Chronic Periodontal Disease and COVID - 19 Complications: Mechanistic Links Through Increase of CD14+ CD16+ Monocytes Blood Count

Introduction: It is well known that the SARS-CoV-2 virus that causes COVID-19 could enter the human host through the oral cavity. In patients with periodontal disease, there is an increase of Furin, Cathepsin, and CD14+ CD16+ monocytes. The hypothesis stated here sheds light on the regular need of periodontal management to reduce inflammation and the levels of deleterious host enzymes and cytokines, which could pave the way for deadly viral diseases such as COVID-19. The Hypothesis: Patients with periodontal disease are at increased risk of SARS-CoV-2 infection due to elevated levels of Furin and Cathepsin in oral cavity and COVID-19 complications like cytokine storm could occur with increased frequency in patients with periodontal disease due to the significant increase of CD14+ CD16+ monocytes in blood. Evaluation of the Hypothesis: Oral and periodontal examination of patients with mild, moderate, and severe SARS-CoV-2 infection could shed light on the significant role played by periodontal disease in making an individual more prone to get SARS-CoV-2 infection by elevation of Furin and Cathepsin and the elevation of CD14+CD16+ monocytes and proinflammatory cytokines in the blood that could consequently worsen COVID-19 complications like cytokine storm. The blood counts of CD14+CD16+ monocytes need to be assayed in SARS-CoV-2 patients with and without periodontal disease to observe if periodontal disease as a coexisting condition elevates the proportion of CD14 CD16 + monocytes in SARS-CoV-2 patients. In fact, assessment of monocyte subsets in peripheral blood could be used as an immunosurveillance marker in SARS-CoV-2 patients. Hence, SARS-CoV-2 positive patients with chronic periodontal disease should be closely monitored for potential signs of a cytokine storm and its related complications.