Objective: To investigate the safety and effectiveness of HLA-mismatched allogeneic hematopoietic stem cell transplantation (allo-HSCT) combined with related haploidentical bone marrow infusion for treatment of hematologic malignancies and to explore the mathod for reduction of aGVHD incidence and clinical significance.
Methods: A total of 30 patients with hematologic malignancies (8 cases of AML, 17 AML, 2 MDS and 3 Mix-AL) received related haploidentical and unrelated HLA-mismatched allo-HSCT combined with related haploidentical bone marrow infusion. Among them 20 cases received related haploidentical transplantation of the first donor, 10 cases received unrelated HLA-mismatched treaplantation. The new conditioning regimen for the patients underwent allo-HSCT consisted of fludarabine, busulfan, Me-CCNU and cyclophosphamide. The drugs for GVHD prophylaxis included cyclosporine A and methotrexate, while mycophenolate mofetil and rabbit anti-T-lymphocyte globulin (ATG) were used.
Results: All the patients achieved full engraftment. The median time for neutrophils to reach over 0.5 × 10(9)/L was 14 days (8-26 days), while the median time for platelets to reach over 20 × 10(9)/L was 11.5days (10-24 days). The incidence of I-II grade of aGVHD at 100 d was 22.28% (95% CI 9.9%-34.7%), the incidences of II-IV and III-IV grade of aGVHD were 22.7% (95% CI, 10%-35.4%) and 12.7% (95% CI 6.9%-15.5%) respectively. The incidences of I-II and III-IV cGVHD were 13.3% (95% CI, 1.4%- 26.8%) and 3.3 % (95% CI, 0%-12.2%), one case (3.3%) was in extensive cGVHD. DFS and OS of 2 years were 81.1% (95% CI, 66.0%-96.2%) and 68.2% (95% CI 51.0%-85.4%).
Conclusion: These data suggest that the incidence of grade II-IV grade of aGVHD in recipients of 2 partially HLA-matched units was lower, co-infusion of haplo-BM and partially matched units in allogeneic transplantation is safe and effective for reducing the incidence of aGVHD and improving the survival in DFS.