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

Did you know?

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

March is awareness month for autoimmune disorders, bleed disorders, multiple sclerosis, colorectal cancer, endometriosis, traumatic brain injuries and trisomy, a genetic condition characterized by the presence of three copies of a specific chromosome instead of the usual pair (two copies). —Scott Lafee, San Diego Union-Tribune, 3 Mar. 2026

She’s beaten the best the game has to offer and is winning her biggest fight against Sjögren's Syndrome, a long-term autoimmune disease that was diagnosed in 2011. —Cedric Golden, Austin American Statesman, 1 Mar. 2026

Type 1 diabetes is an autoimmune condition that prevents the pancreas from producing enough insulin to regulate blood sugar levels. —Tom Gavin, EverydayHealth.com, 27 Feb. 2026

That includes people who are undergoing chemotherapy or taking medications like steroids that reduce immunity; people recovering from another infection, such as the flu or COVID-19; and those living with HIV or autoimmune diseases. —Angela Haupt, Time, 23 Feb. 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