Mobilization and collection of PBSC in healthy donors: comparison between two schemes of rhG-CSF administration

Procurement of a high number of progenitor cells is of primary interest in allogeneic PBSC transplantation. We have retrospectively compared toxicity, mobilization effect and progenitor cell yields of two different rhG-CSF schedules in 11 consecutive healthy individuals donating their PBSC. Five of them received rhG-CSF 16 micrograms/kg/d for 4 subsequent d in 2 divided subcutaneous injections (group A); similarly, 6 donors received rhG-CSF 10 micrograms/kg/d for 5 d (group B). The aphereses were started the last day of rhG-CSF treatment; 9 donors underwent 2 aphereses, one underwent 1 and another 3 procedures, always on subsequent days. Toxicity was mild, but moderate thrombocytopenia developed following apheretic collections, irrespective of rhG-CSF schedule. In all the donors WBC, as well as circulating CD34+ cells, CFU-GM, CFU-GEMM and BFU-E dramatically increased over the baseline values, peaking on d 5 or 6, with no statistical difference between the 2 groups for the height of the cell peaks. Also the peripheral lymphoid cell populations (CD3+, CD19+ and CD56+/CD3-) increased following the rhG-CSF administration. The number of MNC, CFU-GM, BFU-E, CFU-GEMM, as well as CD34+, CD3+, CD19+ and CD56+/CD3- cells collected by apheresis showed no statistical difference in the 2 groups. Overall, 8 of the 11 donors collected the target number of CD34+ cells > 4 x 10(6)/kg ideal recipient body weight with the first apheresis, with no difference between the 2 groups. Mobilization with rhG-CSF in healthy donors enables the collection of large number of progenitor cells with modest side effects. A schedule of 10 micrograms/kg for 5 d is as effective as 16 micrograms/kg for 4 d. A single apheresis would be enough in 80% of cases.