Platelet recovery is associated with CD34 cell number.

There was a relatively weak association between CD34 cell dose in G-PBMC grafts from HLA-identical sibling donors and time to platelet engraftment among patients (n = 144) who reached a sustained platelet count of more than 20 000/μL before dying or returning to the care of the referring physician (R = .18, P = .03). Closed circles represent patients who engrafted before dying or being sent home; open circles represent patients who did not engraft before dying or being sent home. Vertical lines separate first through fourth quartiles of CD34 cells.