Elevated emdogenous serum macropkage colony-stimulating factor in the early stage of fungemia following bone marrow transplantation

Murine studies have reported elevated serum macrophage colony-stimulating factor (M-CSF) concentrations in animals inoculated with fungus; however, the human cytokine response to fungemia has not been described. Endogenous M-CSF serum concentrations were measured in 18 autologous bone marrow transplant patients with positive blood fungal cultures. Seventeen of the 18 patients received the same high-dose chemotherapy regimen with autologous hematopoietic support. M-CSF concentrations were determined in serum samples obtained 1 week before and within 2 days of the first positive blood culture. Serum M-CSF rose more than three-fold in a majority of patients at the time of positive culture in contrast to concentrations obtained in the previous week (medians 11.1 and 2.8 ng/mL, respectively; p=0.001). Median values at the time of positive blood culture were also significantly higher than those obtained in a matched control group of patients without positive blood cultures (n=18; median 2.60 ng/mL; p=0.001). These data demonstrate that endogenous serum M-CSF is elevated in the early stages of human systemic fungal infection and thus may have important diagnostic and therapeutic implications.