The purpose of this study is to assess the clinical response to IL-6 inhibition defined as Low Disease Activity (DAS44) <2.4) at the follow-up visit at 12 months and the correlation between the biomarkers and treatment response.

Inclusion criteria:

• Signed informed consent form;
• Patients aged 18 - 75 years;
• RA classified in compliance with the 2010 ACR/EULAR criteria;
• Patients that have to suspend a previous treatment with DMARDs for total ineffectiveness or intolerance to drugs and/or patients that have not responded adequately to first-line combination DMARDs / biological treatment;
• Patients for which is indicated to start a treatment with an inhibitor of IL-6R for high values indicative of systemic inflammation (ESR>=28 mm/hour, PCR>5 mg/l , Fibrinogen >400 mg/dl and or Albumin <3.5 g/dl) and high disease activity (DAS>2.4), or contraindications to DMARDs use which make it necessary to take biological drug in monotherapy.
• Corticosteroids therapy stable (< = 7.5 mg)for at least four weeks;
• Joint symptoms for at least three but no more than 24 months from the screening visit;
• DAS44 >2.4 and/or SDAI >11
• Willing and able to comply with study procedures and timing.

Exclusion criteria:

• On going pregnancy or lactation;
• Severe active infections;
• Patients with other clinically significant concomitant diseases whose treatment or outcome could interfere with the expected evaluations of the study protocol.
• Blood AST or ALT levels >5 times the upper normal limit;
• ANC count <0.5 x 109/L
• Platelet count <50 x103 /μL
• Patients with other autoimmune rheumatic diseases, in addition to AR (for example systemic lupus erythematosus [SLE], scleroderma, polymyositis, ecc…)
• Medical history or concomitant joint diseases in additions to AR (for example tophaceous gout, reactive arthritis, psoriatic arthritis).