BACKGROUND: Anti-neutrophil cytoplasmic antibody (ANCA) Renal Risk Score has not been widely validated in Chinese patients with myeloperoxidase -ANCA-associated glomerulonephritis and its predictive ability needs to be improved. METHODS: Three hundred and forty patients with biopsy-proven myeloperoxidase-ANCA-associated glomerulonephritis were included in this study. They were divided into an oliguric group (urine volume <
400 ml/24 h) and a non-oliguric group (urine volume ≥ 400 ml/24 h). The ANCA Renal Risk Score and Berden classes were used to predict the risk of end-stage kidney disease (ESKD), and Cox regression analysis was performed to evaluate the impact of oliguria on ESKD risk. RESULTS: The predictive performance of ANCA Renal Risk Score was significantly higher than that of Berden classes (AUC: 0.79 vs. 0.709, P = 0.003). Thirty-six (10.6%) patients presented with oliguria. Patients in the oliguric group had significantly lower levels of baseline estimated glomerular filtration rate (eGFR) [6.51(4.55-7.72) vs. 21.22(11.49-36.63) ml/min/1.73 m CONCLUSIONS: This study has validated the ANCA Renal Risk Score for predicting kidney outcomes among Chinese patients with myeloperoxidase-ANCA-associated glomerulonephritis. Furthermore, the ANCA Renal Risk Score-U model with oliguria as a variable can further improve the prediction of ESKD risk in patients with myeloperoxidase-ANCA-associated glomerulonephritis.