Figure 1

IgM antibodies directed at IgG₁-advanced glycation end-product (AGE) or IgG₃-AGE in two patients with rheumatoid arthritis (RA) when sera were diluted 1/1000–1/8000: [◆], RA1 anti-IgG₁-AGE; [■], RA2 anti-IgG₁-AGE; [△], RA1 anti-IgG₃-AGE; [○], RA2 anti-IgG₃-AGE. Binding to bovine serum albumin (BSA) for RA1 and RA2 (sera diluted 1/500) was 0.031 and 0.078, respectively, and for BSA-AGE for RA1 and RA2 (sera diluted 1/500) 0.029 and 0.025, respectively. OD, optical density.