Prognostic factors and outcomes for pediatric patients receiving an haploidentical relative allogeneic transplant using CD3/CD19-depleted grafts.

Haploidentical hematopoietic stem cell transplantation using T-cell-depleted grafts is a valid option for pediatric patients with hematological malignancies in need of an allogeneic transplantation and lacking an HLA-identical donor. Seventy-five transplantations were performed in 70 patients. Thirty-eight patients had ALL, 32 had AML, 3 had advanced myelodysplastic syndromes and 2 juvenile myelomonocytic leukemia; 19 were in first CR, 30 in second CR, 12 in greater than second CR and 14 were considered to be in refractory disease at time of transplantation. Four patients developed graft failure. Among engrafted patients, the median time to neutrophil and platelet recovery was 13 (range 8-20) and 10 days (range 8-70), respectively. In 64 (85%) cases, ⩾1 infections were diagnosed after transplant. The probability of nonrelapse mortality by day +100 after transplantation was 10±4%. With a median follow-up of 22 months, the probability of relapse was 32±6% and disease-free survival was 52±6%. Haploidentical transplantation using CD3/CD19 depletion is associated with encouraging results especially in patients in early phase of disease. Killer-cell Ig-like receptor B haplotype donors confer a rapid natural killer cells expansion early after transplantation, resulting in lower probability of relapse and suggesting a GvL effect apart from graft-versus-host reactions. Donor infusion of high numbers of CD34+ cells is recommended in order to improve T-cell reconstitution.