Some fourth-generation models, such as the Juul device, are associated with unique changes in markers of immune response in the human airways, according to a new peer-reviewed paper by UNC School of Medicine researchers led by toxicologist Ilona Jaspers, Ph.D.
Lead author Dr. Elise Hickman, a recent graduate of the Jaspers lab, and colleagues published their study in the American Journal of Respiratory and Critical Care Medicine and found that users of fourth-generation nicotine-salt-containing devices exhibited unique mixed indications Cellular biomarkers of immunosuppression.
“Our work demonstrates the importance of considering device type in future clinical, epidemiological and mechanistic studies of the health effects of e-cigarettes,” said Jaspers, professor of pediatrics, microbiology and immunology. “We also believe this research can help regulators determine which products cause the most severe biological changes in airway cells, which are important for maintaining proper health.”
E-cigarettes have grown in popularity over the past decade.
Some people are starting to use them as a means to quit smoking, believing that e-cigarettes are a safer option, both short- and long-term. Additionally, because e-cigarettes are tar-free, consumers believe that vaping will reduce their future cancer risk.
“It’s impossible to know whether e-cigarettes reduce cancer risk or many other long-term conditions,” Jaspers said. “It took 60 years of research to show that smoking causes cancer. E-cigarettes have been around for about 15 years. However, studies in our lab and many others have shown that many of the same exist in the airways that we have documented in smokers. Acute biological effects. Frankly, we’re seeing some changes in cellular and immune defenses in vapers that we haven’t seen before, which is very concerning.”
The biggest worry for researchers, doctors and public health officials is that teens who wouldn’t otherwise try cigarettes are turning to e-cigarettes, which contain nicotine — a drug with health effects of its own that go beyond addiction — and thousands of chemicals , many of which are FDA-approved for consumption but not for inhalation.
Several studies have shown that inhaling chemical-laden nicotine aerosols suppresses the immune response in the respiratory tract of smokers and e-cigarette users.
Several studies, including some from UNC, detail how different chemicals in various e-cigarettes, including those that make up thousands of different flavors, can adversely affect airway cells.
The Jaspers lab, which has been at the forefront of such research, set out to study the effects of different types of vaping devices. For the study, her team collected central airway (sputum) samples from non-smokers, smokers, and users of third- and fourth-generation vaping devices.
Third-generation devices include vape pens and box mods. The fourth generation includes e-cigarettes containing nicotine salts, such as Juul products and disposable e-cigarettes, which have grown in popularity as sales of Juul products have been restricted.
A significant increase in bronchial epithelial cells in the sputum of fourth-generation e-cigarette users indicates airway damage, as bronchial epithelial cells normally constitute an intact barrier in the airways and were not found in sputum samples. Levels of two proteins, sICAM1 and sVCAM1, were significantly lower in fourth-generation e-cigarette users compared with all other groups. These proteins are important in fighting infections and other diseases.
In addition, fourth- and third-generation e-cigarette users had significantly lower levels of CRP, IFN-g, MCP-1, uteroglobin, MMP-2, and VEGF proteins, all of which are important for overall immune defense. Therefore, the more these proteins are reduced, the more suppressed our immune system is.
Another key finding of the study was that fourth-generation e-cigarette users had the most pronounced changes across all groups when examining a cocktail of immune markers as a whole rather than individually, suggesting a shift in immune homeostasis.
The study did not reveal evidence that e-cigarettes cause cancer, emphysema, chronic obstructive pulmonary disease or other long-term diseases associated with long-term smoking. But researchers believe that altered immune responses in the airways over the years, especially in adolescents, may play an important role in the development of long-term health conditions and susceptibility to inhaled pathogens.
The National Institutes of Health funded the study.
