Unmanipulated HLA-mismatched/haploidentical peripheral blood stem cell transplantation for high-risk hematologic malignancies

BACKGROUND: Haploidentical hematopoietic stem cell transplantation (HSCT) has been increasingly applied in high-risk hematologic patients due to the absence of HLA-matched donors. The aim of this study was to investigate the efficacy and safety of unmanipulated haploidentical allogeneic peripheral blood stem cells transplantation (PBSCT) for hematologic malignancies. STUDY DESIGN AND METHODS: Patients who underwent unmanipulated HLA-mismatched/haploidentical PBSCT from July 2007 to March 2010 with high-risk hematologic malignancies were enrolled for retrospective analysis. RESULTS: Twenty-one patients with high-risk hematologic malignancies underwent unmanipulated HLA-mismatched/haploidentical PBSCT with myeloablative conditioning. The numbers of CD34+ cells infused at transplantation were 4.81 (range, 2.61-11.47) x 106/kg. Patients achieved myeloid and platelet engraftment at a median of 16.5 and 20 days, respectively. The cumulative incidence of acute graft-versus-host disease (GVHD) on Day 100 was 52.7 +/- 10.7%, and the 2-year cumulative incidence of chronic GVHD was 39.5 +/- 10.6%. The cumulative incidences of cytomegalovirus antigenemia and hemorrhagic cystitis within 100 days after PBSCT were 59.5 +/- 16.7 and 34.8 +/- 13.3%, respectively. One hundred-day transplantation-related mortality (TRM) rate and the 2-year cumulative TRM rate were 14.3 and 20.5 +/- 7.8%, respectively. The 2-year cumulative overall survival was 62.1 +/- 11.4% and the probability of disease-free survival at 2 years was 55.6 +/- 10.7% with a 16-month median follow-up. CONCLUSION: Unmanipulated PBSCT is a promising protocol in HLA-mismatched/haploidentical transplant settings.