rhG-CSF in Healthy Donors: Mobilization of Peripheral Hemopoietic Progenitors and Effect on Peripheral Blood Leukocytes

Abstract

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) 16 μg/kg/day was given to 9 healthy donors to recruit hemopoietic progenitors (HP) for allogeneic transplantation or donor leukocyte infusion. rhG-CSF was administered s.c. for 5 days. No side effects were encountered except for moderate bone pain and lumbago. Mobilization was effective, reaching a peak median value of 187 × 10³ CD34+ cells/ml (range 51.2–1127) and 2170 × 10³ colony-forming units–granulocyte macrophage (CFU-GM)/ml (range 1138–4190). Peak values were obtained at a median of 4 days of rhG-CSF and represented, respectively, a 13-fold and a 37-fold increase from baseline values (p = 0.0007 and p = 0.006). White blood cell (WBC) counts increased 6-fold from baseline values (p < 0.0007) and reached a median peak of 34 × 10⁶/ml (23.5–59). Polymorphonuclear (PMN), and mononuclear (MNC) cells increased 10-fold and 2-fold, respectively (p = 0.0039 and p = 0.0026) and reached a median peak of 32.1 × 10⁶/ml (18.2–52) and 4.42 × 10⁶/ml (3.14–12.42). Absolute lymphocyte and monocyte counts increased at peak day in all donors 1.5-fold and 5.7-fold from baseline values (p = 0.0017 and p = 0.0018). In 7 of 9 donors, lymphocyte subsets were analyzed in detail. CD3+ and CD19+ lymphocytes increased 1.5-fold and 3-fold, respectively (p = 0.032 for both). NK and activated T lymphocytes doubled at a median of 4 days of rhG-CSF (p = 0.032 and p = NS, respectively). Similar changes were observed in lymphocytes collected in leukapheresis product. T helper and T suppressor subsets displayed a similar increase. Thus, besides the anticipated priming effect on HP and PMN, rhG-CSF in healthy donors produced an unexpected and still unexplained modification of lymphocyte subsets in peripheral blood.