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Kidney Week

Abstract: FR-PO831

Effect of Different Dialysis Procedures on Mid-Term Protein-Bound Toxins Plasma Levels

Session Information

Category: Dialysis

  • 601 Standard Hemodialysis for ESRD


  • Krieter, Detlef H., University Hospital, Wuerzburg, Germany
  • Kerwagen, Simon, University Hospital, Wuerzburg, Germany
  • Rueth, Marieke, eXcorLab GmbH, Obernburg, Germany
  • Lemke, Horst-Dieter, eXcorLab GmbH, Obernburg, Germany
  • Wanner, Christoph, University Hospital, Wuerzburg, Germany

Protein bound uremic toxins (PBT) are involved in dialysis associated morbidity. If dialysis procedures differ in their effect on PBT plasma levels over longer periods has barely been studied. Purpose of the present trial was to monitor PBT plasma levels over a 6-week period in patients on different extracorporeal dialysis forms.


In a prospective, randomized, controlled, cross-over trial enrolling 15 maintenance dialysis patients (DRKS00010788), low-flux and high-flux hemodialysis (HD) were compared to high convective volume (≥25 L) postdilution hemodiafiltration (HDF). Each patient was subjected thrice weekly to each treatment mode for 6 consecutive weeks. Dialysis membrane material was always identical (PUREMA® L and H, resp.). Dialysate flow rates differed in HD and HDF (500 vs. 700 mL/min). Blood flow rates and treatment time were kept identical for individual patients. Plasma levels of free and total para-cresyl sulfate (pCS) and indoxyl sulfate (IS) were determined at baseline (t0), after 3 (t3) and 6 weeks (t6) of each treatment period. Reduction ratios were measured at t0 and t3. Serum CRP and albumin were also monitored.


During HDF, plasma concentrations of total IS decreased from t0 (18.9±13.0 mg/L) to t3 (16.6±12.1 mg/L, P=0.027). Total IS levels at t0 and t3 during HDF were lower compared to low-flux HD (20.8±14.4 mg/L, P=0.046, and 20.0±12.7 mg/L, P=0.021, resp.), but did not differ from high-flux HD (20.1±12.6 and 19.3±11.6 mg/L). Total IS reduction ratio in HDF (t0, 48.1±9.6; t3, 46.0±18.3%) were much higher (P<0.001) compared to low-flux (36.5±10.7; 34.3±8.2%) and high-flux HD (35.9±8.7; 37.0±10.5%). Although, reduction ratios for free IS and pCS as well as for total pCS were also significantly higher in HDF, no differences in these PBT plasma levels were determined. Interestingly, free and total IS concentrations highly correlated with CRP (r 0.378 and 0.520, resp.; each P<0.001), but not with albumin.


Differences in instantaneous removal by dialysis therapies have only limited impact on mid-term plasma levels of PBT. The association of inflammation and IS further indicates that other factors are more important determinants of PBT concentrations.


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