Though research on the significance of that gene suppression is still ongoing, the initial results suggest that e-cig users may have compromised immune responses, making them potentially more vulnerable to infections and diseases.
“The gene expression changes we’re seeing are consistent with a modified immune response,” lead researcher Ilona Jaspers of the University of North Carolina at Chapel Hill told Ars. “Any time you change [the immune system], it's probably out of balance," she said, explaining that a hyper-immune response or a weak response is problematic. Whether the imbalance caused by e-cigs leads to boosted infection risks or other immune diseases, “we don’t know,” Jaspers added.
For the study, Jaspers and colleagues mined the noses of different groups of healthy people—around a dozen each of cigarette smokers, e-cigarette vapers, and people who didn’t use either. The researchers fit the volunteers into the three categories based on smoking “diaries” that they filled out for three weeks prior to nose-sampling. The researchers homed in on the schnoz because cellular and immune responses there can offer clues to those responses in the lungs, which are harder to sample, Jaspers noted.