BACKGROUND: The influence of different non-myeloablative conditioning regimens on clinical outcome remains undefined.

MATERIAL AND METHODS: We retrospectively analyzed the hematopoietic reconstitution, graft-versus-host disease (GVHD), and quality of life (QOL) in 56 patients with hematologic malignancies who underwent non-myeloablative stem cell transplantation (NST) with a conditioning regimen based on anti-thymocyte globulin (ATG), followed by donor lymphocyte infusion (n=24), or Fludarabine (FLU) (n=32). Hematopoietic stem cells were derived from low-resolution HLA-matched identical sibling donors.

RESULTS: The blood type transformation and platelet reconstitution presented significantly earlier in the FLU group than the ATG group (P<0.05). Within 100 days post-transplantation, the incidence of grade I-IV acute GVHD was significantly lower in the ATG group than the FLU group (P<0.05). After 100 days post-transplant, extensive chronic GVHD (cGVHD) was more prevalent in the ATG group than the FLU group (P<0.05). There were lower cumulative risk of relapse and higher non-relapse-related mortality in the ATG group, but better QOL in the FLU group within 24 months, and no difference in 3-year disease-free survival (DFS) or overall survival (OS) between the 2 groups (P>0.05).

CONCLUSIONS: The FLU-based conditioning regimen improved hematopoietic reconstitution and decreased extensive cGVHD, but there was no difference in 3-year DFS or OS between the 2 groups.

Keywords: Antilymphocyte Serum - therapeutic use, Adolescent, Child, Graft vs Host Disease - prevention & control, Hematologic Neoplasms - therapy, Immunosuppressive Agents - therapeutic use, Myeloablative Agonists - therapeutic use, Quality of Life, Transplantation Conditioning, Vidarabine - therapeutic use, young adult