Rheumatoid arthritis (RA) is a chronic inflammatory disease (a long-lasting disease causing pain and swelling) associated with significant health problems. It is a difficult disease to manage as the disease is often unpredictable. RA causes inflammation (swelling) of the joints that can cause joint damage, deformity, and progressive disability and impairment. It is estimated that 1% of the world's population suffers from this disease.

The purpose of this research study is to determine if a change in inflammation seen on the ultrasound is a good indicator of how subjects' rheumatoid arthritis is responding to treatment of subcutaneous abatacept at 3 weeks, 3 months, 6 months, and 12 months.

Inclusion Criteria:

1. Over 18 years old
2. Has a diagnosis of rheumatoid arthritis
3. Stable DMARDs for at least 1 month (methotrexate, leflunomide, hydroxychloroquine, or sulfasalazine)
4. Disease activity score DAS28/ESR > 3.2 or all must be met: TJC (tender joint count)>=4, SJC (swollen joint count)>=4
5. Must be able to understand information in the Informed Consent and comply with study requirements
6. Total ultrasound synovitis (inflammation of joint-lining membrane) power Doppler score >=1 for at least 2 joints and total synovitis score >=1 for at least 1 joint

Exclusion Criteria:

1. Current or prior use of biologic drugs (TNF inhibitors, IL-6 inhibitors, CD20 inhibitors, IL-1 inhibitors, etc.)
2. Pregnancy or breast feeding
3. Daily prednisone > 10mg (stable dose for at least 1 month)
4. Intra-articular steroid injection of the wrist or joints within last 2 months
5. History of a concomitant autoimmune disease such as lupus, psoriatic arthritis
6. History of cancer
7. Previous exposure to abatacept

12 months

This is a very small open-label study of 25 patients on a FDA approved drug, where efficacy (by standard validated measures) and safety were not the primary end points.