IADR Abstract Archives
Alveolar/Periarticular Bone Loss Link in Periodontitis-Autoimmune Arthritis Mouse Model
Objectives: The objective of our pilot study is to determine whether interproximal alveolar bone mineral density by microCT analysis may predict the periarticular bone loss of the knee in a Porphyromonas gingivalis (Pg)-induced periodontitis mouse model bearing a human HLA/DR1 allele and challenged for collagen-induced arthritis (CIA). Both periodontitis and autoimmune arthritis are chronic inflammatory diseases characterized by soft tissue and bone destruction and have a strong genetic component. Recent findings associate the “shared epitope” HLA-DR1 with both rheumatoid arthritis and periodontitis.
Methods: Periodontal disease was induced by inoculation of P gingivalis on C57BL/6 mice bearing the human major histocompatibility complex (MHC) allele DRB*0101 as a transgene and null for the murine class II, while control mice received no Pg treatment. The interproximal alveolar bone density between the mandibular molars M1-M2 and the periarticular bone density in the proximal 2mm of the tibia were evaluated, and linear regression analysis was performed (N=3 per group).
Results: Infection of periodontal tissues by Pg was confirmed by PCR analysis. Sixty days after the induction of periodontitis, mice were sacrified and alveolar bone loss was detected in the P gingivalis group between the mandibular M1-M2 molars (Control: 1014.22±35.84, Pg: 932.13±35.61 mg HA/ccm). Accordingly, knee periarticular bone loss was also detected in the Pg-treated group (Control: 910.02±9.36, Pg: 854.4±3.2). Regression analysis revealed strong association between the alveolar and periarticular bone loss (p<0.05, R2 adjusted=0.65), suggesting that 65% of the periarticular variance is due to the independent variable of alveolar density.
Conclusions: Our results in a small sample of mice bearing a common suscpeptibility polymorphism for both rheumatoid arthritis and periodontitis, inoculated with Pg and CIA-challenged suggest that periodontal bone loss may be able to predict in part periarticular bone damage. Further studies are needed where multiple factors can be evaluated and associated with arthritic disease activity.
Methods: Periodontal disease was induced by inoculation of P gingivalis on C57BL/6 mice bearing the human major histocompatibility complex (MHC) allele DRB*0101 as a transgene and null for the murine class II, while control mice received no Pg treatment. The interproximal alveolar bone density between the mandibular molars M1-M2 and the periarticular bone density in the proximal 2mm of the tibia were evaluated, and linear regression analysis was performed (N=3 per group).
Results: Infection of periodontal tissues by Pg was confirmed by PCR analysis. Sixty days after the induction of periodontitis, mice were sacrified and alveolar bone loss was detected in the P gingivalis group between the mandibular M1-M2 molars (Control: 1014.22±35.84, Pg: 932.13±35.61 mg HA/ccm). Accordingly, knee periarticular bone loss was also detected in the Pg-treated group (Control: 910.02±9.36, Pg: 854.4±3.2). Regression analysis revealed strong association between the alveolar and periarticular bone loss (p<0.05, R2 adjusted=0.65), suggesting that 65% of the periarticular variance is due to the independent variable of alveolar density.
Conclusions: Our results in a small sample of mice bearing a common suscpeptibility polymorphism for both rheumatoid arthritis and periodontitis, inoculated with Pg and CIA-challenged suggest that periodontal bone loss may be able to predict in part periarticular bone damage. Further studies are needed where multiple factors can be evaluated and associated with arthritic disease activity.