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Abstract: TH-PO1081

Kidney Clearances of Protein-Bound Uremic Toxins in Various Stages of CKD and Their Predictive Role for Clinical Prognosis

Session Information

Category: CKD (Non-Dialysis)

  • 2302 CKD (Non-Dialysis): Clinical, Outcomes, and Trials


  • Xie, Danshu, Shanghai Ninth People's Hospital, Shanghai, China
  • Jiang, Mengdi, Shanghai Ninth People's Hospital, Shanghai, China
  • Li, Jiaolun, Shanghai Ninth People's Hospital, Shanghai, China
  • Ding, Feng, Shanghai Ninth People's Hospital, Shanghai, China
  • Wang, Wenji, Shanghai Ninth People's Hospital, Shanghai, China

Studies on the characteristics of 24-hour kidney clearances of protein bound uremic toxins (cPBUTs) in patients with CKD are limited.


Patients with non-dialyzed CKD from 2018 to 2020 were enrolled. The concentrations and 24-hour kidney clearances of indole sulfate (IS), p-cresol sulfate (pCS), and indole-3-acetic acid (IAA) among different CKD stages and levels of proteinuria were analyzed. 186 patients were followed up until September 2022. The primary and secondary outcomes were renal and hospitalization events, respectively.


This was a single-center prospective cohort. The 24-hour kidney clearances of IS, IAA and pCS (cIS, cIAA and cPCS) decreased with eGFR (CKD5 VS CKD1: IS, 2.2 ml/min VS 26.7 ml/min; pCS, 1.8 ml/min VS 18.4 ml/min; IAA, 2.1 ml/min VS 12.1 ml/min). Only cIAA was positively correlated with level of proteinuria in CKD1 and CKD5 (p= 0.003; p= 0.007). The cPBUTs could effectively predict renal events (cIS: area under the curves [AUC]=0.764, p<0.001; cIAA: AUC=0.624, p=0.026; cPCS: AUC=0.657, p=0.006) . Higher kidney clearance of PBUTs were associated with increased cumulative renal event free survival rates (Figure 1). Increased cIS and cIAA were associated with reduced renal events' risk ratio respectively in adjusted Cox regression models (cIS, hazard ratio [HR], 0.957, p=0.029; cIAA, HR 0.925, p=0.014). The cIAA was also associated with hospitalization risk ratio (HR, 2.55; p = 0.024) (Table 1).


The clearances of IS and IAA decreased with eGFR decline. They were independent predictors of worse prognosis.

Table 1. Multivariate Cox regression analysis of renal and hospitalization events related to PBUTs
Characteristics Renal Events Hospitalization Events 
  HR (95% CI)p ValueHR (95% CI)p Value
cIS (ml/min)     
cIAA (ml/min)     

Figure 1. Kaplan-Meier proportion of surviving patients of renal events.


  • Government Support – Non-U.S.