Persistent airway inflammation and emphysema progression on CT scan in ex-smokers observed for 4 years.
BACKGROUND
Tobacco smoking is a principal cause of COPD-emphysema (COPD-E). Whether discontinuing smoking for at least 4 years halts airway inflammation and progression of COPD-E in prior smokers is unknown. In this study we investigated whether discontinuing smoking for approximately 4 years in ex-smokers with GOLD (Global Initiative for Chronic Lung Disease) stage IIb (moderately severe) COPD-E stopped airway inflammation (ie, sputum biomarkers) and halted the progression of COPD-E on chest CT scan.


METHODS
Ten ex-smokers with COPD-E who had quit smoking underwent chest CT scans to document the extent of COPD-E, assessment of lung function (FEV(1) and diffusing capacity of lung for carbon monoxide), sputum induction for biomarkers of inflammation (measured by enzyme-linked immunosorbent assay), and blood cotinine levels at baseline and approximately 4 years later. Normal healthy subjects (n = 7) and normal current smokers with no CT scan evidence of COPD-E (n = 8) served as sputum biomarker comparison groups.


RESULTS
After approximately 4 years of not smoking (documented by cotinine levels), ex-smokers with COPD-E had persistent increased levels of mediators of inflammation in sputum (myeloperoxidase, leukotriene B4, IL-8, monocyte chemoattractant protein-1, matrix metalloprotease-9), which was associated with significant progression of COPD-E on chest CT scan.


CONCLUSIONS
Cessation of tobacco smoking in heavy smokers with moderately severe COPD-E is associated with evidence of persistent airway inflammation and progression of COPD-E on CT scan 4 years later. Discontinuing smoking may slow the rate of progression of moderate severity COPD-E, but it does not prevent persistent airway inflammation and significant progression of COPD-E on CT scan.
Department of Medicine, University of California, San Diego, CA.
Marina
M
Miller
Department of Medicine, University of California, San Diego, CA.
Jae Youn
JY
Cho
Department of Medicine, University of California, San Diego, CA.
Alexa
A
Pham
Department of Radiology, University of California, San Diego, CA.
Paul J
PJ
Friedman
Department of Medicine, University of California, San Diego, CA.
Joe
J
Ramsdell
Department of Medicine, University of California, San Diego, CA. Electronic address: dbroide@ucsd.edu.
David H
DH
Broide
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000000981:diagnostic imaging* / Q000378:metabolism; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000209:etiology / Q000378:metabolism; D012907:Smoking / Q000009:adverse effects / Q000378:metabolism / Q000473:pathology; D016540:Smoking Cessation; D013997:Time Factors; D014057:Tomography, X-Ray Computed
D018836:Inflammation Mediators