Vasculitides: classification, clinical aspects and pathology. A review

The Consensus Conference of Chapel Hill (1994) laid a common base for a standardized classification of vasculitides which, after a pre-existing historical diversity, enabled a comparison of different studies. The criteria for this classification are foremost anatomico-pathological and are based on the caliber of affected blood vessels. In addition the quality of the inflammatory reaction, and the entirety of clinical symptoms, as well as the results of immunological tests are included. Moreover a unified pathogenetic concept is proposed for all types of vasculitis. The diagnosis of vasculitis of large, medium or small vessels is made primarily by biopsies and examination of HE-stained sections. However, overlap of calibers of vessels affected and lack of specificity of inflammatory reaction with individual vasculitis types have to be paid attention to. Immunohistochemical methods are only rarely routinely applied. In contrast the complete clinical picture and the results of immunological laboratory tests (especially antineutrophil cytoplasmic antibodies, ANCA) play an important role in the differential diagnosis of various vasculitis types. Definitions, clinical findings and pathology of the various types of vasculitis are described. Also mentioned are secondary vasculitides, e.g concurrent to collagen diseases or infections. Not only the diagnosis vasculitis but also the recognition of the specific type and, last but not least monitoring by histological controls, may be decisive for an optimal therapy.