Presentation Category
Research, Clinical
Introduction/Context/Diagnosis
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been suggested to replicate and be found in the oral cavity. The objective of this preliminary literature review is to determine the effects of cigarette smoke on the risk of SARS-CoV-2 infection in the oral cavity, and the risk for the overall health. SARS-CoV-2, which causes coronavirus disease 2019 (COVID-19), uses the ACE2 receptor and protease TMPRSS2 for entry into host cells. The cigarette smoke condensates upregulates these receptors in human gingival epithelial cells. Because smoking can alter expression of COVID-19 viral entry genes, smokers are more susceptible to SARS-CoV-2 infection. Several studies have also shown that people with respiratory diseases caused by tobacco are at higher risk of developing severe COVID-19 symptoms. More research is needed to further assess the relationship and mechanism of cigarette smoking on the risk of SARS-CoV-2 infection in the oral cavity, in efforts to minimize the severity and treat patients contracted with the disease.
Methods/Treatment Plan
A review of the current literature was identified by searching the PubMed database for published articles. Keywords such as “smoking,” “oral cavity,” “innate immunity,” “COVID-19” were used to gather articles relevant to the topic for further analysis. Results by year were filtered from March of 2020 to most current. While most studies focused on the relationship between smoking and risk of COVID-19 infection in the respiratory system rather than the oral cavity, all relevant articles were noted and organized based on molecular biology pathways and more broadly epidemiological studies.
Results/Outcome
According to our search, five articles were identified and analyzed. It is evident that smoking can play a detrimental role in the infection of SARS-CoV-2 in the oral cavity not only by weakening the immune system but also by upregulating the receptors that allow the entry of SARS-CoV-2 into host cells. According to research, active smokers have twice the risk of contracting severe COVID-19 compared to non-smokers. Several epidemiological studies have shown higher smoking prevalence among COVID-19 infected patients. Other literature suggest the mechanism whereby cigarette smoke may increase the chances of developing SARS-CoV-2 infection in the GECs. In addition, smokers exhibiting AhR-dependent regulation of ACE2 receptors in the oral cavity have increased susceptibility to SARS-CoV-2 infection, and thus have higher chances of developing severe symptoms of COVID-19.
Significance/Conclusions
Cigarette smoke is harmful for both oral and systemic health in humans. While more research on this topic is needed to further assess the mechanism in which smoking can increase the susceptibility of COVID-19, this preliminary review has provided a solid foundation in which to gather more information and build on for a better understanding of this disease. In addition, delving deeper in the mechanisms involved in SARS-CoV-2 infection in cells of the oral cavity may suggest therapeutic interventions for preventing viral infection and transmission. Other interesting topics to investigate in the future would be whether oral diseases such as xerostomia, caries, or periodontitis increases the chances of contracting COVID-19 or complications thereof. Researching the effect of COVID-19 infection on oral health could also provide more insight into how the disease can affect vital parts of the human body.
Format
Event
The Effects of Cigarette Smoke on SARS-CoV-2 Infection in the Oral Cavity – a Preliminary Literature Review
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been suggested to replicate and be found in the oral cavity. The objective of this preliminary literature review is to determine the effects of cigarette smoke on the risk of SARS-CoV-2 infection in the oral cavity, and the risk for the overall health. SARS-CoV-2, which causes coronavirus disease 2019 (COVID-19), uses the ACE2 receptor and protease TMPRSS2 for entry into host cells. The cigarette smoke condensates upregulates these receptors in human gingival epithelial cells. Because smoking can alter expression of COVID-19 viral entry genes, smokers are more susceptible to SARS-CoV-2 infection. Several studies have also shown that people with respiratory diseases caused by tobacco are at higher risk of developing severe COVID-19 symptoms. More research is needed to further assess the relationship and mechanism of cigarette smoking on the risk of SARS-CoV-2 infection in the oral cavity, in efforts to minimize the severity and treat patients contracted with the disease.
