Juvenile Arthritis - Causes

A number of possible causes for JA have been suggested. Some researchers feel that the disorder may have a genetic basis. It seems to occur more often in some families than in others. Other researchers think the disorder may be caused by an infectious agent, such as a bacterium or a virus, but no such agent has ever been found.

Some evidence suggests that JA may be an autoimmune disorder (see autoimmune disorder entry). An autoimmune disorder is one in which the body's immune system becomes confused. It behaves as if some normal part of a person's body is actually a foreign substance. The immune system then sets out to attack and destroy that part of the body. According to this explanation, a person's immune system mistakenly attacks his or her joints, causing the symptoms of juvenile arthritis.