A Comparison of Clinical Outcomes of Non-T-Cell-Depleted (Non-TCD) Unrelated Donor Heamatopietic Stem Cell Transplantation (HSCT) and Non-TCD Haploidentical Related Donor HSCT.

Unrelated donor HSCT and haploidentical related donor HSCT have been evaluated as alternative transplant options for the approximately 70% of patients without an HLA-identical sibling donor. To compare the clinical outcomes between Non-TCD unrelated donor HSCT and Non-TCD haploidentical HSCT, we studied 55 patients with high-risk or advanced leukemia who underwent Non-TCD HSCT from unrelated or haploidentical related donors from June 2001 to May 2006. Group A including 25 patients received HLA-matched unrelated donor HSCT, group B, including the other 30 patients, received HLA-haploidentical family donor HSCT. 20 recipient/donor pairs were allele matched and 5 pairs were 1–2 alleles disparity mismatched in the group A, HLA-haploidentical family donors in the group B included mother (22 cases), sibling(5 cases) and offspring (3 cases). Patients with myeloid leukemia were conditioned with the regimen consisting of Simustine (MeCCNU) 250mg/m²×1day, Ara-c 4g/ m²×2days, busulfan (Bu) 4mg/kg×3days, and cyclophosphamide (Cy)1.8g/m²×2days, patients with lymphoblastic leukemia were conditioned with the regimen consisting of MeCCNU 250mg/m²×1day, total-body irradition(TBI) 8Gy×1day, Ara-c 4g/ m²×2days, and Cy 1.8g/m²×2days. 15 patients received Non-TCD bone marrow transplantation (BMT), and 10 patients received Non-TCD peripheral blood stem cell transplantation (PBSCT) in the group A. 17 patients received G-CSF-primed bone marrow grafts that had not been depleted ex vivo of T cells, and 13 patients received G-CSF-primed bone marrow grafts plus G-CSF-mobilized peripheral blood stem cell without ex vivo T cell depletion in the group B. Prophylaxis against GVHD was performed with cyclosporine (CSP), short-term methotrexate (MTX), and mycophenolate mofetil (MMF), some patients received the combination of CSP, MTX and MMF plus antithymocyte globulin (ATG). When GVHD developed, methylprednisolone(MP) was given at first, if the response was poor, anti-CD25 monoclonal antibody was given to the patients as quickiy as possible and CSP was replaced with tacrolimus. All patients of the group A and 29 patients of the group B were engrafted successfully. Acute GVHD grades III-IVoccurred in 10 and 11 patients in the group A and B, respectively(the cumulaitive incidence 40% vs 37.9%, P>0.05). 2 patients relapsed in each group (the actuarial probilities of relapse 8% vs 6%, P>0.05). The 2-year probabilities of event-free survival(EFS) for the group A and B were (58.7±5.9)% and (42.2±2.0)%, respectively (P>0.05). 10 patients of the group A and 17 of the group B died of transplantation- related disease. The primary causes of death included severe acute GVHD and pulmonary infection. These results suggested that both Non-TCD unrelated donor HSCT and Non-TCD haploidentical related donor HSCT are effective treatments for patients with refractory or high-risk hematologic malignancies, the high transplantation related mortality due to GVHD and infection is still a major challenge.