Granulocyte-macrophage Colony Stimulating Factor (GM-CSF) and Interleukin 8 (IL-8) Production by Human Bronchial Epithelial Cells (HBEC) in Asthmatics and Controls. Lack of In Vitro Effect of Salbutamol Compared to Sodium Nedocromil

Summary: The bronchial epithelium produces cytokines that could contribute to inflammatory events in airways. In this study we determined the basal and TNFα stimulated productions of GM-CSF and IL-8 by human bronchial epithelial cells (HBEC) collected from 12 control and six asthmatic patients. Spontaneous and TNFα-induced GM-CSF or IL-8 released levels increased significantly with time. Epithelial cells from asthmatic patients spontaneously released high levels of GM-CSF (24 h), TNFα potentiated GM-CSF and IL-8 release in control subjects and only the IL-8 production in asthmatics. Nedocromil sodium, an antiinflammatory drug, and salbutamol, a beta2-agonist, are commonly used in asthma. They were evaluated on the spontaneous and TNF-induced expression of GM-CSF and IL-8 in cultured bronchial epithelial cells. Nedocromil sodium, at the concentration of 10^-6 M, reduced the TNF-induced increase in GM-CSF but not the IL-8 release. Salbutamol, at the concentration of 10^-6 or 10^-5 M, did not affect the constitutive or stimulated production of both cytokines.