E-cigarettes: A source of chronic lung inflammation

Vaping has become more popular than regular cigarettes in the previous years. Industry has been trying to promote these products as healthier alternatives to conventional smoking, despite the multiple pathogenic changes induced by these novel products [1].

Over 40% of high school students vape. Most e-cigarette liquid contains purified nicotine, making them equally addictive as conventional cigarettes. Prof. Shama Ahmad (University of Alabama at Birmingham, USA) pointed out that nicotine vapours in new devices, such as the electronic IQOS, are generated using low heat, and are therefore marketed as “safer e-cigs”. However, the nicotine content of these products is on the rise, often even exceeding those of a traditional cigarette. They exert rapid physiological effects, including a significant increase in peripheral airway resistance and an elevated heart rate. According to Prof. Ahmad’s hypothesis, acute high concentration nicotine inhalation causes increased inflammation and lung injury through the release of damage-associated molecular patterns (DAMPS). This has been shown in experimental animals. Inhaled nicotine causes an increase of different inflammatory cells, such as neutrophils, eosinophils, and basophils. In addition, a loss of pulmonary barrier proteins measured by transepithelial electrical resistance, a decrease in E-cadherin expression, and an increase in epithelial cell death has been demonstrated. The additional release of proinflammatory cytokines like TNF, IL-6 and IL-8 following cigarette smoking perpetuates chronic inflammatory processes in e-smokers. Epithelial cell death and inflammation have also been demonstrated following nicotine inhalation in human alveolar epithelial cells. Thus, Prof. Ahmad concluded, the claim of a “healthier” cigarette is not justified.

 

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   1. Ahmad S. Electronic cigarette nicotine-mediated lung damage: Is it nicotine or DAMPs or both? Session A90, ATS 2020 Virtual, 5-10 Aug.

 



Posted on 29 October 2020