Assessment of proteinuria using random urine samples.

Area of Science:

• Nephrology
• Clinical Chemistry
• Biomarker Validation

Background:

• Accurate assessment of proteinuria is crucial for diagnosing and monitoring renal disease.
• Traditional 24-hour urine collection is cumbersome and prone to errors.
• Exploring reliable alternatives for proteinuria assessment is essential.

Purpose of the Study:

• To evaluate the feasibility of using random urine samples for proteinuria assessment.
• To compare the accuracy of the urinary protein/creatinine ratio (Up/Ucr) with 24-hour urine protein excretion.
• To establish reference values for Up/Ucr in a diverse age group.

Main Methods:

• Collected 24-hour urine samples from healthy volunteers and pediatric patients with renal disease.
• Measured protein concentration using a Coomassie blue binding technique.
• Compared total protein excretion with Up/Ucr and established reference ranges using random samples from 219 healthy individuals.

Main Results:

• A highly significant correlation (r = 0.99; P < 0.001) was found between 24-hour protein excretion and Up/Ucr.
• Established age-related reference values for Up/Ucr, with 95th percentiles defining the upper limit of normal.
• Demonstrated Up/Ucr as an accurate measure of quantitative protein excretion.

Conclusions:

• The urinary protein/creatinine ratio (Up/Ucr) is a valid and accurate method for assessing proteinuria.
• Up/Ucr can largely replace the need for timed urine sample collection.
• This simplifies the diagnostic process for proteinuria, especially in pediatric nephrology.