IMMUNIZATION WITH ANTICARDIOLIPIN COFACTOR (BETA-2-GLYCOPROTEIN-I) INDUCES EXPERIMENTAL ANTIPHOSPHOLIPID SYNDROME IN NAIVE MICE

Beta-2-GPI is a 50 kDa glycoprotein which is known to be a serum co-fa ctor, with a role in determining the binding of pathogenic anticardiol ipin antibodies to phospholipids. Immunization of naive mice with beta -2-GPI resulted in elevated levels of antibodies directed against nega tively charged phospholipids (cardiolipin, phosphotidylserine, phospha tidylinositol). The presence of increased titres of antiphospholipid a ntibodies in the sera of the mice was later followed by prolonged acti vated partial thromboplastin time (APTT), thrombocytopenia, and when t he mice were mated, by a high percentage of fetal resorptions in the u terus. These data point to the ability of beta-2-GPI to induce pathoge nic anti-cardiolipin antibodies following active immunization.