Lung's Immune Response Damaged by E-cigarettes

E-cigarettes—thought by many to be a “healthier” alternative to tobacco cigarettes—were found by John Hopkins Bloomberg School of Public Health investigators to not only compromise the lung’s immune system, but to also include some of the same chemicals present in traditional cigarettes.

The paper’s senior author, Shyam Biswal, PhD, a professor in the Department of Environmental Health Sciences at the Bloomberg School, pointed out in a statement that their findings are specifically relevant for chronic obstructive pulmonary disease (COPD) patients, a susceptible group who typically transition to e-cigarettes from nicotine cigarettes.

“Patients with COPD experience multiple viral and bacterial exacerbations of their disease, which is the major cause of COPD-related morbidity and mortality. Therefore, our main interest was to determine whether e-cigarette exposure has any impact on pulmonary immune defenses against bacteria or viruses that are commonly associated with acute exacerbations of COPD,” the investigators wrote in their study published in PLOS ONE.

For a two week period, the researchers exposed mice to either air or e-cigarette vapor. The mice were then separated the mice into three groups where they were given nasal drops which contained a bacteria that causes pneumonia and sinusitis called Streptococcus pneumoniae,the Influenza A virus, or a mixture containing neither virus or bacteria.

In doing so, they discovered mice subjected to e-cigarette vapor experienced a 34% increase in inflammation, with evidence that immunity measures which would fight off bacteria were “significantly impaired.” The writers also noted the e-cigarette mice began to lose weight at 10-12 days, followed by death in 20% of them—compared to none in the uncompromised group.

Another standout discovery was that e-cigarettes contained the same free radical vapors, which are linked to combustion, that are present in tobacco cigarettes and air pollutants.

“We were surprised by how high that number was, considering that e-cigarettes do not produce combustion products,” said the lead author, Thomas Sussan, PhD, assistant scientist in the Department of Environmental Health Sciences at the Bloomberg School. “Granted, it’s 100 times lower than cigarette smoke, but it’s still a high number of free radicals that can potentially damage cells.”

“Our findings suggest that e-cigarettes are not neutral in terms of the effects on the lungs,” Biswal deduced.