The purpose of this study is to determine the kinetics of change in quantitative measures of joint inflammation by state of the art power Doppler vascular imaging and to identify biomarkers in biological samples (synovial biopsies, DNA, RNA, PBMC, serum, plasma, urine and stool samples) from parallel cohorts of RA patients undergoing different treatments. This will be achieved implementing MSUS assessments, standard laboratories techniques (such as ELISAs, gene profiling, transcriptome analysis etc.) and the novel CyTOF™ technology.

Inclusion Criteria:

• Written confirmed diagnosis of Rheumatoid Arthritis as per ACR/EULAR 2010 criteria.
• If patient is on oral corticosteroids, dose must be stable for 6 weeks prior to baseline visit.
• Willingness and ability to comply with all the study procedures.

Exclusion Criteria:

• Any systemic inflammation conditions (other than RA), connective tissue disease or chronic pain disorders that may interfere with the interpretation of the outcome data. Examples include psoriatic arthritis, reactive arthritis, gout, systemic lupus erythematosus (SLE), polymyalgia rheumatic and/or temporal arteritis, Lyme's disease, fibromyalgia and chronic fatigue syndromes.
• Major surgery planned within 8 weeks prior to screening or planned surgery throughout the study period.
• Treatment with any investigational agent ≤ 4 weeks prior to baseline (or 5 ≤ half-lives of the investigational drug, whichever is the longer).
• Intramuscular/intra-articular glucocorticoids for 6 weeks prior to baseline visit.
• Active infection.
• Septic arthritis within a native joint within the last 12 months.
• Sepsis of a prosthetic joint within 12 months or indefinitely if the joint remains in situ.
• Known HIV or hepatitis B/C infection.
• Latent TB infection unless they have completed adequate antibiotic prophylaxis.
• Malignancy (other than basal cell carcinoma) within the last 10 years.
• New York Heart Association (NYHA) grade 3 or 4 congestive cardiac failure.
• Demyelinating disease.
• Presence of a transplanted organ (with the exception of a corneal transplant > 3 months prior to screening).
• Known recent substance abuse (drug or alcohol).

Rheumatoid Arthritis Patients