Rheumatoid arthritis and salivary biomarkers of periodontal disease

Aim: To test the hypothesis that rheumatoid arthritis (RA) influenced levels of salivary biomarkers of periodontal disease. Methods: Medical assessments, periodontal examinations and pain ratings were obtained from 35 RA, 35 chronic periodontitis and 35 age- and gender-matched healthy controls in a cross-sectional, case-controlled study. Unstimulated whole saliva samples were analysed for interleukin-1 (IL-1), matrix metalloproteinase-8 (MMP-8) and tumour necrosis factor-± (TNF-±) concentrations. Results: The arthritis and healthy groups had significantly less oral disease than the periodontitis group (P<0.0001), with the arthritis group having significantly more sites bleeding on probing (BOP) than matched controls (P=0.012). Salivary levels of MMP-8 and IL-1 were significantly elevated in the periodontal disease group (P<0.002), and IL-1 was the only biomarker with significantly higher levels in the arthritis group compared with controls (P=0.002). Arthritis patients receiving anti-TNF-± antibody therapy had significantly lower IL-1 and TNF-± levels compared with arthritis patients not on anti-TNF-± therapy (P=0.016, 0.024) and healthy controls (P<0.001, P=0.011), respectively. Conclusion: RA patients have higher levels of periodontal inflammation than healthy controls, i.e., an increased BOP. Systemic inflammation appears to influence levels of select salivary biomarkers of periodontal disease, and anti-TNF-± antibody-based disease-modifying therapy significantly lowers salivary IL-1 and TNF-± levels in RA.