ABSTRACT
Objective To analyze the related factors of relapse of leukemia after transplantation of nonmyeloablative allogeneic hematopoietic stem cells. Methods Among the twenty-nine patients with acute leukemia who received transplantation of nonmyeloablative allogeneic peripheral blood stem cells, relapse of leukemia occurred in 5 patients. The nonmyeloablative protocol included the pretreatment of CD3 monoclonal antibody, cyclosporine A, cyclophosphamide, cytarabine, and fludarabine was added in 3 patients. Results All the 5 patients went through smoothly the hematopoietic suppression stage, and engraftment of the donor cells was successful. Leukemia relapsed in 4 patients with full donor chimerism (full donor chimerism was converted from the mixed chimerism in 2 patients), and relapse occurred in 1 patient with stable mixed chimerism. Except for 1 patient, all of them did not show acute GVHD or chronic GVHD. Second complete remission after double transplant was achieved in one patient, but leakemia relapsed in two months. In other four patients treatment was given up. Conclusion Transplantation of nonmyeloablative allogeneic peripheral blood stem cells is a safe and effective method for the treatment of acute leukemia.