What Are Autoantibodies?

human antibodies
Autoantibodies target your own cells. Science Picture Co./Getty Images

Autoantibodies are proteins produced by your body's immune system.

You probably know that your immune system is designed to fight threats like viruses and bacteria that make their way into your body. But an autoantibody turns its attack on the wrong thing: Instead of attacking foreign invaders, autoantobodies mistakenly attack parts of your own body.

When they do this, autoantibodies cause inflammation and damage to whatever bodily system they happen to be attacking.

This damage results in what we call "autoimmune disease" — literally, "auto" means "self." The autoantibodies appear before symptoms of the actual disease become obvious.

Why Does Your Body Make Autoantibodies?

That's not clear. Genetics likely play a role in this process, as do environmental factors. But researchers haven't pinpointed why some people with similar genetics and/or similar environmental triggers start to make autoantibodies and then go on to develop an autoimmune disease, while others do not.

In celiac disease, for example, your body responds to the ingestion of the gluten protein in the foods you eat by creating autoantibodies that then proceed to attack the lining of your small intestine.

Now, the vast majority of people with celiac disease carry one of two genes that predispose them to the condition. But these so-called celiac disease genes are very common, and only a small fraction of those who have the genes begin to make the autoantibodies and go on to develop celiac disease.

So obviously there's something else in play that triggers your body to start making autoantibodies. Research is ongoing to figure out what that "something" might be.

What Else Should I Know About Autoantibodies?

Some autoantibodies attack a specific organ — for example, autoantibodies in celiac disease attack the small intestine, autoantibodies in autoimmune thyroid disease attack the thyroid gland, and autoantibodies in type 2 diabetes attack the insulin-producing cells in the pancreas.

These organ-specific autoantibodies generally lead to fairly specific symptoms that can help your physician to make an accurate diagnosis. For example, there are several hundred possible celiac disease symptoms, but the most common symptoms, which include digestive issues and anemia, can provide a clue to assist in diagnosis.

Other autoantibodies are what's called "systemic," which means they attack in various places throughout your body. These may induce more general symptoms, such as joint pain and rashes, that make a specific condition more difficult to diagnose.

For example, it may be difficult to tell the difference between the autoimmune disease lupus and fibromyalgia, which doctors believe is not an autoimmune condition. To help make the diagnosis, doctors can order blood tests looking for autoantibodies called anti-nuclear antibodies, or ANA. These are autoantibodies that attack parts of your cells' nuclei, and nearly everyone who has lupus will test positive for them, compared to only a small percentage of those with fibromyalgia.


Arbuckle MR et al. Development of autoantibodies before the clinical onset of systemic lupus erythematosus. New England Journal of Medicine. 2003 Oct 16;349(16):1526-33.

Dönmez S et al. Autoimmune rheumatic disease associated symptoms in fibromyalgia patients and their influence on anxiety, depression and somatisation: a comparative study. Clinical and Experimental Rheumatology. 2012 Nov-Dec;30(6 Suppl 74):65-9.

Fujii T. Direct and indirect pathogenic roles of autoantibodies in systemic autoimmune diseases. Allergology International. 2014 Dec;63(4):515-22. 

Hu ZD et al. Autoantibodies in pre-clinical autoimmune disease. Clinica Chimica Acta: The International Journal of Clinical Chemistry. 2014 Nov 1;437:14-8. 

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