The urine podocin/creatinine ratio as a novel biomarker of cardiorenal syndrome in dogs due to degenerative mitral valve disease

Abstract

Dysfunction of heart leads inevitable to the dysfunction of kidney which is termed as the cardiorenal syndrome (CRS). Previous studies have confirmed existence of CRS in dogs with degenerative mitral valve disease (DMVD). The goal of the study was to assess the usefulness of commercial test to measure podocyturia in dogs and test the urine podocine/creatinine ratio (UPoC) as an early marker of kidney injury. Urine podocine/creatinine ratio was calculated because numbers of podocytes is dependent on the urine concentration. Fifty dogs was divided into three groups: fifteen healthy (control group), twenty nine with DMVD class C-chronic according to ACVIM (heart group) and six with chronic kidney disease (kidney group). Each dog underwent a clinical examination: electrocardiography, echocardiography, chest radiograph, abdominal ultrasound, blood haematological and biochemical analysis including symmetric dimethylarginine (SDMA) and cystatin C (Cyst C), routine urine analysis and analysis of podocytes using an ELISA test. UPoC was calculated. Mean value ± standard deviation for UPoC was respectively 9.7 ± 4.8 × 10–10 for control group, 49.0 ± 80.0 × 10–10 for heart group, 33.7 ± 18.0 × 10–10 for kidney group. The UPoC in the heart and kidney group was significantly higher than in the control group (P < 0.0001, sensivity 0.83, specyfity 0.20). Commercial ELISA tests may be used to assess podocyturia in dogs. An UPoC increase exceeding 12.93 × 10–10 indicates glomerular damage in DMVD dogs. Based on UPoC, 79.3% of dogs with C-chronic stage of DMVD developed CRS.