloodstains (Larkin et al. 2012 ). Surface tension is also varied if there is some chemical or other chemical present in the blood (Raymond et al. 1996 ). The surface roughness, permeability, and porosity also effect the formation of bloodstain formation. So, these factors are also needed to be given consideration when studying bloodstains (Bear 1975 ).

Study of fake bloodstains using Awlata dye highlights these potential aspects and on basis of existing literary works carried by other scientists a more definite version of BPA can be worked upon. Study of fluid dynamics should also be given consideration while studying bloodstain formation (Attinger et al. 2013 ). To open new gateways of research in BPA and support investigative observations, the findings depicted in this paper can be used as a source to validate actual blood stains and also carry out future studies. Domains like how angle variation with respect to height effects formation of blood stains can be explored on the basis of these findings. This finding can help to understand the formation of blood stains for future research and development.

The future of BPA is promising and more research needs to be done to improve BPA. A more precise method of blood interpretations should be created to make investigations more accurate, so that crime scene reconstruction can be carried out efficiently. The study conducted using Awlata dye can be a contributor to the existing literature on BPA. This paper is a review work which can be utilized by students, scientists, or experts as a reference for carrying out future studies or to enhance their knowledge. Blood pattern analysis is indeed a useful tool in forensic science which can help in crime scene reconstruction and if BPA is coupled with DNA analysis and other investigative findings, more conclusive and thorough details of the sequence of events can be obtained from blood evidence.

Limitations of Awlata dye

The composition of Awlata dye (Alta) and blood vary; hence, Awlata dye (Alta) cannot be considered as blood. Awlata was used to create fake bloodstains which can give an approximate idea towards BPA and resemblance somewhat similar to actual blood stains. The actual scenario at the crime scene that led to the formation of blood stains and that made by Awlata dye has scope for human errors too as studying blood stains in real and that in experimental conditions differ.

Awlata dye use in the forensic scenario

Studying BPA is a very skillful task, and at the crime scene when real blood is concerned, the scenarios are simultaneous and unpredictable. To carry studies to understand bloodstains is not always possible; it requires a large amount of blood which is subjected to ethical clearance. Awlata dye can be an emerging substitute to this problem, as it is cost-effective, readily available, and can also be made in the lab. Awlata dye can be used to create experimental conditions to study different forensic scenarios. Fake blood created with Awlata dyes can be used to make simulated crime scenes from forensic and investigative findings to derive case supportive conclusions.

From the experiment done using Awlata dye ( Alta ), it can be concluded that blood stains can help experts estimate the approximate height of the assailant. The formation of the bloodstain can correspond to the height it originated from, thus being a vital source of information. A relation of formation of blood stains with change in varying height was established in accordance with interpretation of spines and satellite stains. Though Awlata is not similar to blood, it can be used to carry out experimental studies to explore more about BPA. Existing studies on BPA depict that blood patterns are very useful source of information and it can help investigators to examine the crime scene precisely.

Availability of data and materials

Not applicable

Abbreviations

Blood pattern analysis

Deoxyribonucleic acid

Ultra violet

Attinger D, Moore C, Donaldson A, Jafari A, Stone H (2013) Fluid dynamics topics in bloodstain pattern analysis: Comparative review and research opportunities. Forensic Sci Int 231(1-3):375–396. https://doi.org/10.1016/j.forsciint.2013.04.018

Article   PubMed   Google Scholar  

Barni F, Lewis S, Berti A, Miskelly G, Lago G (2007) Forensic application of the luminol reaction as a presumptive test for latent blood detection. Talanta 72(3):896–913. https://doi.org/10.1016/j.talanta.2006.12.045

Article   CAS   PubMed   Google Scholar  

Bear J (1975) Dynamics of fluids in porous media. Soil Sci 120(2):162–163. https://doi.org/10.1097/00010694-197508000-00022

Article   Google Scholar  

Bevel T, Gardner R (2012) Bloodstain pattern analysis with an introduction to crime scene reconstruction, 3rd edn. Taylor and Francis, Hoboken

Google Scholar  

Brodbeck S (2012) Introduction to bloodstain pattern analysis. SIAK J J Police Sci Pract 2:51–57 Avaialble via DIALOG. https://www.bmi.gv.at/104/Wissenschaft_und_Forschung/SIAK-Journal/internationalEdition/files/Brodbeck_IE_2012.pdf

Buck U, Kneubuehl B, Näther S, Albertini N, Schmidt L, Thali M (2011) 3D bloodstain pattern analysis: Ballistic reconstruction of the trajectories of blood drops and determination of the centres of origin of the bloodstains. Forensic Sci Int 206(1-3):22–28. https://doi.org/10.1016/j.forsciint.2010.06.010

Comiskey P, Yarin A, Kim S, Attinger D (2016) Prediction of blood back spatter from a gunshot in bloodstain pattern analysis. Phys Rev Fluids. 1(4). https://doi.org/10.1103/physrevfluids.1.043201

de Bruin K, Stoel R, Limborgh J (2011) Improving the point of origin determination in bloodstain pattern analysis. J Forensic Sci 56(6):1476–1482. https://doi.org/10.1111/j.1556-4029.2011.01841.x

James S, Kish P, Sutton T (2005) Principles of bloodstain analysis. CRC, Boca Raton, Fla. https://doi.org/10.1201/9781420039467

Book   Google Scholar  

Karger B, Rand S, Fracasso T, Pfeiffer H (2008) Bloodstain pattern analysis—casework experience. Forensic Sci Int 181(1-3):15–20. https://doi.org/10.1016/j.forsciint.2008.07.010

Kunz S, Brandtner H, Meyer H (2013) Unusual blood spatter patterns on the firearm and hand: a backspatter analysis to reconstruct the position and orientation of a firearm. Forensic Sci Int 228(1-3):e54–e57. https://doi.org/10.1016/j.forsciint.2013.02.012

Kunz S, Brandtner H, Meyer H (2015) Characteristics of backspatter on the firearm and shooting hand-an experimental analysis of close-range gunshots. J Forensic Sci 60(1):166–170. https://doi.org/10.1111/1556-4029.12572

Larkin B, El-Sayed M, Brownson D, Banks C (2012) Crime scene investigation III: exploring the effects of drugs of abuse and neurotransmitters on bloodstain pattern analysis. Anal Methods 4(3):721. https://doi.org/10.1039/c2ay05762j

Article   CAS   Google Scholar  

Peschel O, Kunz S, Rothschild M, Mützel E (2011) Blood stain pattern analysis. Forensic Sci Med Pathol 7(3):257–270. https://doi.org/10.1007/s12024-010-9198-1

Quickenden T, Creamer J (2001) A study of common interferences with the forensic luminol test for blood. Luminescence 16(4):295–298. https://doi.org/10.1002/bio.657

Raymond M, Smith E, Liesegang J (1996) The physical properties of blood–forensic considerations. Sci Justice 36(3):153–160. https://doi.org/10.1016/s1355-0306(96)72590-x

Saferstein R, Hall A (2020) Forensic science handbook. CRC Press, Taylor & Francis Group, Milton. https://doi.org/10.4324/9781315119939

Swgstain S (2009) Scientific Working Group on bloodstain pattern analysis: recommended terminology. Forensic Sci Commun 11(2):14–17 Available via DIALOG. http://theiai.org/docs/SWGSTAIN_Terminology.pdf

Download references

Acknowledgements

Author information, authors and affiliations.

School of Forensic Science, National Forensic Sciences University, Gandhinagar, Gujarat, India

Prashant Singh & Nandini Gupta

Department of Chemistry, Biochemistry and Forensic Sciences, Amity University, Manesar, Haryana, India

You can also search for this author in PubMed   Google Scholar

Contributions

PS and NG worked on researching relevant data and writing of this review paper. RR was our guide and mentor who constantly guided us and helped formulate the different sections of the review and did the final check. We clarify that all authors have read and approved the final manuscript.

Corresponding author

Correspondence to Prashant Singh .

Ethics declarations

Ethics approval and consent to participate, consent for publication, competing interests.

The authors declare that they have no competing interests.

Additional information

Publisher’s note.

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ .

Reprints and permissions

About this article

Cite this article.

Singh, P., Gupta, N. & Rathi, R. Blood pattern analysis—a review and new findings. Egypt J Forensic Sci 11 , 9 (2021). https://doi.org/10.1186/s41935-021-00224-8

Download citation

Received : 28 September 2020

Accepted : 09 May 2021

Published : 21 May 2021

DOI : https://doi.org/10.1186/s41935-021-00224-8

Share this article

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

• Bloodstains

Solving the riddle of the sphingolipids in coronary artery disease

Weill Cornell Medicine investigators have uncovered a way to unleash in blood vessels the protective effects of a type of fat-related molecule known as a sphingolipid, suggesting a promising new strategy for the treatment of coronary artery disease.

In the study, published March 8 in Circulation Research , the researchers showed that boosting levels of a sphingolipid called S1P in artery-lining endothelial cells slows the development and progression of coronary artery disease in an animal model. The lead author was Dr. Onorina Laura Manzo, a postdoctoral researcher in the laboratory of Dr. Annarita Di Lorenzo, an associate professor of pathology and laboratory medicine at Weill Cornell Medicine.

Sphingolipids are named for the enigmatic sphinx of ancient mythology because their functions in biology traditionally have been somewhat mysterious. In recent years, there has been increasing evidence of their relevance in coronary artery disease; bloodstream levels of S1P, for example, are lower in patients with this condition. But the precise roles of these lipids have remained unclear.

In the new study, the researchers sought a better understanding of those roles -- and of sphingolipids' potential as therapeutic targets. Despite the availability of cholesterol-lowering drugs and other interventions, coronary artery disease -- the underlying cause of most heart attacks and many strokes -- continues to be the world's leading cause of mortality, affecting more than 20 million people in the United States alone.

Using a novel mouse model developed by the same group, the researchers found that blood pressure-related stress on arteries -- which eventually will induce coronary artery disease -- triggers an increase in S1P production in endothelial cells, as part of a protective response. This response normally is only temporary, but deleting a protein called NOGO-B, which inhibits S1P production, allows the rise in endothelial S1P production to be sustained -- and made the animals much more resistant to coronary artery disease and associated mortality.

Another key finding is related to a different group of sphingolipids called ceramides. Prior studies have linked coronary artery disease to high bloodstream levels of some ceramides, and their causative role in the disease has been widely assumed. In their model, however, the researchers observed that while ceramide levels were high in the bloodstream, levels in artery-lining endothelial cells remained about the same regardless of coronary artery disease status. This suggests that the current view of ceramides' role in the disease should be revised.

All in all, the findings lay the foundation for the development of drugs that boost S1P to treat or prevent coronary artery disease, the researchers concluded.

The work reported in this story was supported by the National Heart, Lung, and Blood Institute, part of the National Institutes of Health, through grant numbers R01HL126913 and R01HL152195 and a Harold S. Geneen Charitable Trust Award for Coronary Heart Disease Research.

• Heart Disease
• Stroke Prevention
• Cholesterol
• Chronic Illness
• Alzheimer's Research
• Diseases and Conditions
• Parkinson's Research
• Ischaemic heart disease
• Coronary circulation
• Coronary heart disease
• Blood pressure
• Saturated fat
• Pulmonary embolism

Story Source:

Materials provided by Weill Cornell Medicine . Note: Content may be edited for style and length.

Journal Reference :

• Onorina L. Manzo, Jasmine Nour, Linda Sasset, Alice Marino, Luisa Rubinelli, Sailesh Palikhe, Martina Smimmo, Yang Hu, Maria Rosaria Bucci, Alain Borczuk, Olivier Elemento, Julie K. Freed, Giuseppe Danilo Norata, Annarita Di Lorenzo. Rewiring Endothelial Sphingolipid Metabolism to Favor S1P Over Ceramide Protects From Coronary Atherosclerosis . Circulation Research , 2024; 134 (8): 990 DOI: 10.1161/CIRCRESAHA.123.323826

Cite This Page :

Explore More

• Humans and Earth's Deep Subsurface Fluid Flow
• Holographic Displays: An Immersive Future
• Harvesting Energy Where River Meets Sea
• Making Diamonds at Ambient Pressure
• Eruption of Mega-Magnetic Star
• Clean Fuel Generation With Simple Twist
• Bioluminescence in Animals 540 Million Years Ago
• Fossil Frogs Share Their Skincare Secrets
• Fussy Eater? Most Parents Play Short Order Cook
• Precise Time Measurement: Superradiant Atoms

Trending Topics

Strange & offbeat.

Hoxworth Blood Center's Research Division shines with 2023 national and international publications

A milestone year in transfusion medicine.

Hoxworth Blood Center, University of Cincinnati, serves as the sole blood provider for over 30 hospitals in 18 counties, and is the oldest blood center in the nation. In addition to its vital roles in blood banking and transplant medicine for Tri-State local hospitals, Hoxworth is the home for world-renowned researchers and groundbreaking innovations.

Since its beginning in 1938 under the leadership of Dr. Paul I. Hoxworth, Hoxworth Blood Center has been dedicated to advancing the hemotherapy field. All Hoxworth divisions aim to bridge fundamental research with clinical care. Hoxworth is committed to enhancing the quality, safety and effectiveness of the blood and hematopoietic cell therapies. Hoxworth research includes clinical research , basic biological research and translational transfusion medicine and transplant research.

