
Antiphospholipid Syndrome (
APS/Hughes syndrome) is an
autoimmune,
hypercoagulable state caused by antibodies against cell-membrane phospholipids. The most common of these antibodies,
lupus anticoagulant (
LA) and
anticardiolipin antibodies (
aCL), are the basis of laboratory diagnosis.
Primary Antiphospholipid Syndrome - thrombosis or multiple pregnancy loss with the laboratory findings of persistent paradoxical prolongation of activated partial thromboplastin time (aPTT) or high titers of aCL antibodies.
Secondary Antiphospholipid Syndrome: associated with other autoimmune diseases, infection, drugs, and malignancy. Primary and secondary APS can result in venous or arterial thrombosis in virtually any location; lower extremity deep vein thrombosis (
DVT) is the most common presentation. Thrombotic stroke/transient ischemic attack (
TIA) is the leading arterial manifestation of APS.
Up to 46% of stroke patients <50 years old have antiphospholipid antibodies.