[A comparative study of unrelated donor and matched-sibling donor allogeneic hematopoietic stem cell transplantation in children and adolescents with acquired severe aplastic anemia].

To evaluate the efficacy of unrelated donor allogeneic hematopoietic stem cell transplantation(URD allo-HSCT) for children and adolescents with severe aplastic anemia (SAA). Clinical data of 34 SAA children and adolescents undergoing allo-HSCT were retrospectively analyzed from October 2001 to October 2015. According to the source of donor, the patients were divided into matched sibling donor allo-HSCT group (MSD group) and unrelated donor group (URD group). The clinical outcome of SAA children and adolescents receiving URD allo-HSCT was assessed, and patients in MSD allo-HSCT group were enrolled as control at the same period. The rate of hematopoietic reconstitution, the time of neutrophil and platelet engraftment, incidence of chimerism and graft rejection between two groups were not statistically different.The incidence of acute graft-versus-host disease (GVHD) in URD group was significantly higher than that in MSD group [42.9%(6/14) vs 10.5%(2/19), =0.047]. The incidence of grade Ⅱ-Ⅳ acute GVHD and chronic GVHD in URD were higher than those in MSD group [21.4%(3/14) vs 5.3%(1/19), =0.288; 35.7%(5/14) vs 5.3%(1/19), =0.062, respectively], yet without significant difference between two groups. Other transplant-related complications including pulmonary complications, hemorrhagic cystitis, incidence of EBV and CMV reactivation and venous occlusive disease were comparable with two regimens. Estimated 5-years overall survival (OS) rate and disease free survival (DFS) rate were not statistically significant between URD group and MSD group [(84.4±6.6)% vs (89.4±7.1)%, (82.5±5.4)% vs (82.1±4.3)%; =0.766, =0.884, respectively]. By multivariate analysis, the outcome of URD allo-HSCT in SAA children and adolescent is similar to MSD allo-HSCT. It could be an alternative option as the first-line treatment for SAA children and adolescents without HLA matched sibling donors.