Correlation between total urinary protein quantitation and random urine sample protein/creatinine ratio in children

Area of Science:

• Pediatric Nephrology
• Clinical Chemistry
• Biomarker Validation

Background:

• Accurate quantification of proteinuria is crucial for diagnosing and managing pediatric renal diseases.
• Traditional 24-hour urine collection for protein assessment can be cumbersome and prone to errors in children.
• The protein/creatinine ratio in random urine samples (Up/Ucr) is a potential alternative for estimating daily protein excretion.

Purpose of the Study:

• To evaluate the correlation between the random urine protein/creatinine ratio (Up/Ucr) and total daily protein excretion in children.
• To determine the clinical utility of Up/Ucr as a reliable measure of proteinuria in pediatric patients with renal diseases.

Main Methods:

• Prospective collection of random and 24-hour urine samples from 5 healthy children and 28 children with renal diseases (aged 2-14 years).
• Protein concentrations measured using a validated Coomassie blue binding technique.
• Statistical analysis including log-transformed data to assess the linear correlation between Up/Ucr and daily protein excretion.

Main Results:

• A strong correlation was observed between Up/Ucr and 24-hour urine protein excretion across 61 urine samples (r=0.97 for log-transformed data).
• Specific Up/Ucr values corresponding to clinically significant protein excretion levels were identified (e.g., 25.1 mg/mmole at 4 mg/h/M2).
• The Up/Ucr demonstrated high accuracy in estimating quantitative protein excretion.

Conclusions:

• The random urine protein/creatinine ratio (Up/Ucr) is a precise and reliable indicator of daily protein excretion in children.
• Up/Ucr offers a practical and suitable method for quantifying proteinuria in pediatric renal disease management.
• This method simplifies the assessment of proteinuria, improving clinical workflow and patient compliance.