Evaluation of kidney injury biomarkers in an experimental pyelonephritis model induced by uropathogenic escherichia coli

Objective: The aim of this study is to determine the levels of biomarkers at different days of the disease in rats where a pyelonephritis model was created by applying uropathogenic Escherichia coli. Materials and Methods: Forty rats were used in the study; 10 were designated as the control group, and the remaining 30 rats were intrarenally administered uropathogenic Escherichia coli to create a pyelonephritis model. Blood and urine samples were collected on days 1, 4, and 7 of the experiment. Urea, creatinine, albumin, total protein, and GGT levels in serum and urine samples were analyzed by spectrophotometric methods, while NGAL, L-FABP, clusterin, CRP, KIM-1, and cystatin C levels were analyzed by ELISA. Results: Histopathologically, it was determined that pyelonephritis occurred in all experimental groups. In serum samples, significant changes were observed in Klu, L-FABP, and Klu/Cr levels among the groups. In urine samples, while no significant changes were detected in creatinine, clusterin, NGAL/Cr, and Klu/Cr levels, significant alterations were identified in NGAL, L-FABP, KIM-1, Cystatin C, CRP, KIM-1/Cr, Cystatin C/Cr, and L-FABP/Cr levels. Conclusion: In the scope of the study, changes in the identified biomarkers in the serum and urine samples of rats with induced pyelonephritis were particularly evident, especially in urine samples. In evaluations conducted on different days of the disease, it was observed that urine NGAL, L-FABP, KIM-1, and Cystatin C levels increased up to the 4th day compared to the control group. These findings suggest that urine biomarkers, in particular, may play a significant role in the diagnosis of pyelonephritis.