Median rheumatoid factor (U/ml), anti-citrullinated protein antibody (U/ml), Disease Activity Score with C-Reactive Protein and Simple Disease Activity Index for RA patients were 74.8 (29.5–150.0), 28.8 (11.6–54.0), 2.04 (1.80–2.73) and 1.50 (1.28–4.67), respectively. Here, CRP is linked to rheumatoid arthritis.