Antiphospholipid antibodies in systemic lupus erythematosus.

Antiphospholipid antibodies (aPL) are associated with a clear but variable risk for thromboses at multiple vascular sites and with a wide spectrum of clinical features comprising both the primary and secondary antiphospholipid antibody syndromes (APS). The recent literature reviewed here includes refined and more quantitative descriptions of aPL-associated clinical phenomena and APS features in studies of increasingly larger patient cohorts, and better understanding of the heterogeneity of aPL relative to binding dependency on beta 2 glycoprotein I and other phospholipids. There is expanded knowledge of pathogenesis of aPL from in vitro and in vivo studies in murine and human models and intriguing data on therapeutic modalities, old and new.