Collection of progenitor cells for allogeneic transplantation from peripheral blood of normal donors.

Fourteen donors were given recombinant G-CSF to mobilize progenitor cells. Circulating CD34+ cells were monitored daily and leukapheresis was performed at 3-5 days when the level exceeded 20 x 10(6)/L. Monitoring of CD34+ cells collected at intervals during apheresis gave results within 20 min. Yields of 2.6-7.4 x 10(6) per kg recipient body weight were achieved in single aphereses of 2-4 h in all but two cases where the donor was substantially smaller than the recipient. These products were sufficient to establish engraftment, at least of granulocytes, in 11 five or six antigen matched recipients with high risk malignancy. Despite some complications donors tolerated the procedure well and the five individuals who had previously given marrow preferred these manoeuvres to bone marrow harvest. The ability to monitor CD34+ cells rapidly in the circulation and leukapheresis product facilitates an efficient collection technique for allogeneic BCT donors. Adequate yields could probably be achieved by a single harvest on days 2-4 in most donors.