KM TAYLOR1, S HERATH1,2, L SUCCAR1, M FERNANDO1,2, JH ERLICH1,2, ZH ENDRE1,2
1Prince of Wales Clinical School, UNSW, Randwick, Australia, 2Department of Nephrology, Prince of Wales Hospital, Randwick, Australia
Aim: To demonstrate the efficacy of transcutaneous measurement of FITC-sinistrin clearance as a marker of glomerular filtration rate (GFR) in a model of acute kidney injury (AKI) on a background of subclinical chronic kidney disease (SCKD).
Background: Estimated GFR (eGFR) based on serum creatinine (sCr) is the primary means of assessing renal function. However, sCr is slow to respond to changes in GFR and is influenced by multiple factors, making alternative methods of assessing GFR desirable. Direct measurement of GFR is faster, suffers from less technical issues, and is less sensitive to sample processing issues, making it advantageous.
Methods: AKI was induced on a background SCKD in male Sprague-Dawley rats and animals were culled 14 days later. GFR was measured over the course of the study and compared to both sCr and Cystatin C (CysC) levels and histology.
Results: Transcutaneous measurement showed significantly reduced GFR with SCKD (1.65 vs 1.16mL/min/100g; p < 0.05) and following AKI (1.65 vs 1.18ml/min/100g; p < 0.05). Changes in sCr were only significant 24hrs post AKI (18 vs 127µmol/L, p < 0.05) despite there being significant histological damage prior to AKI. CysC did not significantly change over the course of the experiment.
Conclusions: While eGFR based on sCr is one of the most commonly used measures of renal function, sCr has limited sensitivity. In this study, both sCr and sCys performed more poorly compared to a clearance-based measure of GFR, demonstrating the utility of the technique for assessing renal function in the context of both CKD and AKI.
Kylie Taylor is a research associate in the Australian Kidney Biomarker Laboratory at the Prince of Wales Clinical School within UNSW. She completed a PhD within the School of Medical Sciences at UNSW. Her research focus is on kidney biomarkers in animal models, including IRI and transplants, and novel approaches to prevent injury in these contexts.