Anti-Endothelial Cell Antibodies (AECA) comprise a heterogeneous population of autoantibodies directed to various, so far poorly characterized endothelial structures.AECA have been found in several vascular diseases with clinical manifestation of inflammation, coagulation and hypertension.So far it is unknown ifAECA are causal or just a spinoff in vascular disease.However, a pathogenic role for AECA is considered as indicated by experimental in vitro studies with endothelial cells.