Clinical characteristics and laboratory findings in patients with active rheumatoid arthritis (RA), inactive RA, patients with knee osteoarthritis (OA) and healthy controls (HC).

<p>Data are presented as mean ± SD or number (percentage); NA: not applicable.</p><p>RF: rheumatoid factor; Anti-CCP: anti-cyclic citrullinated peptide antibodies; CRP: C-reactive protein; DAS28: disease activity score for 28-joints; DMARDs: disease-modifying anti-rheumatic drugs.</p><p>A result was considered positive for RF when the concentration was ≧15 IU/ml; a result was considered positive for anti-CCP antibodies if the titer was≧20 IU/ml. *p<0.001, versus inactive RA group, determined using the Mann-Whitney U test.