To study the effect of ICS baseline treatment on inflammation in the absence of PA infection, the levels of the key anti-inflammatory cytokine IL-10 and proinflammatory cytokine IL-8 were determined in both BAL and serum of COPD + ICS, COPD, smokers (N), and nonsmokers (NS). This evidence concerns the gene CXCL8 and chronic obstructive pulmonary disease.