Research suggests vapers are vulnerable to pneumonia

8 February, 2018

The vapour from e-cigarettes may help pneumonia-causing bacteria stick to the cells that line the airways, increasing the risk of infection, according to research published in the European Respiratory Journal.

In a cross-centre study, researchers sought to examine the effects of e-cigarette vapour on platelet-activating factor receptors (PAFR) to assess whether exposure to e-cig vape was similar to that of traditional cigarette smoke, which is known to help bacteria stick to airway lining cells.

A research team at Queen Mary University of London began by looking at human nose lining cells. They exposed cells to e-cigarette vapour, some containing nicotine and some without, and left other cells unexposed. Cells exposed to either nicotine-containing or nicotine-free vapour produced levels of PAFR that were three times higher.

When researchers introduced pneumococcal bacteria to these cells, they found that exposure to either nicotine-containing or nicotine-free vapour doubled the amount of bacteria that stuck to airway cells.

Another team based at the University of Liverpool then tested the effect of e-cigarette vapour in mice. They found that inhaled exposure to e-cigarette vapour also increased levels of PAFR on airway lining cells and increased the number of pneumococcal bacteria in the respiratory tract after infection, making mice more susceptible to disease.

Finally, the team studied PAFR levels in cells lining the nose of 17 people. Of these, ten were regular users of nicotine-containing e-cigarettes, one used nicotine-free e-cigarettes, and six were not vapers. First, PAFR levels in the airways of all 17 volunteers were measured. Then, vapers were asked to take at least ten puffs on their e-cigarettes over five minutes. One hour after vaping, PAFR levels on airway cells increased three-fold.

Lead researcher, Jonathan Grigg, Professor of Paediatric Respiratory and Environmental Medicine at Queen Mary University of London, said: "Together, these results suggest that vaping makes the airways more vulnerable to bacteria sticking to airway lining cells. If this occurs when a vaper gets exposed to the pneumococcal bacterium, this could increase the risk of infection.

"Some people may be vaping because they think it is totally safe, or in an attempt to quit smoking, but this study adds to growing evidence that inhaling vapour has the potential to cause adverse health effects. By contrast, other aids to quitting such as patches or gum do not result in airway cells being exposed to high concentrations of potentially toxic compounds."

The research team hope to continue to study vaping and infections in humans and to look at the effects of using newly launched 'heat-not-burn' e-cigarettes.