LAUSR

The process of vaping may increase the cytotoxic effects of e-cigarette liquid (ECL) and increase the negative effects on alveolar macrophages yet many studies have used only unvaped fluid. We sought to examine the potential cytotoxic and functional effects of vaped and unvaped e-cigarette fluid on alveolar macrophages (AM). AMs were treated with e-cigarette vapour condensate (ECVC)/ECL +/- nicotine. Viability, apoptosis/necrosis, cytokine release, phagocytosis and ROS generation were then assessed. AM culture with ECL/ECVC resulted in dose dependent reduction in cell viability. ECVC was cytotoxic at lower concentrations than ECL (0.8% vs 5%, n=6). 24hr culture with 0.8% ECVC resulted in a 25% increase in apoptosis and necrosis (p ECVC is significantly more toxic to AMs than non-vaped ECL. Elevated inflammatory cytokine production and ROS suggests ECIG users may be inducing a chronic inflammatory state in vapour exposed AMs. Impaired phagocytic ability following ECVC exposure suggests AMs in the lung of ECIG users may show impaired bacterial clearance. Taken together this suggests ECIG users may experience more frequent and more severe bacterial infections due to impaired innate immune response by AMs.