autoantibody

noun

antibody produced by the immune system that is directed against one or more of the individual's own proteins - many autoimmune diseases (notably lupus erythematosus) are caused by such autoantibodies

Wiktionary

noun

Etymology: Etymology tree Proto-Indo-European *h₂ewder.? Proto-Indo-European *sóder.? Proto-Indo-European *h₂ewder. Ancient Greek αὖ (aû) Ancient Greek τόν (tón)? Ancient Greek αὐτός (autós) Ancient Greek αὐτο- (auto-)lbor. English auto- English antibody English autoantibody From auto- + antibody.

An antibody formed in response to an agent (autoantigen) produced by the organism itself.
“In addition to having a relative with Type 1, people in that subgroup had insulin autoantibody levels equal to or greater than 80 milliunits per milliliter.”
“The current study investigates autoantibodies against steroid synthesis enzymes in dogs with spontaneous hypoadrenocorticism.”