OPERA aims to better understand and predict the responsiveness of rheumatoid arthrits (RA) patients to biological disease modifying anti-rheumatic drugs (bDMARDs).

Our objectives will be (i) to determine, at baseline, the differences of oxylipin response between responders vs non-responders to Anti-Tumor necrosis factor (Anti TNF) and (ii) to investigate the relationships between the oxylipin response, the polyunsatured fatty acid (PUFA) content of immune cells and the cytokine response.

30 RA patients starting an anti-TNF will be recruited.

Before and after 6-months of anti-TNF treatment, blood will be collected using the TruCulture system (2x 1ml in non-stimulated and Lipopolysaccharide (LPS)-stimulated TruCulture tubes) to measure Whole Blood Oxylipin Response (WBOR), cytokine response, PUFA cell content and gene expression under homeostatic and stimulated conditions (i.e. LPS).

At baseline and after 6 months of treatment, the rheumatologist will perform a clinical evaluation of their RA patients using Disease Activity Score using 28 joint-count (DAS28-CRP). Non-responders will be defined as RA patients failing to achieve good or moderate EULAR response after 6 month of anti-TNF treatment, discontinued the drug, initiated a new bDMARD, or increased dosage of oral corticosteroids greater than 10 mg/d at the second visit.

Inclusion Criteria:

• Rheumatoid patient according to ACR-EULAR (American college of rheumatology-European League Against Rheumatism) 2010 criteria,
• Active disease defined by a DAS28-CRP>3.2,
• Biological and targeted synthetic DMARDs naïve,
• Indication for treatment with anti-TNF
• Stable corticosteroid therapy ≤ 10 mg/day

Exclusion Criteria:

• Contra-indications to a biological DMARDS (current or recent cancer, active infection),
• Non-steroidal anti-inflammatory drugs (NSAIDs) treatment during the last 2 weeks before inclusion