Hoxworth faculty and staff have published in many prestigious, peer-reviewed, national and international journals. In 2023, Hoxworth Blood Center made notable contributions to the field. Hoxworth authors are bolded below.

• Singh AK, Prasad P, Cancelas JA . Mesenchymal stromal cells, metabolism, and mitochondrial transfer in bone marrow normal and malignant hematopoiesis. Frontiers in Cell and Developmental Biology. 2023;11.
• Vandenbroeke T, Gloor C, Wingfield T, Leite C, Carr K, Turner C, Ngamsuntikul S, Sutor L, Compton F, Nestheide S, Rugg N, Cancelas JA , Dumont LJ. In vitro quality parameters of whole blood‐derived platelets pooled using two different platelet pooling sets and stored up to 7 days are similar. Transfusion . 2024 Jan;64(1):132-40.
• Solomon M, Song B, Govindarajah V, Good S, Arasu A, Hinton EB, Thakkar K, Bartram J, Filippi MD, Cancelas JA , Salomonis N. Slow cycling and durable Flt3+ progenitors contribute to hematopoiesis under native conditions. J ournal of Experimental Medicine. 2023 Nov 1;221(1):e20231035.
• Sarkar A, Niraula G, LeVine D, Zhao Y, Tu Y, Mollaeian K, Ren J, Que L , Wang X . Development of a Ratiometric Tension Sensor Exclusively Responding to Integrin Tension Magnitude in Live Cells. ACS Sensors. 2023 Sep 22;8(10):3701-12.
• Thant M, Cancelas J , Kaplan A. The enhanced direct antiglobulin test in current practice has a limited impact on management of adult patients. Transfusion and Apheresis Science. 2023 Oct 1;62(5):103768.
• Qian F, Nettleford SK, Zhou J, Arner BE, Hall MA, Sharma A, Annageldiyev C, Rossi RM, Tukaramrao DB, Sarkar D, Hegde S . Activation of GPR44 decreases severity of myeloid leukemia via specific targeting of leukemia initiating stem cells. Cell Reports . 2023 Jul 25;42(7).
• Dandamudi A, Seibel W, Tourdot B, Cancelas JA , Akbar H, Zheng Y. Structure–Activity Relationship Analysis of Rhosin, a RhoA GTPase Inhibitor, Reveals a New Class of Antiplatelet Agents. International Journal of Molecular Sciences. 2023 Feb 19;24(4):4167.
• Dandamudi A, Akbar H, Cancelas J , Zheng Y. Rho GTPase Signaling in Platelet Regulation and Implication for Antiplatelet Therapies. International Journal of Molecular Sciences . 2023 Jan 28;24(3):2519.
• Galletta TJ, Lane A, Lutzko C, Leemhuis T, Cancelas JA , Khoury R, Wang YM, Hanley PJ, Keller MD, Bollard CM, Davies SM. Third-party and patient-specific donor-derived virus-specific T cells demonstrate similar efficacy and safety for management of viral infections after hematopoietic stem cell transplantation in children and young adults. Transplantation and Cellular Therapy. 2023 May 1;29(5):305-10.
• Menéndez-Gutiérrez MP, Porcuna J, Nayak R , Paredes A, Niu H, Núñez V, Paranjpe A, Gómez MJ, Bhattacharjee A, Schnell DJ, Sánchez-Cabo F. Retinoid X receptor promotes hematopoietic stem cell fitness and quiescence and preserves hematopoietic homeostasis. Blood . 2023 Feb 9;141(6):592-608.
• Salazar RD, Weidner KR, Alquist CR . Therapeutic plasma exchange in refractory Susac's syndrome: A brief report. Journal of Clinical Apheresis. 2024 Feb 1.
• Connelly‐Smith L, Alquist CR , Aqui NA, Hofmann JC, Klingel R, Onwuemene OA, Patriquin CJ, Pham HP, Sanchez AP, Schneiderman J, Witt V. Guidelines on the Use of therapeutic apheresis in clinical practice–Evidence‐Based approach from the Writing Committee of the American Society for Apheresis: The Ninth Special Issue. Journal of Clinical Apheresis. 2023 Apr;38(2):77-278.
• C Alquist and HC Sullivan. Chapter 18: Laboratory Management. In: HC Sullivan ed. Transfusion Medicine Self-Assessment and Review, 4th ed. AABB. Bethesda, MD: October 2023. Developed to be used with the Technical Manual , this popular resource helps trainees learn and review concepts in an examination format. This edition contains 900 brand-new multiple-choice questions covering 18 topics in blood collection/transfusion and biotherapies.
• Alquist C , Greenspan N, Wald D. Chapter 5: HLA Molecular Basis, Typing, and Matching. In: Cancelas J, Bandarenko, N, eds. Cellular Therapy: A Handbook . 2nd ed. Bethesda, MD: AABB, September 2023:91-112.
• Ipe TS and Alquist CR . Chapter 17: Transfusion-Service-Related Activities: Pretransfusion Testing and Storage, Monitoring, Processing, Distribution, and Inventory Management of Blood Components. In: Delaney M and Cohn CS (eds.) The Technical Manual , 21st ed. Bethesda, MD: AABB, August 2023. 70 yr anniversary edition of AABB’s most popular book, a must-have resource for health care professionals and students working in blood banking and transfusion medicine throughout the world. Adopted by all branches of the United States Armed Services as their official manuals for blood banking and transfusion medicine activities.

Learn more about Hoxworth Blood Center’s research faculty and division. 

Featured photo at top of donated blood. Photo/University of Cincinnati.

• College of Medicine

Related Stories

Barda partners with hoxworth blood center to develop and validate an improved method to evaluate next-generation blood products.

October 10, 2023

Hoxworth Blood Center secures BARDA contract to revolutionize red cell product research & approval process

April 22, 2024

Hoxworth Blood Center's Research Division Shines with 2023 National and International Publications: A Milestone Year in Transfusion Medicine.

UC to open national trial to study self-testing for HPV, cervical cancer

April 11, 2024

The University of Cincinnati Cancer Center is one of 25 sites across the country hosting the SHIP trial testing whether samples self-collected by patients for HPV testing are as accurate and effective as clinic-collected samples.

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

• View all journals
• Explore content
• About the journal
• Publish with us
• Sign up for alerts
• News Feature
• Published: 21 January 2015

Ageing research: Blood to blood

• Megan Scudellari 1  

Nature volume  517 ,  pages 426–429 ( 2015 ) Cite this article

19k Accesses

52 Citations

2083 Altmetric

Metrics details

• Developmental biology
• Medical research
• Therapeutics

By splicing animals together, scientists have shown that young blood rejuvenates old tissues. Now, they are testing whether it works for humans.

Two mice perch side by side, nibbling a food pellet. As one turns to the left, it becomes clear that food is not all that they share — their front and back legs have been cinched together, and a neat row of sutures runs the length of their bodies, connecting their skin. Under the skin, however, the animals are joined in another, more profound way: they are pumping each other's blood.

Parabiosis is a 150-year-old surgical technique that unites the vasculature of two living animals. (The word comes from the Greek para , meaning 'alongside', and bios , meaning 'life'.) It mimics natural instances of shared blood supply, such as in conjoined twins or animals that share a placenta in the womb.

In the lab, parabiosis presents a rare opportunity to test what circulating factors in the blood of one animal do when they enter another animal. Experiments with parabiotic rodent pairs have led to breakthroughs in endocrinology, tumour biology and immunology, but most of those discoveries occurred more than 35 years ago. For reasons that are not entirely clear, the technique fell out of favour after the 1970s.

In the past few years, however, a small number of labs have revived parabiosis, especially in the field of ageing research. By joining the circulatory system of an old mouse to that of a young mouse, scientists have produced some remarkable results. In the heart, brain, muscles and almost every other tissue examined, the blood of young mice seems to bring new life to ageing organs, making old mice stronger, smarter and healthier. It even makes their fur shinier. Now these labs have begun to identify the components of young blood that are responsible for these changes. And last September, a clinical trial in California became the first to start testing the benefits of young blood in older people with Alzheimer's disease.

Science writer Megan Scudellari discusses the rejuvenating effects of young blood

“I think it is rejuvenation,” says Tony Wyss-Coray, a neurologist at Stanford University in California who founded a company that is running the trial. “We are restarting the ageing clock.”

Many of his colleagues are more cautious about making such claims. “We're not de-ageing animals,” says Amy Wagers, a stem-cell researcher at Harvard University in Cambridge, Massachusetts, who has identified a muscle-rejuvenating factor in young mouse blood. Wagers argues that such factors are not turning old tissues into young ones, but are instead helping them to repair damage. “We're restoring function to tissues.”

She emphasizes that no one has convincingly shown that young blood lengthens lives, and there is no promise that it will. Still, she says that young blood, or factors from it, may hold promise for helping elderly people to heal after surgery, or treating diseases of ageing.

“It's very provocative,” says Mark Mattson, chief of the Laboratory of Neurosciences at the US National Institute on Aging in Bethesda, Maryland, who has not been involved in the parabiosis work. “It makes you think. Maybe I should bank some blood of my daughter's son, so if I start to have any cognitive problems, I'll have some help,” he says, only half-joking.

The power of two

Physiologist Paul Bert performed the earliest recorded parabiosis experiment in 1864, when he removed a strip of skin from the flanks of two albino rats, then stitched the animals together in hopes of creating a shared circulatory system 1 . Biology did the rest: natural wound-healing processes joined the animals' circulatory systems as capillaries regrew at the intersection. Bert found that fluid injected into a vein of one rat passed easily into the other, work that won him an award from the French Academy of Sciences in 1866.

Since Bert's initial experiments, the procedure has not changed much. It has been performed on hydra — small freshwater invertebrates related to jellyfish — frogs and insects, but it works best on rodents, which recover well from the surgery. Up to the mid-twentieth century, scientists used parabiotic pairs of mice or rats to study a variety of phenomena. For example, one team ruled out the idea that dental cavities are the result of sugar in the blood by using a pair of parabiosed rats, of which only one was fed a daily diet of glucose. The rats had similar blood glucose levels owing to their shared circulation, yet only the rat that actually ate the sugar developed cavities 2 .

Clive McCay, a biochemist and gerontologist at Cornell University in Ithaca, New York, was the first to apply parabiosis to the study of ageing. In 1956, his team joined 69 pairs of rats, almost all of differing ages 3 . The linked rats included a 1.5-month-old paired with a 16-month-old — the equivalent of pairing a 5-year-old human with a 47-year-old. It was not a pretty experiment. “If two rats are not adjusted to each other, one will chew the head of the other until it is destroyed,” the authors wrote in one description of their work 4 . And of the 69 pairs, 11 died from a mysterious condition termed parabiotic disease, which occurs approximately one to two weeks after partners are joined, and may be a form of tissue rejection.

Today, parabiosis is performed carefully to reduce animal discomfort and mortality. “We observe the mice at length and have long discussions with our animal-care committee,” says Thomas Rando, a Stanford neurologist who has used the procedure. “We don't take this lightly.” Mice of the same sex and size are socialized with each other for two weeks before attachment, and the surgery itself is done in a sterile setting with anaesthesia, heating pads and antibiotics to prevent infection. Using inbred lab mice, genetically matched to one another, seems to reduce the risk of parabiotic disease. Joined mice eat, drink and behave normally — and they can be separated successfully.

In McCay's first parabiotic ageing experiment, after old and young rats were joined for 9–18 months, the older animals' bones became similar in weight and density to the bones of their younger counterparts 5 . More than 15 years later, in 1972, two researchers at the University of California studied the lifespans of old–young rat pairs. Older partners lived for four to five months longer than controls, suggesting for the first time that circulation of young blood might affect longevity 6 .

Despite these intriguing findings, parabiosis fell out of use. Those who have studied the technique's history speculate that researchers thought they had learned all they could from it, or that the bar for getting institutional approval for parabiosis studies had become too high. Whatever the reason, the experiments stopped. That is, until a stem-cell biologist named Irving Weissman brought parabiosis back to life.

Back to the source

Weissman learned to join mice together at the age of 16, under the supervision of a hospital pathologist in the small town of Great Falls, Montana, in 1955. His supervisor was studying transplantation antigens, proteins on the surface of transplanted cells or tissues that determine whether they are accepted or rejected by the host. Weissman remembers adding a fluorescent tracer to the blood of one mouse in a pair and watching it go back and forth between the animals. “It was really amazing,” he says.

He went on to spend three decades studying stem cells and regeneration in natural parabionts, sea squirts of the species Botryllus schlosseri . In 1999, Wagers, then a new postdoctoral fellow in Weissman's Stanford lab, wanted to study the movement and fate of blood stem cells, so Weissman recommended that she use parabiotic mice and fluorescently label the cells she wanted to track in one animal of a pair. Wagers' experiments led to two rapid-fire discoveries on the nature and migration of blood stem cells 7 , 8 . It also inspired her Stanford neighbours.

In 2002, Irina Conboy, a postdoctoral fellow in Rando's lab, presented one of Wagers' papers at a journal-club meeting. Michael Conboy, Irina's husband and a postdoc in the same lab, was dozing in the back of the meeting room.

