Risk factors in patients undergoing haploidentical hematopoietic stem cell transplantation for high-risk childhood acute leukemia.

In the present study, we sought to analyze the risk factors following haploidentical hematopoietic stem cell transplantation (haplo-HSCT) in children with high-risk acute leukemia. We retrospectively reviewed data from 73 children with high-risk leukemia. Univariate and multivariate analyses were performed to evaluate relationships between variables and patient outcomes. The mean time for neutrophil engraftment was significantly shorter in children given a graft with a higher number of nucleated cells (>10.13 × 108/kg vs ≤10.13 × 108/kg: 13.79 ± 2.73 vs 17.71 ± 3.90 days, P < 0.001) and in younger children (≤10 years vs >10 years: 14.21 ± 3.12 vs 17.71 ± 3.90 days, P < 0.001). Time to platelet engraftment was clearly shorter in children given a graft with higher number of nucleated cells (>10.13 × 108/kg vs ≤10.13 × 108/kg: 12.12 ± 8.62 vs 32.1 ± 24.83 days, P < 0.028). Overall survival was 64.6 ± 9.1%, 41.1 ± 10.1%, and 81.6 ± 9.6%, respectively, in children with HR-ALL in CR1, ALL in CR2-4, and AML (P = 0.012). The number of total nucleated cells was significantly associated with transplant-related mortality (TRM). We suggest that outcomes of haplo-HSCT may be improved by increased infusion of nucleated cells.