抄録
Megaloblastic bone marrow was observed in a 26 years old women suffering from idiopathic thrombocytopenic purpura after 10 days administration of azathioprine (100mg per day). Serum and red cell folate levels were within normal limits. Administration of 10 mg of folic acid did not improve the megaloblastosis of the marrow. Merely discontinuation of azathioprine brought disappearance of the megaloblastosis dramatically. This is the first case of megaloblastic anemia induced by azathioprine in Japan.