Abstract: Objective  To investigate the effect of Roxadustat (Rox) on residual renal function (RRF) in patients undergoing peritoneal dialysis (PD) and its possible mechanism.  Methods  A total of 78 patients undergoing PD were divided into erythropoietin (ESA) treatment group (ESA group) and Rox treatment group (Rox group). Urinary 8-hydroxydeoxyguanosine (8-OHdG), β2-microglobulin (β2-MG), N-acetyl-β glucosamine glucosidase (NAG) enzyme, retinol binding protein (RBP), blood Nrf2 mRNA and HO-1 mRNA were measured. These laboratory parameters were compared between the two groups before and after treatment. The correlations of the laboratory parameters with the levels of Nrf2 mRNA, HO-1 mRNA and urinary 8-OHdG were analyzed.  Results At the end of follow-up in Rox group, urinary β2-MG, NAG enzyme, RBP and 8-OHdG were significantly lower than those before treatment (t=3.751, 2.522, 3.292 and 3.829 respectively; P＜0.001, =0.014, =0.002 and ＜0.001 respectively), and were significantly lower than those in ESA group (t=3.889, 1.627, 3.694 and 2.769 respectively; P＜0.001, =0.035,＜0.001 and P=0.007 respectively); while Nrf2 mRNA and HO-1 mRNA were significantly higher than those before the treatment (t=2.797 and 1.724 respectively; P=0.007 and 0.032 respectively) and those in ESA group (t=3.507 and 2.087 respectively, P=0.001 and 0.040 respectively). After the treatment, RRF was significantly higher in Rox group than in ESA group (t=4.710, P＜0.001). Nrf2 mRNA was negatively correlated with urinary β2-MG, NAG enzyme, RBP and            8-OHdG (r=-0.617, -0.511, -0.598 and -0.591 respectively; P＜0.001, =0.001, ＜0.001 and ＜0.001 respectively), and positively correlated with RRF (r=0.579, P＜0.001). HO-1 mRNA was negatively correlated with urinary β2-MG, RBP and 8-OHdG (r=-0.668, -0.406 and 0.606 respectively; P＜0.001, =0.013 and ＜0.001 respectively), and positively correlated with RRF (r=0.532, P=0.001). Urinary 8-OHdG was positively correlated with urinary β2-MG, NAG enzyme and RBP (r=0.456, 0.453 and 0.639 respectively; P =0.005, =0.005 and ＜0.001 respectively), and negatively correlated with RRF (r=-0.343, P=0.038).  Conclusion  Rox may alleviate the damage of renal tubular epithelial cells and protect RRF in PD patients by activating Nrf2/HO-1 signal pathway and inhibiting oxidative stress reaction.

Key words: Roxadustat, Peritoneal dialysis, Nrf2/HO-1 signal pathway, Residual renal function