Low mortality of children undergoing hematopoietic stem cell transplantation from 7 to 8/10 human leukocyte antigen allele-matched unrelated donors with the use of antithymocyte globulin.

Human leukocyte antigen (HLA)-matched sibling donor hematopoietic stem cell transplantation (HSCT) is available for only approximately 30% patients needing HSCT. Use of alternative donors is associated with a high incidence and severity of graft-versus-host disease (GVHD). Here we report our experience with GVHD prophylaxis using pre-transplant rabbit antithymocyte globulin (rATG), in addition to post transplant cyclosporin A and methotrexate. Seventy-five children received unmanipulated grafts from 7 to 10/10 HLA allele-matched unrelated donors. Median follow-up was 25 months (range, 6-65 months). Only 2/75 patients (2.5%) developed acute GVHD grades III-IV, and 17/75 (25%) developed extensive chronic GVHD. Overall survival was 79%. It was similar in patients receiving grafts from 7 or 8/10 to 9 or 10/10 allele-matched donors, and similar in patients receiving peripheral blood stem cells and marrow. Six (11%) patients died owing to relapse, and 10 (13%) due to transplant-related complications. The addition of rATG appears to result in a low incidence of severe GVHD and overall mortality.