Nonmyeloablative allogeneic hematopoietic stem cell transplantation in 26 cases of hematological malignancies

The purpose of this study was to investigate the efficacy of non-myeloablative allogeneic stem cell transplantation (allo-NST) and its related technologies in hematological malignancies. 26 patients with hematological malignancies (acute leukemia 10, chronic myeloid leukemia 14, multiple myeloma 2) received allo-NST following conditioning regimens with fludarabine/cyclophosphamide/ATG in 14 cases or busulfan or melphalan/cyclophosphamide/ATG in 12 cases prior to infusion of 2 or 3 collections of G-CSF (600 microg/d) or G-CSF (300 microg/d) plus GM-CSF (300 microg/d) mobilized blood stem cell on the fifth day. A combination of cyclosporine A (CsA) and methotrexate (MTX) was administered for GVHD prophylaxis. Patients were eligible for donor lymphocyte infusion (DLI) (or donor stem cell infusion (DSI)) given in graded increments according to the chimeric formation and clinical feature. Generally, the dose of the first infusion was 1 x 10(7)/kg in 4th week post-transplantation. The engraftment analyses included the detection of microsatellite short tandem repeats (STRs), bcr/abl fusion gene, Philadelphia chromosome, HLA-locus analysis, sex chromosome and ABO blood type or blood subtype. The results showed that out of 26 patients, 22 (84.62%) were engrafted, 18/22 were full donor chimerism (FDC) up to now. Acute GVHD occurred in 3/26 (11.54%), while chronic GVHD was diagnosed in 6 out of 26 (23.07%) patients. The incidence and degree of infection and hemorrhage were low and slight. It is concluded that NST is a safe and effective therapy for hematological malignancies, whereas related technologies such as adaptation selected, conditioning regimen and transplantation immunotherapy should be studied further.