Vasculitic syndromes and renal injury

This review emphasizes our increasing understanding of renal involvements in vasculitic syndromes. Systemic vasculitis of various size vessels (large, medium, and small) can be classified according to the ANCA positivity. Large vessel vasculitides are usually ANCA negative and the occurrence of renal vasculitis or glomerulonephritis is rare. Inflammatory aneurysm of abdominal aorta exhibits peculiar renal injury. In this disease, marked fibrosis of periaorta often induces hydronephrosis. On the other hand, ANCA is positive in most of small vessel vasculitides. C-ANCA is specific for Wegener's granulomatosis and P-ANCA for pauci-immune crescentic glomerulonephritis with or without pulmonary hemorrhage. Pathogenetic role of ANCA in renal involvements in small vessel angitis can be well explained from the standpoint of ANCA-cytokine sequence theory. Another modern topic is lupus vasculopathy. Renal vascular changes in lupus nephritis are various in relation to the presence of anti-DNA antibody, anti-phospholipid antibody, and anti-endothelial cell antibody, or long administration of corticosteroids.