Vaping alters airway protein markers, defence proteins
The use of e-cigarettes changes the innate defence protein profiles in airway secretions, a new study has shown. These changes may lead to questions about e-cigarettes as the supposed healthier alternative to smoking.
In the study, induced sputum samples from 14 current cigarette smokers, 15 current e-cigarette smokers and 15 never smokers were analysed using quantitative proteomics. Mucin concentration and neutrophil extracellular trap (NET) formation were also investigated.
In the nonsmoker group, levels of markers for nicotine and tobacco exposure, cotinine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), respectively, were below the detection limits.
In contrast, serum cotinine and urine NNAL levels in the cigarette group were significantly correlated to the number of sticks smoked per day (p<0.05). Serum cotinine in the e-cigarette group was also significantly associated to the number of daily e-cigarette puffs (p<0.0001) while urine NNAL levels did not show significant correlations.
Proteomic analysis of sputum samples revealed that e-cigarette users have quantitatively and qualitatively altered protein profiles compared with nonsmokers and cigarette smokers.
Notably, compared with cigarette smokers, e-cigarette smokers showed more proteins with different abundances relative to nonsmokers, with both groups showing altered levels of 44 and 81 proteins, respectively.
Levels of specific markers associated with cigarette smoking—such as thioredoxin, glutathione S-transferase and anti-thrombin 3—were also significantly increased in e-cigarette smokers. In contrast, levels of mucosal defence proteins were elevated in cigarette smokers but not in e-cigarette users.
“Taken together, our results indicate that the effects of e-cigarettes are both overlapping with and distinct from what is observed in otherwise healthy cigarette smokers,” said researchers.
“In conclusion, our results challenge the concept that e-cigarettes are a healthier alternative to cigarettes and reverse smoking-induced adverse health effects,” they added.