Investigation of the mechanisms underlying respiratory abnormalities in vaping product users 9281

Abstract Description Symptomatic and asymptomatic effects of vaping are poorly understood. To address this issue, our research group initiated a prospective research cohort (VapALERT) monitoring respiratory health of individuals who vape for up to 5 years. So far, identified anomalies are airway hyperresponsiveness (AHR), reduced diffusion capacity and increased ventilation heterogeneity. To research the underlying mechanisms of potential immunological nature, we leveraged data from VapALERT non-invasive tests, including oscillometry and induced sputum, as well as our pre-clinical model of vaping aerosol exposure. Oscillometry assessment using the TremoFlow showed that 20 individuals out of 68 had abnormally elevated resistance at 5 Hz (R5) and/or 19 Hz (R19), suggesting smaller caliber of distal and proximal bronchi potentially caused by ongoing inflammation. Also, of the individuals with elevated R5 and/or R19, 40% had a PC20 below 4 mg/ml compared to 17% in the group with normal R5 and R19. Moreover, FeNO, sputum eosinophils and neutrophils were within normal range in volunteers able to provide sputum. Using our in vivo model, we established that a short-term exposure to nicotine- and flavor-free vaping aerosols did not cause lung inflammation or AHR. Overall, further investigations are required to identify the involvement of the immune system in the lungs of individuals who vape. Chronic exposure protocol may be required to reproduce in mice what has been observed in humans. Funding Sources Funded by Health and Social Services Ministry, AIRS network and CIHR Topic Categories Immune Mechanisms of Human Disease (HUM)