Laminin and transforming growth factor beta-1 in children with vesicoureteric reflux

Evaluation of subclinical cardiovascular risk and cardiac function in children with vesicoureteral reflux: a prospective study

BACKGROUND

Vesicoureteral reflux is a prominent congenital anomaly of the kidney and the urinary tract. Further, renal scarring is known to be related to chronic inflammation. However, there have been limited studies to date regarding the cardiovascular consequences of vesicoureteral reflux.

OBJECTIVE

The aim of this study is to evaluate the possible subclinical atherosclerosis and cardiovascular complications in children with vesicoureteral reflux.

METHODS

Patients with vesicoureteral reflux and age matched healthy controls were prospectively included in this case-control study. Patients were divided into two groups concerning renal scarring status. To assess cardiac functions, carotid artery intima media, epicardial adipose tissue, and periaortic adipose tissue thicknesses were evaluated.

RESULTS

There were 50 patients with vesicoureteral reflux; 26 patients without renal scarring and 24 patients with renal scarring, as well as 40 healthy controls. Myocardial performance indexes (Tei indexes) measured by tissue Doppler echocardiography from septum and left ventricle were significantly increased in study group (for all, p < 0.001). Also, intima media, epicardial adipose tissue, and periaortic adipose tissue thicknesses of the study groups were significantly higher than the control group (for all, p < 0.001). However, no statistical difference was observed between renal scarring (-) and renal scarring (+) groups.

CONCLUSIONS

Results of our study showed early deterioration of cardiac systolic and diastolic functions in children with vesicoureteral reflux regardless of renal scarring. Also, diagnosis of vesicoureteral reflux is an important risk factor for subclinical atherosclerosis, independent of renal scarring, which should be considered in the follow-up of these patients.

Biomarkers in vesicoureteral reflux: an overview

Aim: This article aimed to review the role of cytokines, chemokines, growth factors and cellular adhesion molecules as biomarkers for vesicoureteral reflux (VUR) and reflux nephropathy (RN). Methods: We reviewed articles from 1979 onward by searching PubMed and Scopus utilizing the combination of words: 'VUR' or 'RN' and each one of the biomarkers. Results: Genetic, inflammatory, fibrogenic, environmental and epigenetic factors responsible for renal scarring need to be better understood. TGF-β, IL-10, IL-6, IL-8 and TNF seem to exert a role in VUR particularly in RN based on the current literature. Serum levels of procalcitonin have been also associated with high-grade VUR and RN. These molecules should be more intensively evaluated as potential biomarkers for renal scarring in VUR. Conclusion: Further studies are necessary to define which molecules will really be of utility in clinical decisions and as therapeutic targets for VUR and RN.

Prognostic value of urinary TGF-β1 in hemolytic uremic syndrome: A pilot study

BACKGROUND

Transforming growth factor β1 (TGF-β1) is the main profibrotic cytokine. Its urinary excretion reflects intrarenal production; thus, we conjectured that it is elevated during hemolytic uremic syndrome related to Shiga-toxin-producing Escherichia coli (STEC-HUS). In this pilot study, we explored the ability of baseline TGF-β1 excretion (exposure variable) to predict renal prognosis at 6 months (outcome variable). In a secondary investigation, we compared changes in cytokine levels during the study period between patients with opposite renal outcomes.

METHODS

Urinary TGF-β1 concentrations were measured prospectively in 24 children with STEC-HUS on admission, and at 15, 30, 60, 90, and 180 days. Normal values were obtained from 20 healthy subjects.

RESULTS

Baseline TGF-β1 concentrations predicted renal outcomes with an area under the curve of 1 (95%CI 0.85-1; sensitivity 100%, specificity 100%) with the best cutoff level >293.7 pg/mg uCr. All patients with high TGF-β1 levels developed persistent renal impairment, unlike none with low concentrations (4/4 vs. 20/0 respectively, P = 0.0001). The latter had higher cytokine levels (P < 0.05) at each time point without reaching normal concentrations (<45 pg/mg uCr).

CONCLUSIONS

Baseline urinary TGF-β1 levels accurately predicted short-term renal outcomes in STEC-HUS children, and cytokine excretion during the first 6 months after diagnosis was higher among those with worse evolution. Larger studies are needed to validate these findings.

Urinary excretion of pentraxin-3 correlates with the presence of renal scar following acute pyelonephritis in children

PURPOSE

Acute pyelonephritis is associated with considerable morbidity and potential for renal scarring. Pentraxin3 (PTX3) is a recently discovered mediator of inflammation. The objective of this study was to investigate the changes in serum and urine PTX3 levels in children who had a history of pyelonephritis and were diagnosed with renal parenchymal scar (RPS) and/or vesicoureteral reflux (VUR).

