TNF-αand OSX mRNA of salivary small extracellular vesicles in periodontitis: a pilot study.

This cross-sectional study explored extracellular vesicle (EV)-derived gene expression of markers for bone turnover and pro-inflammatory cytokines in periodontal disease. Whole unstimulated saliva was collected from fifty-two participants (18 healthy, 13 gingivitis and 21 stages III/IV periodontitis), from which small extracellular vesicles (sEVs) were enriched using the size-exclusion chromatography (SEC) method, and characterised by morphology, EV-protein, and size distribution, using transmission electron microscopy (TEM), enzyme-linked immunosorbent assay (ELISA), and Nanoparticle Tracking Analysis (NTA), respectively. Bone turnover markers and pro-inflammatory cytokines in salivary sEVs were evaluated using RT-qPCR. Salivary sEVs morphology, mode, size distribution and particle concentration were comparable between healthy, gingivitis, and periodontitis patients. A CD9+ subpopulation was significantly higher in periodontitis-derived salivary sEVs compared to healthy. The detection of sEVs mRNA for osterix (OSX) and tumour necrosis factor-alpha (TNFα) was significantly decreased and increased, respectively, in periodontitis compared to healthy controls, with good discriminatory power for periodontitis diagnosis [area under the curve (AUC) >0.72]. Our study demonstrated that salivary sEVs mRNAs may serve as a potential non-invasive biomarker source for periodontitis diagnosis.