Table 3 Proposed diagnostic criteria for kidney involvement in AAV [16]

clinical manifestations

a rapidly progressive GN with a decline in kidney function accompanied by sub–nephrotic-range proteinuria, microscopic hematuria, and hypertension over days to a few months

Serology

Anti-MPO antibody or anti-PR3 antibody positive

Pathological findings

pauci-immune focal necrotizing crescentic GN

Rare patients with AAV have a prominent tubulointerstitial nephritis, which can be associated with vasculitis of the vasa recta