Demographic and clinical features of the patients.

Values are represented in mean ± SD when relevant. Among 31 RA patients, 22 serums and 15 SF were collected. Other inflammatory arthritis include ankylosing spondylitis (n = 5; HLA B27 3/5 positive), rhizomelic pseudo-polyarthritis (n = 8), psoriatic arthritis (n = 4), and undifferentiated inflammatory arthritis (n = 3). Rhizomelic pseudo-polyarthritis, psoriactic arthritis, and undifferentiated inflammatory arthritis subjects are HLA-B27 −; anti CCP - and rheumatoid factor - Patients with infection and microcristallin arthritis were excluded from the study.(-), not evaluated in the group; BASDAI, bath ankylosing spondylitis disease activity index; BASFI, bath ankylosing spondylitis functional index; CRP, C-reactive protein; DAS28, disease activity score using 28 joints counts; ESR, erythrocyte sedimentation rate; NR, not relevant; NSAID, non-steroidal anti-inflammatory drug; DMARD, disease-modifying anti-rheumatic drug.