Urinary cytokine profiles in unilateral congenital hydronephrosis

Intraoperative urinary ACR as a prognostic biomarker in unilateral pelviureteric junction obstruction in paediatric population-an observational study

BACKGROUND

Many urinary biomarkers like MCP1, EGF, KIM1, CCL5/RANTES, CA19.9, NAG, TTF and micro albumin have been used as indicators of renal damage in HDN patients. Urine albumin-to-creatinine ratio (ACR) is widely used to detect renal damage in systemic diseases like diabetes and hypertension. While extensively studied in medical renal diseases, its role as an intraoperative prognostic biomarker for renal damage remains unexplored. ACR offers advantages such as low cost, easy availability, and spot testing.

AIMS

To determine the correlation between urinary ACR from obstructed pelvis in the prognostication of renal function of children with unilateral pelviureteric junction obstruction.

METHODS

This prospective observational pilot study included 30 patients with unilateral PUJO, aged over six months, undergoing Anderson-Hynes pyeloplasty. Patients underwent a standardized diagnostic protocol, including USG-KUB and technetium-99m DTPA renal scans. Preoperative urinary ACR from voided urine was measured. During surgery, urine from the obstructed pelvis was aspirated for ACR analysis. Data analysis compared preoperative and postoperative variables and intra-operative urinary ACR levels were correlated with change in differential renal function on DTPA.

DISCUSSION

Postoperative outcomes currently rely on dynamic nuclear renal scans and USG performed 3 months after surgery. Intraoperative urinary ACR from the obstructed renal pelvis shows promise as an early biomarker for predicting renal function outcomes after pyeloplasty. It provides immediate results, alleviating parental anxiety by eliminating the usual delay in postoperative assessments.

CONCLUSION

This study highlights the potential role of urinary ACR for peri-operative prognostication in children with PUJO, though larger studies are required to confirm these findings.

LEVEL OF EVIDENCE

Level 2B - Prospective observational study.

Evaluation of predictive performance of fetal urinary inflammatory markers of postnatal kidney function in fetuses with posterior urethral valves

BACKGROUND

There are proposed roles for inflammation in the development of congenital obstructive uropathy in the setting of posterior urethral valves (PUV). However, the value of inflammatory proteins as predictive markers of postnatal kidney function, key in the management of fetuses with PUV, has not been explored. We screened fetal urine of fetuses with PUV with a panel of inflammatory proteins to determine their predictive value of postnatal kidney function.

METHODS

Twenty-five different chemokines and cytokines were measured using a multiplex immunoassay in fetal urine of 79 PUV patients from retrospective cohorts, separated in discovery (n = 52) and validation (n = 27). The candidate markers were also quantified in amniotic fluid samples obtained from 16 PUV and 25 other congenital anomalies of the kidney and the urinary tract pregnancies. The performance of validated candidate inflammatory proteins was compared to the previously published 12PUV fetal urine peptide signature.

RESULTS

Fetal urine chemokines CCL2 (MCP-1), CXCL9 (MIG), and CCL4 (MIP-1β) were identified as predictive of postnatal kidney failure in fetuses with PUV from the discovery cohort. Their predictive potential was confirmed in the validation cohort (AUCs of 0.87, 0.81, and 0.86, respectively). The performance of these individual chemokines was lower than the previously published 12PUV fetal urine peptide signature. However, the combination of the three chemokines performed similarly to 12PUV. In contrast, these three chemokines were not predictive of outcome in amniotic fluid.

CONCLUSIONS

We identified chemokines in fetal urine of PUV pregnancies that, after external validation, could serve as predictive biomarkers of postnatal outcome and contribute to improve prenatal PUV management.

Urinary epidermal growth factor and monocyte chemotactic protein-1 as biomarkers of renal injury in patients with obstructed nephropathy

OBJECTIVE

To evaluate the role of urinary Monocyte Chemotactic Protein-1 (MCP1) and urinary epidermal growth factor (EGF) in diagnosing of upper urinary tract obstruction (UUTO).

