[Development of severe aplastic anemia during steroid therapy for autoimmune hemolytic anemia].

A 50-year-old male patient was admitted for close monitoring of anemia (hemoglobin level, 5.0 g/dl). Autoimmune hemolytic anemia (AIHA) of warm type was diagnosed based on the elevated reticulocyte and bone marrow erythroblast counts, elevated indirect bilirubin level, serum haptoglobin level below the detection limit, and positive direct Coombs test result. The patient responded to prednisolone 60 mg/day (1.0 mg/kg); however, pancytopenia was observed during gradual dose tapering and maintenance therapy. The bone marrow showed remarkable hypoplastic findings, and magnetic resonance imaging scans of the thoracolumbar spinal cord showed an overgrowth of the adipose tissue. Thus, the patient was diagnosed with aplastic anemia (AA) stage 4. He was successfully treated with a combination of immunosuppressive therapy (anti-thymocyte globulin +cyclosporine), which allowed him to reduce his dependence on transfusions. However, the direct Coombs test result remained positive even after hematopoietic recovery. Aplastic anemia following AIHA treatment is extremely rare and has not been reported previously.