To confirm a diagnosis of celiac disease, a biopsy of the small intestine is examined to detect damage to the intestinal villi. However, given the invasive nature and cost of a biopsy, antibody tests are often used to identify those individuals with high probability of having celiac disease.
Autoimmune hepatitis is a disease in which the body's immune system attacks liver cells. This immune response causes inflammation of the liver, also called hepatitis. Researchers think a genetic factor may make some people more susceptible to autoimmune diseases.
Systemic lupus erythematosis is an autoimmune disease that attacks body tissues, including the lungs, kidneys, and skin. Many types of auto-antibodies are found in the blood of people with lupus. No one knows exactly what causes autoimmune diseases, but many factors seem to be involved.