1. Antibodies produced by an individual against antigens from another individual of the same species, typically arising from blood transfusions or pregnancy.
Usage: medical/immunology term; plural form; singular is isoantibody; also called alloantibodies in modern usage

Examples

• Isoantibodies can develop in patients who receive multiple blood transfusions from different donors.
• During pregnancy, a mother may develop isoantibodies against fetal red blood cells if there is an Rh incompatibility.
• The presence of isoantibodies in a patient's serum must be detected before transfusion to prevent hemolytic reactions.
• Isoantibodies against ABO blood group antigens are naturally occurring in most individuals.
• Testing for isoantibodies is a critical step in the blood bank screening process.