ABSTRACT
Vasculitis is a condition characterized by inflammation of blood vessels. Its clinical manifestations are dependent on the localization and size of the involved vessels as well as on the nature of the inflammatory process. Vasculitis can be secondary to other conditions or can constitute a primary, in most of the cases, idiopathic disorder (1). Underlying conditions in the secondary vasculitides are infectious diseases, connective tissue diseases, and hypersensitivity disorders. Immune complexes, either deposited from the circulation or formed in situ, are involved, in many cases, in the pathophysiology of the secondary vasculitides. These complexes are supposedly composed of microbial antigens in the case of underlying infectious diseases, autoantigens in the connective tissue diseases, and nonmicrobial exogenous antigens in the hypersensitivity disorders. Although immune deposits can be demonstrated in the involved vessel wall by direct immunofluorescence in biopsy material, the specificities of the antibodies and their corresponding antigens have not been demonstrated in most of the cases.
