Antiphospholipid Antibody Syndrome (APLS) is an immune system disorder marked by the presence of unusual antibodies in the bloodstream, leading to issues such as abnormal blood clotting, headaches, recurrent miscarriages, and low platelet counts. These antibodies target phospholipids, which are phosphorus-containing fats. APLS can occur independently (primary APLS) or as a result of another condition (secondary APLS). Approximately one-third of individuals with primary APLS exhibit abnormalities in heart valves. These antiphospholipid antibodies decrease the levels of annexin V, a protein that binds to phospholipids and has significant activity. The decrease in annexin V may be a factor contributing to the increased blood clotting and miscarriage risk associated with antiphospholipid antibody syndrome.