AM23-MN-21-O: New Insights into the Development and Consequences of RBC Alloimmunization (Enduring)

The development and consequences of RBC alloimmunization have been a long-standing challenge in transfusion medicine. While a significant amount of work has focused on characterizing the important alloantigen targets of RBC alloimmunization, the immune pathways responsible for the development and consequences of alloantibodies following transfusion have remained incompletely understood. This session will provide an overview of the distinct innate immune signaling pathways, from toll-like receptor and interferon signaling, to recent insight into the key B cells, T cells, and antigen-presenting cells involved in the development of alloantibodies against RBC alloantigens. Similarly, while antibody engagement of RBC target antigens can result in a hemolytic transfusion reaction following an incompatible transfusion, hemolytic transfusion reactions are not an inevitable outcome of RBC transfusion. Indeed, a variety of outcomes can occur following an incompatible transfusion, including antibody-mediated removal of the target antigen from the RBC surface. Despite the complexity that governs the development and overall consequences of RBC alloimmunization, key themes are emerging that may provide promising approaches to not only actively prevent but possibly alleviate the most severe complications of RBC alloimmunization. We will explore recent developments in the formation of RBC alloantibodies and the regulators that govern the consequences of incompatible RBC transfusion by evaluating results across a broad spectrum of recent studies in the field.