Feasibility of an outpatient HLA haploidentical stem cell transplantation program in children using a reduced-intensity conditioning regimen and CD3-CD19 depletion.

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) has been developed as an alternative transplant strategy for children with hematological disorders who do not have an HLA-matched donor. We report the analysis of the outcome for 18 consecutive pediatric patients with various hematological diseases, who underwent haplo-HSCT using a reduced-intensity conditioning regimen and CD3/CD19 depletion in an outpatient setting. Twelve of the 18 patients (66.6%) engrafted either transiently or definitively (9 patients engrafted with full donor chimerism and 3 with mixed chimerism). Six patients with acute lymphoblastic leukemia were disease-free between 2 and 35 months (median 25 months) post-HSCT. The overall survival was 33.3% with a median of 25 months (range 2-35). Our results suggest that haplo-HSCT can be a feasible therapeutic alternative for children who do not have a suitable family donor or available cord blood units. These results also demonstrate that it is possible to perform this regimen on an outpatient basis.