Cornec D, et al. – This study tried to develop a method to detect and phenotype circulating proteinase 3 (PR3)–specific B–cells in patients with PR3–ANCA associated vasculitis (AAV). It was observed that circulating PR3–specific B cells could be detected in healthy controls (HC) and patients with PR3–AAV. Based on their progressive enrichment during B–cell maturation, this study suggested that they were actively selected and escape peripheral tolerance checkpoints in patients.