August 7, 2020 -- Patients with inflammation caused by periodontitis may experience more severe COVID-19 complications, according to an article published online July 30 in the Journal of the California Dental Association.
Good oral hygiene prevents bacteria in the gums from entering the bloodstream and triggering inflammation, which prompts the release of the protein interleukin-6 (IL-6). Since high IL-6 levels can destroy tissue and the linings in blood vessels and lungs and reduce oxygen, sources of inflammation, like gum disease, should be eliminated to prevent complications, according to the authors.
Oral pathogens such as SARS-CoV-2 enter systemic circulation and can cause upregulated production of inflammatory mediators leading to lethal cytokine storm. Patients with periodontitis are prone to producing these proinflammatory cytokines. Moreover, oral bacteria can predispose individuals to pneumonia, chronic obstructive pulmonary disease, and potentially COVID-19 pulmonary complications.
"Dentists should promote screening, plaque control, and periodontal treatment because a healthy periodontium can help decrease the severity and complications related to COVID-19," wrote the group, led by Dr. Shervin Molayem, a periodontist in private practice in Los Angeles.
Bad bacteria, more risk
Scientists, public health officials, and agencies at all government levels continue to search for ways to fight and prevent the spread of SARS-CoV-2, but they still don't have a definitive answer as to why approximately 158,000 people have died from the virus while others get it and don't even know they have it. Though they have found links between the novel coronavirus and comorbidities, like diabetes and hypertension, experts continue to search for other clues. These comorbidities also have been associated with heightened risks of complications and death from the novel coronavirus that were associated with altered oral biofilms and periodontal disease. An analysis of COVID-19 studies and other data strengthens the connections, according to the authors.
Evidence has shown that high levels of IL-6 are a predictor of respiratory failure, with a 22 times greater risk for respiratory complications. There was a strong link between the need for ventilation and IL-6 serum levels above 80 pg/mL. Additionally, a recent meta-analysis found that severe COVID-19 cases presented a 2.9-fold increase in IL-6 levels compared with mild to moderate cases without complications, according to the authors.
Another small study showed the importance of IL-6 for COVID-19-related pulmonary complications. In China, patients with severe COVID-19 were given tocilizumab. About 91% of patients recovered after taking the humanized IL-6 receptor monoclonal antibody, which has high affinity for IL-6 receptors, for an average of 13.5 days. Tocilizumab binds to the receptors, preventing IL-6 from altering cellular behavior and, in the end, improving inflammation, they wrote.
Promoting oral hygiene to reduce COVID-19 risk
Dentists should recommend that patients maintain good oral hygiene, including brushing for two minutes twice each day. Professional deep cleanings can also be scheduled, and genetic testing may be useful. Genetic IL-6 testing can assess a patient's risk, the group noted.