Millions of life-saving red blood cell (RBC) units are transfused annually in the United States, and the overwhelming majority of these RBC units are derived from allogeneic donors. Hence, these donor red cells must be shown to be compatible for the recipient before transfusion is performed, meaning that there are no antibodies to donor RBCs in the recipient’s blood. The inherent risk of incompatible RBC transfusion is the possibility of inducing a hemolytic transfusion reaction in the recipient, a situation that carries significant morbidity and mortality. Type (ABO)-compatible RBC transfusion eliminates one mode of incompatibility.
However, patients who have a history of prior RBC transfusion or pregnancy may have developed allo-antibodies to specific non-self-antigens that are carried on donor red cells. Certain patient populations, e.g., those with sickle cell disease, have a high rate of developing alloantibodies. Other patient groups, such as those with myelodysplasia, also have a high rate of alloimmunization after RBC transfusion. Although blood banks and transfusion centers are highly proficient at detecting alloantibodies, the natural history of these antibodies is that their titers wane over time such that they become undetectable, termed “evanescence.” After incompatible transfusion, these antibodies rapidly reappear and cause delayed hemolytic transfusion reactions, in some groups, leading to death rates as high as 11%.
When a patient blood sample is sent for the first time to a blood bank/transfusion center for type and screen or type and cross, evanescent antibodies will not be detected. Even if evanescent antibodies had been identified previously at another institution and that information is stored in their blood bank information system (BBIS), there is currently no interface to share that information between transfusion services at different institutions. Contacting other institutions by phone to gather such information is error-prone and does not provide complete information since patients may receive care at multiple institutions over the years. Therefore, because our knowledge of alloantibody history is incomplete and transfusion records are fragmented by inter-facility travel, RBC transfusions may carry the risk of a delayed hemolytic transfusion reaction.
The blood bank/transfusion community has long been cognizant of this challenge and has sought ways to improve this aspect of patient safety. Most recently, the American Society of Clinical Pathology has convened an inclusive group of stakeholders to address development of a nationwide patient RBC alloantibody database/registry. A recent AABB survey has shown that the majority of institutions would welcome development of a RBC registry, and transfusion-related registries have been shown to improve patient safety in other countries. The strategy for this current initiative has begun with developing an accurate alloantibody history using a BBIS-centric approach. Engagement of BBIS vendors is therefore key to its success, and we are very pleased to announce that SCC SoftBank is the first vendor to formally “sign on” with this project. Stay tuned on the ePolicy website for future announcements of progress and informational items.
Committee institutional members include ASCP, AABB, ASH, ImpactLife, Georgia Health Policy Center, Vitalant, Lantana Consulting Group, Mount Sinai, Vanderbilt, American Red Cross, ABC, and Yale.