Occur in 0.5% of RBC transfusions and 30% of platelet transfusions.
Febrile reaction may occur without hemolysis. Recipient antibodies directed against HLA antigens on donor WBCs or platelets are the most common cause, although cytokines released from WBCs of stored products (particularly platelets) may also be a cause. Relatively common in multitransfused or multiparous patients.
Clinically, febrile reactions consist of a temperature increase of ≥ 1° C, chills, and sometimes headache and back pain. This can take up to 2 hours to manifest. Simultaneous symptoms of allergic reaction are common. Because fever and chills also herald a severe hemolytic transfusion reaction, all febrile reactions must be investigated as with any transfusion reaction.
Most febrile reactions are treated successfully with acetaminophen and, if necessary, diphenhydramine. Patients should also be treated (eg, with acetaminophen before future transfusions. If a recipient has experienced more than one febrile reaction, special leukoreduction filters are used during future transfusions; many hospitals use prestorage, leukoreduced blood components.