Biomarcadores urinários em pacientes pediátricos com rim solitário funcional congênito: um estudo piloto

Abstract

Background: Solitary Functioning Kidney (SFK) is an important subgroup of the Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) spectrum. Serum urea and creatinine levels are still the most used markers to assess renal function, even though these measurements do not allow early detection of renal injury. In this sense, the aim of this pilot study was to measure urinary concentration of kidney biomarkers in pediatric patients with SFK and to compare with the same biomarkers measurements in healthy children and adolescents. Patients and methods: This cross sectional study included 30 pediatric patients with congenital SFK (renal agenesis, primary renal hypodysplasia, and multicystic dysplastic kidney) and 20 healthy individuals paired for gender and age (controls). All the participants underwent a single urine collection to measure seventeen urinary biomarkers, known to be related to kidney function and/or lesion. Results: Cystatin C, Osteopontin, Calbindin, Osteoactivin, Tissue inhibitor of metalloproteinase 1, Kidney injury molecule-1, Protein induced by interferon, Renin, Epithelial Growth Factor and Clusterin were significantly reduced in urine samples of patients in comparison with controls. Lipocalin-2/NGAL was the only molecule with significantly increased levels in patients when compared with controls. The remaining molecules were similar in both groups. Serum levels of creatinine increased significantly from baseline to the last outpatient visit before closing the database of this study, whereas estimated GFR reduced. Conclusion: In pediatric patients with congenital SFK, the behavior of some urinary molecules is different from healthy controls. Longitudinal studies should be performed to validate the clinical utility of these biomarkers. KEYWORDS: Renal function, urinary biomarkers, solitary functioning kidney, CAKUT, chronic kidney disease, pediatrics.