The administration of granulocyte colony-stimulating factor (G-CSF) to increase the white blood cell count in granulocyte donors prior to donation is becoming an increasingly common practice. G-CSF is given subcutaneously to the donor on the day prior to donation, generally 12 to 24 hours before the start of apheresis. It would be advan-tageous to be able to give G-CSF and collect granulocytes on the same day. However, the single most important factor in optimizing granulocyte collection is the donors pre-collec-tion granulocyte count. Therefore, any decrease in count would result in a less cellular component. The purpose of this study is to assess granulocyte counts in healthy subjects during an 8-hour period after a single 5 mg/kg intravenous dose of G-CSF with or without dexamethasone. Sixteen subjects will be studied. Each donor will be studied four separate times. The four mobilization protocols to be studied are G-CSF 5 mg/kg given intravenously, G-CSF 5 mg/kg subcutaneously, G-CSF 5 mg/kg intravenously plus dexamethasone 8 mg orally, and G-CSF 5 mg/kg subcutaneously plus dexamethasone 8 mg orally. The order of the route of administration will be assigned randomly. White blood cell counts, neutrophil counts and donor symptoms will be measured before G-CSF administration and at 1, 2, 4, 6, 8, and 24 hours after administration. The neutrophil counts measured within the first 8 hours after G-CSF will be compared with counts measured 24 hours after G-CSF. This study has just begun and no data are available.
