INTRODUCTION: E-cigarette use has been linked to respiratory mucosal inflammation and other markers of toxicity. Dual use, or the use of e-cigarettes in combination with conventional cigarettes or other inhaled products has increased in prevalence, but there is limited understanding of the health effects associated with dual use. The aim of this study was to establish whether nasal mucosal cytokine profiles among people who never use tobacco, people who exclusively use electronic cigarettes, and people who dual tobacco product use change over time and whether dual use significantly differs from exclusive e-cigarette use. METHODS: This study utilized a repeated sampling study design, collecting nasal epithelial lining fluid from young adult participants (n=64) who never used tobacco, exclusively used electronic cigarettes, and used dual tobacco products, once weekly for four weeks using a remote, non-invasive sampling technique. Nasal mucosal immune mediators and salivary cotinine were then analyzed by ELISA. RESULTS: Differences in mucosal immune mediators were identified between e-cigarette, dual tobacco product and never tobacco product participant groups; however, these markers did not vary across time within group. People who exclusively use e-cigs or dual tobacco products exhibited increased proinflammatory markers compared to people who never use. Chemokine profiles were uniquely altered in the dual tobacco product group. Sex differences were identified in cytokine and chemokine production across groups. Conclusions: These results suggest that remote, non-invasive nasal sampling is adequate for assessing immune profiles from people who use tobacco products and cross-sectional sampling is likely representative of consistent respiratory immune profiles across multiple weeks. Dual product use results in distinct respiratory immune profiles, which suggests that long term disease outcomes may differ from people who exclusively use e-cigs.
Thies et al. (Sun,) studied this question.