Autoimmunity

Part of speech: noun

Pronunciation: /ˌɔː.təʊ.ɪˈmjuː.nɪ.ti/

Definitions

1. A medical state where the body's defense system erroneously targets its own healthy cells and proteins, leading to potential tissue damage and disorder
2. A condition characterized by the immune response incorrectly identifying the body's own tissues as foreign, consequently causing harm and dysfunction
3. A pathological condition occurs when the immune system mistakenly attacks the body's own healthy cells and tissues, resulting in various disorders and damage

Etymology: Autoimmunity is a modern compound, built from "auto-", the Greek combining form meaning "self," and "immunity," the older word for protection against disease. The Greek "autós" itself belongs to a family of words meaning "self" that also gave English terms like "automatic" and "autonomy," so the first half of the word carries the same idea of self-directed action found across many scientific coinages. The second half is where the twist lies. "Immunity" originally meant exemption from a legal duty or obligation, a sense that goes back to Latin "immunitas," literally "freedom from service." Medicine borrowed the idea of being exempt from disease, so an immune body was one that had been excused from illness. Autoimmunity then describes a strange reversal: the body's defences, meant to exempt it from harm, turn their exemption-protecting power against its own tissues.

Synonyms: autoimmune response, self-immunity

Antonyms: immunity, resistance