S122 Effects of vaped e-cigarette liquid condensate upon human alveolar macrophage function. to vape or not to vape that is the question?

Abstract

Introduction and objectivesElectronic cigarette usage or “vaping” has risen exponentially in recent years in smokers and ex-smokers. Published data suggests that vaping e-cigarette liquid (ECL) may not be as benign as propounded by e-cigarette companies which are increasingly owned by “big tobacco”. Much of the current literature has focused on the effect of non-vaporised ECL – such studies do not fully reflect the exposure of the user, as the process of vaping causes chemical changes in ECL. To investigate the effect of unvaped ECL and vaped e-cig condensate (ECVC) using our novel system, with and without nicotine, on alveolar macrophage (AM) viability and immune responses.MethodsWe developed a novel method to produce ECVC to allow direct comparison with unvaped ECL. Nicotine concentration as assessed by GFID was 31 mg/ml in ECL and 26 mg/ml in ECVC. AMs were obtained from lung resection tissue and treated with ECVC/ECL ± nicotine. Cell viability was assessed by cell titre aqueous assay, apoptosis, necrosis and markers of macrophage phenotype (CD68, CD80, CD163, CD206) were assessed by flow cytometry. IL-8 release by AMs was assessed by ELISA.ResultsAM culture with ECL or ECVC resulted in dose dependent reduction in cell viability. ECVC was cytotoxic at lower concentrations than ECL (0.8% ECVC vs 5 %ECL, n = 6). 24 hour culture with 1% ECVC resulted in a 5fold increase in AM apoptosis and 2 fold increase in necrosis compared with 1%ECL (p = 0.079, n = 5). Nicotine containing ECVC caused more apoptosis vs nicotine free ECVC (27.2% vs 13.4%, (p = 0.0079,n = 4). Culture with 0.6%ECVC significantly increased supernatant levels of IL-8 compared with 1% ECL (p = 0.015, n = 4). ECVC was also found to affect macrophage phenotype, showing both nicotine dependent/independent regulations of markers of macrophage m1/m2 polarisation (CD80 p = 0.0357, CD163 p = 0.0179, CD206 p = 0.0357, n = 6).ConclusionsOur novel system creates ECVC which is sterile, minimises loss of nicotine and prevents dilution of the vapour. Vaped E-cigarette condensate is significantly more toxic to AMs than non-vaped e cigarette liquid. Furthermore, ECVC with nicotine is significantly more toxic than ECVC without Nicotine. Effects shown on inflammatory cytokine production and markers of macrophage polarisation indicate both nicotine dependent and independent effects of ECVC on alveolar macrophages.

E-cigarettes: Effects in phagocytosis and cytokines response against Mycobacterium tuberculosis

“…Free radicals are involved in the tobacco cytotoxicity and they are produced not only in the tobacco combustion, but also when e-liquid is heated in the atomizer [37]. Scott et al detected lower cytotoxicity in alveolar macrophages in the liquid form compared to the vaped [38]. The lower cytotoxicity observed in e-vapor extract can be related with the low concentration of toxicants due to the low temperature of evaporation of the e-liquid compared with the tobacco combustion when a cigarette is smoked [32,37,39].…”

Review of the British Thoracic Society Winter Meeting 2016, 7–9 December, London, UK

“…She noted that approximately 75% of e-cigarettes contain diacetyl, a chemical approved for food use but associated with respiratory disease (popcorn worker's lung) if inhaled 75. Subsequently, in the spoken session, e-cigarette vapour condensate was shown to be toxic to alveolar macrophages in vitro, especially in the presence of nicotine76 and the flavouring in e-cigarette vapour extracts was shown to alter macrophage function 77. Dr Onno Van Schayk (Maastricht, The Netherlands) discussed the development of nicotine vaccines for the treatment of tobacco addiction.…”