A case of atypical hypoplastic anemia that responded to azathioprine is reported. The patient was a 30-year-old female who developed anemia in 1964. She had been treated with blood transfusions before she was admitted to our hospital in 1972, when a diagnosis of hypoplastic anemia was made. She was started on steroid hormone and ACTH with some improvement of pancytopenia. However, despite the same treatment, she gradually became pancytopenic (RBC 124×104/cmm, WBC 2,100/cmm and platelets 2.7×104/cmm) in November 1975. Therefore, in addition to the two drugs, she was placed on azathioprine 50mg/day and this regimen was continued until February 1977. With azathioprine there was a steady increase of RBC followed by some increase of WBC and platelets, as shown by RBC 316×104/cmm, WBC 3,600/cmm and platelets 11.7×104/cmm in April 1977.
The hematological remission obtained in this case appears to be related to azathioprine administered. The mechanism of action of immunosuppressive agents in hypoplastic anemia is discussed with respect to suppressor lymphocytes.
