Autoantibody levels initially decrease and then steadily rise over time, paralleled by disease activity.
Levels in arbitrary units (aU/mL) of four representative autoantibodies and DAS over the first year of treatment as measured in the serum of seropositive RA patients (for levels: N 0 months = 356; N 4 months = 225; N 8 months = 209; N 12 months = 212; for DAS: N 0 months = 381; N 4 months = 374; N 8 months = 361; N 12 months = 357). Patients clustered at the maximum were above the highest standard of the ELISA. Black lines indicate median level in arbitrary units per milliliter or mean DAS. Red lines indicate estimated marginal mean (EMM) arbitrary units per milliliter or DAS with 95% confidence intervals (calculated by GEE). p values (asterisk) refer to the change between two time points. *p < 0.05, **p < 0.01, ***p < 0.001