title: [Association between interleukin-8 in lung tissues and stages of chronic obstructive pulmonary diseases].
abstract: 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 (P<0.05). The patients with advanced COPD had higher levels of IL-8 mRNA and protein than the patients with mild COPD (P<0.05). The COPD patients who smoked had higher levels of IL-8 mRNA and protein than those who did not smoke (P<0.05). 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 (P>0.05). Increased expression of IL-8 in patients with COPD was positively correlated with stages of COPD (r=0.81, P<0.05); negatively correlated with lung function (FEV1/FVC%, FEV1% pred) (r=-0.62, -0.56, P<0.05), and positively correlated with volumes of cigarette smoking (r=0.53, P<0.05).
  
  
  CONCLUSIONS
  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.
authors: Department of Respiratory Medicine, Division of Pulmonary Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
authors: Xiao-Rong
authors: XR
authors: Hu
authors: Su-Xia
authors: SX
authors: Han
authors: Tao
authors: T
authors: Wang
authors: Ming-Ke
authors: MK
authors: Zhang
authors: Lei
authors: L
authors: Chen
authors: Fu-Qiang
authors: FQ
authors: Wen
mesh_terms: D000368:Aged; D015415:Biomarkers; D005260:Female; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D008168:Lung / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000145:classification / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012907:Smoking / Q000009:adverse effects
chemical_list: D015415:Biomarkers; C508606:CXCL8 protein, human; D016209:Interleukin-8; D012333:RNA, Messenger