Urinary biomarkers of latent inflammation and fibrosis in children with vesicoureteral reflux.

Purpose: To investigate the urinary levels of TGF-β1, VEGF, and MCP-1 as potential biomarkers of latent inflammation and fibrosis in the kidney before and 6 months after correction of vesicoureteral reflux (VUR) in children.

Methods: A total of 88 patients (mean age 26 months) with VUR were divided into three groups: group A-patients with grades II-III VUR, conservative treatment; group B-patients with grades III-V VUR, endoscopic correction of VUR; group C-patients with grades III-V VUR, ureteral reimplantation after failed endoscopic correction. Control group included 20 healthy children. Biomarker levels were measured by ELISA. Tc-DMSA scintigraphy and renal histology were performed if possible.

Results: At admission, TGF-β1 was close to control in all study groups, VEGF increased with severity of the disease, and MCP-1 increased in group C. Six months after correction of VUR, despite clinical and laboratory improvement, TGF-β1 and MCP-1 increased while VEGF decreased compared to the admission values in all groups; no amelioration of renal scarring was detected either by Tc-DMSA scintigraphy or renal histology.

Conclusion: The results support our hypothesis that successful correction of VUR is not sufficient to stop or reduce the latent inflammatory and fibrotic processes that have already started in the kidney regardless of the reflux grade and treatment option. Measuring the urinary levels of TGF-β1, VEGF, and MCP-1 may aid in the development of non-invasive, pathophysiologically relevant approach to diagnosis and monitoring of kidney injury and fibrosis in children with VUR.