Responsiveness to G-CSF before leukopenia predicts defense to infection in high-dose chemotherapy recipients

An active assessment of the host capacity to prevent infection during myelosuppression should be beneficial in patients receiving high-dose chemotherapy. A single dose of granulocyte colony-stimulating factor (G-CSF) (5 microg/kg) was given to 57 patients with multiple myeloma early after the completion of 85 high-dose chemotherapy (melphalan 200 mg/m2) courses. This provoked a highly variable white blood cell (WBC) peak after 12 to 14 hours. The median WBC count was 21,000/microL (range, 6400-60,600/microL) after a first high-dose therapy (n = 50) and 13,500/microL (range, 4700-24,800/microL) after a second high-dose therapy (n = 35). The responsiveness to single G-CSF was associated with the risk of infection during subsequent cytopenia (P =.003). This association was significant after adjustment for neutropenia duration. Notably, the result of testing G-CSF responsiveness was opportunely available before the onset of leukopenia, and G-CSF responsiveness was more informative than neutropenia duration regarding the risk of infection. Furthermore, there was an association between the responsiveness to G-CSF and stem cell engraftment (P <.005), which remained significant after adjustment for the number of transplanted CD34+ cells. Our results show for the first time that G-CSF potentially could be used for an early in vivo assessment of defense to infection in recipients of high-dose chemotherapy.