Clinical Disease Activity and Modulation of Synovial Lymphoid Structures and B Cell Function in Rheumatoid Arthritis

Inclusion Criteria: * Men and women ≥ 18 and ≤ 75 years of age, with RA as defined by the 1987 revised ACR classification criteria. * Patients must fulfill the National Institute for Clinical Excellence guidelines for TNF Blocking Therapy in RA. * Patients must be on MTX for at least 4 months, with a stable dose of 7.525 mg/week for a minimum of 4 weeks. * Men and women of childbearing potential must use adequate birth control measures (eg, abstinence, oral contraceptives, intrauterine device, barrier method with spermicide, or surgical sterilization) for the duration of the study. * Patients must be able to adhere to the study visit schedule. * Patients must be capable of giving informed consent and the consent must be obtained prior to any screening procedures. * Must have a chest Xray within 3 months prior to commencement of antiTNFα with no evidence of malignancy, infection or fibrosis. Exclusion Criteria: * Women who are pregnant or breast feeding. * Use of any investigational drug within 1 month prior to screening or within 5 half-lives of the investigational agent, whichever is longer. * Previous use of antiTNF biologics. * Treatment with any other therapeutic agent targeted at reducing TNF (eg, pentoxifylline, thalidomide, etc.) within 3 months of screening. * Serious infections (such as, HIV, HBV, pneumonia or pyelonephritis) in the previous 3 months. Less serious infections (such as acute upper respiratory tract infection \[colds\] or simple urinary tract infection) need not be considered exclusions at the discretion of the investigator. * Have active TB or have evidence of latent TB (old or latent TB on chest Xray, without adequate therapy for TB initiated prior to first dose of study drug). Also excluded are patients with evidence of an old or latent TB infection without documented adequate therapy. * Presence of a transplanted organ (with the exception of a corneal transplant \>3 months prior to screening). * Malignancy within the past 5 years (except for squamous or basal cell carcinoma of the skin that has been treated with no evidence of recurrence). * History of lymphoproliferative disease including lymphoma, or signs and symptoms suggestive of possible lymphoproliferative disease, such as lymphadenopathy of unusual size or location (such as nodes in the posterior triangle of the neck, infraclavicular, epitrochlear, or periaortic areas), or splenomegaly. * Known recent substance abuse (drug or alcohol). * Poor tolerability of venepuncture required blood sampling during the study period.