The mention of stitching mice together jolted him awake. “We had been in discussion for years that ageing seems to be all cells in the body, that all tissues seem to go to hell in a handbasket together,” says Michael. Yet they had been unable to think of a realistic experiment with which to investigate what coordinates ageing throughout the body.

“I thought, 'Hey wait, they're sharing blood,'” says Michael. “'This could answer that question we've been asking for years.'” At the end of the presentation, he ran up to Irina and Rando. He had not even finished his pitch before Rando said: “Let's do it.”

I thought, 'Hey wait, they're sharing blood. This could answer the question we've been asking for years.'

The researchers teamed up with Wagers, who performed the old–young pairings for the experiment and taught Michael the technique (see 'Share and share alike'). Rando says that he did not expect the experiment to work, but it did. Within five weeks, the young blood restored muscle and liver cells in the older mice, notably by causing aged stem cells to start dividing again 9 . The team also found that young blood resulted in enhanced growth of brain cells in old mice, although the work was left out of their 2005 paper describing the results. All in all, the results suggested that blood contains the elusive factor or factors that coordinate ageing in different tissues.

After the team published its results, Rando's phone started ringing incessantly. Some of the calls were from men's health magazines looking for ways to build muscle; others were from people fascinated by the prospect of forestalling death. They wanted to know whether young blood extended lifespan. But despite the hints that this was true from the 1970s, no one has yet properly tested the idea. It would be an expensive, labour-intensive experiment.

Instead, members of the original research team branched out into separate efforts to determine what exactly in the blood is responsible for the rejuvenating effects. In 2008, Irina and Michael Conboy, by then at the University of California, Berkeley, linked 10 muscle rejuvenation to the activation of Notch signalling — which promotes cell division — or to the deactivation of the transforming growth factor (TGF)-β pathway, which blocks cell division. Then, in 2014, they identified 11 one of the age-defying factors circulating in the blood: oxytocin, a hormone best known for its involvement in childbirth and bonding, and already a drug approved by the US Food and Drug Administration for inducing labour in pregnant women. Oxytocin levels decline with age in both men and women, and when injected systemically into older mice, the hormone quickly — within a couple of weeks — regenerates muscles by activating muscle stem cells.

All the organs

Wagers was following up on the anti-ageing work at Harvard, where she had started her own lab in 2004. She recruited the help of experts in various organ systems to help her to evaluate the impact of young blood on their respective tissues. With neuroscientist Robin Franklin at the University of Cambridge, UK, her team showed 12 that young blood promotes repair of damaged spinal cords in older mice. With Harvard neuroscientist Lee Rubin, she found 13 that young blood sparks the formation of new neurons in the brain and olfactory system. And with cardiologist Richard Lee at Brigham and Women's Hospital in Boston, Massachusetts, she found 14 that it reverses age-related thickening of the walls of the heart.

With Lee, Wagers began screening for proteins that were particularly abundant in young blood but not old blood. One leapt out at them: growth differentiation factor 11, or GDF11. Wagers and Lee showed 14 that direct infusions of GDF11 alone were sufficient to physically increase the strength and stamina of muscles, as well as to reverse DNA damage inside muscle stem cells. No mouse studies outside of Wagers lab have yet replicated the finding, but a similar protein in fruit flies extends lifespan and prevents muscular degeneration 15 .

You often have these lucrative markets emerge on a slender foundation of credible work.

It is perhaps fitting that parabiosis' newfound popularity has spread among labs with close ties. Wyss-Coray, who worked in the room next to Rando's lab, had previously discovered prominent changes in levels of proteins and growth factors in the blood of ageing humans and people with Alzheimer's disease. Following up on Rando's unpublished brain results, he used old–young mouse pairs to show 16 that old mice exposed to young blood did indeed have increased neuron growth, and that young mice exposed to old blood had reduced growth. Plasma alone had the same effects. “We didn't have to exchange the whole blood,” says Wyss-Coray. “It acts like a drug.” Next, the team looked at overall changes in the brain, and found that young plasma activates brain plasticity and memory formation in older mice, and increases learning and memory. “We could not believe that this worked,” says Wyss-Coray.

Neither could the reviewers. The first time Wyss-Coray submitted the work to a journal, it was rejected, he says, responding that it was too good to be true. So his team spent a year repeating the experiments at the University of California, San Francisco — a different facility with different staff, instruments and tools. The researchers got the same results. “After that, I was really reassured,” says Wyss-Coray. “I'm convinced it works.”

His research, published last May 17 , caught the attention of a company in Hong Kong owned by a family with a history of Alzheimer's disease, which is characterized by neuron loss. One family member's condition had reportedly temporarily improved after they received a plasma transfusion. So the company put forward the initial funding to translate Wyss-Coray's approach to human clinical trials. Wyss-Coray formed a start-up company, Alkahest in Menlo Park, California, and in September 2014 it began a randomized, placebo-controlled, double-blind trial at Stanford, testing the safety and efficacy of using young plasma to treat Alzheimer's disease. Six out of a planned 18 people with Alzheimer's, all aged 50 or above, have already begun to receive plasma harvested from men aged 30 or younger. In addition to monitoring disease symptoms, the researchers are looking for changes in brain scans and blood biomarkers of the disease.

Wagers is eager to see the results, but she worries that a failure would be difficult to interpret and so could set the whole field back. Plasma from a 30-year-old donor may not contain factors beneficial to patients with Alzheimer's, for example. She, Rando and others would prefer to see testing for a specific blood factor or combination of known factors synthesized in the lab, for which the mechanism of action is fully understood.

There are also lingering concerns as to whether activating stem cells — which is what the young blood most often seems to do — over a long period of time would result in too much cell division. “My suspicion is that chronic treatments with anything — plasma, drugs — that rejuvenate cells in old animals is going to lead to an increase in cancer,” says Rando. “Even if we learn how to make cells young, it's something we'll want to do judiciously.”

Michael Conboy is concerned for another reason: he has seen enough paired mice die of parabiotic disease to be cautious about trying it in humans. “I would be leery” of any trial in which significant amounts of blood or plasma were transfused into an older person regularly, he says. Alkahest's chief executive, Karoly Nikolich, says that he understands the safety concerns, but he emphasizes that millions of blood and plasma transfusions have been carried out safely in humans.

The initial Alkahest study is expected to conclude by the end of this year, and the company plans to initiate further studies testing young plasma in the treatment of different types of dementia and age-related conditions.

All the caution over young blood is justified, given the history of dashed hopes in the anti-ageing field. In the past two decades, researchers have identified the anti-ageing properties of numerous treatments, including calorie-restricted diets; resveratrol, a chemical found in the skin of grapes; telomerase, an enzyme that protects the integrity of chromosomes (see Books & Arts, page 436); rapamycin, an immune-suppressing drug that extends lifespan in mice; and stem cells, which decline in function and number as people age.

Only two of these — caloric restriction and rapamycin — have been shown to reliably slow or reverse the effects of ageing across many mammalian tissue types, but neither has turned into an anti-ageing treatment. The former has produced conflicting results in primates; the latter has toxic side effects.

Young blood, by contrast, seems to turn back the effects of ageing, potentially with few known safety concerns in humans and, so far, with corroborated results from parabiotic ageing studies in multiple labs. But scientists and ethicists still worry about the treatment being tried in people outside approved clinical trials before evidence on its safety and effectiveness is in. Unlicensed stem-cell transplants are already a booming industry, warns Mattson, and unlicensed transfusion of young blood would be even easier.

“You often have these lucrative markets emerge on a slender foundation of credible work,” says Leigh Turner, a bioethicist at the University of Minnesota in Minneapolis who has studied the anti-ageing field.

For now, any claims that young blood or plasma will extend lifespan are false: the data are just not there. An experiment to test such claims would take upwards of six years — first waiting for the mice to age, then for them to die naturally, then analysing the data. “If we had funding to do this, I'd do it. But we don't,” says Michael Conboy. Still, he adds, “I hope that someone, somewhere is.”

Bert, P. J. Anatomie Physiologie 1 , 69–87 (1864).

Google Scholar  

Kamrin, B. B. J. Dent. Res. 33 , 824–829 (1954).

Article   CAS   Google Scholar  

McCay, C. M., Pope, F., Lunsford, W., Sperling, G. & Sambhavaphol, P. Gerontologia 1 , 7–17 (1957).

McCay, C. M., Pope, F. & Lunsford, W. Bull. New York Acad. Med. 32 , 91–101 (1956).

CAS   Google Scholar  

Horrington, E. M., Pope, F., Lunsford, W. & McCay, C. M. Gerontologia 4 , 21–31 (1960).

Ludwig, F. C. & Elashoff, R. M. Trans New York Acad. Sci. 34 , 582–587 (1972).

Wright, D. E., Wagers, A. J., Gulati, A. P., Johnson, F. L. & Weissman, I. L. Science 294 , 1933–1936 (2001).

Article   ADS   CAS   Google Scholar  

Wagers, A. J., Sherwood, R. I., Christensen, J. L. & Weissman, I. L. Science 297 , 2256–2259 (2002).

Conboy, I. M. et al. Nature 433 , 760–764 (2005).

Carlson, M. E., Hsu, M. & Conboy, I. M. Nature 454 , 528–532 (2008).

Elabd, C. et al. Nature Commun. 5 , 4082 (2014).

Ruckh, J. M. et al. Cell Stem Cell 10 , 96–103 (2012).

Katsimpardi, L. et al. Science 344 , 630–634 (2014).

Loffredo, F. S. et al. Cell 153 , 828–839 (2013).

Demontis, F., Patel V. K., Swindell, W. R. & Perrimon, N. Cell Rep. 7 , 1481–1494 (2014).

Villeda, S. A. et al. Nature 477 , 90–94 (2011).

Villeda, S. A. et al. Nature Med. 20 , 659–663 (2014).

Download references

Author information

Authors and affiliations.

Megan Scudellari is a science journalist based in Boston, Massachusetts.,

Megan Scudellari

You can also search for this author in PubMed   Google Scholar

Related links

Related links in nature research.

Pet dogs set to test anti-ageing drug 2014-Oct-29

Medical research: Treat ageing 2014-Jul-23

Biomarkers and ageing: The clock-watcher 2014-Apr-08

Blood hormone restores youthful hearts to old mice 2013-May-10

Ageing: Much ado about ageing 2010-Mar-24

Blog post: ORI: former Harvard postdoc guilty of misconduct

Rights and permissions

Reprints and permissions

About this article

Cite this article.

Scudellari, M. Ageing research: Blood to blood. Nature 517 , 426–429 (2015). https://doi.org/10.1038/517426a

Download citation

Published : 21 January 2015

Issue Date : 22 January 2015

DOI : https://doi.org/10.1038/517426a

Share this article

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

This article is cited by

Peripheral blood amyloid-β involved in the pathogenesis of alzheimer’s disease via impacting on peripheral innate immune cells.

• Mingchao Shi

Journal of Neuroinflammation (2024)

Identification of two different coagulation phenotypes in people living with HIV with undetectable viral replication

• Asbjørn Fink
• Andreas Dehlbæk Knudsen
• Susanne Dam Nielsen

Scientific Reports (2021)

Endothelial progeria induces adipose tissue senescence and impairs insulin sensitivity through senescence associated secretory phenotype

• Agian Jeffilano Barinda
• Noriaki Emoto

Nature Communications (2020)

The potential of non-myeloablative heterochronous autologous hematopoietic stem cell transplantation for extending a healthy life span

• Primož Rožman

GeroScience (2018)

The brain, sirtuins, and ageing

• Akiko Satoh
• Shin-ichiro Imai
• Leonard Guarente

Nature Reviews Neuroscience (2017)

Quick links

• Explore articles by subject
• Guide to authors
• Editorial policies

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

share this!

April 16, 2024

This article has been reviewed according to Science X's editorial process and policies . Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

trusted source

Deadly bacteria show thirst for human blood: Research outlines the phenomenon of bacterial vampirism

by Josh Babcock, Washington State University

Some of the world's deadliest bacteria seek out and feed on human blood, a newly-discovered phenomenon researchers are calling "bacterial vampirism."

A team led by Washington State University researchers has found the bacteria are attracted to the liquid part of blood, or serum, which contains nutrients the bacteria can use as food. One of the chemicals the bacteria seemed particularly drawn to was serine, an amino acid found in human blood that is also a common ingredient in protein drinks.

The research finding , published in the journal eLife , provides new insights into how bloodstream infections occur and could potentially be treated.

"Bacteria infecting the bloodstream can be lethal," said Arden Baylink, a professor at WSU's College of Veterinary Medicine and corresponding author for the research. "We learned some of the bacteria that most commonly cause bloodstream infections actually sense a chemical in human blood and swim toward it."

Baylink and the lead author on the study, WSU Ph.D. student Siena Glenn, found at least three types of bacteria, Salmonella enterica, Escherichia coli and Citrobacter koseri, are attracted to human serum. These bacteria are a leading cause of death for people who have inflammatory bowel diseases (IBD), about 1% of the population. These patients often have intestinal bleeding that can be entry points for the bacteria into the bloodstream.

