Expression Levels of miR-181 Family Members in Oral Biofluids as Biomarkers for Periodontitis Severity.

This study aimed to assess the diagnostic potential of microRNA-181 (miR-181) family members in oral biofluids, namely saliva and gingival crevicular fluid (GCF), as biomarkers for periodontitis severity. A cohort of 150 patients with periodontitis, including 82 with mild to moderate and 68 with advanced periodontitis, along with 90 healthy controls, were recruited. Analysis of miR-181 family expression using quantitative real-time polymerase chain reaction (qRT-PCR) revealed differential expression levels in oral biofluids among the study groups. Salivary miRNAs, particularly miR-181a, displayed significant discriminatory ability in distinguishing periodontitis patients from healthy controls and between different stages of periodontitis severity, with high sensitivity and moderate to high specificity. In GCF samples, miR-181a and miR-181b exhibited robust discriminatory ability, while miR-181c showed moderate discriminatory ability. Conversely, miR-181d demonstrated lower discriminatory power in both saliva and GCF. Additionally, combination diagnosis using miR-181 family showed superior performance compared to individual miRNAs. Furthermore, enzyme-linked immunosorbent assay (ELISA) analysis of inflammatory biomarkers (TNF-α, IL-6, and IL-1β) in GCF revealed elevated levels in periodontitis patients compared to healthy controls, with a further increase observed in advanced periodontitis. Spearman correlation analysis demonstrated a significant negative correlation between miR-181 family expression in GCF and inflammatory biomarker levels, indicating their potential role in modulating periodontal inflammation. Overall, these findings suggest that miR-181 family members in oral biofluids, particularly saliva, hold promise as diagnostic biomarkers for periodontitis severity. Additionally, their negative correlation with inflammatory biomarkers highlights their potential as modulators of periodontal inflammation, providing valuable insights into the pathogenesis of periodontitis.