Clinical evaluation of haploidentical hematopoietic combined with human umbilical cord-derived mesenchymal stem cells in severe aplastic anemia

Background: This study not only evaluated the clinical effects of treatment using haploidentical hematopoietic stem cells (haplo-HSCs) combined with human umbilical cord mesenchymal stem cells (UC-MSCs) in patients with severe aplastic anemia (SAA), but also investigated the factors related to graft versus host disease (GVHD). Methods: Cotransplantation of haplo-HSCs and UC-MSCs was performed in 24 SAA patients. The conditioning regimens consisted of rabbit anti-human T-lymphocyte immunoglobulin (ATG), cyclophosphamide, and fludarabine with or without busulfan. GVHD was prevented using cyclosporine A, ATG, anti-CD25 monoclonal antibody, and mycophenolate material. Results: The incidence of acute GVHD was 50%. The incidence of severe acute GVHD was not related to gender, age, donor-recipient relations, and patient/donor pair, while patient/donor pair (r = 0.541, P = 0.022) was significantly correlated with incidence of chronic GVHD. Upon follow-up for a median of 13 months, 5 of the 24 patients (20.8%) were dead. The survival rates at 3 and 6 months in all patients were 87.5% (21/24) and 83.3% (20/24), respectively. Conclusion: Cotransplantation of haplo-HSCs combined with UC-MSCs was an effective and safe approach for the treatment of patients with SAA. The appropriate conditioning regimen and early treatment for infection also played a critical role in the success of HSCT.