Measuring albuminuria or proteinuria: does one answer fit all?

Area of Science:

• Nephrology
• Clinical Chemistry

Background:

• Accurate measurement of proteinuria is essential for diagnosing and monitoring kidney disease.
• Various methods exist to measure total proteinuria or albuminuria, using random or timed urine collections.

Purpose of the Study:

• To review international guidelines on proteinuria measurement.
• To discuss contexts where the optimal measure is unclear or controversial, including specific clinical settings.

Main Methods:

• Review of international guidelines and supporting evidence.
• Discussion of factors influencing the choice of proteinuria measurement.

Main Results:

• The urinary albumin-to-creatinine ratio is internationally recommended but not universally available or consistently cost-effective.
• Accuracy of different measures can vary based on albuminuria levels, patient sex, and clinical context.

Conclusions:

• The optimal choice of proteinuria measurement requires consideration of guideline recommendations, availability, cost, and specific patient factors.
• Clinical contexts such as glomerulonephritis, transplantation, and pregnancy present unique challenges in selecting the appropriate proteinuria assay.