A serological test detects IgG autoantibodies directed against a variety of phospholipids, such as cardiolipin, phosphatidylserine, and phosphatidylinositol. These antibodies are part of the antiphospholipid (aPL) group, a key laboratory diagnosing antiphospholipid syndrome (APS). Their presence is associated with an increased risk of venous or arterial thrombosis and pregnancy complications such as recurrent miscarriage.