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

Immune system research wins Nobel Prize in medicine Discoveries about how our immune systems avoid attacking our own bodies — research which helped create new pathways for treating autoimmune diseases — won the 2025 Nobel Prize for Physiology or Medicine. —Matthew Martin, semafor.com, 6 Oct. 2025

The findings have led to the development of potential medical treatments that scientists hope could cure autoimmune diseases, the committee said, as well as providing more effective cancer treatments and reducing complications after stem cell and organ transplants. —Katie Hunt, CNN Money, 6 Oct. 2025

Alongside colleagues in Japan in the 1980s and 1990s, Sakaguchi wanted to figure out why, when batches of immune cells from healthy mice were injected into mice that had their thymuses removed, the cells didn't trigger an autoimmune disease. —Beth Mole, ArsTechnica, 6 Oct. 2025

The mom of three has made very few public appearances since her stiff-person syndrome diagnosis — she was diagnosed with the rare autoimmune and neurological disorder in August 2022 — but has previously stepped out to enjoy live music. —Bailey Richards, PEOPLE, 5 Oct. 2025

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