Impact of CD34 Positive Cell Dose on Engraftment in Patients with Acute Leukemias receiving Allogeneic Stem Cell Transplant

Abstract

Objective: To evaluate the impact of CD34+ cell dosing and transplant type on engraftment measures, complications, and survival in a resource-limited setting.

Methodology: A retrospective cross-sectional study was conducted on 70 patients (Matched: 61.4%; Haploidentical: 38.6%) diagnosed with acute leukemia at a tertiary care center in Pakistan (2016–2023). Variables included CD34+ dose, engraftment timing, GVHD incidence, and 5-year survival, reported as per STROBE guidelines.

Results: The mean CD34+ dose was 8.8*10^6/kg. Neutrophil engraftment was faster in matched transplants (13.7 vs. 16.1 days), though haploidentical grafts showed a higher cumulative success rate (92.6%). Pediatric patients received the highest CD34+ doses and achieved the fastest platelet recovery (9.7 days). At Day 100, successful neutrophil recovery was higher in the matched group (62.7% vs. 48.1%). Acute GVHD and graft failure were more frequent in the haploidentical cohort (37.0% and 25.9%, respectively), while chronic GVHD was higher in matched recipients (18.6%). The 5-year survival was 30.2% for matched and 14.8% for haploidentical transplants, significantly perplexed by high attrition rates (20.9% and 37% lost to follow-up).

Conclusion: Higher CD34+ dosing correlates with enhanced hematopoietic recovery, particularly in pediatric cohorts. While haploidentical transplants are worthwhile alternatives, they face higher rates of acute complications and attrition. Optimizing transplant outcomes in resource-limited settings requires both personalized clinical protocols and resilient longitudinal patient-tracking infrastructure.