Antiphospholipid Antibody Syndrome (APS) (Anticardiolipin Antibody Syndrome; Lupus Anticoagulant Syndrome) By Joel L Moake, MD, Baylor College of Medicine Reviewed / Revised Jan 2021 | Modified Sep 2022 View Patient Education Diagnosis Treatment Antiphospholipid antibody syndrome is an autoimmune disorder in which patients have autoantibodies to phospholipid-bound proteins.