Risk Assessment and Antithrombotic Strategies in Antiphospholipid Antibody Carriers

Antiphospholipid antibodies (aPL) are a cluster of autoantibodies directed against plasma proteins with affinity for membrane phospholipids. The most frequently tested aPL are lupus anticoagulant (LA), anti-cardiolipin antibodies (aCL), and anti-β2-glycoprotein I antibodies (anti-β2GPI). aPL play a key pathogenic role in the development of the antiphospholipid syndrome (APS), a systemic autoimmune disease characterized by recurrent thrombotic and/or pregnancy complications in patients with persistent aPL. However, aPL positivity is occasionally documented in patients with no previous history of thrombotic or pregnancy morbidity. LA activity, multiple aPL positivity, high-titer aPL, and a concomitant systemic autoimmune disease are recognized risk factors for future thrombotic events in asymptomatic carriers. Moreover, an accelerated atherosclerosis with increased cardiovascular (CV) risk has also been associated with aPL positivity, thus exposing aPL carriers to fatal complications and chronic disability requiring cardiac rehabilitation. Overall, an accurate risk stratification is recommended for aPL-positive subjects in order to prevent both venous and arterial thrombotic complications. In this review, we provide an overview of the main antithrombotic and risk assessment strategies in aPL carriers.