s24ab_5

Synovial fluid cytokine levels in Behçet's disease

I. Ertenli¹, S. Kiraz¹, M.çalgüneri¹, I.çelik², M. Erman², I.C. Haznedaroglu², S. Kirazli²

¹Department of Rheumatology, ²Department of Internal Medicine, Hacettepe University School of Medicine, Ankara, Turkey.

ABSTRACT
Objective
To investigate the synovial fluid levels of interleukin-1 b (IL-1b), tumour necrosis factor-a (TNF-a), transforming growth factor-b (TGF-b), IL-1 receptor antagonist (IL-1ra), soluble IL-2 receptor (sIL-2r) and IL-8 in patients with Behçet's disease (BD) and to compare them to levels in rheumatoid arthritis (RA), and osteoarthritis (OA).

Methods
The cytokine levels of BD (n = 14), RA (n = 15) and OA (n = 15) patients were assessed by enzyme-linked immunosorbent method.

Results
Median synovial IL-1b and TNF-a levels were higher in RA compared to BD and OA patients. IL-1b levels were also higher in BD than OA whereas TNF levels were similar in these two groups. IL-1ra and TGF-b activity in BD were higher than OA but lower than RA. sIL-2r and IL-8 levels were increased in BD and RA in comparison to OA patients.

Conclusion
The arthritis of BD is non-erosive and accordingly, its synovial fluid contains lower levels of cytokines primarily involved in cartilage destruction, namely IL-1b and TNF-a, than RA. IL-1ra and TGF might serve as protective factors against erosion in the inflamed joints. High synovial fluid levels of sIL-2r and IL-8 probably reflect a non-specific inflammatory process.

Key words
Behçet's disease, rheumatoid arthritis, osteoarthritis, tumour necrosis factor, transforming growth factor beta, interleukin-1, interleukin-8, soluble interleukin-2 receptor, interleukin-1 receptor antagonist.

Please address correspondence to: Dr. Ihsan Ertenli, 37. sokak, 11/5, 06490, Bahçelievler, Ankara, Turkey.
E-mail:ermanm@tr.net