title: Persistence of oxidant and protease burden in the airways after smoking cessation.
abstract: BACKGROUND
  Oxidative stress is associated with the pathogenesis of cigarette smoke related lung diseases, but longitudinal effects of smoking cessation on oxidant markers in the airways are unknown.
  
  
  METHODS
  This study included 61 smokers; 21 with chronic bronchitis or COPD, 15 asthmatics and 25 asymptomatic smokers followed up for 3 months after smoking cessation. Fractional exhaled nitric oxide (FeNO), sputum neutrophil counts, sputum 8-isoprostane, nitrotyrosine and matrix metalloproteinase-8 (MMP-8) were investigated at baseline and 1 and 3 months after smoking cessation.
  
  
  RESULTS
  After 3 months 15 subjects had succeeded in quitting of smoking and in these subjects symptoms improved significantly. Unexpectedly, however, sputum neutrophils increased (p = 0.046) after smoking cessation in patients with chronic bronchitis/COPD. At baseline, the other markers did not differ between the three groups so these results were combined for further analysis. Sputum 8-isoprostane declined significantly during the follow-up at 3 months (p = 0.035), but levels still remained significantly higher than in non-smokers. The levels of FeNO, nitrotyrosine and MMP-8 did not change significantly during the 3 months after smoking cessation.
  
  
  CONCLUSIONS
  Whilst symptoms improve after smoking cessation, the oxidant and protease burden in the airways continues for months.
authors.affiliation: Department of Medicine, Division of Pulmonary Medicine, University of Helsinki, Finland. noora.louhelainen@helsinki.fi
authors.forename: Noora
authors.initials: N
authors.lastname: Louhelainen
authors.forename: Paula
authors.initials: P
authors.lastname: Rytilä
authors.forename: Tari
authors.initials: T
authors.lastname: Haahtela
authors.forename: Vuokko L
authors.initials: VL
authors.lastname: Kinnula
authors.forename: Ratko
authors.initials: R
authors.lastname: Djukanović
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000378:metabolism*; D029481:Bronchitis, Chronic / Q000378:metabolism*; D015237:Dinoprost / Q000031:analogs & derivatives / Q000378:metabolism; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008168:Lung / Q000378:metabolism; D008297:Male; D020784:Matrix Metalloproteinase 8 / Q000378:metabolism; D008875:Middle Aged; D009504:Neutrophils / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D016877:Oxidants / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology; D010447:Peptide Hydrolases / Q000378:metabolism*; D011446:Prospective Studies; D012907:Smoking / Q000009:adverse effects / Q000378:metabolism*; D016540:Smoking Cessation; D013147:Spirometry; D013183:Sputum / Q000378:metabolism; D055815:Young Adult
chemical_list: D016877:Oxidants; C075750:8-epi-prostaglandin F2alpha; D009569:Nitric Oxide; D015237:Dinoprost; D010447:Peptide Hydrolases; D020784:Matrix Metalloproteinase 8