Transfusion therapy in autoimmune hemolytic anemia.

Autoimmune hemolytic anemias include warm and cold reactive autoimmune hemolytic anemias (WAIHA and CAD), paroxysmal cold hemoglobinuria (PCH), and drug-induced hemolytic anemias. If autoimmune hemolytic anemia is suspected, the clinical history should be communicated to the transfusion service, because specific tests to confirm these diagnoses are not routinely performed. This includes evaluation of the patient's RBCs for bound IgG and complement (direct antiglobulin test) and evaluation of the patient's serum for antibodies with RBC specificity. For warm or cold autoimmune hemolytic anemia, special procedures including autoabsorption may be necessary to identify underlying RBC alloantibodies prior to transfusion. Transfused RBCs may not have normal survival in patients with RBC autoantibodies. The decision to transfuse should consider the patient's need for oxygen-carrying capacity, the risk of withholding transfusion, and the potential benefit of alternative therapy.