Nationwide Antibody Registry Could Help Further Reduce Risk of Adverse Events Among Patients Receiving Blood Transfusions

Throughout the past several decades, the blood community has continually advanced the field and worked tirelessly to ensure the optimal safety of blood transfusions. However, the potential for adverse events has not been completely eliminated.

The risk is most likely to be elevated when there is incompatibility between the recipient of a blood transfusion and the unit of blood he or she is given. In particular, if a recipient has developed red blood cell antibodies following a blood transfusion or pregnancy, a delayed hemolytic transfusion reaction is possible if a hospital is unaware of the existing antibody. These risks are especially a concern among patients who require frequent blood transfusions and who have relatively high prevalence rates of red blood cell alloimmunization, including those with sickle cell disease, thalassemia, and select other diseases.

Currently, there are several systems in place to try to address these issues. When a patient is known to have a particular alloantibody, health care providers will specifically order blood products lacking that antigen. However, these antibodies can decrease over time, sometimes falling below the level of potential detection (then referred to as “evanescent antibodies”). In such cases, transfusion with a particular unit of blood may appear to be compatible but the opposite could actually be true.

An additional concern is that patients are not always treated at the same facility or by the same health care providers. In instances where a patient moves or begins receiving care at a different facility, information about their antibodies might not be shared. Health care providers may try to get more information about their patient by calling the patient’s previous providers, but this is not always effective. Additionally, while the practice of sharing medical records has increased in recent years, data about a patient’s antibodies is often not included or fully detailed in such records.

Nationwide Registry Proposal

Jeanne Hendrickson, MD, professor of laboratory medicine at Yale University, is working with many others on developing a proposal for the creation of a nationwide registry to track patients’ antibodies. Hendrickson, along with her colleagues George Hauser, MD, and Chris Tormey, MD, both from Yale University; and Claudia Cohn, MD, PhD, from the University of Minnesota and AABB’s chief medical officer, recently wrote a white paper highlighting the need and potential benefits of a nationwide antibody registry.

Hendrickson said such a registry would be an important advancement in further optimizing the safety of blood transfusion for patients throughout the United States. “Transfusion safety will be improved by having an accurate antibody history for patients who require a blood transfusion,” she told AABB. “Evanescent antibodies can be evaded if a blood bank knows about them and can select red blood cells lacking the cognate antigens for transfusion.”

Hendrickson noted that nationwide antibody registry systems are in place in other countries and have helped to further improve transfusion safety. “A registry like the one we are proposing has existed in the Netherlands for more than a decade and has been shown to significantly improve transfusion safety, reducing the risk of delayed hemolytic transfusion reactions by 50%,” she said.

Widespread Support

Hendrickson said that thus far, she and her colleagues and collaborators have met with strong support for their proposal. “There has been overwhelming interest and support from the community and from every organization that we have talked to,” Hendrickson said. “Members of the blood community understand this will improve patient safety.”

In June 2020, AABB submitted comments to the Department of Health and Human Services that advocated for the establishment of a national red blood cell antigen typing patient database and noted that such a resource would improve patient outcomes by expediting access to compatible units of blood for individuals with special transfusion requirements. Since that time, AABB has been working with the American Society for Clinical Pathology, the American Society for Hematology, America’s Blood Centers, the American Red Cross and others to identify opportunities to drive progress.

In a recent survey about the development of such a registry among members the AABB Transfusion Medicine Subsection Coordinating Committee, 97% of respondents said they were in favor of a nationwide red blood cell antibody registry.

Gagan Mathur, MD, MBA, director of transfusion medicine and associate professor of clinical pathology at the Keck School of Medicine of the University of Southern California, is a strong supporter of the development of a nationwide antibody registry. He recently collaborated with colleagues on a paper published in Vox Sanguinis titled “A Case for National Registry of RBC Antibodies.”

This paper highlights a patient with an increased risk for bleeding who was undergoing a liver transplant. The initial antibody screening was negative but a history of anti-Jka was identified in a review of the patient’s history in a local registry of RBC antibodies. The surgery was, therefore, postponed until well-matched antigen-negative blood products could be transfused.

Mathur told AABB that without the local registry, this patient’s evanescent antibodies would not have been identified, thus increasing the risk for a transfusion-related adverse event. “The registry allowed us to identify the patient’s increased risk and administer the appropriately match units of blood,” Mathur said. “We were fortunate that there happened to be a local registry, but that is not always the case. This patient’s story sheds light on the need for a nationwide registry. I believe it is essential for patient safety and improved outcomes.”

Next Steps

Hendrickson and her colleagues and collaborators are working to make their proposal a reality. They have formed a nonprofit group to help move this project forward and have shared their proposal with various government agencies and health care leaders.

Some key issues need to be addressed before the registry can be realized. First, the blood bank information systems at facilities throughout the country need to be set up to coordinate with one another and share information. There are currently about six major blood bank information systems, none of which currently communicate with one another. Hendrickson and her colleagues have been in communication with leaders of these major blood bank information systems to explain the proposal for the nationwide antibody registry and gain their support. One of the systems has already signed on to the project and is developing an interface to coordinate with a nationwide registry. Hendrickson and her colleagues are hoping to gain the support of the other blood bank information systems soon.

In addition, there is inconsistency with the terminology used at various facilities to describe antibodies. Hendrickson said consistent terminology throughout the country is essential in ensuring the success of this project. “We have developed a working group of dedicated volunteers who are compiling a uniform antibody list, focused around ISBT terminology,” Hendrickson said.

Hendrickson said that although much additional work is needed, she is optimistic that the registry will eventually be implemented. “The time is right to initiate a nationwide registry,” she said. “Such a registry will be particularly important for alloimmunized patients who have been cared for at more than one hospital system. If this project is successfully implemented, it will further advance our goal of optimizing transfusion medicine quality and safety for all patients.”