Protein in urine linked to severe inflammatory response in dogs

Abstract

BACKGROUND: Proteinuria is an established characteristic of renal disease in dogs, providing diagnostic and prognostic information. Little is known about the occurrence and severity of proteinuria in dogs with severe inflammatory response syndrome (SIRS). HYPOTHESIS: The quantitative and qualitative urinary protein (UP) excretion is altered in dogs with SIRS. ANIMALS: Thirty-nine dogs with SIRS and 15 healthy control dogs at admission. METHODS: A case control study was performed. Diagnosis of SIRS was based on clinical and clinicopathological findings. Urinary protein (UP) was measured by a colorimetric assay. Urinary albumin (UAlb) and urinary retinol-binding protein (URBP) were measured by ELISA and quantified in relation to urinary creatinine (UC). Sodium dodecyl sulfate polyacrylamid-gel electrophoresis was conducted to identify the qualitative pattern of proteinuria. Mann-Whitney U-test was used to assess differences in UP/UC, UAlb/UC and URBP/UC between the groups. P-values < .05 were considered significant. RESULTS: Dogs with SIRS had higher ratios of UP/UC, UAlb/UC and URBP/UC (all P < .001) in comparison to healthy control dogs. Dogs with SIRS had a total of 11 protein bands compared to 3 bands in healthy controls. In dogs with SIRS, 58% of the total counted bands were in the low molecular weight range (<60 kDa) whereas 42% were in the middle (60-80 kDa)/high molecular weight range (>80 kDa). CONCLUSIONS AND CLINICAL IMPORTANCE: SIRS alters UP excretion in dogs. Further studies should evaluate whether or not the magnitude of proteinuria is predictive of the severity and outcome of dogs with SIRS.