Abstract: Objective To study the effect of Porphyromonas gingivalis infection on rheumatoid arthritis in mice model. Methods The mice were divided into rheumatoid arthritis (CIA) group and periodontitis combined with rheumatoid arthritis (CIA+Pg) group. Periodontitis models were constructed by oral inoculation of Porphyromonas gingivalis, and the rheumatoid arthritis model was induced by bovine II collagen. To determine the effect of Porphyrinomonas gingivalis infection on the severity of rheumatoid arthritis, the severity of rheumatoid arthritis was assessed by rheumatoid arthritis score. The level of rheumatoid factor in plasma was detected by enzyme linked immunoassay kit. Results The onset of rheumatoid arthritis in the CIA+Pg group were significantly shorter than those of the CIA group, and the symptoms were more serious. The inflammatory factors related to rheumatoid arthritis such as TNF-α, IL-1, IL-6 and IL-17 were also significantly higher in CIA+Pg group. Conclusion The infection of Porphyromonas gingivalis can promote the occurrence of rheumatoid arthritis and aggravate the symptoms of it.

Key words: Periodontitis, Rheumatoid arthritis, Porphyromonas gingivalis, Inflammatory factor