Effect of infliximab treatment on biological markers. Anti-CCP2 (A), RF IgM (B), anti-P. gingivalis antibodies (C), anti-P. intermedia antibodies (D), and MMP3 (E) were evaluated at baseline and after 6 months of infliximab therapy. Dots represent results for each patient, with values at baseline in round and at 6 months of infliximab therapy in square. From the bottom up, the bars indicate the interquartile range and the median. Anti-CCP2: anti-cyclic citrullinated petides 2nd generation; RF: rheumatoid factor; MMP-3: metalloproteinase 3; AU: arbitrary units; IU: International units; *: p < 0.05; ***: p < 0.001; ****: p < 0.0001.