Rheumatoid Arthritis: A Chronic Autoimmune Disease

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease. The synovial lining of joints is the most common target of the dysregulated immune response, although RA can affect many organs including the skin, heart, lungs and nervous system.[32] Due to synovial inflammation and proliferation, patients experience joint swelling, pain, and resultant disability.

The pathophysiology is complex, involving an interplay between genetic and environmental factors.[32] There is no cure, but through a better understanding of the immune pathways involved, many treatment options are now available.

Rheumatoid arthritis is the most common inflammatory arthritis. The global prevalence of RA

(age 5-100 years) is 0.24%, with higher estimates of 0.5-1%

As such, patients have difficulty using the affected joints and often have impaired function or disability as a result. The small joints of the hands and feet are most commonly involved, although involvement of large joints is also common and any synovial joint can be affected. Over time, if the synovial inflammation persists, joints can become irreversibly damaged through loss of cartilage and bony erosions. As rheumatoid arthritis is not just confined to the joints, systemic symptoms such as fatigue are common. Depression is also common, with a prevalence between

13-42%. There is no single clinical feature or diagnostic test that confirms a diagnosis. Instead, rheumatologists rely on a constellation of signs, symptoms, and laboratory or

Similar to other rheumatic diseases, classification criteria have been developed to assist with classifying patients with inflammatory arthritis as having rheumatoid arthritis. The classification criteria for RA were first developed in 1958, then revised in 1987 and again in

2010.[42-44] The latest criteria were designed to enable patients to be classified early in the disease, as early diagnosis and treatment are paramount to achieve optimal outcomes. As such, clinical features present in older criteria that are uncommon early in the disease (radiographic joint damage, rheumatoid nodules) were removed. The new criteria include the number and pattern of joints involved, duration of symptoms, laboratory markers of systemic inflammation

(Erythrocyte Sedimentation Rate (ESR) and C-reactive protein (CRP)) and autoantibodies associated with rheumatoid arthritis (rheumatoid factor (RF) and anti-cyclic citrullinated