Using a high-powered microscope system designed by Baylink called the Chemosensory Injection Rig Assay, the researchers simulated intestinal bleeding by injecting microscopic amounts of human serum and watching as the bacteria navigated toward the source. The response is rapid—it takes less than a minute for the disease-causing bacteria to find the serum.

As part of the study, the researchers determined Salmonella has a special protein receptor called Tsr that enables bacteria to sense and swim toward serum. Using a technique called protein crystallography, they were able to view the atoms of the protein interacting with serine. The scientists believe serine is one of the chemicals from blood that the bacteria sense and consume.

"By learning how these bacteria are able to detect sources of blood, in the future we could develop new drugs that block this ability. These medicines could improve the lives and health of people with IBD who are at high risk for bloodstream infections ," Glenn said.

Scientists Zealon Gentry-Lear, Michael Shavlik, and Michael Harms of the University of Oregon, and Tom Asaki, a mathematician at WSU, contributed to the research.

Provided by Washington State University

Explore further

Feedback to editors

Artificial intelligence helps scientists engineer plants to fight climate change

7 hours ago

Ultrasensitive photonic crystal detects single particles down to 50 nanometers

8 hours ago

Scientists map soil RNA to fungal genomes to understand forest ecosystems

9 hours ago

Researchers show it's possible to teach old magnetic cilia new tricks

Mantle heat may have boosted Earth's crust 3 billion years ago

Study suggests that cells possess a hidden communication system

Researcher finds that wood frogs evolved rapidly in response to road salts

10 hours ago

Imaging technique shows new details of peptide structures

Cows' milk particles used for effective oral delivery of drugs

New research confirms plastic production is directly linked to plastic pollution

Relevant physicsforums posts, the cass report (uk).

11 hours ago

Major Evolution in Action

Apr 22, 2024

If theres a 15% probability each month of getting a woman pregnant...

Apr 19, 2024

Can four legged animals drink from beneath their feet?

Apr 15, 2024

Mold in Plastic Water Bottles? What does it eat?

Apr 14, 2024

Dolphins don't breathe through their esophagus

More from Biology and Medical

Related Stories

'Bad' antibodies let blood infections rage

Jun 28, 2018

Infections from nontuberculous mycobacteria are on the rise: New blood test cuts diagnosis time from months to hours

Mar 14, 2024

Pathogenic bacteria use a sugar in the intestinal mucus layer to infect the gut, study shows

Jul 3, 2023

How harmless E. coli turns dangerous

Aug 18, 2023

Antibiotics found to promote the growth of antibiotic-resistant bacteria in the gut

Aug 30, 2023

Research into bacteria may lead to new ways of treating infections, improving human health

May 8, 2023

Recommended for you

Vast DNA tree of life for plants revealed by global science team using 1.8 billion letters of genetic code

13 hours ago

Researchers uncover 'parallel universe' in tomato genetics

Giant virus discovered in wastewater treatment plant infects deadly parasite

Can climate change accelerate transmission of malaria? New research sheds light on impacts of temperature

Let us know if there is a problem with our content.

Use this form if you have come across a typo, inaccuracy or would like to send an edit request for the content on this page. For general inquiries, please use our contact form . For general feedback, use the public comments section below (please adhere to guidelines ).

Please select the most appropriate category to facilitate processing of your request

Thank you for taking time to provide your feedback to the editors.

Your feedback is important to us. However, we do not guarantee individual replies due to the high volume of messages.

E-mail the story

Your email address is used only to let the recipient know who sent the email. Neither your address nor the recipient's address will be used for any other purpose. The information you enter will appear in your e-mail message and is not retained by Phys.org in any form.

Newsletter sign up

Get weekly and/or daily updates delivered to your inbox. You can unsubscribe at any time and we'll never share your details to third parties.

More information Privacy policy

Donate and enjoy an ad-free experience

We keep our content available to everyone. Consider supporting Science X's mission by getting a premium account.

E-mail newsletter

• Washington State University
• Go to wsu twitter
• Go to wsu facebook
• Go to wsu linkedin

Deadly bacteria show thirst for human blood

PULLMAN, Wash. –  Some of the world’s deadliest bacteria seek out and feed on human blood, a newly-discovered phenomenon researchers are calling “bacterial vampirism.”

A team led by Washington State University researchers have found the bacteria are attracted to the liquid part of blood, or serum, which contains nutrients the bacteria can use as food. One of the chemicals the bacteria seemed particularly drawn to was serine, an amino acid found in human blood that is also a common ingredient in protein drinks.

The research finding, published in the journal eLife , provides new insights into how bloodstream infections occur and could potentially be treated.

“Bacteria infecting the bloodstream can be lethal,” said Arden Baylink, a professor at WSU’s College of Veterinary Medicine and corresponding author for the research. “We learned some of the bacteria that most commonly cause bloodstream infections actually sense a chemical in human blood and swim toward it.”

Baylink and the lead author on the study, WSU Ph.D. student Siena Glenn, found at least three types of bacteria, Salmonella enterica, Escherichia coli and Citrobacter koseri, are attracted to human serum. These bacteria are a leading cause of death for people who have inflammatory bowel diseases (IBD), about 1% of the population. These patients often have intestinal bleeding that can be entry points for the bacteria into the bloodstream.

Using a high-powered microscope system designed by Baylink called the Chemosensory Injection Rig Assay, the researchers simulated intestinal bleeding by injecting microscopic amounts of human serum and watching as the bacteria navigated toward the source. The response is rapid — it takes less than a minute for the disease-causing bacteria to find the serum.

As part of the study, the researchers determined Salmonella has a special protein receptor called Tsr that enables bacteria to sense and swim toward serum. Using a technique called protein crystallography, they were able to view the atoms of the protein interacting with serine. The scientists believe serine is one of the chemicals from blood that the bacteria sense and consume.

“By learning how these bacteria are able to detect sources of blood, in the future we could develop new drugs that block this ability. These medicines could improve the lives and health of people with IBD who are at high risk for bloodstream infections,” Glenn said.

Scientists Zealon Gentry-Lear, Michael Shavlik, and Michael Harms of the University of Oregon, and Tom Asaki, a mathematician at WSU, contributed to the research. The study was funded by WSU and the National Institute of Allergy and Infectious Diseases.

Media Contacts

• Arden Baylink , WSU College of Veterinary Medicine , [email protected]

Spanish, bilingual course from WSU Extension creates climate ambassadors

Recent news.

Todd Butler resigns as College of Arts and Sciences dean

Tri-state team releases calendar guide for more productive, sustainable pastures

WSU to study effect of controversial drug on racehorses

Voiland College names 2024 outstanding students

Regents start search process for next WSU president

Second chances: Graduate student receives NSF research fellowship

• Open access
• Published: 20 April 2024

Periparturient blood T-lymphocyte PD-1 and CTLA-4 expression as potential predictors of new intramammary infections in dairy cows during early lactation (short communication)

• Ana Cláudia Dumont Oliveira 1 ,
• Carolina Menezes Suassuna de Souza 2 , 3 ,
• Eduardo Milton Ramos-Sanchez 4 , 5 ,
• Soraia Araújo Diniz 6 ,
• Ewerton de Souza Lima 2 , 3 ,
• Maiara Garcia Blagitz 7 ,
• Robson Cavalcante Veras 8 ,
• Marcos Bryan Heinemann 9 ,
• Alice Maria Melville Paiva Della Libera 1 ,
• Sarne De Vliegher 10 ,
• Artur Cezar de Carvalho Fernandes 2 , 3 &
• Fernando Nogueira Souza 1 , 2 , 3 , 10 , 11  

BMC Veterinary Research volume  20 , Article number:  146 ( 2024 ) Cite this article

125 Accesses

Metrics details

The periparturient period in dairy cows is marked by immunosuppression which increases the likelihood of infectious disorders, particularly also mastitis. An in-depth understanding of peripartum leukocyte biology is vital for the implementation of highly successful post-partum disease prevention measures. Immune checkpoint molecules, such as programmed death 1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4), are critical inhibitory receptors expressed on immune cells, particularly T cells, that drive immunosuppressive signaling pathways. However, the potential role of immune checkpoint molecules expression in T-cells on udder health has never been explored. Thus, the association between the occurrence of new postpartum intramammary infections (IMIs) and the expression of programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) on blood T-cells during the peripartum period was investigated.

In this study, the incidence of IMIs by any pathogen in early lactation was not associated with a higher expression of PD-1 and CTLA-4 in the periparturient period. However, the incidence of IMIs by major pathogens throughout the first month of lactation was significantly associated with higher expression of PD-1 at 14 days before calving ( P  = 0.03) and CTLA-4 at parturition ( P  = 0.03) by blood T-cells. Also, the expression of CTLA-4 at D0 ( P  = 0.012) by T-cells was associated with the occurrence of persistent IMIs during the first month of lactation.

Conclusions

To our knowledge, this is the first report to investigate the expression of PD-1 and CTLA-4 by blood T-lymphocytes during the periparturient period in dairy cows and to explore their relationship with the incidence of new IMIs in the postpartum period. Thus, a comprehensive understanding of leukocyte biology during peripartum would appear to be a prerequisite for the identification of resilient dairy cows or targets innovative (immunological) non-antibiotic approaches in the transition period.

Peer Review reports

The periparturient period in dairy cows is characterized by immunosuppression and marked metabolic changes [ 1 ]. During this period, dairy cows are usually in a state of negative energy balance (NEB), which is associated with the mobilization of body fat reserves leading to increased blood non-esterified fatty acids (NEFA) and β-hydroxybutyric acid (BHB) concentrations [ 2 ]. This critical period accounts for most of the episodes of new infectious diseases, also mastitis, and metabolic disorders in dairy cows [ 1 , 2 , 3 ].

There is a growing interest in specific molecules in immune cells, especially in T-cells, such as programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4). For instance, the success of immune checkpoint inhibition in human cancer therapy suggests that targeting similar pathways might also be useful for preventing and treating infectious diseases [ 4 ]. T-cell exhaustion, reflected by the expression of so-called immune checkpoint molecules, is a hallmark of persistent infections as it restrains cell-mediated protective immunity [ 5 ]. Indeed, recent studies have demonstrated that immunoinhibitory molecules play a critical role in the immune exhaustion and progression of bovine leukemia viral disease, Johne’s disease and bovine anaplasmosis [ 6 , 7 ]. Interestingly, immune checkpoint blockade in bovine leukemia virus-infected dairy cows restored the antiviral immunity [ 8 ]. Hence, we must explore the role of the checkpoint molecules during the periparturient period, a most critical period of the cow’s life, and their potential associations with the costliest disease in dairy cows, i.e., mastitis, the inflammation of the mammary gland in response to invading bacteria.

Thus, we investigated the expression of PD-1 and CTLA-4 by blood T-lymphocytes during the periparturient period in dairy cows and their relationship with the incidence of new intramammary infections (IMIs) in the postpartum period.

The bacteriological outcomes of the udder quarters milk samples are presented in the Table  1 . Using a generalized logistic regression model, there were no significant association between parity and breed with the occurrence of IMIs by all pathogens or by major mastitis pathogens only, persistent IMIs by all pathogens, or new IMIs by all pathogens or major pathogens only. The serum concentration of BHB, NEFA, and Hp did not show any relationship with the new IMIs.

Using the logistic regression model, no effect on the expression of CTLA-4 and PD-1 by T-cells was observed on: (1) occurrence of IMIs by any pathogen (including all pathogens); (2) occurrence of IMIs by major mastitis pathogens only; or on (3) new IMIs by any pathogen (including all pathogens). However, using the logistic regression model, the expression of the immune checkpoints CTLA-4 measured at D0 ( P =  0.03) and PD-1 measured at D-14 ( P =  0.03) by T-cells was associated with the occurrence of new IMIs by major pathogens throughout the first month of lactation. Another interesting finding of our study was the association between the expression of CTLA-4 at D0 ( P =  0.012) by T-cells with the occurrence of persistent IMIs throughout the first month of lactation. Indeed, the Kaplan-Meier survival curve analysis showed that the dairy cows with high expression of CTLA-4 at D0 and PD-1 at D-14 had a higher incidence of new IMIs by major mastitis pathogens through the first month of lactation (Fig.  1 ).

Kaplan-Meier survival curve showing higher incidence of new intramammary infections by major mastitis pathogens in udder quarters in dairy cows during the first month of lactation with high expression (geometric mean fluorescence intensity) of CTLA-4 at parturition (A; P  = 0.001) and PD-1 at 14 days before the expected day of calving (B; P  = 0.03) by blood T-lymphocytes. CTLA-4: cytotoxic T-lymphocyte-associated antigen-4; PD-1: programmed cell death protein 1. A drop in survival probability indicates the occurrence of new IMIs (“failure”) by major mastitis pathogens within that specific period

T-cell exhaustion is characterized by the expression of immune checkpoints, such as CTLA-4 and PD-1, and it is associated with negative regulation of T-cell immunity. Despite the relevance of T-cells for mucosal immunity [ 9 ], including for bovine mammary gland [ 10 , 11 ] and the growing evidence that immunosuppression underpins the susceptibility of periparturient dairy cows to mastitis, this study was the first to investigate the role of immunological checkpoints in bovine mastitis. In agreement, Souza et al. [ 9 ] showed that higher expression of CTLA-4 and PD-1 in blood T-lymphocytes at parturition was associated with postpartum uterine health in dairy cow status.

