Rheumatoid arthritis (RA) is the presence of chronic inflammation and symmetrical erosive synovitis leading to joint deterioration and deformity. RA occurs more frequently in women than men, and while patients may present at any age, the disease process most often begins between the fourth and sixth decades. Both genetic and environmental factors may contribute to the initiation of the inflammatory process. RA is an autoimmune disease in which the immune system targets connective tissues: T-lymphocytes produce pro-inflammatory cytokines and cytotoxic substances, activated B-lymphocytes differentiate into plasma cells which produce antibodies, and macrophages release prostaglandins and cytotoxins, all of which ultimately cause continued inflammation, cellular damage, and erosion of bone, cartilage, and joint tissues.
Early in the disease course, patients develop vague and generalized symptoms such as fatigue, malaise, diffuse musculoskeletal pain, and morning stiffness in joints lasting longer than 30 minutes. In the majority of cases, symptoms develop insidiously over weeks to months. The small joints of the hands, wrists, and feet are most likely to be involved and may appear swollen and feel warm to the touch. At later stages, joints of the fingers may become deformed because of the erosive effect of the disease on bones, tendons, and ligaments. Patients with RA may have extra-articular involvement associated with their disease such as vasculitis, Sjögren’s syndrome, rheumatoid nodules, and pulmonary or cardiac complications, and these extra-articular manifestations tend to be a poor prognostic factor.
There are no specific laboratory tests that establish a diagnosis of RA, but several tests suggest the diagnosis. Approximately 60% to 70% of patients with RA test positive for rheumatoid factor (RF). Anti-citrullinated peptide antibody (ACPA) is useful in the evaluation of early RA as it may be produced before the development of symptoms. Patients with increased RF and ACPA tend to experience more aggressive disease. Other nonspecific markers include antinuclear antibody (ANA), which is seen in approximately 25% of patients with RA, as well as elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels. A complete blood count (CBC) may reveal anemia of chronic disease or thrombocytosis.
The American College of Rheumatology’s Rheumatoid Arthritis Classification Criteria are used to classify patients who present with one or more joints with definitive synovitis that cannot be explained by another disease state. Patients with a score of more than 6 of 10 are classified as having definite RA. Points are allotted based on joint involvement (with an increasing number of points given for the number of joints involved), serologies (levels of RF and ACPA), acute-phase reactants (CRP and ESR), and duration of symptoms (with a point being awarded for symptoms lasting at least 6 weeks).
RA varies in activity and severity among individuals and within the same patient. The American College of Rheumatology’s treatment recommendations take into consideration both the duration of disease and disease activity. Patients are considered to have early RA if ...