Introduction

There are few markers in urine able to detect the renal damage or the earlier kidney failure. New molecules have been recently investigated in human and veterinary medicine.

Objective

The aim of the present study was to evaluate the utility of the determination in urine of three new markers, cystatin C (CysC), beta-2-microglobulin (B2M) and retinol-binding protein (RBP), in the diagnosis of renal disease in dogs.

Methods

A total of 59 dogs were included and classified in groups depending on the pathology: CKD (20), urinary tract pathologies other than CKD (18) and systemic diseases (21). Twenty healthy dogs were the control population.

New markers were determinate in urine with a particle-enhanced turbidimetric or nephelometric immune-assay (PETIA or PENIA). The concentrations were related to urinary creatinine, and results were correlated with traditional markers and compared between groups.

Results

A low sensitivity was found in the assay of new markers in the urine samples collected.

RBP were the best detected, especially in the group of dogs with CKD. The average of urinary retinol-binding protein-to-creatinine ratio (uRBP/c) and urinary cystatin C-to-creatinine ratio (uCys C/c) were higher in dogs with CKD than in normal dogs, but did not show significant difference. Only uRBP/c was correlated with traditional markers in dogs with evidence of renal damage.

Conclusion

Determination of urinary RBP by PENIA seems to be a promising, specific and early method in the diagnosis of canine renal disease. Additional studies with more number of animals are necessary to conclude this affirmation.