[Clinical analysis of predictive factors for the response to antithymocyte globulin in patients with aplastic anemia]

We report the results of a retrospective study of antithymocyte globulin (ATG) treatment in 17 adult patients with aplastic anemia (AA). We evaluated 24 ATG treatments which included re-treatment with ATG in patients who had not responded to the first ATG treatment or who had relapsed after the first remission. The median age was 66 years, and the median follow-up period was 52 months. The response and relapse rates of ATG treatment were 70.8% and 23.1%, respectively. The response rate of ATG re-treatment was 57.1%. Overall survival and event-free survival at 10 years were 66.7% and 50.7%, respectively. The shorter duration from diagnosis to ATG treatment, the higher reticulocyte count before ATG treatment, and being female independently correlated with the efficacy of ATG treatment. Two patients developed monosomy 7 clonal abnormality. These results suggest that ATG treatment can achieve a high response rate and long-term survival among patients with adult AA. However, we have to pay attention to the development of the clonal diseases.