A comparison of clinical outcomes between unrelated donor and HLA-haploidentical donor hematopoietic stem cell transplantation

Objective: To compare the clinical outcomes between unrelated donor hematopoietic stem cell transplantation (URD-HSCT) and HLA-haploidentical (Hi)-HSCT.

Methods: Twenty-five patients with hematologic malignancies received URD-HSCT and thirty patients received Hi-HSCT. The conditioning regimen consisted of modified BUCY or modified total body irradiation (TBI) plus CY. Acute graft-versus-host disease (aGVHD) prophylaxis consisted of cyclosporin ( CsA), short-term methotrexate (MTX), mycophenolate mofetil (MMF), or the combination of CsA, MTX and MMF plus antithymocyte globulin (ATG) or antilymphocyte globulin (ALG), or the combination of CsA, MTX, MMF, ATG/ ALG and CD25 monoclonal antibody.

Results: All patients in the URD-HSCT group and 29 patients in the Hi-HSCT group were engrafted successfully. The median follow-up duration was 7 (2 -59) months for URD-HSCT group and 7.3 (1 - 35) months for Hi-HSCT group. The 3-year probabilities of disease-free survival (DFS) for URD-HSCT and Hi-HSCT group were (54.1 +/- 11.9)% and (43.1 +/- 9.1)%, respectively (P =0.13). Grade III - IV aGVHD occurred in 10 patients in URD-HSCT group and 11 in Hi-HSCT group (the cumulative incidence 40.0% vs 37.9%, P > 0.05), respectively. Ten patients (40.0%) died of transplantation-related mortality (TRM) in URD-HSCT group and 17 (56.7%) in Hi-HSCT group (P >0. 5). Two patients relapsed in each group (the rate of relapse 8.0% vs 6.0%, P >0.05). The primary causes of death included severe aGVHD with infection,severe pulmonary infection and relapse.

Conclusions: Both URD-HSCT and Hi-HSCT are effective and curable treatment for refractory or high-risk hematologic malignancies. The optimal donor should be chose individually. The severe aGVHD and consequent infection are still the main cause of TRM.