Overall, our results are consistent with the hypothesis that T-cell exhaustion, which may result in weakened effector function, poor recall responses, and a transcriptional state distinct from that of effective effector or memory T-cells, which was associated with limit pathogen clearance [ 4 ] resulting in higher susceptibility to infections in dairy cows during the periparturient period and favoring infection persistence.

As a result, as antibodies that block these immune checkpoints have been successfully used to treat and control several types of cancer and even infectious diseases, research into these immune checkpoints has the potential to develop clinical strategies for treating and controlling veterinary infectious diseases by enhancing the host’s immune response to fight diseases [ 4 , 12 ].

We hypothesized that the low number of dairy cows ( n  = 6, 23.08%) with subclinical ketosis (BHB levels > 0.8 mmol/L) [ 13 ] could justify the lack of any association between the serum concentration of BHB and NEFA with the new IMIs. Finally, although the serum concentration of Hp is useful for diagnosing pathological conditions during the periparturient period in dairy cows, its increased levels are not strictly related to mastitis [ 14 ], which could explain our results of any association between Hp and the new IMIs.

In conclusion, our findings highlight the potential value of studying immune checkpoints to identify early dairy cows that are at a higher risk of developing bovine mastitis by major mastitis pathogens during the post-partum period, and also open new paths for the development of novel non-antibiotic approaches for managing bovine mastitis through boosting the host’s immune response.

Animals, samples and experimental design

Twenty-six clinically healthy dairy cows, with no detectable clinical disease at first sampling (seven primiparous and 19 multiparous dairy cows between 2nd and 5th lactations; mean + SEM = 3.26 + 0.21) from two commercial dairy farms (sixteen Guzerá dairy cows at farm A and 10 Girolando dairy cows at farm B) were included. Each of the two dairy farms had 45 lactating dairy cows.

The zebu Guzerá cows were grazed on Massai grass pasture, which is a natural hybrid of Panicum maximum and Panicum infestum, and received concentrates based on their milk production, such as soybean meal, corn meal, and cottonseed meal and cake, along with vitamin and mineral supplements. They were milked once daily by hand with the calf at foot, and produced an average of 20 kg milk per day; the calves were kept with their dams for half of the day due to their high economic values. No pre-dipping and post-dipping, as well dry cow therapy, were performed.

The Girolando dairy cows spent the morning grazing on Mombaça grass (Panicum maximum) pasture and received palm as roughage concentrates based on their milk production, such as soybean meal, corn meal, and cottonseed meal, along with vitamin and mineral supplements. The Girolando dairy cows were milked twice per day by milking machine and produced an average of 27 kg of milk per day. The following mastitis control practices were implemented during milking: forestripping using a strip cup test for clinical mastitis diagnosis; pre-dipping with a solution containing hydrogen peroxide, surfactants, and glycerin (Prima, DeLaval); and drying teats with paper towels. Following milking, post-dipping with iodine (DellaBarrier™, DeLaval) was used. Furthermore, selective dry cow therapy and clinical mastitis treatments were applied. Dairy cows infected by major mastitis pathogens were segregated from the milking line, and milked last.

Blood samples were collected from the 26 aforementioned dairy cows 14 days before the expected day of calving (D-14; mean + SEM = 18.11 + 1.65 days) and at calving (D0) to determine the blood T-lymphocytes expression of CTLA-4 and PD-1. In addition, blood samples were collected at D0, 10 and 30 days after parturition (D10 and D30, respectively) to measure the serum concentrations of BHB, NEFA and haptoglobin (Hp). Milk samples were aseptically collected at D0 and 3 (D3), 7 (D7), 15 (D15), and 30 (D30) days after parturition for microbiological analysis.

Blood sampling

Peripheral blood samples were aseptically collected by venipuncture of the jugular vein in vacutainer® tubes containing sodium heparin (cat. n. 367,871, BD Biosciences, New Jersey, USA) for flow cytometry analysis, and without anticoagulant (cat. n. 367,812, BD Biosciences, New Jersey, USA) for BHB, NEFA and Hp measurement. Blood samples collected without anticoagulant were centrifuged at 2,500 g for 10 min at room temperature.

Milk sampling

First, the strip cup test was performed to determine the presence or not of clinical mastitis. Cows showing clinical mastitis symptoms were not included in the study. After discarding the first three milk streams, the teats apices were scrubbed with 70% ethanol using cotton balls and milk samples ( n  = 520 in total) from the individual udder quarters were aseptically collected for microbiological analysis.

Microbiological analyses

Bacteriological analysis of the milk samples was performed by cultivating 10 µL on 5% defibrinated sheep blood agar plates, which were incubated at 37 °C for 24 to 72 h [ 15 ]. The bacterial identification was performed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, as previously described [ 16 ].

Definition of IMI, new IMI and persistent IMI

An udder-quarter was defined to be infected (= to have an IMI) if at least 100 CFU mL-1/milk were detected in the milk culturing. A new IMI was defined as a non-infected quarter (= without an IMI) initially that became infected at the subsequent milk sampling [ 17 ] or when another pathogen, absent in the previous sampling, was cultured. A persistent IMI was defined when the same pathogen was cultured in the same infected quarter at three consecutive samplings with at least one week interval among samplings [ 18 ]. Milk samples yielding > 3 distinct bacterial species were regarded as contaminated. Staphylococcus aureus , Streptococcus spp., or Gram-negative bacteria were considered major pathogens.

Serum concentrations of NEFA, BHB, and Hp

The BHB and NEFA serum concentrations were measured using an automated analyzer (Randox Rx Daytona Chemistry AnalyserTM, UK) and Randox® commercial kits (Randox Laboratories, UK) for NEFA (Randox, cat. n. FA115) and BHB (Randox, cat. n. RB 1007). The serum concentrations of the acute-phase protein Hp were determined using a colorimetric technique that detects the production of Hp-haemoglobin complexes, indicating variations in peroxidase activity [ 9 , 19 ].

Expression of PD-1 and CTLA-4 in the T-lymphocytes

The expression of PD-1 and CTLA-4 in T-lymphocytes was performed as previously described [ 9 ]. Briefly, a Ficoll-PaqueTM PLUS density gradient (GE Healthcare, Germany) was used to isolate peripheral blood mononuclear cells (PBMCs) following the manufacturer’s instructions. Then, PBMCs were incubated at room temperature for 30 min with the primary monoclonal antibodies: mouse anti-bovine IgG1 antibody CD3 (clone MM1A, cat. n. BOV 2009, Washington State University Monoclonal Antibody Center, USA) and goat anti-human CTLA-4 cross-reactive with cattle (cat. n. AF-386-PB, R&D Systems, USA) or goat anti-human PD-1 with cross-reaction with cattle (cat. no. LS-C55247-100, LSBIO, USA). Then, cells were incubated for 30 min at room temperature with the cross-adsorbed donkey IgG conjugated with Alexa Fluor 488 (cat. n. A11055, Thermo Fisher, USA) and goat anti-mouse IgG1-conjugated secondary antibodies conjugated with PE-Texas Red (cat. n. M32017, Thermo Fisher, USA). Finally, the cells were resuspended in 300 µL of PBS with 1% heat-inactivated foetal bovine serum. The samples were analysed with a BD FACSCantoTM II flow cytometer (BD Biosciences, USA). For this study, 10,000 cells were evaluated from each sample. As compensating controls, non-stained control, secondary antibody control, and simple stained PBMC samples were also generated. The data were analyzed using Flow Jo Tree Star software (FlowJo - Treestar 10.5.3 for Windows, Tree Star Inc., USA).

Statistical analysis

Data distribution was initially assessed using the Shapiro-Wilk test. In this study, the explanatory variables were expression of CLTA-4 and PD-1 by T-lymphocytes at D-14 and D0, respectively, parity (primiparous vs. multiparous) and the breed (Guzerá vs. Girolando), and the dependent variables being (1) occurrence of IMI by any pathogen (including all pathogens); (2) occurrence of new IMI by any pathogen (including all pathogens); (3) occurrence of new IMIs by major mastitis pathogens only; (4) occurrence of IMIs by major mastitis pathogens only; and (5) occurrence of persistent IMIs by any pathogen (including all pathogens). We included in the multivariate logistic model only those variables with P -values  ≤  0.20, as established by a univariate logistic model. Then, all variables of interest were analysed until we found a model that provided the greatest biologically relevant explanation for the measured responses. Serum levels of BHB, NEFA and Hp were analysed for their association with dependent variables using an F-test (ANOVA) and Spearman correlation tests. The statistical analyses were performed using InfoStat (Argentina). The statistical models regard the quarters nested within cows and farm, and the cows nested within the farm.

Furthermore, Kaplan-Meier survival curves were created to determine if expression of blood T-cell expression of CLTA-4 and PD-1 at D-14 and D0, respectively, was associated with the development of new IMIs by any pathogen or new IMIs by major mastitis pathogens only through the first month of lactation using InfoStat (Argentina). As there is no reference standard value for CTLA-4 and PD-1 expression by blood T-cells in dairy cows, we used the median value to distinguish between dairy cows with high and low CTLA-4 and PD-1 expression values. The results are expressed as the mean ± standard error, and α = 5% was used for all analyses.

Data availability

No datasets were generated or analysed during the current study.

Abbreviations

Programmed cell death protein 1

Cytotoxic T-lymphocyte-associated antigen-4

Negative energy balance

Non-esterified fatty acids

β-hydroxybutyric acid

Haptoglobin

Intramammary infections

Peripheral blood mononuclear cell

Phosphate-buffered saline

Aleri JW, Hine BC, Pyman MF, Mansell PD, Wales WJ, Mallard B, Fisher AD. Periparturient immunosuppression and strategies to improve dairy cow health during the periparturient period. Res Vet Sci. 2016;108:8–17.

Article   CAS   PubMed   Google Scholar  

Guan RW, Wang DM, Wang BB, Jiang LY, Liu JX. Prognostic potential of pre-partum blood biochemical and immune variables for postpartum mastitis risk in dairy cows. BMC Vet Res. 2020;16(1):136.

Article   CAS   PubMed   PubMed Central   Google Scholar  

Pyörälä S. Mastitis in post-partum dairy cows. Rep Dom Anim. 2008;43:252–9.

Article   Google Scholar  

Wykes MN, Sharon RL. Immune checkpoint blockade in infectious diseases. Nat Rev Immunol. 2018;18(2):91–104.

Dyck L, Mills KHG. Immune checkpoints and their inhibition in cancer and infectious diseases. Eur J Immunol. 2017;47(5):765–79.

Konnai S, Murata S, Ohashi K. Immune exhaustion during chronic infections in cattle. J Vet Med Sci. 2017;79(1):1–5.

do Nascimento AMM, de Souza CMS, Oliveira ACD, Blagitz MG, Ramos Sanchez EM, Della Libera AMMP, Leite RMH, Fernandes ACC, Souza FN. The bovine leukemia virus infection prolongs immunosuppression in dairy cows during the periparturient period by sustaining higher expression of immunological checkpoints in T cells. Vet Immunol Immunopathol. 2023;263:110636.

Article   PubMed   Google Scholar  

Nakamura H, Konnai S, Okagawa T, Maekawa N, Sajiki Y, Watari K, Kamitani K, Saito M, Kato Y, Suzuki Y, Murata S, Ohashi K. Combined Immune Checkpoint Blockade enhances antiviral immunity against bovine leukemia virus. J Virol. 2023;97(1):e0143022.

Souza CMS, Lima ES, Ordonho RF, Oliveira BRRS, Rodrigues RC, de Moura MF, Souza FN, Fernandes ACF. Brief Research Report: expression of PD-1 and CTLA-4 in T lymphocytes and their relationship with the Periparturient Period and the endometrial cytology of dairy cows during the Postpartum Period. Front Vet Sci. 2022;9:e928521.

Souza FN, Santos KR, Ferronatto JA et al. Bovine-associated staphylococci and mammaliicocci trigger T-lymphocyte proliferative response and cytokine production differently [published online ahead of print, 2023 Mar 2]. J Dairy Sci. 2023;S0022-0302(23)00093 – 0.

Souza FN, Blagitz MG, Batista CF, et al. Immune response in nonspecific mastitis: what can it tell us? J Dairy Sci. 2020;103(6):5376–86.

Okagawa T, Konnai S, Nishimori A, Maekawa N, Ikebuchi R, Goto S, et al. Anti-bovine programmed death-1 rat-bovine chimeric antibody for immunotherapy of bovine leukemia virus infection in cattle. Front Immunol. 2017;8:650.

Article   PubMed   PubMed Central   Google Scholar  

Chapinal N, Leblanc SJ, Carson ME, et al. Herd-level association of serum metabolites in the transition period with disease, milk production, and early lactation reproductive performance. J Dairy Sci. 2012;95(10):5676–82.

Humblet MF, Guyot H, Boudry B, Mbayahi F, Hanzen C, Rollin F, Godeau JM. Relationship between haptoglobin, serum amyloid A, and clinical status in a survey of dairy herds during a 6-month period. Vet Clin Pathol. 2006;35(2):188–93.

