ABO blood group system, transfusion reactions

Synonyms

Immunologic blood tranfusion reactions.

Definition

There are several types of transfusion reactions which include febrile nonhemolytic, acute hemolytic, delayed hemolytic, anaphylactic and urticarial. These occur in 1–6% of all blood transfusions and are more common in patients with pre-existing oncologic or hematologic disorders. Febrile nonhemolytic transfusion reactions are the most common type of transfusion reaction and are believed to be caused by cytokines (i.e. IL-1, IL-8 and TNF-α). These cytokines are present in stored blood products and increase over time. Also possible is an interaction between donor leukocytes and recipient antibodies which might cause the release of IL-1, resulting in a fever during the transfusion. These transfusion reactions can also occur after platelet transfusions and thus, another proposed etiology involves the release of platelet-derived CD154 (CD40 ligand), which is capable of producing proinflammatory cytokines from...