Multiple Alloantibodies after Transfusion in an Infant Treated with Infliximab

To the Editor: Infliximab (Remicade) is a humanized mouse monoclonal antibody that blocks tumor necrosis factor α. 1 It down-regulates type 1 helper T-cell (Th1) immune responses and increases type 2 helper T-cell (Th2) responses, thereby favoring antibody production. 2 There are many reports of autoantibody formation after the administration of infliximab, including a case of autoimmune hemolytic anemia. 1 We report on a 10-month-old boy who received infliximab for systemic-onset juvenile rheumatoid arthritis and who had a severe hemolytic transfusion reaction. At the time of his initial admission, the patient's hemoglobin level was 8.3 g per deciliter, and his hematocrit was 19.2%. . . .