Granulomatosis with polyangiitis and microscopic polyangiitis: common features and differences

Patients with ANCA-associated vasculitides usually present similar clinical manifestations (fever, joint pain, lung and kidney diseases, purpura, etc.). However, signs of granulomatosis inflammation the upper lower respiratory tract and/or orbit allow to differentiate polyangiitis (GPA) from microscopic (MPA). Circulating ANCAs are key laboratory sign vasculitis, although they can be negative in a proportion patients found other diseases. GPA is associated againts proteinase-3, whereas against myeloperoxidase more common MPA. The authors two discuss features differences between MPA new classification criteria.