Anti‐β2‐glycoprotein I antibodies

Anti‐β 2 ‐glycoprotein I (anti‐β 2 GPI) antibodies are the main antiphospholipid antibodies, along with anticardiolipin and lupus anticoagulant, that characterize the autoimmune disease antiphospholipid syndrome (APS). While the exact physiological functions of β 2 GPI are unknown, there is overwhelming evidence that anti‐β 2 GPI antibodies are pathogenic, contributing to thrombosis, pregnancy morbidity, and accelerated atherosclerosis in APS and systemic lupus erythematosus patients. The revelation that these antibodies play a central role in the pathogenesis and pathophysiology of APS has driven research to characterize the physiology and structure of β 2 GPI as well as the pathogenic effects of anti‐β 2 GPI antibodies. It has also resulted in the development of improved testing methodologies for detecting these antibodies. In this review we discuss the characteristics of β 2 GPI; the generation, pathogenic effects, and standardized testing of anti‐β 2 GPI antibodies; and the potential use of therapies that target the β 2 GPI/ anti‐β 2 GPI interaction in the treatment of APS.