Association of endogenous G-CSF with anti-inflammatory mediators in patients with acute respiratory distress syndrome

Upregulation of the anti-inflammatory mediators, soluble tumor necrosis factor-a receptors I and II (sTNF-RI/RII) and interleukin-1 receptor antagonist (IL-1RA), by granulocyte colony-stimulating factor (G-CSF) may contribute to the pathophysiology of lung injury. We determined the relation of endogenous G-CSF to proinflammatory and anti-inflammatory mediators in bronchoalveolar lavage fluid (BALF) and serum of patients with acute respiratory distress syndrome (ARDS) and acute lung injury (ALI). Nineteen patients with ARDS and 10 with ALI were included in this prospective investigation. BAL was performed within 12 h and 24 h after onset of lung injury. Concentrations of G-CSF, TNF-alpha, IL-6, sTNFRI and sTNFRII, IL-1RA and IL-10 in BALF as well as in serum were determined by ELISA. G-CSF was associated with alveolar neutrophilia. Results in patients with ARDS and ALI exhibited significant positive correlations in BALF of G-CSF levels with that of IL-6, sTNFRII, and IL-1RA and of G-CSF levels in serum with that of serum IL-6, IL-1RA, and IL-10. Given the potential of G-CSF to directly induce anti-inflammatory cytokines in vitro, significant associations of endogenous G-CSF levels with these mediators early in the development of severe lung injury suggest an endogenous anti-inflammatory role of G-CSF in vivo.