Kidney Week

Abstract: TH-PO1214

Uremic Toxin Kinetics to Optimize and Personalize Hemodialysis Prescription for Children

Session Information

• Pediatric Nephrology: CV Health, CKD, AKI, Dialysis, Transplantation, and Health Services Research
  October 22, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Pediatric Nephrology

• 1800 Pediatric Nephrology

Authors

• Eloot, Sunny, Department of Nephrology, Ghent University Hospital, Gent, Belgium

Sunny Eloot, PhD

• Ghysels, An, Institute of Biomedical Engineering, Ghent University, Gent, Belgium

An Ghysels, PhD

• Collard, Laure, Department of Pediatric Nephrology, CHC Liège, Liege, Belgium

Laure Collard, DrMed

• Adams, Brigitte, Department of Pediatric Nephrology, University Hospital Leuven, Leuven, Belgium

Brigitte Adams, MD

• Chiodini, Benedetta, Department of Pediatric Nephrology, Hôpital Universitaire des Enfants Reine Fabiola, Brussels, Belgium

Benedetta Chiodini, MD

• Shroff, Rukshana, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom

Rukshana Shroff, MD, PhD

• Glorieux, Griet Lrl, Department of Nephrology, Ghent University Hospital, Gent, Belgium

Griet Lrl Glorieux, PhD

• Van Biesen, Wim, Department of Nephrology, Ghent University Hospital, Gent, Belgium

Wim Van Biesen, MD, PhD

• Raes, Ann, Department of Pediatric Nephrology, Ghent University Hospital, Gent, Belgium

Ann Raes, MD

• Snauwaert, Evelien, Department of Pediatric Nephrology, Ghent University Hospital, Gent, Belgium

Evelien Snauwaert, MD, PhD

Background

Children on hemodialysis (HD) accumulate a broad spectrum of uremic toxins (UTs), of which urea is commonly applied as adequacy marker. Urea kinetics are however not representative for the overall removal of UTs. In the absence of pediatric data, we investigated the kinetics of multiple UTs across a wide pediatric age range to better characterize their removal during HD.

Methods

This multicentric study included 24 stable patients (age 3.5-17.9y) undergoing 3x/week 3-4h HD. Blood samples were collected from the dialyzer blood inlet and outlet, and dialysate outlet at different time points during HD. Concentrations were determined for the small water soluble UTs urea and creatinine (Crea), middle molecule beta-2-microglobulin (B₂M), and protein-bound UTs p-cresylglucuronide (PCG), hippuric acid (HA), indole acetic acid (IAA), indoxyl sulfate (IS), and p-cresylsulfate (PCS). Reduction rate (RR), dialyzer clearance (K_D), and protein binding (%PB) were calculated. A two pool kinetic model incorporating patient’s ultrafiltration (UF), kidney function and endogenous toxin generation was fitted to the measured concentration curves. This model yielded estimates of the plasmatic volume (V₁), total distribution volume (V_tot), and intercompartmental clearance (K₁₂), parameters that characterize UT distribution and transport within the patient.

Results

The table summarizes median values of different toxin-, dialysis-, and kinetic parameters. RR and K_D were consistently higher for small versus middle molecules, and both are inversely related to %PB. When stratifying patients into 3 age groups (0-6y, 7-12y, 13-18y), both V_tot and K₁₂ showed an age related increase. The calibrated models provide a framework for HD simulations, for example to explore scenarios of declining residual kidney function, altered toxin generation (e.g., dietary changes), or adjustments in dialyzer type, session duration, or frequency.

Conclusion

This study shows the age-dependency of UT kinetics in pediatrics. The presented models enable individualized HD simulations. Embedding these models into a user friendly application can support pediatric nephrologists in making bedside decisions for a personalized and optimized HD prescription for each child.

Acknowledgment

The authors are indebted to the study nurses Els Holvoet and Stefaan Claus, and the lab technician Sophie Lobbestael.

Funding

• Government Support – Non-U.S.