Granulomatosis with Polyangiitis

Granulomatosis with polyangiitis (GPA), a rare systemic autoimmune disease associated with antineutrophil cytoplasmic antibodies (ANCA), is a small vessel necrotizing vasculitis characterized by granulomatous inflammatory lesions. Presentation ranges from mild to severe clinical disease, due to necrotizing granulomatous involvement of the upper and lower respiratory tract and vasculitis, primarily affecting the lung, kidneys, peripheral nerves, and skin. The diagnosis of GPA is based upon the combination of characteristic clinical findings, laboratory and imaging results, ANCA positivity (mainly directed against proteinase-3), and histopathology features. New classification criteria endorsed by the American College of Rheumatology and the European Alliance of Associations for Rheumatology have been recently developed. Initial treatment of organ- or life-threatening GPA relies on the administration of rituximab or cyclophosphamide and glucocorticoids, which are then switched to less potent immunosuppressive therapies for maintenance of remission. Unfortunately, GPA may be associated with increased morbidity and mortality.