Mechanisms of endothelial injury in systemic vasculitis.

The precise etiology of primary systemic vasculitis remains unknown. However, recent advances in the understanding of the role of and interaction between the vascular endothelium, mediators, and immune effector cells have helped to further elucidate those specific processes that result in endothelial cell damage. In WG and MPA, the evidence favors an autoimmune inflammatory response characterized by specific mediators in which the endothelium is both target and active participant.