Porphyromonas gingivalis in Periodontitis: A Forgotten Enemy Behind COVID-19 Pandemic

Abstract

Introduction: Theories or hypotheses regarding the connection between COVID-19 and periodontal disease are increasing during the COVID-19 pandemic. COVID-19 has been reported to have adverse outcomes related to the establishment of a cytokine storm, which is similar to the cytokine expression profile and cells involved in periodontitis. Nevertheless, the exact etiology why cytokine storm is vulnerable in COVID-19 as well as periodontitis still not clearly understood. The hypothesis: Recently, the phenomenon of angry macrophages can be explained by M1/M2 macrophage polarization. Periodontitis patients that harbored Porphyromonas gingivalis have a greater M1/M2 ratio than healthy patients, thus have more active M1 macrophages that produce pro-inflammatory cytokines. We hypothesize that periodontal disease could be a burden in defense mechanism toward infectious diseases, particularly the COVID-19. Evaluation of the Hypothesis: Endotoxin tolerance caused by P. gingivalis lipopolysaccharides shifts immune response from T helper (Th)-1 toward Th2, which leads to a less effective antivirus system. This mechanism may explain the connection between COVID-19 and periodontal disease through their cytokine profiles, microbial balance, and M1/M2 homeostasis. Recommendation for maintenance of oral hygiene and periodontal treatment is mandatory in the COVID era.

Keywords

• covid-19
• macrophage polarization
• periodontitis
• porphyromonas gingivalis
• th1/th2