Haploidentical transplantation in pediatric non-malignant diseases: A
retrospective analysis on behalf of the Spanish Group for Hematopoietic
Background: We retrospectively analyzed the data of children with non-malignant diseases who have received a haploidentical hematopoietic stem cell transplant (haplo-HSCT). A total of 31 haplo-HSCT were performed in 26 pediatric patients using ex vivo T cell-depleted (TCD) graft platforms or post-transplantation cyclophosphamide (PT-Cy) from January 2001 to December 2016 in 7 Spanish centres. Procedure: A total of five cases were unmanipulated PT-Cy haplo-HSCT, sixteen received highly purified CD34+ cells, ten were ex vivo TCD graft manipulated either with CD3+CD19+ depletion (n= 1), TCΡαβ+CD19+ selection (n= 7) or naive CD45RA+ T cells depletion (n=2). Peripheral blood stem cells were the only source in patients following TCD haplo-HSCT, and bone marrow was the source for one PT-Cy haplo-HSCT. The most common indications for transplant were primary immune deficiency disorders (PIDs) 18, severe aplastic anemia (SAA) 4, osteopetrosis 2 and thalassemia 2. Results: The 1-year cumulative incidence of graft failure was 27.4 %. The 1-year III-IV acute graft versus host disease (aGvHD) and 1-year chronic graft versus host disease (cGvHD) were 34.6% and 16.7% respectively. Besides, the 2-year overall survival (OS) and the 2-year GvHD-free and relapse-free survival (GRFS) were 44.9% for PIDS and 37.6% for the other NMDs. The TRM at day 100 was 30.8%. Conclusions : These results are discouraged and need to be improved to offer a guaranteed treatment for these patients. Improvements will come if procedures are centralized in centres of expertise. The decision between T-cell depletion platforms will depend on the patients’ underlying diseases, comorbidities, and conditioning regimens.