Differential Diagnosis

The antiphospholipid antibody syndrome (APS) is a systemic, acquired, immune-mediated systemic disease characterized by episodes of thrombosis (venous, arterial, or of the microcirculation) and/or pregnancy morbidities, associated with the persistent presence of circulating autoantibodies directed to molecular complexes consisting of phospholipids and proteins (confirmed at least in two occasions 12 weeks apart). APS should always be considered as a potential diagnosis for young patients presenting with a history of thrombotic events, especially when they occur without any obvious external trigger or any inherited thrombophilic mutation (even if 2006 criteria do not exclude APS patients with other inherited or acquired pro-thrombotic conditions) or for women with recurrent pregnancy losses or later fetal deaths. Many other disorders are able to mimic APS, so a broad range of alternative diagnoses should be investigated and ruled out during clinical workup.