Fig. 5

Exacerbation of autoimmune arthritis through brushing with P. gingivalis. Nineteen B6.DR1 mice were brushed daily for one week with P. gingivalis (shaded pink area) and 18 mice were left untreated. Clinical measures of paw swelling were obtained in all groups according to our standard protocol in which each paw is graded on a scale of 0–4 with 0 = no evidence of inflammation and 4 = maximally inflamed. *Statistically significant differences in arthritis incidence between the no-treatment and P. gingivalis groups (p < 0.04 by chi-squared test). ^¶,# p < 0.01 by Student’s t test. ^‡Paw index is calculated as average number of inflamed paws per arthritic mouse. ^§Severity index calculated as average severity per arthritic mouse. Results expressed as average ± SEM (Color figure online)