Proteinuria Assessment in Chronic Kidney Disease

Proteinuria, the presence of excess proteins in urine, is both a hallmark and a driver of chronic kidney disease (CKD). Damage to the glomerular filtration barrier allows plasma proteins—principally albumin, but also lower-molecular-weight proteins—to traverse into the urinary space. Quantification of urinary protein excretion guides diagnosis, prognostication and therapeutic decision-making, as the degree of proteinuria closely parallels loss of renal function and cardiovascular risk. Traditional assessment relies on dipstick urinalysis for semi-quantitative screening, followed by either 24-hour urine collection or calculation of a protein-to-creatinine ratio (UPCR) in a spot sample to yield daily excretion estimates. Advances in mass spectrometry and immunoassays now permit detailed characterisation of the urinary proteome, offering insights into pathophysiology and enabling discovery of novel biomarkers that may refine risk stratification, inform patient management and serve as therapeutic targets. Globally, standardisation of methods, combined with accessible point-of-care approaches, remains essential to reduce the burden of CKD and its complications.

Research from Nature Portfolio

A comprehensive proteomic analysis compared urinary protein profiles across early and moderate CKD stages and healthy controls. Stage-specific shifts in the number and abundance of detected proteins correlated with measured glomerular filtration rate, revealing both negatively and positively associated markers of kidney function. Proteins such as beta-2 microglobulin, fetuin-A and vitamin D–binding protein were robustly inversely associated with renal function, whereas markers including orosomucoid and CD44 showed positive correlations. These findings highlight a panel of candidate biomarkers that reflect filtration barrier integrity and tubular handling, pointing to their potential utility in monitoring disease progression and response to therapy. The study also underscored methodological standardisation in sample preparation and data analysis to ensure reproducibility of urinary proteomic workflows.

Proteinuria Assessment in Chronic Kidney Disease publication trend

The graph below shows the total number of articles in proteinuria assessment in chronic kidney disease across all publications each year (not limited to Nature Index journals).

Technical terms

Proteinuria: Excessive excretion of proteins in urine, reflecting glomerular or tubular dysfunction.

Albuminuria: Urinary excretion of albumin, often an early marker of glomerular damage.

Protein-to-Creatinine Ratio (UPCR): Ratio of urine protein concentration to creatinine concentration in a spot sample, used to estimate daily protein excretion.

Estimated Glomerular Filtration Rate (eGFR): Calculated measure of kidney filtration function, derived from serum creatinine and demographic factors.

Proteomics: Large-scale study of proteins and their functions, often using mass spectrometry to profile the urinary protein complement.

References

1. Early Diagnosis and Treatment of Kidney Injury: A Focus on Urine Protein. International Journal of Molecular Sciences (2024).
2. Urinary Proteomic Shifts over Time and Their Associations with eGFR Decline in Chronic Kidney Disease. Biomolecules (2025).
3. Candidate protein biomarkers in chronic kidney disease: a proteomics study. Scientific Reports (2024).
4. Review: Detection and quantification of proteins in human urine. Talanta (2020).