Autoantibody Testing: MedlinePlus Medical Test

What is autoantibody testing?

Autoantibody testing checks a sample of your blood for autoantibodies, proteins made by the immune system.

Normally, your immune system makes proteins called antibodies to attack germs that could make you sick. Autoantibodies, however, do not attack germs. They instead attack your own healthy tissue and organs, believing them to be foreign substances. This can lead to the development of an autoimmune disease. There are more than 80 types of autoimmune diseases, and they can affect almost any part of your body.

Your immune system makes autoantibodies by mistake. Researchers aren’t entirely sure why, though your body is more likely to make them if you:

• Have a family history of autoimmune diseases.
• Have a viral or bacterial infection, especially if it’s chronic (long-term). This can cause your immune system to be overactive, which can lead to the production of autoantibodies.
• Are exposed to certain environmental toxins.

There are many different types of autoantibodies, and they can affect your body in different ways. Some affect only specific organs and/or parts of your body. These are called organ-specific antibodies. For example:

• Thyroid antibodies, such as anti-TPO, only affect your thyroid.
• Smooth muscle antibodies (SMAs) attack smooth muscle, usually in the liver.
• Islet cell autoantibodies attack cells in your pancreas.

Other antibodies, however, affect multiple organs and can cause a variety of symptoms. These are called systemic antibodies. This type can include:

• Antinuclear Antibody (ANA).
• Antineutrophil Cytoplasmic Antibodies (ANCA).
• Anti-Double Stranded DNA (anti-dsDNA).
• Antihistone Antibodies.
• Rheumatoid Factor (RF).

Other names: antibody serology test, antinuclear antibody (ANA) test, extractable nuclear antigen (ENA) test, anti-dsDNA test, rheumatoid factor (RF) test, antineutrophil cytoplasmic antibodies (ANCA) test, smooth muscle antibody (SMA) test, thyroid antibody test