Figure 2.

(A) IgM-RF and ACPA reactivity and (B) reactivity against five citrullinated (cit.) peptides in patients with rheumatoid arthritis and no (a), moderate (b), or severe (c) periodontitis. No significant differences were observed. ΔOD, optical density of the citrullinated form minus the native form of the peptide; ACPA, anti-citrullinated protein antibody; IgM-RF, immunoglobulin M-rheumatoid factor.