Synovial fluid levels of anti–cyclic citrullinated peptide antibodies and IgA rheumatoid factor in rheumatoid arthritis, psoriatic arthritis, and osteoarthritis
Article first published online: 6 FEB 2006
Copyright © 2006 by the American College of Rheumatology
Arthritis Care & Research
Volume 55, Issue 1, pages 53–56, 15 February 2006
How to Cite
Caspi, D., Anouk, M., Golan, I., Paran, D., Kaufman, I., Wigler, I., Levartovsky, D., Litinsky, I. and Elkayam, O. (2006), Synovial fluid levels of anti–cyclic citrullinated peptide antibodies and IgA rheumatoid factor in rheumatoid arthritis, psoriatic arthritis, and osteoarthritis. Arthritis & Rheumatism, 55: 53–56. doi: 10.1002/art.21691
- Issue published online: 6 FEB 2006
- Article first published online: 6 FEB 2006
- Manuscript Accepted: 9 AUG 2005
- Manuscript Received: 10 APR 2005
- Synovial fluid;
- Rheumatoid arthritis;
- Psoriatic arthritis;
To assess the levels of anti–cyclic citrullinated peptide (anti-CCP) and IgA rheumatoid factor (IgA-RF) in synovial fluids of patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), and osteoarthritis (OA).
Knee effusions of 29 patients with RA (23 women, 6 men; mean ± SD age 60 ± 15 years), 20 with PsA (6 women, 14 men; mean age 51 ± 12 years), and 19 with OA (9 women, 10 men; mean age 73 ± 11.8 years) were aspirated, tested for white blood cell (WBC) counts, centrifuged, and stored at −20°. Sera of 22, 11, and 12 of these patients with RA, PsA, and OA, respectively, were similarly stored. IgG anti-CCP and IgA-RF were detected by enzyme-linked immunosorbent assay. Erythrocyte sedimentation rate and C-reactive protein levels were used as measures of disease activity.
Mean levels of synovial fluid anti-CCP and IgA-RF were significantly increased in RA joint effusions compared with PsA and OA (anti-CCP: 150 ± 134, 34 ± 29, and 24 ± 26 units, respectively [P < 0.003]; IgA-RF: 76 ± 77, 15.7 ± 10, and 18 ± 20 units, respectively). No significant difference was noted between OA and PsA. A significant correlation was found between synovial fluid anti-CCP and serum anti-CCP and IgA-RF. In patients with RA, a significant correlation was found between synovial fluid WBC counts and IgA-RF (P = 0.03) and serum IgA-RF (P = 0.008), but not between synovial fluid and serum anti-CCP levels. In RA patients, C-reactive protein correlated with serum IgA-RF.
Anti-CCP and IgA-RF were significantly increased in synovial fluid of RA in comparison with PsA and OA patients.