ANCA-associated vasculitis from a clinical perspective

ANCA-associated vasculitides (AAV) are small-vessel necrotizing vasculitides, with no or few immune deposits. They are usually associated with the presence of ANCA antibodies (AntiNeutrophil Cytoplasmic Antibody), targeted either against proteinase 3 (PR3-ANCA) or myeloperoxidase (MPO-ANCA). ANCA-associated vasculitides include granulomatosis with polyangiitis (formerly Wegener's), microscopic polyangiitis and eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss syndrome). The most commonly afflicted organs involve the lungs and the respiratory tract, ENT area, and the kidneys. Renal involvement typically manifests as pauci-immune necrotizing crescentic rapidly progressive glomerulonpehritis. Pulmo-renal syndrome with lung haemorrhage and deteriorating kidney function may be acutely life-threatening. Diagnostic methods include ANCA measurement, imaging methods and biopsy. Early recognition of the diagnosis and an early start of adequate treatment are necessary for a good outcome. The current treatment typically consists of corticosteroids and either cyclophoshapmide or rituximab (a monoclonal antibody directed against CD20 antigen). The addition of plasma exchange may be considered in severe cases. Rituximab is preferred for the treatment of all relapsing forms of this vasculitis.