Abstract:

BACKGROUND: Hemopoietic stem cell transplantation is the preferred method for the young patients with severe aplastic anemia (SAA), but most patients with SAA without a suitable donor in China. Haploidentical or unrelated hemopoietic stem cell transplantation is still at the exploratory stage at home and abroad, the reports addressing hemopoietic stem cell transplantation combined with mesenchymal stem cell transplantation are rare.
OBJECTIVE: To observe the efficacy for SAA with stem cell from related/unrelated and/or hemopoietic stem cell transplantation.
METHODS: A total of 10 patients aged 3-52 years with SAA were treated with related HLA-matched (n=2), haploidentical (n=5), unrelated peripheral blood and/or bone marrow hematopoietic stem cell transplantation (n=3), including 5 patients were treated with mesenchymal stem cell co-transplantation. The conditioning regimen mainly included cyclosphosphamide (CY), fludarabine (Flu), and anti-thymocyte globulin (ATG), mycophenolate mofetil, cyclosporin A and short course of methotrexate (MTX) to prevent graft-versus-host disease (GVHD). Patients with haploidentical were treated with myleran and CD25 monoclonal antibody based on the above basis. The conditioning regimen of 5 patients with homogenic is ATG + methylprednisolone. The volume of infusion of mesenchymal stem cells is (0.27-1.85)×10⁶/kg. Patients treated or not treated with mesenchymal stem cell transplantation, transfusion hematopoietic stem cells of them are nucleus cells (7.4-17.38) ×10⁸/kg and (6.09-13.68) ×10⁸/kg, respectively.
RESULTS AND CONCLUSION: Except 1 case was a not successful haploidentical transplant patient and died of complications at 36 days, the chromosome and DNA fingerprint detection after transplantation in the remaining patients showed the donors completely received hematopoietic stem cell transplantation. The volume of neutrophil reached 0.5×10⁹ L^-1 after transplantation, blood platelets count ≥20×10⁹ L^-1, the median time was 12 days and 13 days. The trend of hematopoietic function recovery speed was homogenic transplantation > peripheral blood and/or bone marrow mesenchymal stem cell transplantation > simple peripheral blood and/or bone marrow stem cell transplantation, while the hematopoiesis recovery of the 52-year-old patient with related HLA-matched is the lowest. Case 1 and case 6 with unrelated peripheral blood and/or bone marrow hematopoietic stem cell transplantation suffered gradeⅠacute GVHD, case 2 and case 10 with haploidentical transplantation suffered circumscribed chronic GVHD after gradeⅡ acute GVHD, the quality of life in the remaining patients is good after transplantation, without chronic GVHD. In addition to case 3 suffered severe infection who was not received mesenchymal stem cell transplantation, the remaining patients were not suffered severe infection and hemorrhage after transplantation. The results suggested that hematopoietic stem cells are safe and effective treatment of refractory severe aplastic anemia, which combined with mesenchymal hematopoietic stem cells, rapid hematopoietic recovery and few transplant complications in patients.