[Acute monocytic leukemia following anti-lymphocyte immunoglobulin treatment in a patient with severe aplastic anemia]

A 57-year-old female, who had a 14-year history of rheumatoid arthritis, developed aplastic anemia. Treatment with anti-lymphocyte globulin (ALG) and methylprednisolone pulse therapy achieved complete remission. However, twenty months after ALG treatment she developed acute monocytic leukemia. In spite of the chemotherapy, consisting of cytosine arabinoside and etoposide, she died of pneumonia. Recently, reports from Western countries have claimed that patients with aplastic anemia frequently develop clonal disorders following ALG treatment. To our knowledge, this is the first report in Japan of a case developing acute leukemia following ALG treatment.