Effects on recipients of exposure to allogeneic donor leukocytes

Blood transfusion recipients are exposed to allogeneic donor leukocytes at the time of transfusion. Exposure to allogeneic donor leukocytes has been linked to a variety of complications of transfusion including primary HLA alloimmunization and platelet refractoriness, febrile nonhemolytic transfusion reactions, transmission of leukotropic viruses, transfusion‐associated graft versus host disease, and transfusion‐induced immune suppression. The development of high‐performance leukodepletion blood filters and of low‐leukocyte plateletapheresis machines has provided the technology to reduce recipient exposure to allogeneic donor leukocytes. This article provides a brief review of current information on the utility and shortcomings of these technologies for the prevention of leukocyte‐mediated transfusion complications.