Variability in CD34+ Cell Counts in Umbilical Cord Blood:Implications for Cord Blood Transplants

Objective: To determine if total nucleated cell counts alone are sufficient for predicting the efficacy of cord blood units for transplant from neonatal umbilical cord blood samples. Methods: Umbilical cord blood samples were collected from 200 mothers at delivery and the cord blood units processed. The total nucleated cells and CD34+ cells were enumerated and compared for each sample. Results: Despite an apparent linear correlation between total nucleated cell counts and CD34+ cell counts, each group of total nucleated cell counts demonstrated a high degree of variation in CD34+ cell counts and could be as low as 0.1% of total nucleated cell counts. Conclusions: Large variations in CD34+ cell counts per total nucleated cell count are present for cord blood units from neonatal umbilical cord samples. Hence a CD34+ cell count for each cord blood unit would improve selection of samples for transplant.