PATIENT AND METHODS

Over a period of 6 months (January 2022 to June 2022) this prospective case control comparative study was conducted on 120 participants, 60 of them with UUTO and 60 healthy controls. A morning urine sample of all participants was tested for EGF and MCP-1. after taking a detailed history taking and laboratory and radiological evaluation.

RESULTS

Urinary MCP-1(uMCP-1) was significantly (p-value = 0.000) increased in UUTO group showing a mean ± SD of 518.10 ± 51.19 ng/L compared to a mean ± SD of 143.32 ± 58.03 ng/L in the controls, whereas a significantly (p-value = 0.000) decrease of urinary EGF (uEGF) was observed in patients with UUTO compared to control group. A significant difference of uEGF level and uEGF/uMCP1 ratio was observed between mild compared to moderate/severe UUTO.

CONCLUSIONS

Utilization of the urinary biomarker MCP1, EGF and uEGF/uMCP1 ratio in patients with UUTO can adequately be used as a simple, efficacious and noninvasive way in diagnosis of UUTO.

Role of urinary Neutrophil Gelatinase-Associated Lipocalin (NGAL), Monocyte Chemoattractant Protein-1(MCP-1), and Interleukin-6(IL-6) as biomarkers in pediatric patients with hydronephrosis

OBJECTIVES

The decision to surgically intervene in a hydronephrotic kidney in children is based on many debatable guidelines, some requiring repeated ultrasounds or renal scans. Urinary proteins have the potential to reflect renal disorders and hence can be the alternatives to such scans. Here, we aim to assess the role of urinary Neutrophil Gelatinase-Associated Lipocalin, Monocyte Chemoattractant Protein-1, and Interleukin-6 (IL-6) in such patients.

METHODS

Seventeen children had obstructive hydronephrosis requiring pyeloplasty (UPJO), while seven were kept on conservative management in view of non-obstructive dilation (NOD). Urine samples were measured for the three urinary proteins at the time of presentation and following pyeloplasty using commercially available ELISA kits.

RESULTS

The levels of all three urinary proteins were significantly higher in patients with UPJO children compared to the NOD group. Cut-off values to differentiate obstructive from non-obstructive hydronephrosis were obtained. A significant fall in the post-operative value of urinary IL-6 was also observed.

CONCLUSION

This study highlights the potentiality of urinary proteins as biomarkers in identifying children with hydronephrosis and picking out the ones with obstructive hydronephrosis who will require pyeloplasty. The drop in levels after pyeloplasty can be employed to evaluate the effectiveness of pyeloplasty when sent serially.

Comparing accuracy of urinary biomarkers in differentiation of ureteropelvic junction obstruction from nonobstructive dilatation in children

Multiple urinary biomarkers have been reported in differentiation of nonobstructive dilatation (NOD) from ureteropelvic junction obstruction (UPJO). In this meta-analysis, we compared the accuracy of common urinary biomarkers applicable to UPJO. A systematic literature review of electronic databases was conducted for: (UPJO) OR (NOD) AND (urinary biomarkers) AND (children) for articles published in the last decade. PRISMA guidelines were used to exclude duplicate and erroneous articles. Meta-analysis involved risk of bias analysis, heterogeneity assessment, and comparison of sensitivity/specificity by forest plot analysis using MetaXL 5.3. Among the 264 articles analyzed, 19 articles met the inclusion criteria and reported the following: neutrophil gelatinase-associated lipocalin (NGAL), monocyte chemotactic protein-1 (MCP1), carbohydrate antigen 19-9 (CA 19-9), kidney injury molecule (KIM1), epidermal growth factor (EGF), and interferon gamma induced protein-10 (IP10). There was substantial heterogeneity among articles. There was wide variation in applied cut-offs among studies. Overall sensitivity was highest at 87% for CA 19-9 while overall specificity was highest at 76% for NGAL. Overall accuracy was highest at 78% for CA 19-9 followed by 77% for NGAL and 75% for KIM1. In this meta-analysis, the overall accuracy was highest for CA 19-9 followed by NGAL and KIM1. The small number of studies for CA 19-9 and considerable heterogeneity for all should be considered while interpreting these findings. Based on the current meta-analysis, we support a panel of biomarkers combining NGAL, KIM, and CA 19-9 for the best diagnostic accuracy of UPJO in children.

