Both the levels of CRP and ESR were lower in the OA-like RA group than those in the conventional RA group (CRP: 0.9 ± 1.3 mg/dL vs. 1.6 ± 1.8 mg/dL, p = 0.007; ESR: 39.0 ± 23.1 mm/h vs. 49.7 ± 29.5 mm/h, p = 0.004). Here, CRP is linked to rheumatoid arthritis.