METHODS

The study included 88 children (31 males, 57 females) aged between 3 months and 18 years. The children included in the study were divided into four groups: VUR with RPS (Group 1), RPS without VUR (Group 2), VUR without RPS (Group 3), and healthy children without a history of hydronephrosis or UTI history (Group 4). After the initial evaluation, the participants were further divided into two more groups and re-evaluated: Children with RPS (Group 1 + 2), children without RPS (Group 3 + 4), children with VUR (Group 1 + 3), and children without VUR (Group 2 + 4).

RESULTS

We found that urine pentraxin 3 (uPTX3) and uPTX3/Creatinine levels were significantly higher in the groups with renal scar with or without VUR than the ones without RPS [mean uPTX3, 3.5 pg/ml (min-max 0.0022-12.3668) vs. 2.2 pg/ml (min-max 0.0022-18.5868) and uPTX3/creatinine, 10.5 pg/mg (min-max 0.0035-51.1) vs. 5.8 pg/mg (min-max 0.0004-78.7), p < 0.01]. uPTX3 levels were not different among the groups with and without VUR. In addition, serum PTX3 levels were not different among the groups.

CONCLUSIONS

We showed that urinary PTX3 increased only in patients with scarred kidneys. These results might be helpful to predict RPS due to past pyelonephritis.

Posterior urethral valve in fetuses: evidence for the role of inflammatory molecules

BACKGROUND

The aim of this cross-sectional study was to investigate inflammatory biomarkers in urine samples of 24 fetuses with posterior urethral valve (PUV) collected at 22 ± 4 weeks of gestation and to compare the findings with measurements in urine samples of 22 male healthy preterm neonates at 23 ± 4 weeks (control group).

METHODS

Inflammatory biomarkers in urine were measured using a cytometric bead array [interleukin (IL)-2, IL-4, IL-6, IL-10, interferon (IFN)-γ, soluable tumor necrosis factor receptor (TNFR) 1, sTNFR2, monocyte chemoattractant protein-1/chemokine ligand 2 (MCP-1/CCL2), eotaxin/CCL11 and interferon gamma-induced protein/10/C-X-C motif chemokine 10 (IP-10/CXCL10)] and ELISA assays [TNF, IL-8/CXCL8 and transforming growth factor-beta (TGF-β)]. The Mann-Whitney test was used to compare medians. Markers of glomerular (creatinine) and tubular [beta 2 (β₂)-microglobulin, uromodulin, osmolality] functions were correlated with inflammatory biomarkers (Spearman test).

RESULTS

An intense inflammatory profile was identified, with significantly increased concentrations of urinary IL-2, IL-4, IL-6, TNF, sTNFRI, sTNFRII, IFN-γ, MCP-1/CCL2, eotaxin/CCL11 and IL-8/CXCL8 in the PUV group compared to the controls. The same was observed for the anti-inflammatory cytokine IL-10 and for the fibrogenic mediator TGF-β. In the correlation analysis, β₂-microglobulin positively correlated with the presence of MCP-1/CCL2, sTNFRI and eotaxin/CCL11 and negatively correlated with the presence of creatinine.

CONCLUSIONS

This study shows that inflammatory molecules are already increased in fetuses with PUV at the mean gestational age of 22 weeks, suggesting a physiopathological role for inflammation just after the embryological formation of the urethral membrane.

Vesicoureteral reflux and the extracellular matrix connection

Primary vesicoureteral reflux (VUR) is a common pediatric condition due to a developmental defect in the ureterovesical junction. The prevalence of VUR among individuals with connective tissue disorders, as well as the importance of the ureter and bladder wall musculature for the anti-reflux mechanism, suggest that defects in the extracellular matrix (ECM) within the ureterovesical junction may result in VUR. This review will discuss the function of the smooth muscle and its supporting ECM microenvironment with respect to VUR, and explore the association of VUR with mutations in ECM-related genes.

Interactions between cytokines, congenital anomalies of kidney and urinary tract and chronic kidney disease

Fetal hydronephrosis is the most common anomaly detected on antenatal ultrasound, affecting 1-5% of pregnancies. Postnatal investigation has the major aim in detecting infants with severe urinary tract obstruction and clinically significant urinary tract anomalies among the heterogeneous universe of patients. Congenital uropathies are frequent causes of pediatric chronic kidney disease (CKD). Imaging techniques clearly contribute to this purpose; however, sometimes, these exams are invasive, very expensive, and not sufficient to precisely define the best approach as well as the prognosis. Recently, biomarkers have become a focus of clinical research as potentially useful diagnostic tools in pediatric urological diseases. In this regard, recent studies suggest a role for cytokines and chemokines in the pathophysiology of CAKUT and for the progression to CKD. Some authors proposed that the evaluation of these inflammatory mediators might help the management of postnatal uropathies and the detection of patients with high risk to developed chronic kidney disease. Therefore, the aim of this paper is to revise general aspects of cytokines and the link between cytokines, CAKUT, and CKD by including experimental and clinical evidence.

