Increased inflammatory markers in the exhaled breath condensate of cigarette smokers

Abstract

Cigarette smoking induces an inflammatory response in the airways that may play a key role in the pathogenesis of chronic obstructive pulmonary disease. Noninvasive markers of inflammation may, therefore, be useful in monitoring the airways of smokers as well as in the screening of subjects at high risk of developing airway obstruction.The aim of the present study was to determine whether the concentrations of the proinflammatory cytokine, interleukin (IL)-6, is increased in the exhaled breath condensate of smokers and whether the number of cigarettes smoked has any influence on the exhaled concentrations. The possibility that exhaled IL-6 levels are related to exhaled carbon monoxide (CO) and lung function has also been explored. Another inflammatory marker, leukotriene (LT), was also measured.Twenty-one smokers (39¡7 yrs, 13 male) and 14 nonsmokers (45¡6 yrs, eight male) were recruited. IL-6 and LTB 4 levels in the breath condensate were measured with an immunoassay kit and exhaled CO examined by means of a modified electrochemical sensor. Higher IL-6 and exhaled CO concentrations were found in current smokers (5.6¡1.4 pg?mL -1 and 16.7¡5.5 parts per million (ppm)) than in nonsmokers (2.6¡ 0.2 pg?mL -1 and 2.1¡0.6 ppm). Elevated concentrations of LTB 4 were also observed in smokers compared to nonsmokers (9.4¡0.4 pg?mL -1 versus 6.1¡0.3 pg?mL -1 ). In addition, there was a correlation between IL-6 concentrations, the number of cigarettes smoked per day, exhaled CO, LTB 4 and lung function.Exhaled interleukin-6 and leukotriene B 4 levels may be useful noninvasive markers of airway inflammation in cigarette smokers. Eur Respir J 2003; 21: 589-593. Cigarette smoking is associated with neutrophilic inflammation of the airways which, in 15-20% of cases, is followed by the obstruction of the small airways [1]. Several studies have demonstrated that chronic obstructive pulmonary disease (COPD) is associated with an inflammatory process that takes place in the peripheral airways [2]. However, the mechanism by which the inflammation causes airway obstruction remains unknown [3].An increased number of neutrophils in the airways has been found in cigarette smokers and this is related to the number of cigarettes smoked [4]. The profile of pro-inflammatory cytokines measured in bronchoalveolar lavage (BAL) is also related to the number of cigarettes smoked [5].Interleukin (IL)-6 is a pro-inflammatory cytokine produced by epithelial cells and macrophages in the airways [5,6]. Increased concentrations of IL-6 have been found in the BAL [5] and the induced sputum of smokers [7]. These invasive methods do not allow frequent monitoring of the inflammatory response [8].The aim of present study was to measure IL-6 levels in smokers using a completely noninvasive method, the exhaled breath condensate. To exclude a possible salivary contamination of the breath condensate, measurements of this cytokine in saliva were also taken. Leukotriene (LT)B 4 was also measured in the exhaled breath condensate in some of the subjects,...

Leukotrienes B4, C4, D4 and E4 in the Exhaled Breath Condensate (EBC), Blood and Urine in Patients with Pneumoconiosis

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Airways oxidative stress, lung function and cognitive impairment in aging

“…in studying airways using non invasive methods, such as induced sputum, exhaled NO and exhaled breath condensate has increased [11,16]. These completely non-invasive, safe and repeatable techniques, are ideal to study lung inflammation parameters such as exhaled nitric oxide (NO) in the elderly.…”

8-isoprostane and Leukotrienes in Exhaled Breath Condensate in Czech Subjects with Silicosis

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