Lenograstim-mobilized peripheral blood progenitor cells in volunteer donors: an open label randomized split dose escalating study.

Mobilization of peripheral blood cell progenitor cells was investigated in 36 healthy sibling donors using three different split doses of glycosylated rhG-CSF (lenograstim). The donors were randomized into three groups: group 1 was given lenograstim at 8, group 2 at 11 and group 3 at 15 micrograms/kg/day in two split doses, subcutaneously for 4 and 5 days, respectively. Leukapheresis was performed on day 4 or 5 depending on the WBC and CD34+ cell count. We were able to demonstrate that there was a significant correlation between circulating CD34+ cells on the day of harvest and CD34+ cells in the apheresis products in all three groups. The number of CD34+ cells pre-apheresis was inversely correlated with age in group 1 and group 2. However, in group 3, the number of CD34+ cells pre-apheresis did not correlate with age. There was also a difference between the number of progenitor cells mobilized in the three dose groups regarding the time of harvest. Apheresis was performed in groups 1 and 2 on day 5 of mobilization in order to obtain a sufficient number of stem cells for allogeneic transplantation. In contrast, with the split dose of 15 micrograms/kg/day, harvest could be routinely performed on day 4 of stimulation. We conclude that lenograstim given twice a day at doses of 8, 11 and 15 micrograms/kg/day provided different CD34+ cell yields in normal donors, in particular, with regard to the time of harvest. The number of CD34+ cells pre-apheresis was not correlated with age in the group of donors mobilized with a split dose of 15 micrograms/kg/day, indicating that this dosage might also be suitable for older donors.