Exhaled Carbon Monoxide (eCO) and Serum CC16 Levels in Active Smokers

Background: Toxic particles within tobacco smoke are responsible for several respiratory system problems. Among these toxic particles is Carbon Monoxide (CO), produced from environment and Heme Oxygenase induction. Expiratory CO levels can be measured using CO analyzer. CC16 is a pneumoprotein produced by club cells in distal respiratory tract. In acute condition, CC16 level will increase to maintain homeostasis and anti-inflammation. In chronic condition, i.e. in smokers, CC16 will decrease, following destruction of Club cell. This study aims to determine exhaled CO (eCO) levels and serum CC16 levels in active smokers. Methods: This cross-sectional analytical study design has 40 samples of healthy smokers in Brawijaya University who consents to the research from October 2019 until June 2020. The minimum consumption amount is 1 cigarette per day for at least 1 year. eCO levels are measured using CO analyzer (Smokelyzer), while ELISA is used to measure serum CC16 levels. Results: Among 40 subjects, mean eCO level is 10.18 ± 7.42 ppm. Mean serum CC16 level is 3.17 ± 1.78 ng/mL, lower than normal value of 6.4 ng/mL (Lomas et al., 2008). Conclusion: eCO levels increases and serum CC16 level decreases in active smokers, who smokes at least 1 cigarette/day for at least 1 year. This indicates that CO from tobacco smoke could irritate and damage the Club cells in the respiratory system.