Primary systemic vasculitis.

Systemic vasculitides are multisystem diseases characterised pathologically by necrotising inflammation of blood vessels. The clinical presentation of vasculitis depends on the vessels involved. Classification of such diseases is now by the size of the affected vessel. This review focuses predominantly on the small vessel vasculitides shown to be associated with the presence of anti-neutrophil cytoplasmic antibodies (ANCA), that is Wegener's granulomatosis, microscopic polyangiitis and Churg-Strauss syndrome. It will examine the clinical characteristics of these diseases, the use of ANCA in diagnosis and monitoring of disease along with current and novel treatment strategies. The immunopathology of the ANCA-associated vasculitides will also be explored reviewing the roles of ANCA, neutrophils, T cells and apoptosis in the production of disease.