Impact of CD34+ cell dose on reduced intensity conditioning regimen haploidentical hematopoietic stem cell transplantation

摘要

Abstract Objectives Haploidentical hematopoietic stem cell transplant (haplo‐SCT) has been associated with higher rates of graft rejection, and a higher dose of CD34+?cell dose is frequently requested. We aim to explore the impact of CD34+?cell dose in peripheral blood stem cell (PBSC) grafts using reduced intensity conditioning (RIC) in haplo‐SCT. Methods Sixty‐eight consecutive haplo‐SCT in adult patients were included. Graft‐vs‐host disease (GVHD) prophylaxis consisted on ATG, PTCy, and CsA. The cohort was divided in two groups using CD34+?dose of?≥?9?×?10 6 CD34+/Kg as cutoff point. Median follow‐up was 8.9?months. Results Median cell dose infused was 9.32?×?10 6 CD34+/Kg. Forty (58.8%) recipients received grafts with CD34+?cells ≥9?×?10 6 /kg. The infusion?≥?9?×?10 6 CD34+/Kg cell dose had a negative impact in overall survival ( P ?=?.03) after adjusting for age at transplant. The cumulative incidence of acute GVHD and graft failure were not significantly influenced per CD34+?cell dose. Only four recipients had grade III aGVHD, and all of them received grafts with a CD34+?cell dose?≥?9?×?10 6 . Conclusion In RIC haplo‐SCT, recipients may not benefit from PBSC grafts with a CD34+/kg cell dose higher than 9?×?10 6 cells/kg, as it can have an adverse impact in post‐transplant outcome.