A prospective randomized study on the mobilization of CD34⁺ cells comparing continuous intravenous vs subcutaneous administration of rhG-CSF in normal donors

The efficacy of mobilizing peripheral blood progenitor cells (PBPC) with continuous intravenous (c.i.v.) administration of rhG-CSF was randomly compared to subcutaneous (s.c.) administration, in 15 normal donors in each arm of the study for 6 days. The percentage and absolute numbers of CD34⁺ cells in the c.i.v. and s.c. groups increased maximally at day 3 and 5, respectively, when compared with the steady-state (day 0) level. Peak CD34⁺ cell levels were achieved on day 3 in the c.i.v. group, with more rapid results than in the s.c. group (49.3/ μl vs 35.9/μl, P = 0.043). Plasma rhG-CSF levels declined progressively during mobilization in each group as the WBC increased. The serum level of rhG-CSF did not correlate with CD34⁺ cell counts in the peripheral blood. Toxicity profiles in the c.i.v. and s.c. groups were similar. Each regimen was effective in successfully mobilizing the target CD34 cell number.