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

Lupus is an autoimmune disease in which the body's immune system attacks healthy tissues, rather than targeting the bad bacteria and viruses, causing inflammation that can affect the joints, skin, kidneys, blood cells, brain, heart, and lungs. —Escher Walcott, People.com, 23 June 2025

Take axial spondyloarthritis, for example, an umbrella term for a group of autoimmune diseases that affects about 3.2 million people in the US. —Katie Camero, SELF, 20 June 2025

However, in autoimmune diseases such as type 1 diabetes and rheumatoid arthritis, T cells can either directly harm the body’s own tissues or act as helper cells that enable other immune cells to produce antibodies that attack the body. —New Atlas, 19 June 2025

Psoriasis Plaque psoriasis is an autoimmune skin disease in which the body's immune system mistakenly attacks healthy skin cells. —Cristina Mutchler, Verywell Health, 19 June 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