Oliver SP, Gonzalez RN, Hogan JS, Jayarao BM, Owens WE. Microbiological procedures for the diagnosis of bovine udder infection and determination of milk quality. 4th ed. Verona: National Mastitis Council; 2004.

Google Scholar  

Braga PA, Gonçalves JL, Barreiro JR, Ferreira CR, Tomazi T, Eberlin MN, Santos MV. Rapid identification of bovine mastitis pathogens by MALDI-TOF Mass Spectrometry. Pesqui Vet Bras. 2018;38:586–94.

Reyher KK, Dohoo IR, Muckle CA. Evaluation of clustering of new intramammary infections in the bovine udder, including the impact of previous infections, herd prevalence, and somatic cell count on their development. J Dairy Sci. 2013;96(1):219–33.

Santos RP, Souza FN, Oliveira ACD, de Souza Filho AF, Aizawa J, Moreno LZ, da Cunha AF, Cortez A, Della Libera AMMP, Heinemann MB, Cerqueira MMOP. Molecular typing and Antimicrobial Susceptibility Profile of Staphylococcus aureus isolates recovered from bovine mastitis and nasal samples. Anim (Basel). 2020;10(11):2143.

Makimura S, Suzuki N. Quantitative determination of bovine serum haptoglobin and its elevation in some inflammatory diseases. Jap J Vet Sci. 1982;44:15–21.

Article   CAS   Google Scholar  

Download references

Acknowledgements

The authors are grateful to Empresa Paraibana de Pesquisa, Extensão Rural e Regularização Fundiária - Estação Experimental de Alagoinha, Paraíba for kindly providing the dairy cows for the current study. The authors Ana Cláudia Dumont Oliveira and Carolina Menezes Suassuna de Souza would also like to thank Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-CAPES for their scholarship. Ana Cláudia Dumont Oliveira and Carolina Menezes Suassuna de Souza should be regarded as co-first authors. Artur Cezar de Carvalho Fernandes and Fernando Nogueira Souza should be regarded as co-last authors.Ethics approval and consent to participateThis study was approved by the Animal Research Ethics Committee of the Federal University of Paraíba (protocol n. 4595011020) and the University of São Paulo (protocol n. 1189211022). Therefore, this study is carried out in accordance with ARRIVE guidelines, and all animal-related procedures adhered to current national bioethical regulations and guidelines. The farm owners gave informed consent in writing.

This research was not funded by any organization.

Author information

Authors and affiliations.

Veterinary Clinical Immunology Research Group, Departamento de Clínica Médica, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, 05508-270, Brazil

Ana Cláudia Dumont Oliveira, Alice Maria Melville Paiva Della Libera & Fernando Nogueira Souza

Programa de Pós-Graduação em Ciência Animal, Centro de Ciências Agrárias, Universidade Federal da Paraíba, Areia, 58397-000, Brazil

Carolina Menezes Suassuna de Souza, Ewerton de Souza Lima, Artur Cezar de Carvalho Fernandes & Fernando Nogueira Souza

Departamento de Ciências Veterinárias, Centro de Ciências Agrárias, Núcleo Aplicado à Produção e Sanidade da Glândula Mamária (NAPROSA), Universidade Federal da Paraíba, Areia, 58397-000, Areia, Brazil

Escuela Profesional de Medicina Humana, Facultad de Medicina, Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas, Chachapoyas, 01000, Peru

Eduardo Milton Ramos-Sanchez

Departamento de Salud Publica, Facultad de Ciencias de La Salud, Universidad Nacional Toribio Rodriguez de Mendoza de Amazonas, Chachapoyas, 01000, Peru

Curso de Medicina Veterinária, Instituto de Ciências Agrárias, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Unaí, 38610-000, Brazil

Soraia Araújo Diniz

Bem-Estar e Produção Animal Sustentável na Fronteira Sul, Programa de Pós-Graduação em Saúde, Universidade Federal da Fronteira Sul, Realeza, 85770-000, Brazil

Maiara Garcia Blagitz

Departamento de Ciências Farmacêuticas, Centro de Ciências da Saúde, Universidade Federal da Paraíba, 58051-900, João Pessoa, Brasil

Robson Cavalcante Veras

Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, 05508-270, Brazil

Marcos Bryan Heinemann

M-team & Mastitis and Milk Quality Research Unit, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium

Sarne De Vliegher & Fernando Nogueira Souza

Departamento de Medicina Veterinária, Centro de Ciências Agrárias, Fazenda São Luiz, Universidade Federal de Alagoas, Viçosa, 57700-000, Brazil

Fernando Nogueira Souza

You can also search for this author in PubMed   Google Scholar

Contributions

ACDO wrote the original draft of the manuscript. EMRS, ACCF and FNS created the study conception and designed the experiments. CMSS and ESL were involved in the analysis and interpretation of results. SAD, SDV, FNS and ACDO performed the statistical analysis. MGB, RCV, MBH, AMMPDL, SDV, ACCF and DNS were involved in the interpretation of the results and revised the manuscript. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Eduardo Milton Ramos-Sanchez .

Ethics declarations

Ethics approval and consent to participate.

This study was approved by the Animal Research Ethics Committee of the Federal University of Paraíba (protocol n. 4595011020) and the University of São Paulo (protocol n. 1189211022). Therefore, this study is carried out in accordance with ARRIVE guidelines, and all animal-related procedures adhered to current national bioethical regulations and guidelines. The farm owners gave informed consent in writing.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note.

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ . The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/ ) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Cite this article.

Oliveira, A.C.D., de Souza, C.M.S., Ramos-Sanchez, E.M. et al. Periparturient blood T-lymphocyte PD-1 and CTLA-4 expression as potential predictors of new intramammary infections in dairy cows during early lactation (short communication). BMC Vet Res 20 , 146 (2024). https://doi.org/10.1186/s12917-024-03977-1

Download citation

Received : 04 December 2023

Accepted : 14 March 2024

Published : 20 April 2024

DOI : https://doi.org/10.1186/s12917-024-03977-1

Share this article

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

• Immune checkpoints
• Transition period

BMC Veterinary Research

ISSN: 1746-6148

• General enquiries: [email protected]

ORIGINAL RESEARCH article

Improved mri methods to quantify retinal and choroidal blood flow detect decreased blood flow in a model of glaucoma.

• 1 Department of Radiology, Stony Brook University, Stony Brook, New York, United States
• 2 Renaissance School of Medicine, Stony Brook University, Stony Brook, New York, United States
• 3 School of Health Professions, Stony Brook University, Stony Brook, New York, United States
• 4 Department of Ophthalmology, Stony Brook University, Stony Brook, New York, United States
• 5 Department of Radiology, Albert Einstein College of Medicine, New York City, New York, United States
• 6 Departments of Radiology and Ophthalmology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States

The final, formatted version of the article will be published soon.

Select one of your emails

You have multiple emails registered with Frontiers:

Notify me on publication

Please enter your email address:

If you already have an account, please login

You don't have a Frontiers account ? You can register here

PURPOSE. Blood flow (BF) of the retinal and choroidal vasculatures can be quantitatively imaged using MRI. This study sought to improve methods of data acquisition and analysis for MRI of layerspecific retinal and choroidal BF and then applied this approach to detect reduced ocular BF in a well-established mouse model of glaucoma from both eyes. METHODS. Quantitative BF magnetic resonance imaging (MRI) was performed on glaucomatous DBA/2J and normal C57BL/6J mice. Arterial spin labeling MRI was applied to image retinal and choroidal BF using custom-made dual eye coils that could image both eyes during the same scan. Statistics using data from a single eye or two eyes were compared. BF values were calculated using two approaches. The BF rate per quantity of tissue was calculated as commonly done, and the peak BF values of the retinal and choroidal vasculatures were taken. Additionally, the BF rate per retinal surface area was calculated using a new analysis approach to attempt to reduce partial volume and variability by integrating BF over the retinal and choroidal depths. RESULTS. Ocular blood flowBF of both eyes could be imaged using the dual coil setup without effecting scan time. Intraocular pressure was significantly elevated in DBA/2J mice compared to C57BL/6J mice (P<0.01). Both retinal and choroidal BF were significantly decreased in DBA/2J mice in comparison to the age-matched normal C57BL/6J mice across all measurements (P < 0.01). From simulations, the values from the integrated BF analysis method had less partial volume effect, and from in vivo scans, this analysis approach also improved power. CONCLUSIONS. The dual eye coil setup allows bilateral eye data acquisition, increasing the amount of data acquired without increasing acquisition times in vivo. The reduced ocular BF found using the improved acquisition and analysis approaches replicated the results of previous studies on DBA/2J mice. The impaired blood flowocular hypertensive stress-induced BF reduction found within these mice may represent changes associated with glaucomatous progression.

Keywords: MRI, Blood flow, Glaucoma, imaging, Retina, Choroid, Mouse

Received: 12 Feb 2024; Accepted: 23 Apr 2024.

Copyright: © 2024 Jiang, Chernoff, Galenchik-Chan, Tomorri, Honkanen, Duong and Muir. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) . The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Eric R. Muir, Departments of Radiology and Ophthalmology, University of North Carolina at Chapel Hill, Chapel Hill, 27599, North Carolina, United States

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• Blood Transfus
• v.22(1); 2024 Jan
• PMC10812890

The health impacts of blood donation: a systematic review of donor and non-donor perceptions

Rachel thorpe.

1 Clinical Services and Research, Australia Red Cross Lifeblood, Australia

2 Melbourne School of Population and Global Health, University of Melbourne, Victoria, Australia

Barbara Masser

3 School of Psychology, The University of Queensland, Brisbane, Queensland, Australia

4 National Institute for Health and Care Research Blood and Transplant Research Unit in Donor Health and Behaviour, Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom

Sarah P. Coundouris

Melissa k. hyde, sarah p. kruse, tanya e. davison.

5 Monash Art, Design and Architecture, Monash University, Australia

Associated Data

The health and well-being of volunteer donors is of critical concern for blood collection agencies responsible for ensuring a stable supply of blood products. However, lay understandings of the impact of donating blood on health remain poorly understood. As lay perceptions are likely to influence critical decisions about donation, understanding these perceptions is key for informing evidence-based approaches to donor retention and recruitment. As such, we conducted a systematic review of the blood donation literature to identify donors’ and non-donors’ perceptions of the short and longer-term physiological health effects of whole-blood and/or blood product donation.

Materials and methods

This review was conducted in line with PRISMA guidelines. Studies published from January 1995 to February 2021 were included. Perceptions were defined as both experiences and beliefs. Psychological effects were considered outside the scope of the review.

A total of 247 studies were included. Most studies (89.5%) had donation-related health perceptions as a background rather than a central (10.5%) focus, and they were only assessed in relation to whole blood donation. More results focused on health-related beliefs than experiences (82 vs 18%), specific rather than general beliefs and experiences (80 vs 20%) and more frequently examined negative than positive beliefs and experiences (83 vs 17%). The most commonly studied and reported specific negative beliefs related to increased risk of infectious disease, reduced vitality, vasovagal reactions and low iron. Most studies examining specific negative beliefs were conducted in Asian countries.

Findings reinforce that lay perspectives on how donation impacts health are under-researched, and it is difficult to know how important these are in informing critical decisions about donation for donors and non-donors. We suggest that further research with donation-related health beliefs and experiences as the central focus is needed to provide insights to inform communications with donors and the public.

INTRODUCTION

Blood Collection Agencies (BCAs) rely on volunteer donors to ensure a stable supply of blood products. Globally, BCAs struggle to maintain sufficient supply, with the trend of increasingly lower participation in blood donation exacerbated by COVID-19 1 , 2 . As such, the health and well-being of volunteer donors is of critical concern, both for those who receive blood products and for the ongoing participation of these donors. While research has focused on acute reactions that occur around the time of donation 3 (e.g., injuries, vasovagal reactions), or on the longer-term management of iron deficiency 4 , 5 , 6 , lay understandings of the impact donating blood may have on health remain poorly understood. This is problematic as such perceptions likely impact the decision to donate or not, the frequency at which donations are made, and the products donated 7 . As such, understanding lay perceptions of the impact donating has on health is key to informing evidence-based approaches to donor retention and recruitment.

While not an explicit health-seeking behavior, donating blood is associated with being healthy. Donors undergo health screening to be eligible to donate and may also receive health information such as blood pressure and hemoglobin readings through donating 6 . In turn, those who perceive themselves to be healthy tend to become, and remain donors 8 , 9 . BCAs also undertake activities that further build the association between blood donation and health, for example participating in population-based studies such as SARS-CoV-2 pandemic seroprevalence studies, inviting donors to be part of longitudinal studies of donor health, and establishing biobanks 10 – 12 . Further, some BCAs offer donors additional health information as incentives to donate 13 .

