Haploidentical, unmanipulated G-CSF-primed peripheral blood stem cell transplantation for high-risk hematologic malignancies: an update

Emerging data demonstrate promising results of related haploidentical allogeneic hematopoietic stem cell transplantation (haplo-HCT) for the treatment of hematologic malignancies. Data about G-CSF primed PBSC as reliable source of graft with myeloablative conditioning are lacking. We updated the outcomes in 130 adult patients with high-risk hematologic malignancies who received haplo-PBSC transplantation consecutively under busulfan-based conditioning. PBSC were freshly isolated and infused without ex vivo T-cell depletion into the recipients. Myeloid recovery was achieved in 99.2% patients with full donor chimerism. The cumulative incidence of acute grade 3-4 GvHD, overall and extensive chronic GvHD was 14.9%, 38.6% and 16.5%, respectively. The 3-year non-relapse mortality rate was 24.1%. Non-remission prior to transplant was associated with higher incidence of relapse (P=0.006), inferior overall survival (P=0.017) and leukemia-free survival (P=0.024). These data suggest that PBSC is a reliable graft source in haploidentical, unmanipulated transplant settings under myeloablative conditioning in patients with high-risk hematologic malignancies.