Treatment of normal individuals with granulocyte-colony-stimulating factor: Donor experiences and the effects on peripheral blood CD34+ cell counts and on the collection of peripheral blood stem cells

Background: Granulocyte-colony-stimulating factor (G-CSF) has been used in patients to increase the level of circulating hematopoietic progenitors. Although G-CSF has been administered to some healthy individuals, the kinetics of mobilization of peripheral blood stem cells (PBSCs), the optimum dose schedule and the incidence and nature of adverse reactions in normal individuals are not completely defined. Study Design and Methods: Normal individuals (n = 102) who received G-CSF for 5 or 10 days at doses of 2, 5, 7.5, or 10 μg per kg per day were studied. The sub acts were observed for symptoms and physical changes, and blood samples were obtained for a variety of laboratory tests. After 5 or 10 days of G-CSF treatment, PBSCs were collected by apheresis and analyzed. Results: Overall, 89 percent of the individuals completed the 5-day treatment protocol and 88 percent completed the 10-day protocol without modification of the dose of G-CSF administered. Ninety percent of donors experienced some side effect of G-CSF. The most frequent effects noted were bone pain (83%), headache (39%), body aches (23%), fatigue (14%), and nausea and/or vomiting (12%). The dose of G-CSF administered directly affected the proportion of people with bone pain (p = 0.025) or body aches (p = 0.045) or who were feeling hot or having night sweats (p = 0.02) or taking analgesics (p = 0.01). With the 5-day dose schedule, several changes in serum chemistries occurred, including increases in alkaline phosphatase (p = 0.001), alanine aminotransferase (p = 0.0013), lactate dehydrogenase (p = 0.0001), and sodium (p = 0.0001). Decreases occurred in glucose (p = 0.045), potassium (p = 0.0004), bilirubin (p = 0.001), and blood urea nitrogen (p = 0.0017). In donors who received G-CSF for 5 days, the absolute neutrophil count was increased after one G-CSF dose, and it reached a maximum on Day 6, as did the number of CD34+ cells (64.6 ± 55.9 x 10⁶ cells/L). In those same donors, the platelet count after apheresis on Day 6 was 32 ± 13 percent lower than pretreatment values (250 ± 42 x 10⁹ cells/L). In donors receiving G-CSF for 10 days, the neutrophil count reached a maximum on Day 8, but the number of CD34+ cells peaked on Day 6 (58.3 ± 52.1 x 10⁶ cells/L) and then declined. The platelet count decreased from pretreatment values by 28 ± 12 percent prior to apheresis on Day 11. When individuals were treated for 5 days with G-CSF, the quantity of CD34+ cells collected was directly related to the G-CSF dose. When 5 μg per kg per day was given, 2.80 ± 1.81 x 10⁸ cells were collected, compared with collection of 4.67 ± 3.11 x 10⁸ cells when 10 μg per kg per day was given (p = 0.04). More important, PBSCs collected after 10 days of G-CSF administration (5 μg/kg/day) had significantly fewer CD34+ cells (0.82 ± 0.37 x 10⁸ cells, p = 0.01) than did PBSCs collected after 5 days of G-CSF (5 μg/kg/day). Conclusion: Most normal donors receiving G-CSF experience side effects, but these are mild to moderate in degree. Some alterations in blood chemistries occur, but none were clinically serious. Because of the symptoms associated with G-CSF, these individuals must be monitored closely. The treatment of normal donors with G-CSF for more than 5 days significantly decreased the number of circulating CD34+ cells and the quantity collected by apheresis.