[Clinical study on haploid HLA-matched hematopoietic stem cell transplantation for treatment of malignant hematological disease].

Background & Objective: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the most effective method to treat malignant hematological disease. However the human leukocyte antigen (HLA)-matched sibling donors can be found for only 25%-30% patients. The probability of finding an unrelated matched donor is 1/50000-1/100000, or even lower. If we choose haploid HLA-matched hematopoietic stem cell transplantation instead, we may be able to find donors for 90% patients. Our present study was to explore the feasibility of allo-HSCT by using haploid HLA-matched donor in treatment for malignant hematological disease.

Methods: Twenty-five patients with malignant hematological disease received allo-HSCT with HLA 2 or 3 antigen mismatched related donors. All patients were treated with intensive immunosuppression, granulocyte colony stimulating factor (G-CSF) mobilization, antithymocyte globulin (ATG) and combination of bone marrow and peripheral blood stem cell transplantation. The conditioning regimen was intensified and prolonged by using the combination of cyclosporine (Cs) A, MMF, ATG and anti-CD25 antibody for graft-versus-host disease (GVHD) prophylaxis.

Results: All patients achieved sustained, full donortype engraftment. Acute GVHD occurred in 21 of 25 patients. Eight of them were grade I aGVHD, six grade II aGVHD, two grade III aGVHD and five grade IV aGVHD. The cumulative incidence of grade II-IV aGVHD was 48%,and grade III-IV aGVHD was 28.57%. Chronic GVHD was observed in 12 of 25 patients and none of them developed extensive cGVHD. Sixteen patients were alive and disease free, with 64.0+/- 2.98% 1 year disease-free survival rate. One year overall survival rate was 64.0+/-3.08%. Nine patients died, 1 from relapse and 8 from transplantation related mortality.

Conclusions: Haploid HLA-matched allo-HSCT is a relatively efficient method for the treatment of patients with malignant hematological disease, who have no related matched donors. Nevertheless, strict administration should be carried out since it's a high risk approach.