Excellent Outcome of Haploidentical Hematopoietic Stem Cell Transplantation in Children and Adolescents with Acquired Severe Aplastic Anemia

We evaluated the outcome of children and adolescents with acquired severe aplastic anemia (SAA) who received haploidentical hematopoietic stem cell transplantation (HHCT) with in vitro T cell–depleted peripheral blood stem cells. Twelve patients with acquired SAA received a total of 15 HHCTs with in vitro CD3-depleted grafts between July 2009 and July 2012. Among the 12 patients, 11 achieved neutrophil engraftment at a median of 10 days (range, 9 to 13 days) after HHCT. One patient failed to achieve primary engraftment, and two experienced graft rejection soon after engraftment. All three patients who experienced early graft failure received a second HHCT and achieved sustained engraftment. Thus, the final engraftment rate was 100%. Acute graft-versus-host disease was assessed in 9 patients, excluding the 3 patients with early graft failure. Three of these patients developed acute graft-versus-host disease (two ≥ grade II and one with grade III). All 12 patients survived and were transfusion-independent at a median follow-up of 14.3 months (range, 4.1 to 40.7 months). Hematopoietic stem cell transplantation from haploidentical family donors with in vitro CD3 T cell depletion is a reasonable therapeutic option for children and adolescents with acquired SAA. Our future trial with a uniform protocol will help to solve the problems associated with HHCT and provide a valuable platform for the further development of HHCT as a therapy for SAA.