People who are at risk for rheumatoid arthritis have higher rates of gum disease, according to new research presented June 15 at the Annual European Congress of Rheumatology in Amsterdam.

“It has been shown that RA-associated antibodies, such as anti-citrullinated protein antibodies, are present well before any evidence of joint disease. This suggests they originate from a site outside of the joints,” said study author Kulveer Mankia, of the Leeds Biomedical Research Centre, in a EULAR news release.

“Our study is the first to describe clinical periodontal disease and the relative abundance of periodontal bacteria in these at-risk individuals,” Mankia added. “Our results support the hypothesis that local inflammation at mucosal surfaces, such as the gums in this case, may provide the primary trigger for the systemic autoimmunity seen in RA.”

Gum disease could be a key sign of rheumatoid arthritis, because an oral bacterium, called porphyromonas gingivalis, is the only human pathogen which is known to express an enzyme that creates proteins, to which the body then makes antibodies in RA.

“This is an essential step towards the ultimate goal of disease prevention,” said Robert Landewé, chairman of EULAR’s scientific program committee, of the study in the release.