Origin and pathogenesis of antiphospholipid antibodies.

Antiphospholipid antibodies (aPL) are a heterogeneous group of antibodies that are detected in the serum of patients with a variety of conditions, including autoimmune (systemic lupus erythematosus), infectious (syphilis, AIDS) and lymphoproliferative disorders (paraproteinemia, myeloma, lymphocytic leukemias). Thrombosis, thrombocytopenia, recurrent fetal loss and other clinical complications are currently associated with a subgroup of aPL designating the antiphospholipid syndrome. In contrast, aPL from patients with infectious disorders are not associated with any clinical manifestation. These findings led to increased interest in the origin and pathogenesis of aPL. Here we present the clinical features of the antiphospholipid syndrome and review the origin of aPL, the characteristics of experimentally induced aPL and their historical background. Within this context, we discuss the most probable pathogenic mechanisms induced by these antibodies.