Factors Associated with Peripheral Blood Stem Cell Yield in Volunteer Donors Mobilized with Granulocyte Colony-Stimulating Factors: The Impact of Donor Characteristics and Procedural Settings

Peripheral blood stem cells (PBSCs) are increasingly used as the source of hematopoietic stem cells, but there are large variations in harvest outcome between individuals mobilized by granulocyte colony-stimulating factor (G-CSF). We examined the effects of donor characteristics and procedure factors on the day 1 CD34⁺ cell yield in 373 unrelated healthy donors. G-CSF was administered subcutaneously at a planned dose of 8.3 to 11μg/kg daily for 5 days, followed by harvest started on day 5 of G-CSF treatment. Of the 373 donors, 159 (42.6%) had the radial artery as the inlet access for harvest. Poor day 1 cell yield was defined as <10 × 10⁶ CD34⁺ cells/L of processed blood for the first apheresis; 62 donors (16.6%) did not attain this threshold. The male donors had significantly higher yields at harvest compared with the female donors. The female donors had higher CD34⁺ cell yields if the circulation access was through an artery than if is was through a vein. In a multiple regression analysis, donor age, sex, body mass index (BMI), preharvest white blood cell and circulating immature cell counts, access type, and flow rate correlated with day 1 yield. Female sex, older age, venous access, and a higher flow rate were significantly associated with greater risk for a day 1 poor yield of CD34⁺ cells (odds ratio = 3.0074, 1.045, 4.3362, and 1.1131, respectively). A higher BMI may decrease the risk (odds ratio = 0.8472). In donors at higher risk for poor CD34⁺ cell yield, strategies for increasing CD34⁺ cells must be considered.