Genetics and Origin of Antiphospholipid Syndrome

Abstract

Antiphospholipid syndrome (APS) is a multisystemic autoimmune disorder characterized by vascular thrombosis and/or pregnancy morbidity associated with the concomitant detection of antiphospholipid antibodies (aPL), including lupus anticoagulant (LA), anticardiolipin antibodies (aCL), and anti-β2 glycoprotein I (anti-β2GPI) antibodies. Despite several experimental models and family studies, the underlying genetic factors predisposing to APS have not yet been clearly defined. Similarly, the origin of pathogenic aPL remains to be elucidated, with most of the evidence supporting the role of infectious agents as responsible for the ‘second hit’ in the APS pathophysiological mechanisms, in an individual with a procoagulant phenotype. The focus of this chapter is to gather the most recent scientific evidence with regard to genetics and origin of APS.