Problems after repeated transfusions

Allosensitization can cause severe problems in multiple or chronic transfusion-dependent patients. With time the immune system reacts against many antigens. The heterogeneous leucocytes carry the highest number of allo-antigens. However, except for rare transfusions of phagocytes for certain immunosuppressed, infected patients, the functions of these cells are not needed. Erythrocytes and platelets are now transfused after rigorous leukocyte depletion by very efficient filters. This reduces alloimmune complications, such as febrile transfusion reactions (as well as transfer of infectious agents).