Role of Porphyromonas gingivalis in rheumatoid arthritis and inflammatory spondyloarthropathies

The most recent studies confirm the link between rheumatoid arthritis (RA) and periodontal disease. RA patients have higher prevalence of chronic periodontitis and periodontal disease is often more severe in these patients. Both RA and PD show similar pathophysiological mechanisms and risk factors. Autoimmunity to citrullinated peptides is the primary element in the pathogenesis of RA, not found in other diseases. Porphyromonas gingivalis, the major periodontal pathogen associated with the etiology of chronic periodontitis, is the only bacterium currently known to produce the enzyme peptidylarginine deiminase (PAD) allowing protein citrullination. This bacterium likely fulfils a significant role in the pathogenesis of RA due to its capacity for citrullination of its own protein and host peptides, which may result in a loss of immune tolerance. A few epidemiological studies also indicate the potential link between spondyloarthropathies and periodontal disease.