Sputum and nasal lavage lung-specific biomarkers before and after smoking cessation

• Published in: BMC pulmonary medicine 2011-06, Vol.11 (1), p.35-35, Article 35
• Main Authors: Bouloukaki, Izolde, Tsiligianni, Ioanna G, Tsoumakidou, Maria, Mitrouska, Ioanna, Prokopakis, Emmanuel P, Mavroudi, Irene, Siafakas, Nikolaos M, Tzanakis, Nikolaos
• Format: Article
• Language: English
• Subjects: Adult; beta-Defensins - metabolism; Biological markers; Biomarkers - metabolism; Case-Control Studies; Elafin - metabolism; Female; Genetic aspects; Humans; Longitudinal Studies; Male; Middle Aged; Nasal Lavage Fluid; Patient outcomes; Physiological aspects; Secretory Leukocyte Peptidase Inhibitor - metabolism; Smoking; Smoking - metabolism; Smoking Cessation; Smoking cessation programs; Sputum; Sputum - metabolism; Time Factors; Uteroglobin - metabolism
• ISSN: 1471-2466; 1471-2466
• DOI: 10.1186/1471-2466-11-35

Little is known about the effect of smoking cessation on airway inflammation. Secretory Leukocyte Protease Inhibitor (SLPI), Clara Cell protein 16 (CC16), elafin and human defensin beta-2 (HBD-2) protect human airways against inflammation and oxidative stress. In this longitudinal study we aimed to investigate changes in sputum and nasal lavage SLPI, CC16, elafin and HBD-2 levels in healthy smokers after 6 and 12 months of smoking cessation. Induced sputum and nasal lavage was obtained from healthy current smokers (n = 76) before smoking cessation, after 6 months of smoking cessation (n = 29), after 1 year of smoking cessation (n = 22) and from 10 healthy never smokers. SLPI, CC16, elafin and HBD-2 levels were measured in sputum and nasal lavage supernatants by commercially available ELISA kits. Sputum SLPI and CC-16 levels were increased in healthy smokers before smoking cessation versus never-smokers (p = 0.005 and p = 0.08 respectively). SLPI and CC16 levels did not differ before and 6 months after smoking cessation (p = 0.118 and p = 0.543 respectively), neither before and 1 year after smoking cessation (p = 0.363 and p = 0.470 respectively). Nasal lavage SLPI was decreased 12 months after smoking cessation (p = 0.033). Nasal lavage elafin levels were increased in healthy smokers before smoking cessation versus never-smokers (p = 0.007), but there were no changes 6 months and 1 year after smoking cessation. Only nasal lavage SLPI decrease after 1 year after smoking cessation. We may speculate that there is an ongoing inflammatory process stimulating the production of counter-regulating proteins in the airways of healthy ex-smokers.