Email updates

Keep up to date with the latest news and content from BMC Pulmonary Medicine and BioMed Central.

Open Access Research article

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

Izolde Bouloukaki1*, Ioanna G Tsiligianni12, Maria Tsoumakidou13, Ioanna Mitrouska1, Emmanuel P Prokopakis4, Irene Mavroudi5, Nikolaos M Siafakas1 and Nikolaos Tzanakis12

Author Affiliations

1 Department of Thoracic Medicine, Faculty of Medicine, University of Crete, Crete, Greece

2 Department of Epidemiology, Faculty of Medicine, University of Crete, Crete, Greece

3 Department of Critical Care Medicine and Pulmonary Services, Evangelismos General Hospital, Athens, Greece

4 Department of Otolaryngology, Faculty of Medicine, University of Crete, Crete, Greece

5 Department of Hematology, Faculty of Medicine, University of Crete, Crete, Greece

For all author emails, please log on.

BMC Pulmonary Medicine 2011, 11:35  doi:10.1186/1471-2466-11-35

Published: 2 June 2011

Abstract

Background

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.

Methods

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.

Results

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.

Conclusions

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.