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.

Long-term results of placental blood allografting using reduced-intensity conditioning: multicenter experience in a developing country.

BACKGROUND: Placental blood (PLB) hematopoietic stem cell transplantation has recently been explored in an increasing number of patients; the best conditioning regimen has not been established. MATERIAL AND METHODS: In an eight-year period, 66 consecutive patients, both children and adults (40 males and 26 females), were grafted with allogeneic placental blood cells using a reduced-intensity conditioning regimen: 23 patients were grafted because of a non-malignant condition and 43 patients for a malignant disease. The median age was 7 years (range 5 months to 72 years). RESULTS: Median time to recover >0.5×10(9)/l granulocytes was 19 days, whereas median time to recover >20×10(9)/l platelets was 23 days. Thirty-eight individuals failed to engraft and they either recovered endogenous hematopoiesis or died. Patients have been followed for periods ranging from 0.5 to 66 months, median 9 months. The median overall post-transplant survival (OS) was 22 months and the 36-month OS was 32%; it was significantly better for individuals grafted with 6/6 matched cords (45%). The cumulative incidences of grade II-IV acute graft-versus-host disease (GVHD) and grade III-IV acute GVHD for the patients who engrafted were 33 and 10%, respectively. DISCUSSION: The low engraftment rate should be improved by selecting better cord blood units; additional studies are needed to define if non-myeloablative conditioning is preferable over conventional conditioning.