By – Dr Rujuta Patil
BDS, MDS (Periodontist), PDCR
What Do We Know About COVID19 related Complications?
COVID19, caused by SARS-CoV-2 is being extensively studied by researchers worldwide, and cytokine storm has shown to be a fatal complication in patients with a severe form of the disease. Cytokine storm or CRS (cytokine release syndrome) is a systemic inflammatory response that can be caused by infection, some drugs, or other factors and is characterized by increased levels of proinflammatory cytokines.
Let’s understand the role of IL-6 – ‘A general marker of inflammation in COVID 19 related complications.
Interleukin-6 is a multi-effective cytokine secreted by many cells like monocytes, endothelial cells, epithelial cells, B and T cells. This IL-6 acts by binding to its receptor IL-6R and gp130 which initiates cell signal transduction and thus plays a central role in the cytokine storm. IL-6 also triggers the release of CRP which in turn increases the systemic inflammatory burden.
Recent findings have linked elevated IL-6 levels to significantly higher risk for pulmonary complications and increased need for mechanical ventilation in COVID 19 patients. Therefore, it is of prime importance for dental professionals to understand the role of periodontitis which increases the burden of systemic inflammation.
What Links Periodontitis (gum disease) To COVID19?
Periodontitis is a multifactorial inflammophilic disease that leads to the destruction of periodontium. Now lets explore different proposed hypothesis-
‘IL-6 – The culprit cytokine’
Studies have shown higher levels of inflammatory cytokines like IL-1β, TNF-α, IL-6, and CRP in saliva, GCF, serum, and gingival tissues of patients with periodontitis. Genetic studies have shown increased susceptibility to periodontitis in individuals with IL-6 polymorphisms. Following Periodontal therapy, reduction in serum IL-6 and CRP levels have been evidenced, which points towards reduction in systemic inflammatory burden. Literature shows the casual relationship between periodontitis and respiratory conditions like Chronic obstructive pulmonary disease (COPD), pneumonia, and lung functions.
‘Oral – gut axis’
The ‘oral – gut axis’ states that periodontal pathogens are frequently swallowed through saliva which in turn alter the local gut microbiome leading to gut dysbiosis and systemic inflammation. Such findings potentiate the association between periodontitis and COVID 19 related complications.
Tissue invasive bacteria are associated with pathogenesis of periodontitis which have capacity to adhere to respiratory epithelium and initiate or exacerbate infection indirectly through release of lipopolysaccharides (LPS) or directly via adhesion receptors. Such bacterial superinfection not only enhances cytokine release but also increases production of tissue destructive enzymes like matrix metalloproteinase (MMPs) that has deleterious effects on pulmonary tissues as well. Hence, there is biological plausibility for link between periodontitis, IL-6 levels and COVID 19 related pulmonary problems.
Shared Risk Factors
Primary risk factors for developing severe COVID 19 are diabetes mellitus, cardiovascular diseases, respiratory diseases, and obesity. Poor oral hygiene and periodontitis can exacerbate these conditions as quite a strong link has been established between periodontitis and these systemic conditions. COVID19 patients with diabetes mellitus are at a greater risk of developing severe complications like cytokine storm and a bidirectional relationship has been established between periodontitis and diabetes mellitus.
Hence, periodontitis can be considered as a co-risk factor in aggressive clinical manifestations of COVID 19 diabetic patients. All these findings point towards the importance of interdisciplinary care where dental professionals can look into the oral health of COVID 19 patients and try maintaining optimum oral status of these patients, thereby reducing the systemic inflammatory burden and avoid severe COVID19 related complications like cytokine storm.