Urinary proteome analysis to exclude severe vesicoureteral reflux

OBJECTIVES

High-grade vesicoureteral reflux (VUR, grade IV or V) is a risk factor for renal scarring, impaired renal function, and arterial hypertension. Voiding cystourethrography is the gold standard for detecting the severity of VUR. High-grade VUR is present in the minority of children with urinary tract infection (UTI), thus exposing the majority to invasive diagnostics that have no surgical consequence. We therefore aimed at establishing a noninvasive test to identify children with high-grade VUR.

METHODS

In a case-control study, a specific urinary proteome pattern was established by capillary electrophoresis coupled to mass spectrometry in 18 patients with primary VUR grade IV or V, distinguishing these from 19 patients without VUR after UTI. This proteome pattern was independently validated in a blinded cohort of 17 patients with VUR grade IV or V and 19 patients without VUR.

RESULTS

Sensitivity in detecting VUR grade IV or V in the blinded study was 88%, specificity was 79%. The test's accuracy was independent of age, gender, and grade of VUR in the contralateral kidney. The odds ratio of suffering from VUR grade IV or V when tested positive was 28 (95% confidence interval: 4.5 to 176.0).

CONCLUSIONS

This noninvasive test is ready for prospective validation in large cohorts with the aim of identifying those children with UTI and hydronephrosis in need of further invasive diagnostics, such as voiding cystourethrography, thus sparing most children without pathologic urinary proteome patterns from additional diagnostics.

Urinary levels of TGF β-1 and of cytokines in patients with prenatally detected nephrouropathies

This study aimed to identify noninvasive biomarkers of clinically significant nephrouropathies in patients with antenatal renal and/or urinary tract alterations. Spot-urine levels of interleukin-6 (IL-6), transforming growth factor-β1 (TGF-β1) and tumor necrosis factor-α (TNF-α) were measured in 100 patients with antenatal detected nephrouropathies. Patients were divided in idiopathic hydronephrosis (n = 47), urinary tract malformations (n  = 35), and dysplastic kidneys (n = 18). Urinary concentrations of TGF-β1, IL-6, and TNF-α were compared between groups according to clinical and image findings. Receiver-operating characteristic (ROC) curves were analyzed for the overall diagnostic accuracy of TGF-β1, IL-6, and TNF-α levels in discriminating infants with nephrouropathies. No significant differences in urinary TGF- β1, IL-6, and TNF-α levels were found in the comparison between the groups. TGF-β1 levels tended to be higher in patients with renal hypodysplasia compared to idiopathic hydronephrosis (p = 0.07). Twenty-nine patients had reduced DMSA uptake. In these cases, absolute urinary concentration of TGF-β1 and levels standardized for creatinine were significantly higher than in patients with normal DMSA uptake, while IL6 and TNF-α did not differ between groups. Urinary cytokine measurements were not useful as a screening test for clinically significant nephrouropathies. Conversely, increased concentrations of TGF-β1 pointed out to renal damage as indicated by reduced DMSA uptake.

Biomarkers for pediatric urological disease

PURPOSE OF REVIEW

New disease-specific biomarkers are sorely needed within all fields of medicine. This review covers the current literature of biomarkers within pediatric urology and discusses future perspectives and directions for biomarker discovery.

RECENT FINDINGS

Biomarkers can be used to diagnose disease, monitor response, or sub-classify disease. Within pediatric urology, numerous markers for renal obstruction [ureteropelvic junction (UPJ)] and vesicoureteral reflux (VUR) have been identified and have shown initial promise; however, no markers have been rigorously validated or demonstrated to be clinically effective. Recent advances in proteomic technologies may provide a new discovery method to identify panels of markers for specific disease.

SUMMARY

New clinically significant biomarkers of UPJ or VUR that can improve the diagnostic capability or help determine risk for renal damage are sorely needed. However, rigorous clinical validation of previously identified markers has been limited. Other studies have demonstrated that combining various markers may help improve the ability to define clinical relevance. To improve biomarker discovery efforts, a combination of focused biomarker studies, potentially using new advanced proteomic technologies, and well designed clinical studies are needed.