Fatal Immune Hemolytic Anemia and Hepatic Failure Associated with a Warm‐Reacting IgM Autoantibody

Abstract. Autoimmune hemolytic anemia (AIHA) caused by warm‐reacting IgM autoantibodies is rare. We report a fatal case of primary AIHA with a warm‐reacting IgM autoantibody. Recurrent episodes of intravascular hemolysis, unresponsive to all therapy and progressive hepatic dysfunction characterized the patient's clinical course. Despite corticosteroid therapy, splenectomy and multiple blood transfusions, the patient died from liver failure. The IgM autoantibody caused autoagglutination of the patient's red cells at 37 °C. Eluates prepared from the patient's red cells agglutinated saline‐suspended test cells without the addition of antiglobulin reagent. We propose that warm‐reacting IgM antibodies may lead to in vivo autoagglutination and may be associated with hepatic failure.