Use of urinary protein creatinine index in spot urine sample in patients with urinary tract infection

Background: Urinary tract infection (UTI) is defined as the presence of microbial pathogens in the urinary tract with associated symptoms. In urinary tract infection protein excretion occurs in nondetectable quantity in urine. Non-detectable excretion of proteins could be estimated by using conventional 24-hours urine collection method, but it is recognized that there are problems associated with a collection of 24-hour urine sample. As an alternative, random spot sampling for a urine protein to creatinine index (PCI) has been investigated. Aims: The aim of the study was to determine the PCI for prediction of significant proteinuria with the evaluation of the P/C index in patients of urinary tract infection Materials and Methods: Twenty five clinically diagnosed patients of UTI who fulfilled the criteria comprised the study group and twenty five age matched healthy subjects were taken as a control group. Spot urine samples for measuring urinary PCI were obtained. Pyragallol red colorimetric method was used to estimate urinary protein. The modified Jaffe's alkaline method was employed to estimate urinary creatinine. The urine protein: creatinine index was calculated by dividing the urine protein concentration (mg/L) by urine creatinine concentration (mmol/L) multiplied by 10. Results: Protein: creatinine index was found to be significantly higher in UTI (680+168.41) as compared to the control group (201.21+28.37). There was no UTI subject with frank proteinuria estimated qualitatively. Conclusion: The present study suggests that random urinary PCI can be a good predictor of proteinuria in UTI patients. This test could be a reasonable alternative to 24-hour urine sample collection for the detection of proteinuria in UTI patients. The simplicity, accuracy and the lower cost of the PCI justifies its preferential diagnostic use.