autoimmune

adjective

au·​to·​im·​mune ˌȯ-tō-im-ˈyün 

: of, relating to, or caused by autoantibodies or T cells that attack molecules, cells, or tissues of the organism producing them

autoimmune diseases

autoimmunity

ˌȯ-tō-im-ˈyü-nə-tē 

noun

autoimmunization

ˌȯ-tō-ˌim-yə-nə-ˈzā-shən 

also -im-ˌyü-

noun

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Any healthy body produces a variety of antibodies, proteins in the blood whose job is to protect the body from unwanted bacteria, viruses, and cancer cells. The cells and organs that deal with such infections make up the immune system. In some people and animals, for various reasons, the antibodies become overactive and turn on the body's healthy tissues as well; the result is an autoimmune disease—an immune response directed against one's own self. More than eighty autoimmune diseases have been identified, the best-known being type 1 diabetes, multiple sclerosis, lupus, and rheumatoid arthritis.

Examples of autoimmune in a Sentence

Recent Examples on the Web

Following a trial in a California federal court, a jury yesterday found that Eli Lilly breached a contract with Nektar Therapeutics to co-develop in good faith the autoimmune disease drug rezpeg. — Meghana Keshavan, STAT, 25 Sep. 2026

Other Health Conditions Health conditions, including several autoimmune diseases, can lead directly or indirectly to dry eye syndrome. — Nancy Lebrun, Verywell Health, 24 Sep. 2026

Although the study didn't achieve its goal for CLE, the company plans to continue developing the drug to treat other autoimmune diseases, including Graves' disease. — Scott Schnipper, CNBC, 23 Sep. 2026

In 2022, she was diagnosed with the rare and progressive autoimmune and neurological disorder — which can cause muscle rigidity, mobility issues, painful spasms and shortness of breath. — Bailey Richards, PEOPLE, 20 Sep. 2026

Word History

Etymology

auto- + immune, after autoimmunity, borrowed from French auto-immunité

First Known Use

1952, in the meaning defined above

Kids Definition

autoimmune

adjective

au·​to·​im·​mune ˌȯt-ō-im-ˈyün 

: relating to or caused by an abnormal condition in which an organism's immune system attacks and destroys parts of its own cells or tissues

multiple sclerosis is an autoimmune disease

Medical Definition

autoimmune

adjective

au·​to·​im·​mune -im-ˈyün 

: of, relating to, or caused by antibodies or T cells that attack molecules, cells, or tissues of the organism producing them

autoimmune diseases