Marginal jawbone loss is associated with onset of rheumatoid arthritis and is related to plasma level of receptor activator of nuclear factor kappa-B ligand (RANKL)

Objectives We investigated whether periodontitis, displayed as marginal jawbone loss, preceded onset of symptoms of RA. Furthermore, we analysed plasma levels of receptor activator of nuclear factor kappa-B (RANKL), a cytokine crucial for bone resorption and of anti-citrullinated peptide antibodies (ACPA) in pre-symptomatic individuals compared with controls. Methods Marginal jawbone levels were measured on dental radiographs from the premolar/molar regions of the jaws of 176 subjects of whom 93 had developed RA. Of these, 46 had documented radiographs predating symptom onset and sex, age and smoking status referents could be matched for 45 of them. The plasma RANKL concentrations were analysed using ELISA. The receiver operating characteristic curve was used to define the cut-off value. Results Compared with matched referents, bone loss was significantly higher in never-smoking, pre-symptomatic subjects and increasing levels of bone loss was associated with higher risk to develop subsequent RA (hazard ratio=1.06, 95%CI 1.01, 1.11). No association was found in smokers. In the pre-symptomatic RANKL-positive individuals a significantly higher extent of marginal jawbone loss was detected, and those who were both RANKL- and ACPA positive displayed an even more pronounced jawbone loss. Conclusions Marginal jawbone loss preceded clinical onset of symptoms of RA but the difference was only manifested in non-smokers. Moreover, pre-symptomatic RA-individuals, who were RANKL positive, displayed a significantly higher degree of marginal jawbone loss, particularly in ACPA positive individuals. This article is protected by copyright. All rights reserved.