Immune response to chronic red blood cell transfusion

Patients receiving chronic transfusion for aplastic anemia or hemoglobinopathy are believed to be at high risk for developing red blood cell alloantibodies, while those undergoing chemotherapy for leukemia are believed to be at low risk. To test this hypothesis, we studied the acquisition of new alloantibodies in 703 transfused patients. While none of 99 patients with lymphocytic leukemia made new antibodies, patients with myelogenous leukemia (16%), hemoglobinopathy (29%), aplastic anemia (11%), gastrointestinal bleeding (11%) or renal failure (14%) made antibodies at statistically similar rates. Lymphocytic leukemia or its treatment is characterized by a lack of immunologic response to transfusion. Patients with hemoglobinopathy or aplastic anemia do not appear at statistically significant greater risk of alloimmunization than many other patients requiring chronic transfusion. Neither intensive chemotherapy for myelogenous leukemia nor the uremia of renal failure significantly suppress the formation of blood group antibodies.