The relationship between rheumatoid arthritis and periodontal disease

Abstract

[한글]

[영문]Background: Peridontitis has many similar characteristics of synovitis in rheumatoid arthritis (RA). Recent reports have suggested a significant relationship between RA and periodontal disease (PD) in RA patients. The aim of this study was to investigate the relationship between RA and PD and to evaluate the treatment response in RA and PD in animal model. Method: Twenty-five male DBA/1 mice 8 weeks old were divided into five groups. Group 1 (CONTROL) and Group 2 (CONTROL+TNFi) were the control groups without collagen injection. The other three groups which were experimental groups were given a subcutaneous injection of bovine type II collagen (100μg/mice) emulsified in complete Freund’s adjuvant (Arthrogen-CIA, Redmond, WA) (1:1, w/v) into the base of tail. Three weeks later, the mice were given a booster subcutaneous injection of bovine type II collagen (100μg/mice) in incomplete Freund’s adjuvant (1:1, v/v) into the base of tail. After the development of arthritis (2 weeks after the booster collagen injection), Group 3 (CIA+TNFi) was given the anti-TNF-α (5.5mg/kg), and the Group 4 (CIA+MTX) was given the intraperitoneal injection of methotrexate (MTX) (35mg/kg) twice a week for five weeks. At the same time the Group 5 (CIA) and the Group 1 (CONTROL) were untreated while Group 2 (CONTROL+TNFi) was injected with anti-TNF-α. Arthritis score and paw thickness were measured and histopathological assessment of joint sections was performed. The expression of proinflammatory cytokines and enzymes was evaluated by immunohistochemical staining. Jaws were scanned and reconstructed into a 2 and 3-dimensional structure with micro-CT. The average exposure areas of teeth were measured to calculate the severity of PD.Results: The anti-TNF-α therapy and MTX attenuated the severity of arthritis and histopathological findings in CIA mice. Micro CT confirmed that the periodontal disease existed in CIA mice. There were significant differences in the average area measurements (CONTROL 0.0177 vs CONTROL+TNFi 0.0229 CIA 0.02205 p<0.05) between Group 1 and Group 2 or Group 5. The average exposed area was significantly lower in Group 5 than in Group 3 or Group 4 (CIA 0.02205 vs CIA+TNFi 0.02466, CIA+MTX 0.0254, p<0.05). Conclusions: Collagen induced arthritis was associated with the occurrence of periodontitis. The MTX/TNFi drugs didn’t affect PD while they treated CIA. Further studies will be necessary to investigate the cause of these differences.?