Advancing Insights into Biomarkers in Congenital Anomalies of the Kidney and Urinary Tract: A Scoping Review.

BACKGROUND

Congenital anomalies of the kidney and urinary tract (CAKUT) comprise a heterogeneous spectrum of developmental disorders and represent the leading cause of chronic kidney disease and end-stage renal disease in the pediatric population. Although imaging remains the cornerstone of diagnosis, its limited ability to accurately assess disease severity and predict long-term outcomes has driven growing interest in urinary, serum, and tissue biomarkers as potential indicators of early renal injury.

OBJECTIVES

To systematically summarize the current evidence on diagnostic and prognostic biomarkers in pediatric CAKUT, with particular focus on their potential clinical utility in early detection of renal injury and disease monitoring.

METHODS

A scoping review was conducted in accordance with PRISMA guidelines. PubMed, Embase, and Scopus were searched up to March 2026 using combinations of CAKUT-related terms and "biomarkers." Studies involving human subjects with CAKUT that evaluated the diagnostic, prognostic, or therapeutic utility of biomarkers were included.

RESULTS

Out of 1130 records identified, 101 studies met the inclusion criteria. Urine was the most commonly analyzed biological sample. The principal biomarkers identified included NGAL, KIM-1, MCP-1, TGF-β1, CA19-9, β2-microglobulin, cystatin C, and microRNAs. Across various CAKUT subtypes-including posterior urethral valves, ureteropelvic junction obstruction, vesicoureteral reflux, and multicystic dysplastic kidney-these biomarkers showed significant associations with renal function, inflammatory activity, and fibrotic processes. Several biomarkers, particularly urinary NGAL, MCP-1, and CA19-9, demonstrated good diagnostic performance in differentiating obstructive from non-obstructive hydronephrosis and in predicting renal impairment. However, substantial heterogeneity in study design, along with the lack of standardized cutoff values, limits their translation into routine clinical practice.

CONCLUSIONS

Current evidence underscores the potential of several biomarkers for the diagnosis and monitoring of CAKUT-related renal injury. Nevertheless, well-designed multicenter prospective studies are needed to validate their clinical utility and to support the integration of biomarker-based approaches with imaging in pediatric practice.