[Association between interleukin-8 in lung tissues and stages of chronic obstructive pulmonary diseases].

Objective To investigate the expression of interleukin (IL)-8 in lung tissues from patients with chronic obstructive pulmonary disease (COPD) and its association with stages of COPD. Methods The levels of mRNA and protein of IL-8 were measured with semi-quantitative polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) in patients with mild COPD (n=21),patients with advanced COPD (n=15),and controls (n=15). The correlations between IL-8 levels and stages of COPD,lung function (FEV1/FVC%,FEV1% pred) and cigarette smoking were analyzed with Pearson correlation analysis. Results The levels of IL-8 mRNA and protein in the lung tissues of COPD patients were significantly higher than those in the control group (P0.05). The patients with advanced COPD had higher levels of IL-8 mRNA and protein than the patients with mild COPD (P0.05). The COPD patients who smoked had higher levels of IL-8 mRNA and protein than those who did not smoke (P0.05). But no significant differences in the levels of IL-8 mRNA and protein were found between smokers and and nonsmokers who did not have COPD (P0.05). Increased expression of IL-8 in patients with COPD was positively correlated with stages of COPD (r=0.81,P0.05); negatively correlated with lung function (FEV1/FVC%,FEV1% pred) (r=-0.62,-0.56,P0.05),and positively correlated with volumes of cigarette smoking (r=0.53,P0.05). Conclusion IL-8 is associated with stages of COPD,which may serve as an indication for clinical progress. Cigarette smoking increases IL-8 expression in the lung tissues of COPD patients.