Update on granulomatosis with polyangitis (GPA, Wegener's granulomatosis)

Granulomatosis with polyangitis (GPA, Wegener's granulomatosis) is characterized by a granulomatous inflammation of the respiratory tract and a necrotizing ANCA-associated small to medium-size vessel vasculitis with a predilection for the lungs (pulmonary capillaritis) and kidneys (necrotizing glomerulonephritis). The disease evolves stage-wise and typically starts as inflammation of the respiratory tract followed by development of systemic vasculitis manifestations. Today, treatment is evidence-based and adapted according to activity and disease stage which has resulted in a significant improvement in long-term outcome. Early mortality during the first year of treatment poses one of the main problems and is a result of infections under immunosuppressive treatment. Furthermore, treatment of refractory disease activity which is often represented by granulomatous manifestations is still a challenge and may result in significant organ damage if not treated successfully.