Characteristic Abnormalities in Saliva Biochemistry in Patients with COVID-19: A Systematic Review and Meta-Analysis

Abstract

Background: Outbreak pneumonia announced in Wuhan, China, in December 2019, had its causative factor classified as a new coronavirus (SARS-CoV-2). Since saliva can host several viruses including SARS-CoV-2, the transmission chance of viruses through saliva, particularly those causing respiratory infections, is unavoidable. COVID-19 can be detected through salivary diagnostic testing which has lots of advantages for medical care professionals and patients. However, the utility of saliva in diagnosing COVID-19 infection remains understudied. Aim of the study: In this review, we attempt to provide a comprehensive and updated source of information about salivary markers of liver enzyme, cytokines and oxidative stress in associated with the infections caused by COVID-19 and the various effects it has had on the dental profession and patients visits to dental clinics. Methods: A systematic search was conducted in PubMed/Medline, EMBASE, and Google Scholar, Scopus, and Web of Science, and Google Scholar from December 1, 2020, till April 15, 2021. Results: Nine studies were included in this study. Pooled results showed a significant increase in salivary liver enzymes (ALT, AST, ALP, GGT among patients with Covid‐19. Three studies showed a significant elevations in salivary TNF-α, CRP, IL‐6 and,IL-10 levels among patients with Covid‐19. Four studies that reported a significant in elevation salivary level of MDA, whereas reduction salivary levels of SOD, catalase, GPX. Conclusion: Our meta-analysis shows that deranged of salivary liver enzymes , hyper-inflammation, may indicate severe COVID-19 and could also predict mortality. Larger studies are needed to evaluate the relationship between derangement in salivary biochemical and mortality in COVID-19.