This is according to new research published in the American Journal of Respiratory and Critical Care Medicine.
What are damaging immune responses?
Immune responses are the biological reactions of cells and fluids to an outside substance the body doesn’t recognise as its own. Such immune responses play roles in disease, including lung disease spurred on by cigarette use.
Mehmet Kesimer, PhD, senior author and associate professor of pathology and laboratory medicine at the UNC School of Medicine, and co-authors report findings from what is believed to be the first study of the harmful effects of e-cigarettes using sputum samples from human lungs.
“There is confusion about whether e-cigarettes are ‘safer’ than cigarettes because the potential adverse effects of e-cigarettes are only beginning to be studied,” said Kesimer, who is also a member of the UNC Marsico Lung Institute.
“This study looked at possible biomarkers of harm in the lungs, and our results suggest that in some ways using e-cigarettes could be just as bad as smoking cigarettes.”
A 2016 Surgeon General’s report found that e-cigarette use increased by 900 percent among high school students from 2011 to 2015. Also in 2016, the Food and Drug Administration extended its regulatory oversight of tobacco products to include e-cigarettes.
About the study
The study compared sputum samples from 15 e-cigarette users, 14 current cigarette smokers and 15 non-smokers. They found e-cigarette users uniquely exhibited significant increases in:
- Neutrophil granulocyte- and neutrophil-extracellular-trap (NET)-related proteins in their airways. Although neutrophils are important in fighting pathogens, left unchecked neutrophils can contribute to inflammatory lung diseases, such as COPD and cystic fibrosis.
- NETs outside the lung. NETs are associated with cell death in the epithelial and endothelium, the tissues lining blood vessels and organs. The authors write that more research is necessary to determine if this increase is associated with systemic inflammatory diseases, such as lupus, vasculitis, and psoriasis.
The negative effects
The study also found that e-cigarettes produced some of the same negative consequences as cigarettes. Both e-cigarette and cigarette users exhibited significant increases in:
- Biomarkers of oxidative stress and activation of innate defence mechanisms associated with lung disease. Among these biomarkers are aldehyde-detoxification and oxidative-stress-related proteins, thioredoxin (TXN) and matrix metalloproteinase-9 (MMP9).
- Mucus secretions, specifically mucin 5AC, whose overproduction has been associated with pathologies in the lung including chronic bronchitis, bronchiectasis, asthma, and wheeze.
Study limitations include the fact that, of the 15 e-cigarette users, five said they occasionally smoked cigarettes and 12 identified themselves as having smoked cigarettes in the past.
“Comparing the harm of e-cigarettes with cigarettes is a little like comparing apples to oranges,” Kesimer said. “Our data shows that e-cigarettes have a signature of harm in the lung that is both similar to what we see in cigarette smokers and unique in other ways. This research challenges the concept that switching to e-cigarettes is a healthier alternative.”