Correlation of Urinary Biomarkers (Interleukin-6, Transforming growth factor-β, E-Cadherin, and MCP-1) with Conventional Parameters of Disease Progression in Patients of Posterior Urethral Valves: A Comparative Analysis

AIMS

Posterior urethral valves (PUV) are the leading cause of end-stage renal disease in boys. The study aimed to look at the ongoing renal damage and profibrotic activity by measuring the levels of Interleukin-6 (IL-6), Transforming growth factor-β (TGF-β), E-cadherin, and Monocyte Chemoattractant Protein-1 (MCP-1) and observing trends in subsequent follow-ups and at the same time correlating them with the established parameters of disease progression.

MATERIALS AND METHODS

This prospective study included 36 consecutive patients of PUV, managed over a period of 18 months. IL-6, TGF-β, E-cadherin, and MCP-1 were measured in urine samples at the time of admission, pre-fulguration and 3 months' and 9 months' post fulguration. The observed values were correlated with the conventional parameters used in clinical practice.

RESULTS

All the biomarkers showed statistically significant trends when these values were compared on admission, postoptimization and 3 months' and 9 months' postfulguration. None of the biomarkers showed a significant correlation with renal function tests. E-Cadherin and TGF-β showed a positive and a negative correlation with ultrasonography (USG) kidney, ureter, and bladder (KUB) respectively. E-Cadherin showed a positive correlation, whereas IL-6 and TGFβ showed negative correlation respectively with micturating cystourethrogram (MCUG). IL-6 showed statistically a significant negative correlation with dimercapto succinic acid (DMSA). MCP-1 did not show any significant correlation with USG KUB, MCUG and DMSA.

CONCLUSION

This study concludes that E-Cadherin, IL-6, TGF-β can be promising urinary biomarkers for early detection of the ongoing renal damage in patients of PUV following valve fulguration. MCP-1 may have more complex interactions, with inflammatory markers; which warrants further research.

The use of biomarkers in the diagnosis and treatment of obstruction of the upper urinary tract in children

Antenatal hydronephrosis, dilatation of the upper urinary tract (UUTD), is a common finding on prenatal ultrasound. One of the most common causes is ureteropelvic junction (UPJ) obstruction. Although such prenatally diagnosed UUTD resolves spontaneously in most newborns, further examination of these children is advocated to prevent possible irreversible kidney damage, and ultrasound is mainly used for this. If the dilatation persists or becomes symptomatic, it is necessary to proceed to other relatively demanding and invasive diagnostic examinations for these small patients, where the question of the right timing of indications for possible surgical solutions is still unclear. For this reason, various biomarkers have been investigated in a number of clinical trials as potential mini-invasive diagnostic tools for determining when upper urinary tract dilatation in such children poses a threat to the developing kidneys and they should be operated on, and vice versa, when to proceed conservatively. The aim of this article is to review the findings on and current issues with the use of biomarkers in the diagnosis and treatment of UPJ obstruction in children.

Urinary biomarkers can identify the need for pyeloplasty in presence of supranormal differential renal function in antenatally diagnosed unilateral hydronephrosis

INTRODUCTION

Decision for surgery can be challenging in children with AH (Antenatal Hydronephrosis) especially in the setting of supranormal differential renal function (SnDRF).

OBJECTIVE

Aim of this study is to investigate whether IP-10 (interferon gamma-induced protein 10), MCP-1 (monocyte chemotactic protein-1), NGAL (neutrophil gelatinase-associated lipocalin), CA 19-9 (carbohydrate antigen 19-9), and KIM-1 (kidney injury molecule-1) can identify the need for pyeloplasty in presence of SnDRF in antenatally diagnosed unilateral hydronephrosis.

