OBJECTIVETo observe the therapeutic effect and major complications of haploidentical nonmyeloablative allogeneic peripheral blood stem cell transplantation (NST) for refractory or relapsed leukemia.

METHODSThe results of 30 patients, including 14 cases of acute myeloid leukemia (AML), 11 cases of acute lymphoblastic leukemia (ALL), 5 case of chronic myelogenous leukemia (CML) (accelerated and blastic phase) with refractory or relapsed leukemia (RF/RL) who underwent haploidentical NST from August 2000 to April 2009 were analyzed. The conditioning regimen consisted of fludarabine (flu), antithymocyte globulin (ATG), cyclophosphamide (CTX), total body irradiation (TBI) and cytarabine (Ara-C) or myleran (Bu). Graft-versus-host disease (GVHD) prevention programmes consisted of Cyclosporine (CsA), mycophenolate mofetil (MMF), CD25 monoclonal antibody combined with mesenchymal stem cells (MSC).

RESULTSTwenty six cases of patients were full donor engraftment and 4 cases mixed chimerism into full donor chimerism. The average duration of neutrophil >0.5×10⁸/L after NST was 11 (9-16) days, and platelet >20×10⁸/L 17 (12-60) days. Upon follow-up of 16 to 120 months, 12-month transplant-related mortality (TRM) was 46.7%, acute Ⅱ-Ⅳgraft-versus-host disease (aGVHD) incidence was 40.0%. The probability of 3-year disease relapse, EFS and overall survival (OS) rates were 16.7%, 46.2% and 50.0% respectively.

CONCLUSIONHaploidentical NST could improve OS and EFS of refractory or relapsed leukemia and reducce TRM to some extent.