A Comparison of Lupus Anticoagulant–Positive Patients With Clinical Picture of Antiphospholipid Syndrome and Those Without

Among antiphospholipid antibodies, Lupus Anticoagulant (LAC) is recognized as the strongest risk factor for thromboembolic events or pregnancy morbidity.1 The presence of LAC in a subject with previously documented thromboembolism or a significant history of pregnancy loss defines the Antiphospholipid Syndrome (APS). Some patients, however, are diagnosed with LAC without ever having experienced previous vascular thrombosis or pregnancy morbidity. The antiphospholipid antibody profiles of LAC positive patients with or without associated clinical features of APS have been evaluated by us in a multicenter study.Centers affiliated with Italian Federation of Thrombosis Centers (FCSA) were invited to identify consecutive LAC positive patients diagnosed over a 1-year period. Three hundred twenty-one recruited patients were contacted and after giving informed consent they underwent testing for LAC after at least 12 weeks from the first one using routine laboratory procedures. LAC was not confirmed by Thrombosis Centers in 19 patients (6 were …