Antilymphocyte Globulin Therapy for Aplastic Anemia in Children

ABSTRACT

Immunosuppressive therapy based on the use of antilymphocyte globulin (ALG) has become standard therapy for patients with splastic anemia who are not eligible for bone marrow transplantation. In this study, T cell subsets before and after ALG therapy, hematologic responses, complications and prognostic factors were analysed. Eleven (42%) out of twenty-six patients treated with ALG showed response, but two patients showed relapse. Most of the response (9 cases) was noticed within 6 months after the initiation of ALG therapy (median 3 months). The main complications of ALG therapy were fever (91%), thrombocytopenia (86%), neutropenia (63%), and serum sickness (56%). Four patients were died just ALG therapy because of serum sickness (2 cases), intracranial hemorrhage (1 case), and shock (1 case). Short interval from diagnosis to treatment suggested to show good response (P=0.0575), but it was not significant statistically. Lymphocyte subsets were measured in the blood of 23 patients. Helper T/suppressor T cell ratio (T4/T8 ratio) at the initiation of ALG therapy (day 0) was higher significantly in patients who were responded (P=0.0299). The patients who showed above 1.0 of T4/T8 ratio on day 0 might be speculated good response (P=0.032). More difference of T4/T8 ratio between day 14 after ALG therapy and day 0 might show good response (P=0.0673). Then the actuarial probability of survival at 3 years in patients treated with ALG was 77%. Our data suggest that ALG therapy may be used as an alternative treatment to bone marrow transplantation, and T4/T8 ration of peripheral blood at the initiation of therapy may be used as one of the prognostic factors.