Single-dose pegfilgrastim for the mobilization of allogeneic CD34+ peripheral blood progenitor cells in healthy family and unrelated donors.

Objective: Short-term treatment with granulocyte colony-stimulating factor (G-CSF) has been established as the standard regimen for mobilizing allogeneic peripheral blood progenitor cells (PBPC) from healthy donors. The pegylated form of filgrastim (pegfilgrastim) has a longer elimination half-life because of decreased serum clearance and might be a convenient alternative for stem cell mobilization.

Methods: Twenty-five family (n=15) or unrelated (n=10) healthy donors received a single-dose of 12 mg pegfilgrastim for mobilization of allogeneic PBPC. Donors with inadequate mobilization (blood CD34+ cells

Results: All harvests were completed successfully. In 20 out of 25 donors (80 %) only a single apheresis was necessary. Additional non-pegylated filgrastim had to be given to only one 74-year old family donor. The maximum concentration of circulating CD34+ cells occurred on day 5 (median 67/microL, range 10-385/mL). The median yield of CD34+ cells was 9.3 (range 3.2-39.1)x10(6)/kg of the recipient's body weight. The median number of T cells in the apheresis products was 3.9 (range 2.7-10.8)x10(8)/kg. Bone pain, headaches and transient elevations of alkaline phosphatase and lactate dehydrogenase were the main adverse events.

Conclusions: The study shows that collection of allogeneic PBPC after administration of a single dose of pegfilgrastim is feasible. The toxicity profile, graft composition and impact on the recipients' outcome need further investigation.