Figure 1.

Native immunoglobulin (Ig)G complexes contain additional serum proteins detected by enzyme‐linked immunosorbent assay (ELISA). (a) Circulating native IgG complexes from patients with rheumatoid arthritis (RA) show significantly higher amounts of bound autoreactive IgM and C‐reactive protein (CRP) compared to normal healthy donors (NHD) independently of the time of assessment. (b) Binding of complement components C1q and C3c to circulating IgG immune complexes (ICs) is enhanced in patients with RA at inclusion when compared to NHD. Only the binding of C1q remained significant during the study period. Shown are optical density (OD) values assessed by capture ELISA and the significances are presented after Bonferroni correction.