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

Osmond, who was diagnosed with the autoimmune disease in 1987, died with Suzanne — his wife of more than 50 years — and their eight sons at his bedside, the family confirmed in a statement to Salt Lake City’s NBC affiliate, KSL TV 5. —Jami Ganz, New York Daily News, 21 Apr. 2026

She was diagnosed with neuromyelitis optica, or NMO — a rare, autoimmune disorder that primarily affects the optic nerves and the spinal cord. —Brad Quick, CNBC, 20 Apr. 2026

Nektar Therapeutics said Monday that extended treatment with its experimental drug, called rezpeg, promoted greater hair growth in people with severe alopecia areata, an autoimmune condition that attacks hair follicles. —Adam Feuerstein, STAT, 20 Apr. 2026

Conditions like autoimmune disease, postpartum depression and chronic pain syndromes were too often chalked up to stress or hysteria. —Dr. Sanjay Gupta, CNN Money, 19 Apr. 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