Effect of Antithymocyte Globulin Source on Outcomes of HLA-Matched Sibling Allogeneic Hematopoietic Stem Cell Transplantation for Patients with Severe Aplastic Anemia

We wanted to evaluate efficacy of porcine antithymocyte globulin (ATG) in HLA-matched sibling donor allogeneic hematopoietic stem cell transplantation (MSD-HSCT) for patients with severe aplastic anemia (SAA). The clinical data of 113 SAA patients who received MSD-HSCT from January 2005 to November 2016 were analyzed retrospectively. Of these, 58 patients received rabbit ATG as a part of conditioning regimen (R-ATG group), whereas the other 55 patients received porcine ATG (P-ATG group). Patient baseline characteristics and donor conditions of the 2 groups were similar, except patients were older and more received peripheral blood stem cell transplantation in the P-ATG group. All patients engrafted in 2 groups. There were significant differences in the incidence of acute (20.7% +/- 5.3% versus 43.4% +/- 7.0%, P =.015) and chronic graft-versus-host disease (GVHD; 20.1% +/- 5.8% versus 46.0% +/- 7.9%, P=.003) between the R-ATG and P-ATG groups. However, there were no significant differences in terms of 3-year overall survival (93.1% +/- 3.3% versus 84.4% 5.7%, P=.235), grades III to IV acute GVHD (3.4% +/- 2.4% versus 12.3% +/- 4.7%, P=.098), moderate to severe chronic GVHD (12.6% +/- 4.9% versus 11.5% +/- 4.9%, P=.905), or graft rejection (7.4% +/- 3.6% versus 5.5% +/- 3.1%, P=.852). There was also no significant difference with regard to the incidence of severe bacterial infection (P=.075), invasive fungal disease (P=.701), or cytomeglovirus viremia (P=.770). P-ATG showed satisfactory efficacy and safety compared with R-ATG in the setting of MSD-HSCT for SAA patients. P-ATG could be a potential alternative preparation for R-ATG, further offering the advantage of lower costs. (C) 2017 American Society for Blood and Marrow Transplantation.