Autoantibody tests are blood tests that detect misguided antibodies. Normally, the immune system releases antibodies to fight foreign invaders (antigens), such as bacteria and viruses. In some people, however, antibodies mistakenly attack the body’s own tissues. These are known as autoantibodies.

Autoantibodies are found in many people with autoimmune diseases, including type 1 diabetes. Three autoantibodies are especially common in people with type 1 diabetes:

• Insulin autoantibodies
• Islet cell antibodies
• Glutamic acid decarboxylase (GAD) autoantibodies

Researchers are developing autoantibody tests and genetic tests that can identify who is at risk of type 1 diabetes and that one day may even help prevent the disease.

Patients may also have autoantibody testing for other autoimmune endocrine diseases, such as Hashimoto’s thyroiditis and Graves’ disease, and for autoimmune musculoskeletal conditions including rheumatoid arthritis and lupus.