Diagnostic value of urinary RBP, ALB and AQP2 in neonatal hydronephrosis and the relationship with expression of MCP-1 in the prenatal maternal peripheral blood

Expression of tissue fibrosis genes in congenitally obstructed pyeloureteral junction and biomarkers of renal damage

Introduction

The aim of this study was to investigate the expression of fibrosis-related genes in obstructed ureteral tissue and determine its relationship with biomarkers of renal damage and preoperative renal scan findings.

Material and methods

In all cases, bladder urine and blood samples were collected preoperatively. They were analysed for serum cystatin C, urinary albumin, urinary beta 2 microglobulin, and urinary neutrophil gelatinase-associated lipocalin concentrations, as well as their concentrations standardised by urine creatinine. Pyeloureteral junction obstruction tissue specimens were frozen in liquid nitrogen upon harvesting. RNA was extracted from the samples using TRIzol reagent. qPCR was performed, and the relative expressions of TGFβ1, MMP1, TIMP1, PAI1, CTGF, and VEGFA in stenotic ureteral tissue were calculated. Spearman's rank correlation test was used to calculate the correlation between the relative expression of investigated genes, urine, and blood biomarkers of renal damage and preoperative renal scan findings.

Results

A total of 20 pyeloureteral junctions of 20 patients were harvested at the time of dismembered pyeloplasty. The median age of the patients at the time of the operation was 15.2 [9.07, 66.2] months. There was a significant negative correlation between urinary albumin concentration and relative TGFβ1 expression in pyeloureteral junction tissue (rho = -0.45, p = 0.047), as well as between uAlb and relative VEGFA expression (rho = -0.575, p = 0.008). No correlation with other urine biomarkers of renal damage or renal scan findings was found.

Conclusions

Expression of fibrosis-related genes in the obstructive tissue of the pyeloureteral junction have no direct correlation with biomarkers of renal damage.

Urine Biomarkers Combined With Ultrasound for the Diagnosis of Obstruction in Pediatric Hydronephrosis

Introduction: To establish the efficacy of ultrasound (US) combined with urine biomarkers in differentiating patients who require surgical management from those who do not, avoiding invasive investigations. Materials and Methods: From February 2019 to February 2021, all pediatric patients who presented with hydronephrosis were selected for the study. All renal units (RU) were evaluated by US, and fresh frozen voided urine samples were collected at the time of inclusion. Hydronephrosis grade was evaluated by the Society for Fetal Urology (SFU) and an alternative grading system (AGS). Patients who had high-grade hydronephrosis on US were referred to renal scan (RS) or intervention, when there was an increase of dilatation in subsequent follow-up images. Fresh frozen urine from the control group with no history of renal diseases and no renal anomalies on US was collected. We compared differences of US parameters combined with urine biomarkers between surgically and non-surgically managed patients and between the groups of patients when they were stratified by different RS findings and analyzed whether urinary biomarkers give any additional value to US. Instead of the anterior-posterior diameter (APD), we used its ratio with mid-parenchymal thickness. The additional efficacy of biomarkers to US was calculated when the US component was derived to a cumulative APD/mid-parenchymal ratio. Results: Sixty-four patients with hydronephrosis were prospectively included in the study accounting for a total of 81 patient visits and 162 RUs evaluated. A control group of 26 patients was collected. The mean age at inclusion in the hydronephrosis group was 43.7(±45.5) months, and a mean age in a control group was 61.2(±41.3) months. The cumulative APD/mid-parenchymal ratio combined with urinary albumin, β2 microglobulin (β2-M), and urinary neutrophil gelatinase-associated lipocalcin may have a better performance in the prediction of surgical intervention than the cumulative APD/mid-parenchymal ratio alone (p = 0.1). The best performance to detect the increased tissue transit time and obstructive curve on RS was demonstrated by the β2-M creatinine ratio. An increased cumulative APD/mid-parenchymal ratio with biomarkers together had a fairly good sensitivity and specificity for detection of DRF < 40%. Conclusions: According to our data, the APD/mid-parenchymal ratio alone has good efficacy in prediction of surgery and abnormal RS findings especially when combined with urine biomarkers.