Urine proteome in dogs affected by leishmaniasis

Background: Leishmaniasis is a frequent cause of nephropathy in dogs. Evaluate urine proteome with sensitive methods is a useful and non invasive method to monitor the therapy and discover novel biomarkers. Objective: Comparing different electrophoretic methods for urine protein separation and monitoring the therapy in dogs affected by leishmaniasis. Methods: Urine samples were collected from 43 leishmaniotic dogs. UP/C, UA/C and high resolution electrophoresis (HRE) were performed for all samples. Moreover, SDS-PAGE (26 samples) and a semi-automated SDS-AGE (12 samples) were tested. Results: UP/C and UA/C median (range) values were 1.45 (0.06-20.08) and 0.38 (0.01-14.8) respectively. With HRE different electrophoretic patterns were evidenced and urinary albumin concentrations (median 32 mg/dL; range 5-463 mg/dL) and percentage (mean±SD; 39±13.7) were determined. With SDS-AGE different patterns of proteinuria were found: 9 dogs presented mixed proteinuria (complete or incomplete) and 3 presented non selective glomerular proteinuria. With SDS-PAGE in most of the samples 35-40 different bands were visualized; the most abundant ones were at apparent molecular weights (expressed in kDa) of 71, 66, 55, 46, 37, 26, 22, 14. Conclusion: HRE was a useful and rapid method to monitor renal function and the therapy effectiveness, in addition urinary albumin can also be quantified. SDS-AGE, according to literature, allowed the localization of nephronal damage. SDS-PAGE, due to its high sensitivity, permitted the visualization of many urine proteins, that could be studied as novel biomarkers of nephropathy.