Platelet engraftment as a function of PBPC CD34+ and CD34+MA6+ dose. (A) Time to platelet engraftment stratified by patient cohort is shown. Auto-MDACC (n=30) and auto-Australia (n=64) cohorts have a similar pattern of platelet engraftment (median time to engraftment of 11 days) [P=0.363; hazards ratio (HR) 1.23; 95% confidence interval (CI) 0.78–1.93]. In contrast, the allo-MDACC (n=35) cohort achieved platelet engraftment only after a median of 23 days. (B) Time to platelet engraftment stratified by CD34+ cell dose is shown. The higher the CD34+ cell dose, the greater the probability of engraftment. (C) Time to platelet engraftment stratified by CD34+MA6+ cell dose is shown. The higher the CD34+MA6+ cell dose, the greater the probability of engraftment. (D) Scatter plot of CD34+MA6+ (million cells/kg) versus CD34+ (cells/kg) with regression line (CD34+=4.06+5.75×CD34+MA6+). Pearson correlation=0.657, P<0.001. Spearman correlation=0.366, P<0.001.