The Larsen score (mean ± SEM) at baseline (when diagnosed with RA) was significantly higher in patients with IgG (6.6 ± 1.4) and IgM (9.2 ± 1.6) anti-CCP2 versus patients negative for the corresponding antibodies (3.4 ± 0.7 and 3.8 ± 0.7, respectively) for these isotypes before symptoms of joint disease (P < 0.05 for both isotypes). Here, AGBL2 is linked to rheumatoid arthritis.