Duration of filgrastim mobilization and apheresis yield of CD34+ progenitor cells and lymphoid subsets in normal donors for allogeneic transplantation.

Seventy-seven normal donors underwent leukapheresis for peripheral blood progenitor cell collection beginning on day 4 (n = 45) or day 5 (n = 32) of filgrastim mobilization (12 micrograms/kg/d). The two groups were comparable for age, weight, blood volumes processed during leukapheresis and target CD34+ cell dose to be collected. The day 5 schedule allowed a more consistent achievement of the target cell dose with one apheresis (P = 0.005) and resulted in the initial collection of a significantly larger number of CD34+ cells (P = 0.009). There was no statistically significant difference in the leukapheresis yield of lymphoid subsets and natural killer cells.