ENO1 and rheumatoid arthritis: The serum antibody titers to P. gingivalis (mean ± SE, 34,427 ± 3,510 vs. 18,479 ± 1,428, p = 0.003 by Mann–Whitney test) and ENO1 (2,473 ± 87.97 vs. 2,072 ± 167.4, p < 0.0001) were significantly higher in patients with RA compared to control subjects (Fig. 1).