A case report of refractory cytopenia of childhood effectively treated with low-dose rabbit anti-thymocyte globulin in immunosuppressive therapy

Abstract

Introduction: Although the anti-thymocyte globulin (ATG) formulation has been changed from horse to rabbit ATG [thymoglobulin (TG)], an optimal TG dose has not been established. We report here a case of refractory cytopenia of childhood (RCC) successfully treated with low-dose TG (LDTG). Case: A 2-year-old girl presented with high fever and petechia three weeks before hospitalization and showed pancytopenia (WBC count, 2,100/μL; Hb level, 4.6 g/dL; Plt count, 3,000/μL). After we diagnosed her as having RCC on the basis of bone marrow examination results, she received immunosuppressive therapy (IST) using LDTG (2.5 mg/kg/day for five consecutive days). She recovered from transfusion dependence after a month and showed complete remission six months after the initiation of IST. Conclusion: IST using LDTG was effective for the treatment of pancytopenia; however, the long-term risk of relapse, clonal evolution and infection is still unclear. Further accumulation of cases is required to establish the optimal dose of TG.