HLA (Human Leukocyte Antigen) antibodies are proteins produced by the immune system that typically react to foreign tissues. HLA proteins are found on the surface of cells and help the immune system distinguish the body’s own tissues from foreign ones. However, if an individual has been exposed to foreign HLA antigens through blood transfusion, organ transplantation, or pregnancy, the immune system may produce antibodies against these antigens. These antibodies can be detected through specialized tests, which identify the specific HLA antigens to which the immune system has responded.
