The neutrophil in antineutrophil cytoplasmic autoantibody-associated vasculitis.

Necrotizing, small-vessel vasculitis develops in patients with circulating ANCAs. Neutrophils and monocytes harbor the two major ANCA antigens, PR3 and MPO. A whole body of in vitro experiments implicated ANCA-activated neutrophil effector functions in the pathogenesis of vasculitis, whereas the role of monocytes is less well-characterized. Mouse models for anti-MPO-induced vasculitis were developed to study ANCA-neutrophil interactions in complex in vivo situations. We not only discuss the significance of ANCA-neutrophil interactions for disease induction but also how a detailed understanding of these interactions helps to identify novel treatment targets for ANCA vasculitis.