What are autoantibodies?

Autoantibodies are antibodies (immune proteins) that mistakenly target and react with a person's own tissues or organs. One or more autoantibodies may be produced by a person's immune system when it fails to distinguish between "self" and "non-self." Usually the immune system is able to discriminate between foreign substances ("non-self") and the body’s own cells ("self"). It produces antibodies only when it perceives that it has been exposed to a threat ("non-self"), such as bacteria or viruses. However, when the immune system ceases to recognize one or more of the body's normal constituents as "self," it may produce autoantibodies that react with its own cells, tissues, and/or organs. This may cause inflammation, damage, and/or dysfunction of organs or systems, leading to signs and symptoms of autoimmune disorders.

Some autoantibodies do not cause tissue injury directly but are thought to be part of an overall immune response that can cause inflammation and damage. Their presence in the blood can indicate that an autoimmune process is ongoing. Examples include antibodies related to celiac disease and type 1 diabetes