Salivary miRNA Profiles in COVID-19 Patients with Different Disease Severities

Abstract

The oral mucosa is the first site of SARS-CoV-2 entry and replication, and it plays a central role in the early defense against infection. Thus, the SARS-CoV-2 viral load, miRNAs, cytokines, and neutralizing activity (NA) were assessed in saliva and plasma from mild (MD) and severe (SD) COVID-19 patients. Here we showed that of the 84 miRNAs analyzed, 8 were differently expressed in the plasma and saliva of SD patients. In particular: (1) miRNAs let-7a-5p, let-7b-5p, and let-7c-5p were significantly downregulated; and (2) miR-23a and b and miR-29c, as well as three immunomodulatory miRNAs (miR-34a-5p, miR-181d-5p, and miR-146) were significantly upregulated. The production of pro-inflammatory cytokines (IL-1β, IL-2, IL-6, IL-8, IL-9, and TNFα) and chemokines (CCL2 and RANTES) increased in both the saliva and plasma of SD and MD patients. Notably, disease severity correlated with NA and immune activation. Monitoring these parameters could help predict disease outcomes and identify new markers of disease progression.

Sample‐to‐answer salivary miRNA testing: New frontiers in point‐of‐care diagnostic technologies

“…These miRNA are involved in pathways relevant to SARS-CoV-2, including viral processing and immune response, indicating a need for further research to establish their role as biomarkers in severe cases (Hicks, Zhu, et al, 2023). Saulle et al found significant downregulation of miRNA let-7a, let-7b, and let-7c, and upregulation of miR-23a, miR-23b, and miR-29c, along with three immunomodulatory miRNA (miR-34a-5p, miR-181d-5p, and miR-146) in SARS-CoV-2 infections (Saulle et al, 2023).…”