STUDY DESIGN

A prospectively collected urinary biomarker database was used for the study. There was a total of 53 patients in the AH group. Nineteen children with no history of AH and a normal urinary ultrasonography were taken as controls. Patients with initial ipsilateral DRF (Differential Renal Function) over 50% were included in the SnDRF group while the remaining were named as non-SnDRF. Patients that didn't undergo surgery were classified as non-obstructive dilation (NOD) in both groups.

RESULTS

Pyeloplasty was performed in 6/20 patients in SnDRF group, and in 19/33 patients in non-SnDRF group. Biomarker levels in the pyeloplasty and NOD groups were not affected by the presence or absence of SnDRF (p = 1.00, for both). Urinary NGAL, and CA 19-9 could determine the need for surgery in SnDRF group with 83% and 100% sensitivity, 86% and 79% specificity, respectively whereas urinary IP-10 and KIM-1 could with 84% and 83% sensitivity, 57% and 71% specificity, respectively. Urinary MCP-1 could differentiate patients who underwent surgery with 83% sensitivity and 50% specificity in SnDRF groups.

CONCLUSION

Our results showed that biomarker levels were not affected whether the kidney has SnDRF. Furthermore, in patients with SnDRF, NGAL and CA 19-9 appear to better estimate requirement for surgical correction before deterioration of renal function.

Can urinary biomarkers be used in the outcome assessment of pyeloplasty in children?

Background

To compare the urinary biomarkers—beta 2-microglobulin (β2M), monocyte chemotactic peptide-1 (MCP-1), and transforming growth factor-beta (TGF-β1)—in the outcome assessment of children with pelviureteric junction obstruction (PUJO) undergoing pyeloplasty.

Methods

A prospective study was conducted on children with PUJO who had pyeloplasty in a tertiary care center from July 2016 to March 2018. Urine samples were obtained from freshly voided urine samples before surgery and after 6 months of pyeloplasty. Ratio between the levels of biomarkers and urinary creatinine before and after surgery were compared.

Results

A total of 72 patients had pyeloplasty during this period. The mean levels of standardized urinary β2M, MCP-1 and TGF-β1 before surgery were 3.94 ± 4.06, 96.63 ± 117.68 and 310.65 ± 423.87, respectively, which was significantly higher than the corresponding values in the postoperative period, obtained after 6 months of surgery; postoperative mean values were 3.12 ± 3.95, 25.28 ± 32.06, 109.95 ± 118.72 (P < 0.001), respectively. Using Wilcoxon signed-rank test, fall of MCP-1 and TGF-β1 was more significant compared to β2M.

Conclusion

Urinary biomarkers (β2M, MCP-1 and TGF-β) offer an effective way of outcome assessment of pyeloplasty for PUJO in children, especially MCP-1 and TGF-β1.

Role of Urinary Transforming Growth Factor Beta-B1 and Monocyte Chemotactic Protein-1 as Prognostic Biomarkers in Posterior Urethral Valve

Background:

Posterior Urethral Valves (PUV) are the most common cause of congenital LUT obstruction in males. Biomarkers of glomerular or tubular injury may be of particular value in predicting the need for surgical intervention or in tracing progression of chronic kidney disease. Measurement of biomarker in urine is relatively easy.

Aim:

To evaluate the changes in values of urinary Transforming Growth Factor Beta 1(TGF-B1) and Monocyte Chemotactic Protein (MCP-1) before and after valve ablation and its prognostic value in Posterior urethral valve.

Material and Method:

This prospective study was conducted from September 2016 to August 2018. The study group included 20 consecutive male babies with the diagnosis of PUV treated and followed up versus equal numbers of age matched control without any renal or urinary tract disease. Pre-operative urine samples were collected in Operative room. Cystoscopy and valve ablation was done. Follow up was done clinically by urinary stream and radiologically with VCUG. Follow-up was planned at 1 month, 3 months and 6 months following cystoscopic valve ablation. All collected urine samples were centrifuged at 10,000 rpm for 20 minutes. Supernatant was collected and two divided aliquots were stored at -200c to be thawed on the day of assay. Optical density of each well was recorded at 450 nm and 540 nm A p-value of <0.05 was considered to be statistically significant.

