Kidney Week

Abstract: TH-PO0351

Intraindividual Variability of Urinary Epidermal Growth Factor and Clusterin and Effect of Frozen Storage on Stability: Results from UVALID

Session Information

• Diabetic Kidney Disease: From Early Biomarkers to Novel Therapeutic Targets
  November 06, 2025 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Diabetic Kidney Disease

• 702 Diabetic Kidney Disease: Clinical

Authors

• Moedt, Erik, Universitair Medisch Centrum Groningen Afdeling Klinische Farmacie en Farmacologie, Groningen, GR, Netherlands

Erik Moedt, PharmD, MS, MSc

• Vos, Rémon, Universitair Medisch Centrum Groningen Afdeling Klinische Farmacie en Farmacologie, Groningen, GR, Netherlands

Rémon Vos, MSc

• Ju, Wenjun, University of Michigan Department of Internal Medicine, Ann Arbor, Michigan, United States

Wenjun Ju, PhD

• Bakker, Stephan J.L., Universitair Medisch Centrum Groningen Afdeling Interne Geneeskunde, Groningen, GR, Netherlands

Stephan J.L. Bakker, MD, PhD

• Opseth Rygg, Marte, Steno Diabetes Center Copenhagen, Herlev, Capital Region of Denmark, Denmark

Marte Opseth Rygg, MD

• Rossing, Peter, Steno Diabetes Center Copenhagen, Herlev, Capital Region of Denmark, Denmark

Peter Rossing, MD, DrMed

• Provenzano, Michele, Universita degli Studi di Bologna, Bologna, Emilia-Romagna, Italy

Michele Provenzano, MD

• Hu, Lilio, Universita degli Studi di Bologna, Bologna, Emilia-Romagna, Italy

Lilio Hu, MD

• La Manna, Gaetano, Universita degli Studi di Bologna, Bologna, Emilia-Romagna, Italy

Gaetano La Manna, MD, PhD

• Gorriz, Jose L., Hospital Clinico Universitario, Valencia, Valencian Community, Spain

Jose L. Gorriz, MD

• Huber, Tobias B., Universitatsklinikum Hamburg-Eppendorf, Hamburg, HH, Germany

Tobias B. Huber, MD, FASN

• Lindenmeyer, Maja, Universitatsklinikum Hamburg-Eppendorf, Hamburg, HH, Germany

Maja Lindenmeyer, PhD

• Heerspink, Hiddo Jan L., Universitair Medisch Centrum Groningen Afdeling Klinische Farmacie en Farmacologie, Groningen, GR, Netherlands

Hiddo Jan L. Heerspink, PhD

• Meister, Elisabeth, Universitatsklinikum Hamburg-Eppendorf, Hamburg, HH, Germany

Elisabeth Meister, MD, DrMed

Background

Qualified and validated biomarkers are essential to foster personalized medicine in nephrology. Epidermal growth factor (EGF) and clusterin (CLU) are emerging urinary biomarkers associated with kidney health and treatment response. We investigated intra-individual variation and long-term frozen-storage stability of EGF and CLU.

Methods

UVALID was a multicenter study to validate previously discovered biomarkers in patients with CKD. Participants provided three consecutive first-morning urine samples per visit across three visits over 8 weeks. Intra-individual variability over 3 days and over 8 weeks of uEGF/Cr (standardized by urine creatinine) and CLU/Cr was assessed using geometric coefficient of variation (CV). Long-term stability at -20 °C and -80 °C was assessed by percentage change from baseline after 12 and 15 months of storage.

Results

We analyzed data from 24 UVALID participants (mean age 64.3 years, eGFR 45.9 mL/min/1.73 m², median UACR 11.9 mg/g, 70.8% type 2 diabetes). Over 3 days, median intra-individual variation was 7.2% for uEGF/Cr and 23.3% for CLU/Cr. Over 8 weeks, intra-individual variation was 11.5% and 29.8%, respectively. EGF remained stable after 15 months at both -20 °C and -80 °C, while CLU was only stable at -80 °C (Fig. 1). Stability of CLU at -20 °C was higher in samples with a pH >6.

Conclusion

Short- and long-term intra-individual variation was <15% for uEGF/Cr and <30% for CLU/Cr. Both biomarkers demonstrated stability following prolonged frozen storage at –80 °C, supporting their suitability for clinical implementation.

Digital Object Identifier (DOI)

• doi: 10.1681/ASN.2025ax2d0kr6