OBJECTIVES: To study the association of systemic and local interleukin-35 (IL-35) levels in rheumatoid arthritis. METHODS: 37 patients with treatment naïve early RA, 49 with established RA and 29 control patients with osteoarthritis (OA) were studied. Serum and paired synovial fluid samples were analysed for IL-35. Disease activity of RA patients was assessed according to the 28-Joint Count Disease Activity Score (DAS28). RESULTS: The levels of serum IL-35 were significantly higher in patients with treatment naïve early RA compared to those with established disease and control OA subjects. In addition, serum levels of IL-35 significantly decreased 12 weeks after initiation of glucocorticoids and conventional synthetic disease modifying antirheumatic drugs in patients with treatment naïve early RA. Synovial fluid IL-35 levels were significantly higher in RA compared to OA patients, were significantly elevated compared to serum counterparts and correlated with synovial fluid leukocyte count (r=0.412; p<0.01), serum CRP levels (r=0.362; p<0.05) and DAS28 (r=0.430, p<0.01). CONCLUSION: This is the first study showing elevated circulating levels of IL-35 in treatment naïve early RA, its significant decrease after treatment initiation and positive association between increased synovial fluid IL-35 and disease activity in patients with long-lasting RA.

• MeSH
• Antirheumatic Agents therapeutic use   MeSH
• Biomarkers MeSH
• Adult MeSH
• Glucocorticoids therapeutic use   MeSH
• Immunosuppressive Agents therapeutic use   MeSH
• Interleukins analysis   blood   physiology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Arthritis, Rheumatoid drug therapy   metabolism   MeSH
• Severity of Illness Index MeSH
• Synovial Fluid chemistry   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• Antirheumatic Agents MeSH
• Biomarkers MeSH
• Glucocorticoids MeSH
• Immunosuppressive Agents MeSH
• interleukin-35, human MeSH Browser
• Interleukins MeSH