Leukocyte reduction of cellular blood components. Effectiveness, benefits, quality control, and costs

Cellular blood components contain passenger donor leukocytes. Transfusion of passenger leukocytes may be associated with alloimmunization to leukocyte antigens, febrile transfusion reactions, refractoriness to platelet transfusion, severe pulmonary dysfunction, graft-vs-host disease, the transmission of infectious diseases, and immune modulation. Advanced leukocyte-reduction filters enable the removal of up to 99.9% of leukocytes from cellular blood components. Clinical trials suggest that the use of leukocyte-reduction filters may prevent or diminish the probability of febrile transfusion reactions, alloimmunization, and cytomegalovirus infection, but controversy exists regarding the effectiveness of leukocyte reduction in preventing immune modulation. There is no evidence that available techniques will prevent graft-vs-host disease. Cost-benefit analyses support the use of leukocyte-reduction filters for well-defined indications. Standards for leukocyte reduction of red blood cells have been defined, but issues regarding the quality control of leukocyte-reduced blood components require additional study.