Efek Protrombotik Antibodi Anti Beta-2 Glikoprotein-1 pada Sel Endotel: Kajian Tissue Factor, Trombomodulin, dan Plasminogen Activator Inhibitor-1 = The Prothrombotic Effect of Anti-beta-2 Glycoprotein-1 Antibodies on the Expression of Tissue Factor,Thrombomodulin,and Plasminogen Activator Inhibitor-1 in Endothelial Cells