Periodontitis and rheumatoid arthritis: A search for causality and role of Porphyromonas gingivalis

There is currently much attention for early detection of rheumatoid arthritis, as early recognition enables timely treatment with a chance of remission of the disease before irreversible damage has occurred. In this respect, important questions are: who will develop rheumatoid arthritis, when and why? The main research question of this thesis was if chronic bacterial infection of oral soft- and hard tissues (periodontitis), in particular with the periodontal pathogen Porphyromonas gingivalis, predisposes to production of auto-antibodies specific for (the onset of) rheumatoid arthritis. Besides periodontitis, chronic inflammation of lung mucosal tissues has also been suggested to predispose to rheumatoid arthritis associated auto-antibody production. Indeed, presence of these auto-antibodies in patients without rheumatoid arthritis was associated with oral- or lung mucosal inflammation, although overall levels were low. Anti-Porphyromonas gingivalis antibody levels were not prognostic for development of rheumatoid arthritis. From this observation however, it cannot be concluded that there is no causal relationship between periodontitis and rheumatoid arthritis. Moreover, animal experiments confirm the suggested role of Porphyromonas gingivalis in development of human rheumatoid arthritis. Periodontitis is more prevalent among patients with rheumatoid arthritis. In addition, severity of periodontitis is correlated with rheumatoid arthritis disease activity. From this thesis is can be concluded that oral health assessment is extremely useful in patients with, or at risk for developing rheumatoid arthritis, given the potential role of chronic bacterial infection of oral tissues in development, progression and disease activity of rheumatoid arthritis