Induction of Primary Antiphospholipid Syndrome in Mice by Immunization with a Human Monoclonal Anticardiolipin Antibody (H-3)

Antiphospholipid syndrome (APIS) is characterized by throm-bocytopenia, thromboembolic phenomena, and recurrent fetal loss, associated with anticardiolipin antibodies (ACA) and/or lupus anticoagulant. The syndrome may be primary or may be associated with other conditions such as systemic lupus erythe-matosus. We have previously shown the ability to induce APLS in naive mice following passive transfer of serum and monoclonal ACAs. Similarly we generated the secondary APLS in BALB/c mice following immunization with a pathogenic anti-DNA anti-body. In the current study we report on the induction ofprimary APLS following immunization of BALB/c mice with a human monoclonal ACA (H-3). The mice developed high persistent titers of ACA. The APLS was characterized by prolonged acti-vated partial thromboplastin time, low fecundity rate (21 % vs. 48 % of control immunized mice), high resorption index of fe-tuses (25 % vs. 3%), and low weights of embryos and placentae. Our study points to the ability of inducing primary APLS in naive mice. The induction of various presentations ofAPLS by different ACA may explain the diversity of clinical manifesta-tions seen in patients with APLS. (J. Clin. Incest. 1992. 89:1558-1563.) Key words: autoimmunity * autoantibodies-experimental autoimmune diseases * antiphospholipid antibod-ies * systemic lupus erythematosu