Despite this association between health and donating blood, there has been limited examination of how donors and non-donors perceive donation to be related to health, what informs their perceptions and how this impacts willingness to donate blood. Where these questions have been considered, most insights are elicited incidentally through studies on donor motivation 7 , 14 – 21 . In these, broad health perceptions are identified as both a deterrent to, and motivator of blood donation. For example, Charbonneau and colleagues (2016) surveyed continuing Canadian whole-blood donors on their motivations to donate and found that 27.0% indicated “other health reasons” were factors for reducing donation frequency or stopping donating altogether 7 . In contrast, Glynn et al . (2002) found 9.0% of respondents to a large-scale US-based survey 17 identified the belief “donating is good for my health” as a motivator of blood donation. Outside of North America, 2.2% of respondents to a Swedish survey of donor motivations indicated that donation being “good for health” was the main reason for continuing donation 21 . There is some indication that health-related donation-related beliefs are culturally-specific, with research with donors and non-donors from ethnic minority backgrounds living in France 22 and Australia 23 identifying barriers related to fear of contracting infection and fear of losing strength as a result of donating blood.

However, in the above studies, the specific nature of the health belief, and how it motivates or deters blood donation, was not examined in-depth. For example, donors’ perceptions of their health may act as a deterrent due to a belief that they are ineligible to donate (e.g., to protect the safety of recipients), or, they may want to protect their own health from perceived negative effects of blood donation. Similarly, where health perceptions act as a motivator, the specifics of how donating is seen to be good for health or makes someone feel better have not been interrogated. One interview study with participants in the INTERVAL trial 24 , 25 in which donors could be asked to donate blood more frequently, has explored understandings of blood and the body in relation to more frequent donation. In relation to health impacts, donors in this study perceived that their bodies naturally replenished lost blood, and felt that a general healthy lifestyle enabled them to donate blood regularly without implications for their health. As with earlier donor surveys 20 , it was common for interviewees in Lynch and Cohns’ study 25 to raise both positive and negative health effects of blood donation. This study highlights the potential for research on donor health to generate findings that could be used to help BCAs encourage donors to give blood initially and more frequently.

Despite the potential usefulness of insights generated from these studies, we lack a comprehensive understanding of what perceived health effects of donating whole-blood and blood products have been identified in research. Having this information can help BCAs to communicate with donors and the public to better explain how blood donation affects health and to understand and address beliefs about donation and health that may prevent people from donating or encourage them to donate. This information is particularly important as BCAs continue to expand their participation in the health landscape.

Accordingly, our aims were to provide the first systematic review and integration of the blood donation literature to i. identify donors’ and non-donors’ perceptions (i.e., experiences and beliefs) regarding the short and longer-term physiological health effects of whole-blood and/or blood product donation; ii. identify the extent to which researchers have investigated health effects of whole-blood and/or blood product donation and; iii. explore differences in health perceptions of blood donation in different parts of the world.

MATERIALS AND METHODS

Full details regarding the search strategy and extraction plan are on the pre-registered Prospero record (CRD42021283396). This review was conducted in line with PRISMA guidelines 26 .

Search strategy

A systematic literature search of CINAHL, MEDLINE, PsycINFO, Web of Science, PubMed, Embase, ProQuest Dissertations, and Theses Global was completed in February 2021. The search strategy comprised terms related to the targeted population, their donation perceptions and donor health. A backward citation search of relevant review papers was also completed (see Prospero record for list).

The search was restricted to studies published from January 1995 to account for possible changes in blood donation populations, eligibility criteria, and procedures over time (e.g., in technology, machinery) which may impact donor perceptions. Where possible, the search was further limited to English and human participants. Finally, as the search returned a number of conference abstracts, for those deemed relevant, a supplementary search was completed to identify if a peer-reviewed full study version was available. In instances where this was the case, and the article not already captured by our search, the record was revised to reflect the full-text version.

Eligibility criteria

Following removal of duplicates, title and abstracts were screened for ineligibility by one author (SC) (i.e., not human, not in English, not about whole-blood/blood product donation, autologous and convalescent plasma donors, non-primary research articles). A second author (SK) screened 25% of records to ensure agreement (inter-rater reliability >0.80 acceptable; K=1.00). Full-text screening was then completed independently by two authors (SC and SK). Discussion between authors, including RT and BM, resolved disagreements. Table I outlines (in)eligibility criteria 27 .

Eligibility criteria for the systematic review

Key definitions

Perceptions of health impacts of blood donation were defined as both experiences and beliefs, with each construct explored separately. Experiences referred to personally experienced consequences of donating (e.g., donating caused me to bruise), while beliefs included general understandings or opinions surrounding donation (e.g., donation affects immunity), and included third-party reports (e.g., health professionals’ opinion of patients’ health perceptions). As this study was concerned with longer-term health perceptions, rather than health events that happened during or immediately following donation, experiences were further limited to those occurring off-site and not as an immediate reaction to donation (e.g., citrate reactions during plasmapheresis donations). Consequently, experiences recorded during and/or after donation while still on-site, or recorded of f-site but in explicit reference to on-site experiences (e.g., how did you feel during donation) were considered ineligible. However, cases were permitted where it was unclear if the experience occurred on or off-site (e.g., I donated blood and felt weak) or participants reported both on and off-site experiences (e.g., which of the following symptoms did you experience during or after donation).

The term health was limited to negative and positive physiological(physicalstate, e.g., weakness, good for health) features. Psychological (mental/emotional state, e.g., well-being) effects were considered outside the scope of the review due to a lack of consistency and clarity between and within studies regarding definitions and measurement. In this review, health incorporated both specific and general consequences, which were assessed separately. Specific consequences focused on a single and explicit physical health effect (e.g., blood donation has a negative effect on fertility). General perceptions included statements of broader donation-related health effects. Importantly, such perceptions were only included if they contained a reference to self within the context of health (e.g., blood donation is good/harmful was excluded, however donation is good for my health/harmful to my body was permitted). General perceptions also included statements referring to multiple specific categories that could not be separated (e.g., donating affects fertility and immunity).

Studies that mentioned measuring health perceptions of donation as an aim were classified as central , while studies that measured health effects secondary to the aims of the study were classified as background .

DATA EXTRACTION

Two authors (SC, SK) completed 50% of data extraction and coding each. Discussions between authors occurred when there was uncertainty around inclusion/exclusion of information. The following data were extracted to provide a holistic picture of the extent to which this topic had been addressed in the literature:

• study characteristics : country of origin, study design (quantitative vs qualitative), and interest in health perceptions (central, background);
• participant characteristics : demographics (gender, age, education, ethnicity, and religion), and participant source (high school students, university students, blood donors at a clinic, general population, not specified, mixed);
• donor characteristics : donation type (whole-blood, plasma, platelet, red blood cell, mixed) and donor type (donor, non-donor, first-time, repeat, lapsed);
• health perception information : perception type (experience, belief), health effect type (specific, general), health effect direction (positive, negative), and whether the information was extractable (i.e., study included relevant methodology but not relevant results; yes, no [composite score, unusable statistics, not reported]); and
• outcomes : percentage of studies that investigated each health perception and, where available, the percentage of participants that endorsed each health perception. If one study provided multiple percentages towards the same perception, the largest percentage was extracted. Percentages were averaged when one study reported multiple percentages from different samples (e.g., whole-blood vs plasma) relating to the same perception.

Insufficient data were available for extraction regarding donor remuneration status, donor relationship (related, non-related), or donor sub-group comparisons of outcomes (e.g., non-donor vs donor).

Risk of bias assessment

While the PRISMA checklist features an assessment of risk of bias, for this particular review, a quality assessment may serve as an inaccurate and invalid depiction of bias for three reasons 28 :

• the purpose of this review is to gain insight into the current state of this literature, thus considering all studies, regardless of quality, is important;
• in the majority of studies eligible for extraction, the perceived health effects were not a central focus of the study (see results for more detail), but rather a minor secondary mention; and
• due to the inclusion of various study designs, different quality assessments were required which would prevent a standardized evaluation.

As such, a risk of bias assessment was not undertaken.

Search results

In total, 82,112 records were identified from database searches and 567 from backward citation searches. 31,917 duplicates were removed prior to screening, and 47,907 were excluded at title/abstract screening for ineligibility. 2,855 articles were sought for retrieval and of these 25 could not be retrieved, a further 100 were duplicates, 2,399 were excluded for ineligibility, and 72 included questions about donation-related health perceptions with unusable results (e.g., provided composite total scores only) and were excluded at the full-text screening stage ( Figure 1 ). A total of 259 articles reporting on 247 unique datasets (referred to as studies below) were included in the review.

PRISMA flowchart of study screening and selection procesess

Note . Reason 1 = additional manually-identified duplicates; 2 = not in English; Reason 3 = not primary data; Reason 4 = not regarding human whole blood/blood product donation; Reason 5 = donors’ perceptions of donation-related physiological health not discussed or discussed in relation to during or immediately following donation; Reason 6 = active control group and/or no pre-intervention data; Reason 7 = unusable data (e.g., total composite scale scores, included a relevant question but did not provide results).

Description of included studies

The 247 studies comprised 27 qualitative, 204 quantitative, and 16 mixed-design methods. Most studies (No.=221, 89.5%) had donation-related health perceptions as a background, rather than a central (No.=26, 10.5%), focus. Studies were published between 1995 and 2021, with 73.0% published from 2010 onwards. Over a third (39.3%) of studies originated in Asia, followed by North America (17.8%), Europe (17.0%), and Africa (16.6%). Whole-blood donation was examined most frequently (91.0%) and plasma (1.6%), platelet (0.4%), or a combination of donation types (7.0%), examined least.

Description of participants

Participants comprised either blood donors from a blood clinic/donor centre (34.0%), students (28.4%), or the general public (21.1%). Just over a third of studies included donors only (36.8%) and a third included a mix of donors and non-donors (36.0%), while 6.9% included non-donors only and 20.3% did not specify donor status. Of studies including donors (No.=180; 72.9%), the proportion of donors ranged from 2.4 to 100% (mean 65.9%, median 73.0%). In studies reporting donor experience, on average 38.0% were first-time donors (median 31.9%, range 1.6–100.0%).

Donor age was reported inconsistently as the mean, median, or proportions within age ranges. Where reported, donors were a mean age of 35.6 years (range 19.8–52.6), median 34 years (range 27–41), or most frequently within the 18–40-year age group. The mean proportion of female donors reported in studies was 38.0% (median 40.3%, range 0.0–100.0%). Studies originating in Asia (41.1%), North America (18.3%), and Europe (17.2%) most frequently included donors. Of studies including non-donors (No.=106), the mean proportion of non-donors was 65.6% (median 67.8%, range 18.4–97.6%). Non-donor age was reported in less than a quarter of studies, either as a mean or proportion within age ranges. Non-donors were aged a mean of 27.5 years (range 19.7–39.1) or were most frequently within the 18–30 years age group. The mean proportion of female non-donors reported in studies was 56.0% (median 54.3%, range 0.0–100.0%). Studies originating in Asia (52.8%) and Africa (21.7%) most frequently included non-donors.

Categories of specific health consequences

Table II shows a breakdown of the categories of specific consequences of donating blood (e.g., blood loss, vitality) which were developed after extraction and once an understanding of the literature was achieved. Specifically, two authors (SC, SK) met to discuss the overlap between the specific health-related beliefs and experiences extracted, resulting in the creation of 14 distinct categories. These categories were then examined and approved by remaining authors, before the extracted data was coded accordingly. The aim of this procedure was to meaningfully group consequences to allow for a more comprehensive and consistent comparison of the specific positive and negative health-related beliefs and experiences of donating blood.

Categorisation of specific health consequences

Note: there were two exceptions to weakness being coded as vitality 1) when weakness in relation to anaemia, this was coded as iron ; and 2) when weakness was raised in conjunction with other vasovagal reactions this was coded as adverse events: vasovagal reactions .

Beliefs and experiences

The 247 studies ( Online Supplementary Content Table SI ) included 568 reports of beliefs and/or experiences. Overall, more reports of health perceptions focused on beliefs than experiences (82.0 vs 18.0%), considered specific rather than general beliefs and experiences (80.0 vs 20.0%), and more frequently examined negative than positive beliefs and experiences (83.0 vs 17.0%) ( Table III ). In particular, reports most frequently comprised specific negative beliefs and specific negative experiences. Over 90.0% of reports of general and/or specific beliefs had health as a background rather than primary focus of the study, whereas approximately 50.0% of reports of general and/or specific experiences had health as a background focus ( Table III ).

Beliefs and experiences, specificity, valence, and health focus (No.=568 reports of beliefs and/or experiences in studies) *

Beliefs general

Study reports of general positive beliefs (No.=46) comprised the beliefs that donation was good for health and/or that the beneficial health effects of donation motivated or were a reason for donation. On average, 40.1% of participants in these study reports mentioned general positive beliefs (e.g., “Donation is good for one’s health”) ( Table IV ). Over half of the reports for general positive beliefs occurred in studies conducted in Asia.

Study reports for general positive (No.=46) and general negative (No.=62) beliefs by continent

Study reports of general negative beliefs (No.=62) related to donation posing a risk to health or causing ill health and/or donation-related health risks being a deterrent/ barrier to donation (e.g., “Donation is harmful to your health”). On average, 22.2% of participants in these study reports cited general negative beliefs ( Table IV ). Reports for general negative beliefs occurred in studies conducted most often in Asia (51.6%) and Africa (29.0%).

Beliefs specific

Specific positive beliefs (No.=45) that were reported in studies were coded into seven categories (see health consequences, Table II ) and ranked in order of how frequently they were measured across studies: improving blood, health protective factors, physical appearance (weight loss, look younger), vitality (energy boost), headaches, immunity, and iron (decrease levels) ( Table V ). At least half of reports for the two most common beliefs originated in studies conducted in Asia only or Asia and South America.

