Activation of neutrophils and monocytes by antineutrophil cytoplasmic autoantibodies (ANCA) is regarded as the main mechanism of ANCA-associated vasculitis (AAV). However, accumulating evidence suggest that complement activation, particularly by alternative pathway, may play an important role in the development of AAV. In this review, we provide the experimental and clinical evidence for complement activation in patients with AAV. Inhibition of complement system by targeted medications could be a promising approach to treatment of AAV. Phase 2 clinical trial showed that avacopan, a selective inhibitor of C5a receptor, was safe and effective inreplacing high-dose glucocorticoids in treating vasculitis.
ANCA-associated vasculitis, complement system, avocopan, IFX-1.