18 June 2021 | 1:45pm - 2:30pm (SGT)

Use of SARS-CoV-2 patient's saliva for the diagnosis of infection and monitoring the disease progression based on oral IgG, inflammatory cytokines, and oral microbiome profile

Speaker

Abstract

Given that saliva can be used for direct diagnosis of the SARS-CoV-2 virus infection based on the quantification of the specific immunoglobulins (IgG) produced against it, measurement of IgG in saliva is a useful diagnosis tool for SARS-CoV-2 virus infection. In addition, we suggest that oral bacteria also have a pertinent role in facilitating co-infections with the SARS-CoV-2 virus. Considering that there have been reports that link oral microbiota to the mortality of patients with SARS-CoV-2 infection, we found that it is necessary to consider whether poor oral hygiene could be a modifiable risk factor for SARS-CoV-2 complications during the pandemic.


In this study, we found acute antibody responses to SARS-CoV-2 in 84 patients with COVID-19. During treatment after symptom onset, more than 87% of the patients were tested negative for antiviral IgG and RT-PCR. Following 16S targeted sequencing, we observed a significant diminution of alpha-diversity (species richness) in COVID-19 patients. Quime 2 analysis showed that Prevotella, Veillonella and Soonwooa are associated with SARS-CoV-2 infection. Biomarkers species for healthy oral microbiota are Neisseria, Granulicatella, Porphyromonas, Rothia and Streptococcus. In cytokine multiplexing analysis, we found seven COVID-19-related discriminant cytokines (IL-4, IL-6, IL-15, MCP-1, MIP-1A, IL-2, TNF-α). IL-6 and IL-4 are the most discriminant cytokines for COVID-19 and controls, respectively, as confirmed by their pairwise analysis.


Gaining deeper knowledge of potential changes in the saliva IgG, inflammatory cytokines, and profiling of the oral microbiome in this disease may allow the identification of new diagnostic and prognostic biomarkers. This information and knowledge will improve our understanding of the pathophysiological mechanisms associated with the disease. Saliva as a diagnostic sample can provide useful clinical information about the diagnosis, disease management and control of SARS-CoV-2.