Salivary Biomarkers in Health, Gingivitis, and Periodontitis

Recent national initiatives from the NIDCR have focused on exploring the proteome of saliva and determining the potential for this fluid to provide diagnostic utility for oral and systemic diseases. A goal would be to develop point-of-care devices that could more effectively use saliva in dental and medical healthcare settings. OBJECTIVE: This study examined select biomarkers in periodontally healthy, gingivitis, and periodontitis patients to identify specific patterns of the analytes that reflect changes in oral inflammation and destructive disease. METHOD: Full mouth periodontal evaluations were conducted and whole unstimulated saliva was collected from 42 periodontally healthy subjects, 65 gingivitis patients, and 214 periodontitis patients (age 21-65, 206 females, 115 males; 227 Caucasian, 94 black). Levels of IL-1β, IL-6, MMP-8, PGE₂, TNFα, IFNα, and albumin were measured via Luminex/ELISA. RESULTS: While there was a substantial variation in the levels of these various analytes in saliva from healthy subjects, IL-1ß, MMP-8, IL-6, and IFNα significantly identified the periodontitis patients. Both PGE₂ and IL-1β levels were elevated in gingivitis, albeit only PGE₂ was comparable to levels in periodontitis. Smoking increased the levels of selected analytes in health, gingivitis and periodontitis. Moreover, this environmental factor appears to alter the correlation of the salivary analytes with the extent/severity of periodontitis. Finally CART and Random Forest Analysis strategies identified profiles of salivary biomarkers that accurately determined the existence of periodontal disease, and provided some insight regarding the extent of disease. CONCLUSION: The results demonstrate the likely utility of salivary biomarkers for monitoring oral health. The distinctive patterns of salivary biomarkers should also be capable of providing an adjunctive benefit in identifying the transition to periodontitis for early intervention and patient managment. Supported by NIH U01 DE017793, P20 DE020145.