A comparative study of once-daily versus twice-daily filgrastim administration for the mobilization and collection of CD34+ peripheral blood progenitor cells in normal donors.

Eighty-one first-time normal donors underwent leukapheresis for peripheral blood progenitor cell (PBPC) collection after mobilization with filgrastim administered either twice-daily (6 microg/kg every 12 h; n = 40) or once-daily (12 microg/kg; n = 41) subcutaneously for 3 d. The groups were similar for age, donor blood volume and target CD34+ cell dose to be collected (>/= 4 x 106 CD34+ cells/kg recipient). There was no statistically significant difference in the apheresis yield of CD34+ PBPCs (x 106) per kg recipient weight (5.6 +/- 3.3 vs. 5.6 +/- 4.3; P = 0.94) and per litre of blood processed (30 +/- 17.2 vs. 30.4 +/- 19.5; P = 0.92).