Pathogenic role of anti-endothelial cell antibodies in systemic vasculitis

Antiendothelial cell antibodies (AECA), a heterogeneous group of antibodies quite distinct from the ANCA family, have been detected in variety of dise ases which share a varying degree of vessel wall damage. This review is mai nly focused on Wegener's granulomatosis, Takayasu's arteritis and Kawasaki syndrome, which provide the best examples to evaluate the pathogenic and pr ognostic value of AECA. There is increasing evidence to show that AECA migh t be pathogenic in inducing autoimmune vascular disease. It is relevant to note that the presence and titre of AECA has been correlated with disease a ctivity in systemic vasculitis. Experimental in vitro and in vivo models su pport a potential pathogenic role for AECA in sustaining immune-mediated ve ssel inflammation. Rather than being cytotoxic to endothelial cells, AECA a re able to up-regulate the expression of adhesion molecules (E-selectin, in tercellular adhesion molecule-1 and vascular cell adhesion molecule-1) and to induce the secretion of cytokine and chemokine which, in turn, cause leu kocyte recruitment and adhesion. A recent idiotypic animal model has provid ed further evidence that AECA can be pathogenic.