Anti-phosphatidylethanolamine antibody, thromboembolic events and the antiphospholipid syndrome.

The antiphospholipid syndrome (APS) is an acquired disorder characterized by arterial and/or venous thrombosis and pregnancy morbidity. In solid assays, sera from patients with APS usually react to negatively charged phospholipids (PL) and PL cofactors such as β2-glycoprotein I (β2GPI). Binding to neutral PL such as phosphatidylethanolamine (PE) is less common. PE is one of the main lipid components of the biological membranes, being mostly located in the inner leaflet. In 1989 we reported the first case of primary APS whereby a LA was accompanied not by an anticardiolipin antibody (aCL), but by an antibody to PE (aPE). In this review, we update the literature concerning the presence of aPE in patients with thromboembolic events and obstetric morbidity. We also discuss aPE as the sole antibody detected in many of these clinical circumstances. An eventual link of aPE antibodies with failure of in vitro fertilization is also considered as well as uncommon clinical associations of aPE that are also discussed.