Plasma and Urinary Kidney Injury Molecule-1 as Early Biomarkers for the Diagnosis of Stable Chronic Kidney Disease in Dogs

Early detection of chronic kidney disease (CKD) remains challenging, most likely due to the limited sensitivity of conventional renal biomarkers for identifying subclinical diseases.Kidney injury molecule-1 (KIM-1) is a biomarker for the detection of acute kidney injury; however, its potential role in canine CKD is unclear.This study aimed to evaluate plasma KIM-1 (pKIM-1) and urinary KIM-1-tocreatinine ratio (uKIM-1/uCr) as diagnostic biomarkers for stable CKD in dogs, with or without non-azotemic stages, and assess their correlations with conventional renal biomarkers.Ten healthy control dogs, 14 dogs with non-azotemic stable CKD, and 11 dogs with azotemic stable CKD were prospectively enrolled.Plasma and urinary KIM-1 concentrations were measured using canine-specific ELISA.Conventional renal biomarkers, including blood creatinine, blood urea nitrogen (BUN), symmetric dimethylarginine (SDMA), urine protein-to-creatinine ratio (UPCR), and urine specific gravity (USG) were also analyzed, and the diagnostic accuracy was assessed using receiver operating characteristic (ROC) curve analysis.Results showed that pKIM-1 levels and uKIM-1/uCr ratios were significantly higher in CKD dogs than that in healthy controls (P