Abstract: FR-PO1178
Identification and Characterization of Urinary Amino Acids in Early Nondiabetic CKD
Session Information
- CKD: Mechanisms, AKI, and Beyond - 2
November 07, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 2303 CKD (Non-Dialysis): Mechanisms
Authors
- Wu, Henry, Kolling Institute of Medical Research, St Leonards, New South Wales, Australia
- Cantor, David, Macquarie University, Sydney, New South Wales, Australia
- Chi, Fei, Macquarie University, Sydney, New South Wales, Australia
- Nguyen, Long T., Kolling Institute of Medical Research, St Leonards, New South Wales, Australia
- Chinnadurai, Rajkumar, The University of Manchester Faculty of Biology Medicine and Health, Manchester, England, United Kingdom
- Pollock, Carol A., Kolling Institute of Medical Research, St Leonards, New South Wales, Australia
- Saad, Sonia, Kolling Institute of Medical Research, St Leonards, New South Wales, Australia
Background
The excess excretion of amino acids in urine signifies loss of nutrients and metabolic dysregulation, processes involved in chronic kidney disease (CKD). Whilst urinary amino acids have been investigated as a novel non-invasive metabolomic biomarker for early identification of diabetic kidney disease, this has not been studied in the context of early non-diabetic CKD, which is also a prevalent CKD population at risk of disease progression and associated adverse clinical outcomes.
Methods
This cross-sectional pilot study performed urinary amino acid profiling in 20 adult non-diabetic patients. All patients had kidney biopsy performed and CKD status was determined as per interstitial fibrosis and tubular atrophy (IFTA) category. There were 10 patients with IFTA 0-10% (IFTA 0) and 10 patients with IFTA 10-25% (IFTA 1). The groups were statistically similar in age, sex, estimated glomerular filtration rate and albuminuria status. Pre-biopsy urine samples were collected and processed through high performance liquid chromatography and mass spectrometry (HPLC-MS). Specific metabolites were identified, and urinary amino acid concentration (reflecting absolute abundance) and mole% (reflecting relative abundance) were determined via bioinformatics analyses. Differences in median urinary amino acid concentration and median urinary mole% between the IFTA 0 and IFTA 1 groups were examined.
Results
Eighteen amino acids were identified and characterized across the two study groups. The median urinary concentration (3.6 vs 0.8µg/ml, p=0.012) and median urinary mole% (1.18 vs 0.69%, p=0.034) of valine, and median urinary mole% of alanine (6.95 vs 5.12%, p=0.049) were significantly higher in the IFTA 1 compared to the IFTA 0 group. Conversely, the median urinary mole% of histidine (11.2 vs 15.3%, p=0.041) was significantly lower in the IFTA 1 compared to the IFTA 0 group.
Conclusion
Using HPLC-MS, findings from this study demonstrated that urinary levels of specific amino acids differed between non-diabetic individuals presenting with IFTA 0 and IFTA 1 on kidney biopsy. There is potential in utilizing the urinary levels of valine, alanine and histidine as non-invasive biomarkers for early identification of non-diabetic CKD. Further delineation on the roles of these amino acids in non-diabetic CKD pathophysiology is needed.