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

BACKGROUND: A 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.

METHODS: One-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.

RESULTS: The 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 × 10(9)/L.

CONCLUSION: To 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.