Rheumatoid Arthritis (RA)
Rheumatoid arthritis (RA) is an autoimmune disease that is mainly known for affecting the joints, but can also affect other parts of the body. It is more common in women than men and often starts during middle age, but it can occur at any age. The cause of RA is not well understood, but it seems to involve genetic, environmental, and hormonal factors.
Arthritis means inflammation of the joints. Unlike osteoarthritis (OA), the most common form of arthritis that is caused by general wear and tear, RA is caused by an autoimmune reaction where the immune system attacks the tissue that protects joints, leading to the characteristic pain, swelling, inflammation and eventual joint destruction. RA tends to affect the joints in a different way than OA. RA joints have a distinct, more 'squishy' type of joint swelling in contrast to the type of hard, bony enlargement of joints that is often seen in the fingers of people with OA.
RA symptoms often occur in the hands, wrists, knees, and feet first. Several joints can be affected at one time, and the number of joints affected may increase over time.
RA symptoms include the following:
RA is diagnosed with a combination of medical history (having an immediate family member with RA increases risk), physical exams, X-rays, and lab tests. If RA is suspected, lab tests are performed to look for increased inflammation or signs of autoimmunity.
Diagnostic tests for RA include the following:
- Antinuclear antibody (ANA) test
- C-reactive protein (CRP) test
- Cyclic citrullinated peptide (CCP) antibody test
- Complement blood test
- Erythrocyte sedimentation rate (ESR) test
- Rheumatoid factor (RF) test
- Synovial fluid analysis
Although there is no cure for RA, there are a number of effective treatments. RA treatments are generally designed to provide pain relief, reduce joint stiffness and inflammation, and suppress immune activity to limit further joint damage. When a diagnosis of RA is reached, treatment is started as soon as possible to limit disease activity and prevent joint damage from getting worse.
Treatments such as NSAIDS and steroids target inflammation, which can limit joint damage and are often used in combination with treatments designed to suppress the immune system.
Although there is a clear relationship between diet and the immune system, the relationship between nutritional status and autoimmunity is not well understood. The effect of particular diets (e.g., the Mediterranean diet, vegetarian, elimination diets) on RA symptoms and pathology is currently unclear, but it's an active area of research. Therefore, people with RA should consult closely with their physician or rheumatologist before starting a special diet.
As with other autoimmune diseases, RA is caused by the immune system inappropriately targeting ‘self’ tissues or proteins. The mechanism by which this occurs is an active area of research but is not well understood. In the case of RA, the immune system targets the synovial lining of joints, causing inflammation and progressive damage to the joint and eventual loss of joint function. Both genetics and environmental factors are known to play a role in the disease, but the specific mechanisms driving the autoimmunity are not clear.