Clinical Researches Of HLA Haploidentical And Matched Allogeneic Hematopoietic Stem Cell Transplantation In Treatment Of Hematological Malignancies

Background and ObjectiveAllogeneic hematopoietic stem cell transplantation(allo-HSCT) is a very effective method in treatment of hematologic malignancies. It requires for HLA typing. But only a hand of people can find a HLA-identical donor. Haploidentical-HSCT can expand the application of transplantation.In this paper, we observe and compare the clinical efficacy of HLA haploidentical and sibling HLA-matched allo-HSCT in our hospital on the treatment of hematologic malignancies.Materials and MethodsWe retrospectively analyzed outcomes in79patients with hematologic malignancies who received allogeneic hematopoietic stem cell transplantation in our hospital from August,2006to March,2011, including26patients with related HLA-mismatched donors and53patients with HLA-matched sibling, and compared two groups of the time of hematopoietic reconstitution, incidence of graft versus host disease (GVHD), recurrence rate,2-year survival rate,etc. All patients received "modified Bu/Cy" in HLA-identical sibling HSCT, antihuman thymocyte globulin was added for the patients with haploidentical donors. Methotrexate, cyclosporine A, and mycophenolate mofetil were used to prevent graft-versus-host disease (GVHD). Statistical analysis was executed by SPSS17.0softwares,a value less than0.05was considered as significance.Results78patients achieved full engraftment,but a patient died of severe infection without engraftment at+28d after transplantation. The median time to reach an absolute neutrophil count above0.5x10~9/L was13(9-20) days and that to a platelet count exceeding20×l0~9/L without transfusing platelet for three consecutive days was15(10-68) days in26HLA-haploidentical patients, and that was13(9-17) days and13(9-45) days in53HLA-matched patients, respectively. In26HLA-haploidentical patients,13patients (50.0%) developed grade Ⅱ～Ⅳ acute graft-versus-host disease (aGVHD). In patients with follow-up of more than100days,11/23(47.8%) developed chronic GVHD(cGVHD).3patients(11.5%) relapsed. Transplant-related mortality (TRM) was34.6%. The rate of2-year adjusted disease-free survival(DFS) was (40.6±12.7)%,2-year overall survival(OS) was (50.7±l.l)%. In53HLA-matched patients,14patients(26.4%) developed grade Ⅱ～Ⅳ aGVHD.21/51patients (41.2%) developed cGVHD.13patients(24.5%) relapsed. TRM was7.5%. The rate of2-year adjusted disease-free survival(DFS) was (62.1±6.9)%,2-year overall survival(OS) was (72.0±6.4)%. The incidence of aGVHD in HLA-haploidentical cohorts was significantly higher than in HLA-matched cohorts(.P<0.05).2-year OS in HLA-haploidentical cohorts was lower due to higher transplant-related mortality. There was no significant difference in incidence of cGVHD, incidence of relapse and DFS between HLA-haploidentical and HLA-matched cohorts(P>0.05).Conclusion1The effect of haploidentical HSCT was similar to HLA-matched HSCT in treatment of hematologic malignancies,but the incidence of aGVHD and transplant-related mortality were higher. 2It is the haploidentical hematopoietic stem cell transplantation with "modified Bu/Cy+ATG" conditioning regimen that is a feasible and effective approach in treatment of high-risk and refractory hematologic malignancies, without a HLA-matched related or unrelated donor. Nonetheless, cautious administration should be carried out since it’s a high risk approach.