The role of mesenchymal stem cells in allogeneic hematopoietic stem cell transplantation for patients with refractory severe aplastic anemia

Objective To evaluate the efficacy and safety of mesenchymal stem cells in allogeneic hematopoietic stem cell transplantation for patients with refractory severe aplastic anemia (R-SAA) . Method The clinical data of 25 R-SAA patients receiving co-transplantation of mesenchymal stem cells combined with peripheral blood stem cells from sibling donors (10 cases) and unrelated donors (15 cases) from March 2010 to July 2018 in Zhengzhou University Affiliated Tumor Hospital were retrospectively analyzed. Antithymocyte globulin (ATG) treatment was ineffective/relapsed in 11 cases, and cyclosporine (CsA) treatment ineffective/relapsed in 14 cases. Results There were 13 male and 12 female among these patients. One patient had a primary graft failure, one patient had a poorly engraftment of platelets, and the remaining 23 patients achieved hematopoietic engraftment. The median time of granulocyte engraftment was 12.5 (10-23) days and 15 (11-25) days for megakaryocyte. Incidences of grade Ⅰ/Ⅱ acute graft-versus-host disease (aGVHD) and chronic graft-versus-host disease (cGVHD) were 37.5% (9/24) and 21.7% (5/23) , respectively. There was no severe GVHD and no severe complications that related to transplantation. 21 of 25 (84%) patients were alive with a median follow-up of 22.9 (1.6-107.8) months. The 5-year overall survival rate after transplantation was (83.6±7.5) %. Conclusion The combination of mesenchymal stem cells is reliable and safe in the treatment of R-SAA in peripheral blood stem cell transplantation of unrelated donors and sibling donors, which could significantly reduce the incidence of GVHD and severe transplantation-related complications. Key words: Mesenchymal stem cell; Peripheral blood stem cell; Severe aplastic anemia