Antiheterolysin

A substance in blood serum that inhibits or prevents the action of heterolysin, a type of antibody that destroys foreign cells.

From anti- (against) + heterolysin, which combines hetero- (different, from Greek 'heteros') and -lysin (a substance that causes breaking down, from Greek 'lysis'). This scientific term emerged in early 20th-century immunology research.