Recipient Epidemiology and Donor Evaluation Study (REDS) Program

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What is the goal of the REDS program?

The goal of the REDS program is to evaluate and improve the safety and availability of the blood supply, as well as the safety and effectiveness of transfusion therapies. The program also works to proactively address potential emerging threats to the nation’s blood supply and serves as a resource for ongoing work in transfusion research. Now in its fourth phase, the Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric (REDS-IV-P) program aims primarily at improving the benefits of transfusion while reducing its risks; the REDS program also has a new focus on previously understudied populations.

Over the past 30 years, REDS has been the premier research program in blood collection and transfusion safety in the United States. In its third phase — REDS-III — the program focused on conducting research on all elements of the transfusion chain, from the blood donor to the blood products made from their donation to the adult patients receiving the products through transfusion. The program compiled the linked demographic, clinical, and laboratory data on blood donors and recipients into comprehensive databases that are available through NHLBI’s Biologic Specimen and Data Repository Information Coordinating Center (BioLINCC).

REDS-IV-P builds on REDS-III with an additional focus on research with newborns, children, and pregnant women who need transfusions. The data compiled in REDS-IV-P will allow investigators to rapidly address key research questions in transfusion medicine and inform blood policy decisions, for adults as well as for children and other understudied patient populations.

REDS-IV-P also extends the Brazilian sickle cell disease cohort that was established in REDS-III to evaluate transfusion practices and associated clinical outcomes in sickle cell disease. The REDS-IV-P Brazilian transfusion program continues its monitoring and surveillance efforts for Zika, chikungunya, dengue, and other emerging viral threats to the blood supply.


  • REDS protects the nation’s blood supply through research to improve blood component safety and availability and the safety and effectiveness of transfusions.
  • The REDS program was launched by NHLBI in 1989 and has had three additional phases: REDS-II, REDS-III, and REDS-IV-P.
  • Internationally, REDS seeks to reduce and prevent the transmission of HIV and infectious agents, such as dengue and Zika viruses, through blood transfusion.
  • REDS-III began integrating adult transfusion recipient epidemiology and laboratory research to enhance the safety of transfusions.
  • REDS-IV-P expands the work of REDS-III to include newborns, children, and pregnant women who receive transfusions in the United States.

How does the REDS program contribute to scientific discovery?

The program has established scientific approaches to assessing the risks of contracting transfusion-transmitted infectious agents, established databases to evaluate the blood supply and specific populations of transfused patients, and added shareable biorepository resources for the scientific community.

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- Recipient Epidemiology and Donor Evaluation Study (REDS) Program

Findings from the original REDS program, which was created in response to the emerging HIV/AIDS epidemic, dramatically improved blood safety. REDS-II approached both infectious and noninfectious problems, such as transfusion-related acute lung injury, that could affect the U.S. and international blood supply.

Key scientific contributions from REDS-III include:

  • Studies that informed public health policies, including one that established donor deferral periods for men who have sex with men
  • Studies that helped better estimate the risk of HIV infection from transfusion, including the creation of standardized methods to calculate the risk of HIV infection and the evaluation of new tools to detect transfusion-transmitted infection in countries where tools for screening blood donations are not readily available
  • A comprehensive research database that links information about blood donors, their donations, the blood products made from these donations, and transfusion recipients
  • Strategies to reduce iron deficiency in donors
  • Studies to improve red blood cell storage and identify which donors have red blood cells that are better for routine storage
  • Studies to address emerging infectious disease threats, such as dengue and Zika viruses. These studies include:
    • A U.S. natural history study of Zika virus resulting in the establishment of a shareable biorepository. The virus samples were shared with collaborating academic institutions and commercial assay developers, who are using the samples to study markers of the virus and the immune response. This information will help in the development of tests to diagnose Zika infection.
    • A study conducted in Brazil to estimate the risk of dengue being transmitted by transfusion
  • Studies to look at transfusion outcomes in certain patient populations, such as people in Brazil who have sickle cell disease and women in South Africa who have postpartum hemorrhage

How is the REDS-IV-P program conducted?

The U.S. component of the REDS-IV-P program has four research hubs. Each hub has a blood center and offers transfusion services to support health care and community hospitals. The international component involves collaborations between U.S. and Brazilian researchers. The research activities of all REDS-IV-P hubs are supported by a data coordinating center (Westat, Maryland) and a center for transfusion laboratory studies (Vitalant Research Institute, California).

The REDS-IV-P program serves as a resource to the scientific community by giving investigators outside the program opportunities to:

  • Collaborate with REDS-IV-P researchers
  • Access biospecimens and scientific expertise
  • Analyze data on transfusion and transfusion-associated outcomes in patient populations that are otherwise not available in the United States

Another important part of the collaborative research effort in REDS-IV-P is the training of junior investigators in blood banking and transfusion medicine research. This enables NHLBI to build research capacity in an area of tremendous global public health importance.