Abstract: SA-PO509
Identifying Urine Biomarkers of Disease Progression in Pediatric Autosomal Dominant Polycystic Kidney Disease Patients
Session Information
- ADPKD: Clinical Studies
October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Genetic Diseases of the Kidney
- 1001 Genetic Diseases of the Kidney: Cystic
Authors
- Baliga, Madhurima, University of Colorado School of Medicine, Aurora, Colorado, United States
- Klawitter, Jost, University of Colorado, Aurora, Colorado, United States
- Christians, Uwe, Department of Anesthesiology, University of Colorado Denver, Aurora, Colorado, United States
- Chonchol, Michel, University of Colorado, Aurora, Colorado, United States
- Gitomer, Berenice Y., Div. Renal Diseases and Hypertension,, Aurora, Colorado, United States
- Cadnapaphornchai, Melissa A., Rocky Mountain Pediatric Kidney Center, Rocky Mountain Hospital for Children at Presbyterian St. Luke's Medical Center, Denver, Colorado, United States
- Klawitter, Jelena, University of Colorado Denver , Aurora, Colorado, United States
Background
Autosomal dominant polycystic kidney disease (ADPKD) is the most commonly inherited kidney disease. Though children with ADPKD show normal renal function, rapid cyst development is already occurring. In this study, we aimed to identify urine biomarkers of disease progression in the pediatric ADPKD population.
Methods
Urine samples from 70 ADPKD patients aged 8-26 years were collected at baseline. Following collection at baseline, 37 patients were randomized to a pravastatin treatment group and 33 to a placebo group. Metabolomic analysis of urine was performed using targeted liquid chromatography-mass spectrometry. Within the treatment and placebo groups, differences between biomarkers at baseline and 36 months were evaluated. Metabolites with a P value < 0.05 were identified as significant. Pathway analysis was conducted on significant metabolites.
Results
Within the pravastatin treatment group, 27 metabolites were uniquely and significantly changed. Metabolites involved in glutamine metabolism (glutamic acid, α-ketoglutarate) and pyruvate metabolism (dihydroxyacetone phosphate, acetylphosphate) were all decreased at 36 months. Interestingly, ascorbic acid, a metabolite with antioxidant properties, was increased by 59% at 36 months in the treatment group. Within the placebo group, 37 metabolites were uniquely and significantly changed. Metabolites of the citric acid cycle (oxaloacetic acid, malic acid, cis-aconitic acid, citric acid, pyruvic acid) were decreased, and literature confirms that citric acid cycle activity is decreased in patients with CKD. Trimethylamine N-oxide (TMAO) is a marker of atherosclerotic risk and it has been shown to be elevated in the plasma of patients with CKD, in part due to decreased renal clearance. Our results were consistent with this finding as we found metabolites involved in the TMAO pathway (betaine, choline, and TMAO) to be decreased in the placebo group at 36 months.
Conclusion
Progression of ADPKD was associated with a decline in the renal clearance of citric acid cycle and betaine metabolism intermediates, preceding any loss of renal function. Future work involves correlating urine metabolites to plasma metabolites in order to identify biomarkers that may be able to risk stratify patients over the course of the disease.
Funding
- NIDDK Support