The kinetics of G-CSF mobilization of CD34+ cells in healthy people

• Published in: Transfusion medicine (Oxford, England) England), 1997-03, Vol.7 (1), p.19-24
• Main Authors: Stroncek, D. F., Clay, M. E., Herr, G., Smith, J., Jaszcz, W. B., Ilstrup, S., McCullough, J.
• Format: Article
• Language: English
• Subjects: Adult; Blood Cell Count - drug effects; bone marrow transplantation; CD34+ cells; Female; granulocyte colony-stimulating factor; Granulocyte Colony-Stimulating Factor - administration & dosage; Hematopoietic Stem Cells - cytology; Hematopoietic Stem Cells - drug effects; Humans; Injections, Subcutaneous; Male; Middle Aged; peripheral blood stem cells; Recombinant Proteins - administration & dosage
• ISSN: 0958-7578; 1365-3148
• DOI: 10.1046/j.1365-3148.1997.d01-75.x

When healthy people are given granulocyte colony stimulating factor (G‐CSF) for 10 days the number of CD34+ cells in the peripheral blood begins to increase on the fourth day, reaches a maximum on the sixth day and then decreases. In this study, we further define the time and variability of peak mobilization of CD34+ cells. Twenty‐two healthy people were given G‐CSF (7.5 or 10 μg kg−1 day−1) subcutaneously each morning for 5 days and peripheral blood CD34+ cell counts were analysed immediately prior to the fourth (day 4) and fifth (day 5) G‐CSF injection and 24 h after the fifth injection (Day 6). White blood cell (WBC) and neutrophil counts were greatest on day 6 [WBC = 43.8 ± 13.9 × 109 L−1 (mean ± 1 SD) and neutrophils = 36.6 ± 12.8 × 109 L−1]. In contrast the CD34+ cell counts on day 6 (107 ± 104 × 106 L−1) were less than on day 5 (128 ± 136 × 106 L−1) (P= 0.048) but still greater than on day 4 (60.7 ± 40.2 × 106 L−1) (P < 0.0001). The CD34+ cell counts of 10 donors were measured 2, 4 and 6 h after the fifth injection to determine if the counts increased further between days 5 and 6. The number of CD34+ cells in the blood on day 5 2 h after the fifth injection (193 ± 277 × 106 L−1) was greater than the number prior to the injection (158 ± 190 × 106 L−1), 4 h post‐injection (139 ± 158 × 106 L−1) and 6 h post‐injection (170 ± 236 × 106 L−1), but the differences were not significant (P= 0.29, 0.25 and 0.45). The number of CD34+ cells in the blood of 12 people were measured before and after the fourth G‐CSF dose. Prior to the day 4 injection the CD34+ count was 61 ± 40 × 106 L−1. At 2, 4 and 6 h the counts were 60 ± 40, 61 ± 29 and 64 ± 30 × 106 L−1, respectively, and the differences were not significant (P= 0.99, P= 0.98, and P= 0.73). In conclusion, when healthy volunteers are given daily G‐CSF injections, the number of mobilized CD34+ cells was the greatest on day 5, slightly less on day 6 and the least on day 4. If only one PBSC component is needed, PBSCs can be collected on day 5 after only 4 days of G‐CSF. If PBSC components are collected on both days 5 and 6, the fifth dose can be given either before or after the collection of the first PBSC component.