Menke J de Smit1, Johanna Westra2, Elisabeth Brouwer2, Koen M J Janssen3, Arjan Vissink3, Arie Jan van Winkelhoff1,4. 1. Center for Dentistry and Oral Hygiene, University of Groningen and University Medical Center Groningen, Groningen, The Netherlands. 2. Department of Rheumatology and Clinical Immunology, University of Groningen and University Medical Center Groningen. 3. Department of Oral and Maxillofacial Surgery, University of Groningen and University Medical Center Groningen. 4. Department of Medical Microbiology, University of Groningen and University Medical Center Groningen.
Abstract
BACKGROUND: Currently, in the field of rheumatology, there is much attention given towards the possible causality between periodontitis and rheumatoid arthritis (RA), specifically regarding the role of Porphyromonas gingivalis (Pg). This bacterium is unique, having a citrullinating enzyme. Antibodies against citrullinated proteins are rather specific for RA. METHODS: Because causality is ultimately tested in longitudinal cohort studies which currently do not exist for periodontitis and RA, this commentary applied Bradford Hill criteria on the existing literature to assess causality as the most likely interpretation of this association. CONCLUSIONS: From an epidemiologic point of view, patients with RA have a higher incidence of periodontal disease than individuals without RA. In addition, there is a dose-response pattern in the association between the severity of periodontitis and RA disease activity. There are indications that periodontitis precedes RA, but there is no evidence yet available to show that Pg plays a direct role in this temporal relationship. The role of the unique characteristic of citrullination by Pg remains unexplained. However, in animal models, citrullination by Pg plays a distinct role in the development and aggravation of experimental arthritis. Although the role of Pg in RA remains speculative, a causative role for periodontitis as a chronic inflammatory disease caused by infectious agents in RA seems biologically plausible.
BACKGROUND: Currently, in the field of rheumatology, there is much attention given towards the possible causality between periodontitis and rheumatoid arthritis (RA), specifically regarding the role of Porphyromonas gingivalis (Pg). This bacterium is unique, having a citrullinating enzyme. Antibodies against citrullinated proteins are rather specific for RA. METHODS: Because causality is ultimately tested in longitudinal cohort studies which currently do not exist for periodontitis and RA, this commentary applied Bradford Hill criteria on the existing literature to assess causality as the most likely interpretation of this association. CONCLUSIONS: From an epidemiologic point of view, patients with RA have a higher incidence of periodontal disease than individuals without RA. In addition, there is a dose-response pattern in the association between the severity of periodontitis and RA disease activity. There are indications that periodontitis precedes RA, but there is no evidence yet available to show that Pg plays a direct role in this temporal relationship. The role of the unique characteristic of citrullination by Pg remains unexplained. However, in animal models, citrullination by Pg plays a distinct role in the development and aggravation of experimental arthritis. Although the role of Pg in RA remains speculative, a causative role for periodontitis as a chronic inflammatory disease caused by infectious agents in RA seems biologically plausible.
Authors: Sytske Anne Bergstra; Arvind Chopra; Manjit Saluja; David Vega-Morales; Nimmisha Govind; Tom W J Huizinga; Annette van der Helm-van Mil Journal: RMD Open Date: 2017-12-10