Comparison of Frontline Haploidentical Hematopoietic Stem Cell Transplantation and Salvage Haploidentical Hematopoietic Stem Cell Transplantation for Patients with Severe Aplastic Anemia

Abstract

To compare the clinical efficacy between frontline haplo-identical hematopoietic stem cell transplantation (haplo-HSCT) and salvage haplo-HSCT for patients with severe aplastic anemia (SAA). A total of 39 patients with severe aplastic anemia or very severe aplastic anemia from May 1st, 2013 to December 31st, 2018 were analyzed retrospectively. All of them underwent bone marrow + peripheral blood hemopoietic stem cell transplantation. There were 20 cases who accepted frontline haplo-HSCT for a median course of 1 (1-3) month, and 19 cases who accepted salvage haplo-HSCT for a median course of 72 (6-168) months. Conditioning regimen: 22 cases received Flu/Cy+ATG, and 17 cases received Bu/Cy+ATG. The time of hematopoietic reconstitution, infection rate, and grade I-Ⅱ and Ⅲ-Ⅳ acute/chronic graft versus host disease showed no statistically significance between the frontline haplo-HSCT group and the salvage haplo-HSCT group. In the frontline haplo-HSCT group, 1 case (5%) failed in second engraftment, in the salvage haplo-HSCT group 2 cases (10.5%) failed in primary engraftment and 4 cases (21.1%) in second engraftment. The incidence of engraftment failure was higher in the salvage haplo-HSCT group than that in the frontline haplo-HSCT group (P=0.04). The median time of follow-up after allo-HSCT was 45 months (ranging from 3 to 92). The mortality was 10% (2/20) in the frontline haplo-HSCT group, and 42.1% (8/19) in the salvage haplo-HSCT group. The estimated 5-year failure-free survival rate (FFS) of the frontline haplo-HSCT group was higher than that of the salvage haplo-HSCT group (90% vs 57.4%) (P=0.02). The frontline haplo-HSCT is an effective and safe approach for the patients with severe aplastic anemia who lack a HLA-matched sibling donor.