Autoimmune Hemolytic Anemia Associated with an IgA Autoanti-Gerbich

A third patient with autoimmune hemolytic anemia due to autoantibodies against Gerbich antigens is described. The patient's serum contained strong hemagglutinating antibodies of the IgA plus IgG classes which reacted with all red blood cells (RBC) tested, but not with Gerbich-negative cells. Although the patient was typed as Gerbich positive, his serum failed to react with his own RBC, and the sensitization of his erythrocytes with autoantibodies was only demonstrable if eluates of his RBC were used. The failure of the autoantibodies to react with autologous RBC at the peak of hemolysis most likely reflects a weakening of Gerbich antigens during the course of autoimmune hemolytic anemia.