Vaping simulation kills lung macrophages, inhibits phagocytosis

  • Scott A & al.
  • Thorax
  • 13 Aug 2018

  • curated by Jenny Blair, MD
  • Clinical Essentials
Access to the full content of this site is available only to registered healthcare professionals. Access to the full content of this site is available only to registered healthcare professionals.


  • Exposure to e-cigarette vapor condensate (ECVC) leads to dose-dependent cell death, inflammatory response, inhibited phagocytosis in alveolar macrophages (AMs). 
  • Vaping and nicotine contributed independently to harm.
  • Authors: “We caution against the widely held opinion that e-cigarettes are safe.”

Why this matters

  • Though touted as a smoking-cessation aid, vaping's long-term safety is unclear.
  • Many studies assess nonvaporized e-cigarette liquid (ECL), but vaping process alters composition.
  • Authors devised a way to generate and study ECVC. 

Key results

  • Viabilities of AMs exposed to ECVC and unvaped ECL, vs untreated controls (UTCs): 
    • ECVC 0.8% volume/volume (v/v): 18.2% viable (interquartile range [IQR], 15.7%-19.5%; P<.001 nicotine-free ecvc viable p>
    • ECL 2.5% v/v: 78.8% viable; nicotine-free ECL, 84.6% viable;
    • All effects were dose-dependent.
  • Compared with UTCs, AMs subject to ECVC exposure also:
    • Increased apoptosis, necrosis;
    • Increased multiplied reactive oxygen species release 50-fold;
    • Increased IL-6, TNF-α, matrix metalloprotease 9;
    • Reduced phagocytosis by 30%.

Study design

  • Researchers assessed viability of AMs from never-smokers after 24-hour exposure to regular, nicotine-free ECVC and regular, nicotine-free ECL.
  • ECVC simulates vaped ECL.
  • Funding: Medical Research Council (UK); British Lung Foundation. 


  • In vitro study reflecting acute exposure only.
  • Flavors not assessed.
  • Real-life nicotine dosage during vaping varies widely. 

Please confirm your acceptance

To gain full access to GPnotebook please confirm:

By submitting here you confirm that you have accepted Terms of Use and Privacy Policy of GPnotebook.