Demonstration of three distinct immunological disorders on erythropoiesis in a patient with pure red cell aplasia and autoimmune haemolytic anaemia associated with thymoma.

A patient with pure red cell aplasia (PRCA) and autoimmune haemolytic anaemia (AIHA), associated with a thymoma which had already been removed, was studied in order to investigate the pathogenesis of PRCA and AIHA. The autoantibody eluted from the surface of the patient's red blood cells (RBC) reacted with the large E antigen of the Rh complex. Immunoglobulin-G (IgG) purified from the patient's serum suppressed CFU-E and BFU-E but not CFU-GM colony formation in the presence of complement. This antibody was not adsorbed with large E antigen. T-lymphocytes in the bone marrow suppressing autologous CFU-E and BFU-E colonies were demonstrated. Thus, three distinct immunological disorders on erythropoiesis were present in this patient with PRCA and AIHA associated with thymoma in a thymectomized state.