Smoking Enigma in Coronavirus Disease 2019: A Tug of War between Predisposition and Possible Way Out.

BACKGROUND

The recent global inclination for smoking during the Coronavirus Disease 2019 (COVID-19) pandemic has drawn attention to the impact of smoking on COVID-19. While smoking increases susceptibility to common respiratory pathogens including the closely related coronaviruses, COVID-19 causing Severe Acute Respiratory Coronavirus 2 (SARS-CoV-2) being a respiratory pathogen intrigues the possible association between smoking and viral pathogenicity.

SMOKING AND COVID-19: The gender dependence of COVID-19 infection rates and a higher prevalence of smokers among males made the scientific world assume smoking to be a confounding variable in sex predisposition to COVID-19. Conversely, the controversial findings of discrepant morbidity and mortality rates of COVID-19 among smokers questioned the credibility of this hypothesis. More importantly, nicotine in smoking has been hypothesized to downregulate Interleukin-6 (IL-6) which plays a role in COVID-19 severity and to interfere with the Angiotensin-Converting Enzyme 2 (ACE2), the receptor of SARS-CoV-2 led the scientists to experiment nicotine patch prophylactically against COVID-19. Besides, interaction between spike protein and nicotinic acetylcholine receptors (nAChRs) supports the nicotinic cholinergic system dysregulation hypothesis in COVID-19 pathophysiology leading to its therapeutic use. However, despite the contradictions in the direct impact of smoking, it surely acts as fomites for viral transmission.

CONCLUSION

Irrespective of the role nicotine in COVID-management, compassionate use of smoking against SARS-CoV-2 cannot be recommended until the therapeutic value gets proved and therapeutic form becomes available.