Granulomatosis with Polyangiitis and Microscopic Polyangiitis

Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are two entities of ANCA-associated vasculitis (AAV). Both diseases are characterised by systemic necrotising small-vessel vasculitis, which can affect any organ. In GPA, extravascular necrotising granulomatous inflammation, usually affecting the respiratory tract, is found in addition. In the majority of cases, the clinical presentation is dominated by a pulmonary-renal syndrome with alveolar haemorrhage and rapidly progressive glomerulonephritis. Other organ involvement is found as well. In GPA, the upper respiratory tract is commonly affected. GPA is associated with anti-neutrophil cytoplasmic autoantibodies (ANCA) with specificity for proteinase 3 (PR3-ANCA) and MPA with specificity for myeloperoxidase (MPO-ANCA). Immunosuppressive therapy depends on disease activity and the severity of organ involvement.

Automated summary

Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are two types of ANCA-associated vasculitis (AAV) characterized by systemic necrotizing small-vessel vasculitis affecting any organ. GPA also involves extravascular necrotizing granulomatous inflammation. It typically presents as a pulmonary-renal syndrome with alveolar hemorrhage and rapidly progressive glomerulonephritis.