What is autoantibody testing?

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

Normally, your immune system makes proteins called antibodies to attack bacteria that can make you sick. However, autoantibodies do not attack bacteria. They instead attack your own healthy tissues and organs, thinking they are foreign substances. This can lead to the development of an autoimmune disease. There are more than 80 types autoimmune diseasesand they can affect almost every part of your body.

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

• Have a family history of autoimmune diseases.
• Have one viral or bacterial infectionespecially if it is 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 only affect 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 gland.
• Smooth muscle antibodies (SMAs) attack smooth muscle, usually in the liver.
• Islet cell autoantibodies attack cells in your pancreas.

However, other antibodies 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