Abstract
Vasculitis in a clinical and pathological process characterized by inflammation and necrosis of blood vessel walls. The clinical expression depends on the site, type, and size of involved vessels, and the severity of the associated inflammatory features. There have been changes in the concept and many attempts at the classification of vasculitis along clinical evidences, histopathological findings, immunological advances and developments of molecular biological research, since Kussmaul and Maier reported a case of periarteritis nodosa in 1866. The animal models of vasculitides have also been established. Recently, a new classification of primary systemic vasculitis which was classified according to the size of involved vessels was proposed. Although the aetiology of primary systemic vasculitis in this classification is unknown yet, genetic factors and enviromental factors are important for the development of vasculitis. In the above classification, microscopic polyangiitis which is characterized by microvasculitis and positive antineutrophil cytoplasmic antibody (ANCA) is distinct from polyarteritis nodosa which is characterized by the mediumsized arteritis and negative ANCA. ANCA does not only contribute to the classification of vasculitis like this but also has given impetus to the studies on pathogenetic mechanisms and therapeutic strategies. In this paper, recent advances of the study in primary systemic vasculitis syndrome were reviewed.
