Researchers quantify salivary inflammatory mediators in COVID-19

Frank A. Boksa, University of Iowa College of Dentistry, Iowa City, IA, presented "Salivary Immune Signature of SARS-nCoV2 Infection" at the hybrid 51^st Annual Meeting & Exhibition of the AADOCR, held in conjunction with the 46^th Annual Meeting of the Canadian Association for Dental Research (CADR), online and onsite in Atlanta, GA, on March 26, 2022.

With more than 219 million confirmed cases of SARS-nCoV2 infection and 4.55 million deaths, the COVID-19 pandemic has led to a dramatic loss of human life worldwide. Besides saliva being a reservoir for the virus, emerging evidence correlates the salivary virus levels to severity of infection, hospitalization, and death. Saliva is a complex secretory fluid with several bacterial and host breakdown products that perform numerous housekeeping functions. The inflammatory complications of COVID-19 are well-established at this time, however, the levels of these inflammatory mediators in saliva are not quantified. The researchers quantified the salivary inflammatory mediators in COVID-19 using a cross-sectional study design.

The researchers collected saliva from 87 patients that were frequency matched for gender, age, BMI, and smoking status were divided into three groups: Symptomatic COVID-19 positive (symptomatic), Symptomatic COVID-19 negative (presenting with a flu-like illness, FLI), Asymptomatic (Negative) based on their titers from RT-PCR in nasopharyngeal swabs and saliva. Levels of proinflammatory cytokines and other immune mediators were quantified using a TH-17 cytokine assay kit and read using the Bio-Plex 200 fluorescent microplate reader. Steel-Dwass test protecting the overall error rate was used to determine statistical significance.

The researchers concluded that identification of inflammatory markers in COVID-19 patients that is different than the other flu-like illnesses indicate a unique immune signature associated with the disease. Salivary levels of several of these immune mediators mirror the systemic levels, indicating a potential role of saliva in COVID pathogenesis.