According to the International Chapel Hill Consensus Conference 2012 (CHCC2012), anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) is a group of necrotizing vasculitis, with few or no immune deposits, predominantly affecting small vessels, such as small arteries, arterioles, capillaries, and venules, associated with ANCA specificity for myeloperoxidase (MPO-ANCA) or proteinase 3 (PR3-ANCA) [1].
