engleski

Urine protein expert system applied for proteinuria interpretation in the population of an endemic nephropathy village in Croatia - a preliminary study

Introduction: Endemic nephropathy (EN) is a chronic, progressive tubulo-interstitial disease found in several geographically restricted areas of Eastern Europe. Its etiology remains elusive despite distinct environmental, viral and genetic factors pointed out as possible causes. The prevalence in endemic foci is 2-10%, but, if proteinuria with possible anemia is taken as a criterion, it rises to 20 percent or higher. EN inevitably leads to terminal renal failure. Proteinuria, predominantly of tubular type, is recognized as an early sign of the disease. Therefore the aim of this study was to determine the proteinuria pattern in the supposedly healthy inhabitants (normal serum creatinine and absence of any clinical signs) of a typical endemic village. Material and methods: 368 second morning urine samples were collected for test-strip screening and quantitative protein measurements (total proteins, albumin, alpha1-microglobulin, all realted to urine creatinine). Urinary Protein Expert System (UPES, an expert system dealing with urinary protein patterns in relation with particular kidney disorders) was used as a tool for data interpretation. Results: Pronounced difference (p<0.001) in the frequency of tubular proteinuria was observed between younger and older subjects (cut-off age: 18 yrs). In a group aged under 18 (n=105), there were 6 cases of tubular proteinuria (5.7 percent) interpreted by UPES as either slight or significant, pointing at tubulo-interstitial disfunction. Among 263 subjects above 18 years of age (18-85, median 53), tubular proteinuria was found in 63 (23.9 percent), among which 44 (16.7 percent) was described as pronounced. In both groups, tubular proteinuria (alpha1-microglobulin) was in most cases (79 and 82 percent, respectively) accompanied by increased albumin excretion, indicating various extents of glomerular involvement as well. The test strip screening failed to detect any tubular proteinurias, and was positive only in albuminurias UPES-defined as pronounced. Discussion and conclusion. The observed frequency and age-distribution of tubular proteinurias is consistent with prevalence data in EN areas. In this setting, UPES proved to be a simple and straightforward tool for early detection of persons at risk for developing manifest disease. Further follow-up of the same population will be performed in an analogous manner.

urine protein expert system; proteinuria; endemic nephropathy

nije evidentirano