Pathogenic mechanisms of the anti-phospholipid antibodies

The antiphospolipid syndrome (APS) is an autoimmune disease characterized by recurrent fetal loss, thrombotic events (arterial or venous) and hemocytopenic disorders associated to high titers of circulating aPL. Two variants of the APS have been described. Primary APS is a clinical entity without evidence of any other autoimmune disease and secondary APS is a clinical disorder mainly associated with Systemic Lupus Erithematosus (SLE). aPL are a widely group of immunoglobulins directed against different components or proteins factors. In 1990 three groups of researchers identified that β2GP-I is the mainly antigenic target of aPL in APS patients. There are evidences that show that more than one pathogenic mechanism is involved in the development of the APS. The best documented clinical manifestations associated with the APS are recurrent fetal loss and thrombotic disorders. The latter is based on observations in vivo in animal models and in vitro on the effects caused by aβ2GP-I antibodies from patients with APS or from animals which cause experimental APS.The objective of the present paper is to show the pathogenic mechanisms that participate in the development of the APS. We also presented evidence that shows that aβ2GP-I induces pro-inflammatory, pro-adhesive and pro-coagulant disorder.

ResumenEl síndrome de antifosfolípidos (SaF) es una enfermedad autoinmune caracterizada por abortos recurrentes, eventos trombóticos (arteriales o venosos) y hemocitopenias asociadas con títulos altos de aFL séricos. Se han descrito dos presentaciones de SaF: el SaF primario, que se presenta como entidad única y el SaF secundario o asociado principalmente a LEG.Los aFL son un grupo heterogéneo de inmunoglobulinas dirigidas contra diversos componentes o factores proteicos. En 1990, tres grupos de investigadores identificaron a la β2GP-I como el principal blanco antigénico de los aFL presentes en los pacientes con SaF. Diversos trabajos han mostrado que existe más de un mecanismo patogénico involucrado en el desarrollo del SaF. Las manifestaciones clínicas mejor documentadas son los abortos recurrentes y las alteraciones trombóticas. Lo anterior se fundamenta en las evidencias observadas in vivo en modelos animales e in vitro causadas por los anticuerpos anti-β2GP-I (aβ2GP-I) de pacientes con SaF o de origen animal.La presente revisión tiene como objetivo mostrar los mecanismos patogénicos que participan en el desarrollo del SaF. Presentamos, además, las evidencias que muestran que los aβ2GP-I inducen un estado proinflamatorio, proadhesivo y procoagulante.