Mechanism of action of β2-glycoprotein I-dependent lupus anticoagulants

Abstract

There is accumulating evidence showing that lupus anticoagulants (LA) are more strongly associated with thrombosis than anticardiolipin antibodies. In addition, indirect evidence has been presented indicating that β₂GPI-dependent LA are more strongly associated with thrombosis than prothrombin-dependent LA. From this, one may assume that anti-β₂GPI antibodies with LA activity are more pathogenic than anti-β₂GPI antibodies without LA activity. Therefore, it is of the utmost importance to understand the molecular basis on which some anti-β₂GPI antibodies behave as LA. In this presentation, the current knowledge on the interaction of β ₂GPI with phospholipids and with anti-β₂GPI antibodies is reviewed and an integrated model for the anti-β₂GPI - dependent LA activity is proposed with implications for a pathogenic role of these particular antibodies.