Allogeneic stem cell transplantation for severe aplastic anemia: graft rejection remains a problem.

We reviewed the outcome in 15 consecutive patients with severe aplastic anemia with a median age of 23 years who received matched sibling peripheral blood stem cell transplantation. Conditioning regimen was cyclophosphamide (Cy)+anti-thymocyte globulin (ATG). Cumulative incidence of transplant related mortality, graft failure, acute and chronic GVHD were 20%, 33%, 25%, and 8.3%, respectively. Conditioning with Cy only, resulted in higher rejection rate compared to Cy plus ATG (75% versus 12.5%, p=0.03). Eighty percent of patients are alive with a median follow-up of 19.5 (4.6-35.6) months. Two of the three patients who were re-transplanted with fludarabine had sustained donor chimerism.