PLASMA-PROTEINS REQUIRED FOR ANTIPHOSPHOLIPID ANTIBODY DETECTION

Autoantibodies to phospholipids have been associated with vascular thr ombosis, thrombocytopenia and recurrent pregnancy losses. Whereas most antiphospholipid antibody studies describe anionic phospholipids and the plasma proteins which bind to them, we have focused our attention upon the zwitterionic phospholipid, phosphatidylethanolamine (PE) and to autoantibodies and plasma proteins which bind to PE. Our data show that high and low molecular weight kininogens as well as the high mole cular weight kininogen-binding proteins (Factor XI and prekallicrein ) are the plasma proteins necessary for the detection of most anti-PE a ntibodies in the ELISA. A novel prothrombotic mechanism is proposed wh ich involves the interaction of PE autoantibodies with kininogens and platelets.