PRTN3 and primary central nervous system vasculitis: NG: Not given; DEI: Disease extent index; Rmab: Rituximab; AZA: Azathioprine; GC: Glucocorticoid; ANCA: Anti-neutrophil cytoplasmic antibody; AAV: ANCA-associated vasculitis; MTX: Methotrexate, PVCNS: Primary vasculitis of the central nervous system; PR3: Proteinase 3; EGPA: Eosinophilic granulomatosis with polyangiitis; GPA: Granulomatosis with polyangiitis; ELISA: Enzyme-linked immunosorbent assay; IQR: Interquartile Range; IV: Intravenous; ESRD: End-stage renal disease; CNSV: Central nervous system vasculitis.