]> 2026-07-31T12:14:40+00:00 WBR0508 0 en Plasma proteins in transfused blood Allergic transfusion reactions are due to activation of IgE-primed mast cells by plasma proteins found in the donor transfused blood. Cytokines from leukocytes in donor blood One of the mechanisms of non-hemolytic febrile transfusion reactions involves a reaction to cytokines produced by leukocytes in the donor blood. These cytokines do not invoke an allergic type I hypersensitivity reaction. Host antibodies against antigens on donor RBCs Transfusion ABO incompatibility is relatively uncommon, but still occurs due to medical errors. Hemolytic transfusion reactions due to ABO mismatch are caused by host antibodies against the main (A/B) antigens on donor RBCs. Host antibodies against donor MHC antigens Another main mechanism of non-hemolytic febrile transfusion reactions is host antibodies against donor MHC antigens found on leukocytes. This mechanism does not invoke an allergic reaction. It can be preveented by using leukocyte filters or blood irradiation. Host antibodies against donor IgA molecules The main etiology of anaphylaxis in patients undergoing transfusions is host antibodies against donor IgA molecules, particularly in patients who are IgA-deficient. These patients might have urticaria, but their symptoms are much more severe, and if untreated progress to cardiovascular collapse. Embryology Pathology A Reproductive 2020-10-28T00:48:08Z 2459150.5334259 WBR0508