There is good evidence that periodontitis and RA are clinically associated.
From a study published on JAMA Network Open, June 7, 2019, by Kulveer Mankia, DM, MRCP; Zijian Cheng, PhD; Thuy Do, PhD; et al
Autoantibodies associated with rheumatoid arthritis (RA) can be detected in the serum years before patients develop joint inflammation, suggesting the joints may be a target rather than the primary cause of this disease.
Such observations suggest a preclinical phase of RA and, importantly, raise the possibility of disease prevention.
The enrichment of serum IgA anticitrullinated protein antibodies (ACPA) in individuals at risk of RA suggests mucosal sites (eg, oral mucosa) may be important in the earliest phase of RA. There is good evidence that periodontitis and RA are clinically associated. Furthermore, periodontitis is associated with a specific bacterial signature characterized by the increased abundance of the pathogenic organism Porphyromonas gingivalis alongside a community of other, predominantly anaerobic, organisms. Porphyromonas gingivalis is capable of citrullinating local antigens by virtue of its peptidylarginine deiminase enzyme. In a putative etiological model, virulent strains of P gingivalis at inflamed periodontal sites generate novel citrullinated antigens that trigger a mucosal immune response in certain individuals, possibly those with genetic predispositions. Recent data suggest the periodontopathic bacterium Aggregatibacter actinomycetemcomitans may also directly induce neutrophil citrullination at the periodontium and therefore potentially initiate ACPA.
Despite these observations, to our knowledge, periodontitis and citrullinating bacteria have not been described in individuals at risk of RA. We sought to comprehensively measure periodontitis and the abundance of key citrullinating bacteria in individuals who were ACPA positive (ie, individuals positive for anti–cyclic citrullinated protein [CCP] without synovitis and at risk of RA), patients with anti-CCP–positive early RA (ERA), and healthy control individuals.
Question: What is the prevalence of periodontal disease and citrullinating periodontopathic bacteria in anti–cyclic citrullinated protein–positive at-risk individuals (CCP+ at-risk) compared with a healthy control group and patients with early rheumatoid arthritis (RA)?
Findings: This cross-sectional study identified an increased prevalence of periodontal disease sites, clinical periodontitis, and periodontal inflamed surface area in CCP+ at-risk individuals and those with early RA compared with a control group. Results showed that CCP+ at-risk individuals had increased abundance of Porphyromonas gingivalis at healthy periodontal sites compared with the control group and patients with early RA.
Meaning: In individuals at risk of RA, periodontitis and P gingivalis were increased before joint disease and may be a target for prevention.
Conclusion: This study is the first, to our knowledge, to demonstrate an increased prevalence of periodontal disease together with an increased abundance of P gingivalis in anti-CCP–positive individuals at risk of RA. These data suggest periodontal inflammation and the enrichment of P gingivalis may precede joint inflammation in RA and support an association between these risk factors and disease initiation. This study adds to an emerging evidence base linking periodontal and systemic disease and, therefore, further highlights the potential importance of improving dental health and reducing the burden of periodontal disease on the risk of chronic systemic diseases such as RA. Importantly, these findings suggest periodontal inflammation may be a legitimate target to explore for preventive intervention in RA.
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Mankia K, Cheng Z, Do T, et al. Prevalence of Periodontal Disease and Periodontopathic Bacteria in Anti–Cyclic Citrullinated Protein Antibody–Positive At-Risk Adults Without Arthritis. JAMA Netw Open. Published online June 07, 20192(6):e195394. doi:10.1001/jamanetworkopen.2019.5394