Vasculitis: clinical approach, pathophysiology and treatment.

Systemic vasculitides constitute a heterogeneous group of diseases characterized by inflammation of blood vessels. Classification of the disease is mandatory for the assessment of prognosis and the institution of treatment. Secondary forms of vasculitis should be distinguished from primary vasculitides, as infections or other conditions underlying the secondary forms require a different approach. The presence of anti-neutrophil cytoplasmic antibodies (ANCA) directed against either proteinase 3 or myeloperoxidase strongly suggest one of the pauci-immune small vessel vasculitides. Their role in the pathogenesis of such vasculitides has been suggested by clinical and experimental data but has not been proven. Treatment of severe systemic vasculitides consists of cyclophosphamide in combination with corticosteroids but this regimen has many adverse effects. Less toxic regimens as well as new treatment modalities based on insight into the pathophysiology of systemic vasculitides have been developed and are currently being tested in multicentre European studies.