a ≥1 clinical relapses during follow-up.bChi square (categoric variables) or ANOVA (continuous variables). NS: not significant. Anti-MPO: anti-myeloperoxidase. Anti-PR3: anti-proteinase-3. MPA: microscopic polyangiitis. GPA: granulomatosis with polyangiitis. EGPA: eosinophilic granulomatosis with polyangiitis. ESRD: end-stage renal disease. IQR: interquartile range. ENT: ear, nose, throat. CNS: central nervous system.