PT - JOURNAL ARTICLE AU - Miranda Ween AU - Paul Reynolds AU - Sandra Hodge TI - Hidden dangers of E-cigarettes: Airway macrophage dysfunction and altered inflammatory response AID - 10.1183/13993003.congress-2016.OA4981 DP - 2016 Sep 01 TA - European Respiratory Journal PG - OA4981 VI - 48 IP - suppl 60 4099 - http://erj.ersjournals.com/content/48/suppl_60/OA4981.short 4100 - http://erj.ersjournals.com/content/48/suppl_60/OA4981.full SO - Eur Respir J2016 Sep 01; 48 AB - E-cigarettes are perceived as being harmless; however, new data suggests that E-cigarettes not only release a wide range of compounds but can to cause physiological damage to users. We hypothesised that E-cigarette vapour caused defective alveolar phagocytosis of apoptotic airway cells ('efferocytosis') and airway bacteria, and that this would be associated with changes to macrophage recognition molecules, and production of pro-inflammatory cytokines. THP-1 macrophages were treated with various concentrations/combinations of the E-cigarette system including E-liquid, nicotine (18mg/mL), vegetable glycerine (VG), propylene glycol (PG), and cigarette smoke extract for comparison. Macrophage phagocytosis of NTHi and apoptotic epithelial cells, pro-inflammatory cytokines, macrophage recognition molecules and IL-1β (as a marker of inflammasome activation) were assessed.Phagocytosis of NTHi was significantly decreased by E-liquid, and E-liquid+nicotine (59%, 33%) and efferocytosis was significantly decreased by E-liquid, Nicotine, and E-liquid+nicotine (28%, 33%, and 35%). Cell surface phagocytosis and efferocytosis recognition marker SRA-1 was also significantly reduced after treatment with e-liquid, nicotine, and e-liquid+nicotine. IL-1β was increased by 35%, 40%, and 47% respectively when macrophages were exposed to E-liquid, Nicotine, and E-liquid+Nicotine.E-cigarette components contribute to suppressed macrophage function and inflammatory response, potentially contributing to chronic lung inflammation. Our data provide important information on the harmful effects of E-cigarettes for health providers, policy makers, and general public.