Health

The treatment of rheumatoid arthritis has changed dramatically since the 1990s, owing to a better understanding of how to slow the progression of joint damage in this disease. Advances in treatment, discussed below, followed decades of research into how the immune system functions.

Until the mid-1960s, physicians lumped together most forms of arthritis that affected four or more joints as rheumatoid arthritis. Then researchers identified rheumatoid factor, an antibody present in the blood of 70%–80% of people with rheumatoid arthritis. The presence or absence of rheumatoid factor helped physicians distinguish rheumatoid arthritis from other types of inflammatory arthritis that may occur in people who have psoriasis, inflammatory bowel disease, or infectious diseases. Rheumatoid factor may also help distinguish between rheumatoid arthritis and osteoarthritis, because people with osteoarthritis are no more likely to have rheumatoid factor than the general population.

Rheumatoid arthritis is a chronic autoimmune disease in which the body's immune system attacks healthy tissue lining the joints. It affects about three million Americans, and strikes two to three times more women than men. Although the disease usually first appears during middle age, it may occur in the 20s and 30s. Some children develop a similar disease, called juvenile chronic arthritis, but this is considered a separate disorder.

The chronic inflammation of rheumatoid arthritis begins in the synovium, where an unknown event triggers an inflammatory reaction. As a result, synovial and other cells produce cytokines, other chemical mediators, and proteolytic enzymes, which together can destroy all the components of the joint. The synovial tissue also begins to proliferate, causing the normally smooth synovium to form pannus, a rough, grainy tissue that grows into the joint cavity and erodes cartilage (see Figure 7). If the tendons become inflamed, they may shorten and immobilize the joint, which can cause bone fusion and loss of mobility. If the tendons rupture, the joint may become loose or floppy.

Rheumatoid arthritis can affect connective tissue in other parts of the body. Inflammatory skin nodules at pressure points, such as the elbow, can appear gradually or suddenly, and may be tender and sometimes inflamed. Occasionally, surgery is needed if these nodules become infected or are bothersome during activity. At times, they may also disappear spontaneously.

Vasculitis (inflammation of blood vessels) can compromise circulation to the hands, feet, and nerves. People with rheumatoid arthritis often develop eye conditions, including keratoconjunctivitis sicca, or dry eye, which causes redness, burning, itching, reduced tearing, and sensitivity to light. Other complications include respiratory, heart, and neurologic disorders. In rare cases, the ligaments that tether the uppermost vertebrae (which support the skull) are damaged, allowing the vertebrae to slip out of alignment and pinch the spinal cord.