ANCA-associated vasculitis

ANCA pattern

Histopathology

Organ involvement

GPA

• Mainly c-ANCA (anti-proteinase-3)

• Neutrophils, granulomas & fibrinoid necrosis

• Necrotizing sinusitis
• Cavitary lung lesions & DAH
• RPGN

EGPA

• Mainly p-ANCA (anti-myeloperoxidase)

• Eosinophils, granulomas & fibrinoid necrosis

• Allergic sinusitis & polyps
• Asthma
• Broadest involvement (eg, RPGN, myocarditis, cutaneous nodules, mononeuritis multiplex)

MPA

• Neutrophils & fibrinoid necrosis (no granulomas)

• RPGN
• DAH

ANCA = antineutrophil cytoplasmic antibodies; DAH = diffuse alveolar hemorrhage; EGPA = eosinophilic granulomatosis with polyangiitis; GPA = granulomatosis with polyangiitis; MPA = microscopic polyangiitis; RPGN = rapidly progressive glomerulonephritis.