Granulomatosis with polyangiitis

Clinical manifestations

• Upper respiratory: sinusitis/otitis, saddle nose
• Lower respiratory: lung nodules/cavitation, interstitial lung disease, diffuse alveolar hemorrhage
• Renal: rapidly progressive GN
• Skin: livedo reticularis, nonhealing ulcers

Diagnosis

• ANCA: PR3 (~70%), MPO (~20%)
• Biopsy:
  • Skin (leukocytoclastic vasculitis)
  • Kidney (pauci-immune GN)
  • Lung (granulomatous vasculitis)

Management

• Corticosteroids & immunomodulators (eg, cyclophosphamide)

ANCA = antineutrophil cytoplasmic antibody; GN = glomerulonephritis; MPO = myeloperoxidase; PR3 = proteinase-3.