Study reports for specific positive beliefs overall and by continent (No.=45)

Reports of specific negative beliefs (No.=313) in studies were coded into 13 categories ( Table II ) and ranked in order of most frequent occurrence across studies: infectious disease, vitality (causes weakness), adverse events involving vasovagal reactions, iron, immunity, non-specific adverse events, reproductive health, adverse events involving other physical injury, physical appearance (weight gain), death, health risk factors (increase blood pressure), blood loss, and headaches ( Table VI ). Reports of these frequently occurring beliefs most commonly occurred in studies originating in Asia and Africa.

Study reports for specific negative beliefs overall and by continent (No.=313)

Five reports of specific beliefs about weight loss or gain after whole-blood donation could not be categorized as positive or negative.

Experiences general

Two reports of general positive experiences (e.g., “I feel physically better after donating today”) and five reports of general negative experiences (e.g., “Persistent ongoing symptoms”) were included in studies ( Table III ). On average, general positive and negative experiences were mentioned by 30.8% and 19.7% of participants, respectively. Study reports of general positive experiences had health as a background focus and originated in Europe. Sixty percent of reports of general negative experiences had health as a central focus and originated in Europe.

Experiences specific

Studies included four reports of specific positive experiences and, of these reports, 3 were from qualitative studies that described improving blood as a result of donating, and specifically replenishment of blood leading to feelings of increased health. These reports were from studies originating in either South America or Asia ( Table VII ).

Study reports for specific positive experiences (No.=4) and specific negative experiences (No.=91)

Study reports of specific negative experiences (No.=91) were coded into eight categories ( Table II ). Study reports of negative experiences were ranked in order of most frequent occurrence across studies: adverse events vasovagal reactions, adverse events non-specific (feeling unwell), adverse events other physical (bruising), vitality (tiredness), immunity, iron, headaches, and infectious disease ( Table VII ). These frequently occurring experiences most often originated in study reports from Asia, Europe, and North America.

The aim of this review was to systematically integrate the literature on the perceived health effects of blood donation. Specifically, we identified donors’ and non-donors’ perceptions operationalized as personal experiences and broader beliefs of the short and longer-term physiological health effects of blood donation. We also sought to examine the extent to which health effects of whole-blood and/or blood product donation have been investigated and differences in health perceptions of blood donation in different parts of the world.

While a large number of studies assessed donation-related health perceptions, in the vast majority these perceptions were the background focus and only assessed in relation to whole-blood. Health was more often a central focus in results reporting experiences, possibly because these studies considered events occurring after donation. Further, health was almost exclusively a background focus when beliefs were considered.

These results could be interpreted as indicating that people do not generally have donation-related health perceptions, and this justifies the lack of focus within research. Alternatively, people may have a wide array of negative and positive donation-related health perceptions that have not yet been comprehensively mapped. The lack of focus on how donors perceive donating whole-blood, plasma, and platelets to impact their health means that the breadth, valence and level of endorsement of perceptions of health still remain largely unknown. Diversifying our focus away from whole-blood is particularly important given the worldwide expansion in plasma collection sites 29 . We know little of the short and long-term effects of donating plasma or on lay understandings of how plasma donation impacts health, and this work is needed to inform approaches to donor communications.

Accepting the limitations of existing research, clear asymmetries were observed. Specifically, most studies focused on beliefs rather than experiences, and on specific negative beliefs, rather than positive. In part this focus and frequent endorsement is explained by known risks of blood donation of vasovagal reactions, iron loss and other adverse events. Donors are routinely educated about these risks and are often encouraged to engage in behaviours during or after donating to mitigate risk and improve donor retention 30 . Negative impacts on vitality are another common-sense outcome of blood donation, likely related to understandings about physiological impacts of losing iron and blood volume 25 . However, and perhaps surprisingly, the most frequently endorsed specific negative belief around blood donation was in relation to infectious diseases. The belief that blood donation carries a risk of acquiring transfusion transmitted infections (TTIs) such as HIV has been documented in some settings 22 , 31 , and is a known deterrent to donation in these settings and by migrant groups. As this belief relates to trust in the system of blood collection, this finding suggests that it remains particularly important to research and address this with those who have connections to countries where such beliefs are more common 22 , 31 , 32 and who may lack knowledge on or trust in the procedures to mitigate these risks in other countries 33 . Other specific negative beliefs identified, such as those relating to negative impacts on physical appearance and reproductive health appear context-specific, with most studies asking about these and reporting findings originating in Asian or African countries. This finding draws attention to the likelihood that ethnic minority groups living in Western countries will hold divergent understandings of the impacts of donation on their health. As BCAs in countries with growing migrant groups aim to improve representation of these groups in blood donor panels more research is needed to understand if, and how, beliefs about health impact willingness to donate blood in these groups.

Results for specific negative experiences most frequently mirrored beliefs, with a focus on vasovagal reactions, non-specific adverse events, and vitality. These were mostly reported in studies with blood donors. However, only one study reported infectious disease as an experience while this was commonly cited as a belief. Negative impacts on immunity and iron levels, and headaches were also mentioned by small numbers of participants. That frequent experiences differed from frequent beliefs is likely explained by studies reporting experiences drawing upon actual rather than anticipated donation.

Consistent with the risk mitigation focus of donor research, specific positive beliefs were only considered in 46 studies and specific positive experiences in four studies. The most frequently mentioned positive beliefs related to improving blood, health protective factors, such as lowering blood pressure, and physical appearance, such as weight loss. The belief that donating blood improves blood quality through removing excess or unclean blood and stimulating production of new blood has its origins in therapeutic bloodletting 33 . Beliefs relating to improving blood and health protective factors were more commonly mentioned in studies from Asia and South America, however few specific positive beliefs were endorsed by ≥20.0% of participants and it remains unclear how widespread these beliefs are. Notably, few studies included specific positive experiences, although most of those that did documented experiences related to improving blood through donation. The existence of positive perceptions that have no basis in fact are challenging for BCAs as they cannot be used to promote blood donation, yet addressing them may deter those motivated by these beliefs. One approach may be to conduct research to improve understanding of positive beliefs (e.g., improving blood) and how they relate to evidence (e.g., changes to iron metabolism and erythropoiesis that take place after donating blood).

CONCLUSIONS

While highlighting some key health perceptions that people have in relation to blood donation, overall, this review reinforces that lay perspectives on the health impacts of blood donation have not been comprehensively researched. Focusing only on physiological impacts due to the inconsistent quality of data on psychological impact, our analysis shows conclusively that health impacts have been treated as peripheral in research to date. Within analyses that have considered these perceived impacts there has been an asymmetrical focus on whole-blood and negative rather than positive impacts. For this reason, and despite inclusion of data from 247 studies in the review, it remains difficult to know how important health beliefs and experience are for donors and non-donors, and to what extent these experiences and beliefs impact critical decisions in the donation process. The discrepancy between reported beliefs and experiences provides an avenue for future research, for example to understand whether certain beliefs are more likely to be held by people who have not donated blood, and whether engaging in blood donation changes the types of beliefs reported. Research should also focus on understanding the cultural context of health beliefs, such as through a multi-continent study, and on developing standardized definitions for measuring psychological impacts of donation. Making donation-related health beliefs and experiences a central research focus, and comprehensively mapping how these relate to differences in donor characteristics and behaviour, geographical region, and products donated has potential to provide insights critical to appropriate education to ensure the ongoing sufficiency of the blood supply. Further, we believe that better understanding health beliefs and experiences, and how these shape blood donation behaviour in different settings, can make a valuable contribution to conceptualisations of blood donation as a reciprocal arrangement that considers benefits and risks to the donor as well as the recipient 35 . Such knowledge is particularly important given the salience of health to activities that BCAs are increasingly inviting donors to participate in, such as biobanks and other health-related research 36 . Having this knowledge could help inform the kind of health information donors value and would like to receive from BCAs, as well as health-related communication and education strategies.

Supplementary Information

AUTHORS’ CONTRIBUTIONS: RT, BM, TED: substantial contributions to the conception or design of the review; SPC, MKH, SPK: substantial contribution to the acquisition and analysis of data; RT, BM, MKH: interpretation of data for the review; RT, BM, SPC, MKH, SPK, TED: drafting the manuscript; MKH: revising the manuscript; RT, BM, SPC, MKH, SPK, TED: final approval of the manuscript.

The Authors declare no conflicts of interest.

Commented by doi 10.2450/BloodTransfus.625

FUNDING: Australian governments fund Australian Red Cross Lifeblood for the provision of blood, blood products, and services to the Australian community.

New study offers hope for a rare and devastating eye cancer

After more than a decade studying a rare eye cancer that produces some of the hardest-to-fight tumors, researchers from University of Pittsburgh Medical Center have found a treatment that works on some patients and, more importantly, a tool that can predict when it is likely to succeed.

The work, published in Nature Communications, is being validated in a clinical trial involving at least 30 patients. It could pave the way for similar methods designed to overcome one of the enduring frustrations of cancer care.

Because tumors differ, not only between patients but even inside the same patient, a treatment that works on one mass may fail on another, even when both are of the same cancer type.

The researchers in Pittsburgh tackled this problem in uveal melanoma, an eye cancer that afflicts only 5 people in a million, but that half the time spreads to other parts of the body, often the liver. The median survival once uveal melanoma has spread has been less than seven months, according to a 2018 study in the journal JAMA Ophthalmology.

“We chose this because it was one of the only cancers that 10 years ago when we started, there was nothing approved for it,” said Udai Kammula, who led the study and directs the Solid Tumor Cell Therapy Program at UPMC Hillman Cancer Center in Pittsburgh.

Scientists had long speculated that the reason uveal melanoma is so tough to fight is that something helps the tumor keep out T cells, a key part of the body’s immune system that develops in bone marrow. However, previous studies by Kammula and his colleagues showed that uveal melanoma tumors actually have T cells inside, and they are turned on.

The problem? The cells lie dormant instead of multiplying and reaching numbers large enough to overwhelm the tumor.

The culprit appears to reside somewhere inside the tumor’s ecosystem of cells, molecules and blood vessels, known formally as the tumor’s “microenvironment.” Kammula compares this ecosystem to the infrastructure that supports a city. Something in that infrastructure helps protect uveal melanoma tumors by preventing the critical T cells from multiplying.

“Ultimately, if we’re going to get rid of cancer, we have to get rid of this infrastructure,” Kammula said.

A tool for predicting success

He and his colleagues have had some success using a treatment known as adoptive cell therapy, which was developed in the 1980s by Steven Rosenberg at the National Institutes of Health.

The treatment involves removing the T cells from the tumor, where they have been unable to proliferate. Scientists then take those T cells and grow them outside the body in a lab dish. They treat patients with chemotherapy to kill off the last of their old immune systems. Finally, they reinfuse the lab-grown T cells into the patient’s blood stream and the cells, now in much greater numbers, go on to attack the tumor.

In this treatment, the T cells are often referred to as tumor-infiltrating leukocytes, or TILs.

Kammula said his team has found that tumors shrink partially or completely in about 35 percent of patients who receive the treatment. But they wanted to know why it doesn’t work in the majority of cases, and whether there might be some way to predict beforehand when it will succeed.

To find out, the researchers analyzed samples from 100 different uveal melanoma tumors that had spread to different parts of the body in 84 patients, seeking to examine all of the tumors’ genetic material.

“We basically put the tumor biopsy in a blender that had the stroma [supportive tissue], the blood vessels, the immune cells, the tumor cells. It had everything,” Kammula said, explaining that they then analyzed all of the tumor’s genetic material.

They found 2,394 genes that could have helped make the tumor susceptible to treatment, some of them genes that experts would regard as “the usual suspects” and others that were unexpected. Using this long list of genes, the scientists searched for characteristics that they shared.

The genes were predominantly involved in helping the body defend itself against viruses, bacteria and other foreign invaders by removing the invaders and helping tissue heal. Kammula and the study’s lead author, Shravan Leonard-Murali, a postdoctoral fellow in the lab, used the different activity levels of these genes to develop a clinical tool.

The tool, known as a biomarker, assigns a score to a uveal melanoma tumor based on the likelihood that it will respond well to the treatment ― removing T cells, growing them outside the body, then reinfusing them.

So far, Kammula said, the biomarker has been “extremely good,” in predicting when the treatment will be effective, though he added, “these findings will need confirmation in the current ongoing clinical trial.”

“I thought it was somewhat of a tour de force, honestly,” said Eric Tran, an associate member of the Earle A. Chiles Research Institute, a division of Providence Cancer Institute in Portland, Ore. Tran did not participate in the study.

He said that while it will be important to validate these results, “I was certainly encouraged by their studies. And from my perspective, I wonder if that sort of strategy can be deployed in other cancers.”

Ryan J. Sullivan, an oncologist at Massachusetts General Hospital and associate professor at Harvard Medical School who was not involved in the study, called the team’s work “timely” and said “it is even more significant that they appear to have a [tool] that appears to predict which patients will benefit.”

The team at UPMC is already investigating possible wider application of both the treatment and the biomarker in a second clinical trial that involves a dozen different cancers.