Periodontal Disease and RA
The role played by P. gingivalis was the focus of Dr. Mikuls’s presentation, in which he outlined evidence supporting an association between periodontal disease and RA. He said that the current data show that periodontal disease and RA coexist more than would be expected by chance alone, suggesting that periodontitis and poor oral health in general should be addressed to optimize overall health in patients.
Among the data he presented was a study he and colleagues recently published that looked at the relationship of P. gingivalis, the bacteria that causes periodontitis, to the presence of autoantibodies in individuals at risk of RA.1 The study found that the antibody to P. gingivalis was associated with the presence of RA-associated autoantibodies in people without RA but who are at increased risk of the developing the disease, said Dr. Mikuls. He said that this suggests that P. gingivalis could explain the associations reported to exist between oral health status and RA.
However, he emphasized that most studies to date looking at the association of periodontal disease and RA only have focused narrowly on the single organism of P. gingivalis and, therefore, could be missing the story. He pointed to a recent study by Scher et al that examined the diversity in the subgingival microbiome in patients with never-treated, new-onset RA.2 Along with finding that periodontal disease was much more common in these patients than in healthy controls, the study found that exposure to P. gingivalis was not unique to RA but did correlate with periodontal disease severity. The study also found that the role of other organisms Anaeroglobus geminatus and Prevotella/Lepotrichia species merited further study.
“Bacteria in the oral cavity coexist as a part of a very complex microbial community,” said Dr. Mikuls, adding that it may be that groups of bacteria or certain patterns of bacteria may be central to the associations between periodontal disease and RA other than simply P. gingivalis.
Although he said that the early evidence does suggest that periodontitis directly leads to autoimmunity or RA, he emphasized that further study is needed. If further evidence does indicate this association, he said that periodontal disease and related infections may then serve as a target for further therapies for RA, as well as disease prevention.
Mary Beth Nierengarten is a freelance medical journalist based in St. Paul, Minn.
References
- Mikuls TR, Thiele GM, Deane KD. Porphyromonas gingivalis and disease-related autoantibodies in individuals at increased risk of rheumatoid arthritis. Arthritis Rheum. 2012;64:3522-3530.
- Scher JU, Ubeda C, Equinda M, et al. Periodontal disease and the oral microbiota in new-onset rheumatoid arthritis. Arthritis Rheum. 2012;64:3083-3094.
