Hematopoietic Stem Cell Transplantation in Patients with Severe Acquired Aplastic Anemia: Iranian Experience

Introduction: Severe acquired aplastic anemia (SAA) is a rare disease and matched related hematopoietic stem cell transplantation (HSCT) is the treatment of choice especially in pediatric patients. Immunosuppressive therapy is the alternative treatment in patients who do not have a donor. We retrospectively analyzed patients who received allogeneic HSCT at our institution. Methods: Between 1991 and 2011, 190 patients received allogeneic HSCT from HLA-matched donors (182 siblings and 8 other relatives). Median age was 20.5 years (range 1 to 50 years). The graft source was peripheral blood stem cells in majority of patients. Conditioning regimen consist with a myeloablative regimen containing cyclophosphamide with or without antithymocyte globulin. For graft-versus-host disease (GvHD) prophylaxis, we used cyclosporine with or without methotrexate at the standard doses. Results: The median follow-up time was 30 months and 3 year overall survival and disease free survival was 82% and 75% respectively. The median time to neutrophil engraftment and median time to platelet engraftment was 12 day and 15 day respectively. Grade 3 and 4 of aGvHD occurred in 26 (23.7%) patients and chronic GvHD occurred in 46 (29.1%) of survived patients 100 days after HSCT. At time of report 82.1% of patients were alive with normal hematologic parameters. The engraftment failure rate was about 8%. The most common cause of death was GvHD. Conclusions: However an available treatment in SAA is immunosuppressive therapy, HSCT should be seriously considered as a therapeutic option particularly if a matched sibling donor is available. The outcome of allogeneic HSCT in patients with SAA at our center was consistent with the result of other previous studies.