BETA(2)-GLYCOPROTEIN-I - TARGET ANTIGEN FOR ANTIPHOSPHOLIPID ANTIBODIES - IMMUNOLOGICAL AND MOLECULAR ASPECTS

It has become clear that beta(2)-glycoprotein I (beta(2)GPI) is the mo st common and best-characterised antigenic target for 'antiphospholipi d' (aPL) autoantibodies. These antibodies preferentially bind beta(2)G PI that has been immobilised on anionic phospholipid membranes or cert ain synthetic surfaces. These surfaces appear to act by increasing ant igen density to allow binding of intrinsically low-affinity anti-beta( 2)GPI autoantibodies. Binding of beta(2)GPI in fluid phase is weak and requires high concentrations of beta(2)GPI. Our understanding of the pathophysiology of the 'Antiphospholipid' Syndrome (APS) has increased exponentially with the number of studies into the interactions of aPL antibodies and beta(2)GPI.