Factors affecting the CD34+ cell yields from the second donations of healthy donors: The steady-state lymphocyte count is a good predictive factor

BackgroundA second allogeneic hematopoietic stem-cell transplantation and donor lymphocyte infusion using cells from the same donor is a therapeutic option in the case of stem-cell graft failure or disease relapse, but little is known about the factors associated with the CD34+ cell yields from second donations.MethodsOne-hundred healthy donors who underwent a second mobilization treatment and peripheral blood stem-cell (PBSC) collection were studied. For both mobilization processes, 5 µg of granulocyte colony-stimulating factor per kg per day was administered. The blood counts of the donors were monitored during the processes.ResultsThe second donations from the same donors provided lower apheresis yields than did the initial collections. The number of CD34+ cells collected from normal donors after a second cycle of PBSC mobilization was associated with their steady-state lymphocyte counts and the intertransplantation interval. Female sex negatively affected the CD34+ cell yields. The cutoff value for the steady-state absolute lymphocyte count was 2.055 × 109/L.ConclusionTo harvest greater numbers of CD34+ cells from second collections, male donors and those with intervals of longer than 9 months between donations should be selected. The lymphocyte counts prior to the first donations may predict the content of CD34+ cells in the allografts prepared using the second donations.