Outcomes after bone marrow versus peripheral blood haploidentical hematopoietic cell transplantation using post-transplant cyclophosphamide-based graft-versus-host disease prophylaxis.

BACKGROUND: This study aims to compare the outcomes of bone marrow (BM) to peripheral blood stem cells (PBSC) grafts in haploidentical hematopoietic cell transplantation using post-transplant cyclophosphamide-based graft-versus-host disease (GvHD) prophylaxis. METHODS: A single-center retrospective analysis of all adult patients who underwent haploidentical transplants with at least one year of follow-up was conducted. Bivariate analyses were performed using chi-square tests and t-tests. Data were analyzed using SPSS with statistical significance being defined at p-value <0.05. RESULTS: The study included 176 transplant recipients: 65 % received PBSC and 35 % received BM grafts. After a median follow-up of 21 months (range: 0-73 months), neither median overall survival nor disease-free survival had been reached. One-year overall survival (BM 75 % versus PBSC 74 %; p-value = 0.898) and one-year disease-free survival (63 % both groups; p-value = 0.994) were similar between groups. PBSC recipients exhibited earlier neutrophil engraftment (17 days versus 18 days; p-value = 0.022). The incidence of cytokine release syndrome was higher in PBSC (90 % versus 37 %) grafts (p-value <0.001). The incidences of Grade II-IV acute GvHD, relapse, non-relapse mortality, platelet engraftment, one-year chronic GvHD, and GvHD-free relapse-free survival were similar across both groups. CONCLUSIONS: Haploidentical HSCT recipients observed similar outcomes regardless of graft source. Marginally faster neutrophil engraftment was observed in PBSC recipients. These findings suggest flexibility in using graft source for haploidentical transplants, though prospective studies are needed to confirm these results.