90%, GPA >90%, EGPA >40%**. Partial correlation of ANCA titre with disease activity*. Correlation of ANCA epitope specificity with disease activity (MPO-ANCA only)*. Disease indication by trans-placental transfer of ANCA (one MPO-ANCA case report)*. Similar disease associated drug-induced ANCA*. HLA genetic associations with MPO-ANCA and PR3-ANCA-assocated disease*. Response to immunosuppressive therapy that targets B cellsIn vitro evidence:*. Activation of cytokine-primed neutrophils by ANCA IgG*. Endothelial injury by ANCA-activated neutrophils*. Alternative complement pathway activation by ANCA-activated neutrophilsEvidence from animal models:*. Induction of pauci-immune vasculitis, glomerulonephritis and graunolomatosis in mice and rats by anti-MPO IgG*. Prevention of murine anti-MPO IgG induced disease by blockade of alternative complement pathway activation or blockade of C8a receptor">