PRTN3 and anti-neutrophil cytoplasmic antibody-associated vasculitis: AAV = ANCA associated vasculitis, GPA = granulomatosis with polyangiitis, PR3 = Proteinase-3 ANCA, eGFR = estimated Glomerular Filtration Rate (CKD-EPI), ml/min/1.73 m2, BVAS = Birmingham Vasculitis Activity Score, RRT = Renal Replacement Therapy, 95% CI = 95% Confidence Interval.