Result and Discussion:

Out of 20 cases of PUV, 14 (70%) cases were 1st born males of their family. The median age at the time of valve ablation in PUV cases was 2.5 (1.20-3.87) years.. Most common symptoms are fever and UTI. The preoperative median serum creatinine level was 1.65 mg/dl(1.22-2.42) pre-ablation, and fall significantly after ablation. Median eGFR level (calculated) was 25.635 (16.38-35.40) and after 6 months was 71.490 (45.44-96.93). Preoperative median MCP1 in PUV cases was 147.2 (82.8-512.5) and significant difference was also found in 1st, 3rd and 6th months after surgery (p<0.001, p=0.004 and p=0.002).Preoperative median TGF-B1 level was 197.8 pg/ml (79.9-386.4). There was no statistically significant change in TGF-B1 level at preoperative to 1 month and preop to 3 months after surgery but at 6 months after surgery the median TGF-B1 level significantly decreased as compared with preoperative TGF-B1 level.

Conclusion:

TGF β1 and MCP1 can be considered as prognostic urinary biomarkers in patients of PUV and can be used to specify and counsel patient's attendant regarding possibility of ESRD and need for further intervention.

Roles Played by Biomarkers of Kidney Injury in Patients with Upper Urinary Tract Obstruction

Partial or complete obstruction of the urinary tract is a common and challenging urological condition caused by a variety of conditions, including ureteral calculi, ureteral pelvic junction obstruction, ureteral stricture, and malignant ureteral obstruction. The condition, which may develop in patients of any age, induces tubular and interstitial injury followed by inflammatory cell infiltration and interstitial fibrosis, eventually impairing renal function. The serum creatinine level is commonly used to evaluate global renal function but is not sensitive to early changes in the glomerular filtration rate and unilateral renal damage. Biomarkers of acute kidney injury are useful for the early detection and monitoring of kidney injury induced by upper urinary tract obstruction. These markers include levels of neutrophil gelatinase-associated lipocalin (NGAL), monocyte chemotactic protein-1, kidney injury molecule 1, N-acetyl-b-D-glucosaminidase, and vanin-1 in the urine and serum NGAL and cystatin C concentrations. This review summarizes the pathophysiology of kidney injury caused by upper urinary tract obstruction, the roles played by emerging biomarkers of obstructive nephropathy, the mechanisms involved, and the clinical utility and limitations of the biomarkers.

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.

Urinary biomarkers in pelvic-ureteric junction obstruction: a systematic review

Antenatal hydronephrosis is a common finding detected on prenatal ultrasound. Although hydronephrosis will spontaneously resolve in the majority of newborns, there is a significant amount of cases that will worsen with the risk of a progressive and permanent loss of renal function. There is an increasing concern among experts that the current criteria for evaluation of clinically significant obstructions are limited. Our aim is to provide a systematic review of the available literature on biomarkers of renal injury, potential targets for diagnosis and prognosis of children with hydronephrosis. The main search was conducted in the electronic databases from inception through March 2019 using various combinations of the keywords: pelvic-ureteric [All Fields] AND junction [All Fields] AND obstruction [All Fields] AND “biomarkers” [MeSH Terms] OR “biomarkers” [All Fields] OR “biomarker” [All Fields]. To broaden the research, additional articles were identified through hand-searching review of the references reported in each study previously selected. Histopathological studies, studies with no control group or with participants suffering from concomitant urological diseases and articles published in language other than English were excluded. Data on study design, sample size, average patient age, hydronephrosis definition used, surgical indication, duration and pattern of follow-up, details on biomarker studied, diagnostic test characteristics, area under the curve (AUC) on receiver operating characteristic (ROC) analysis with the best cut-off (BCO) values, sensitivity, specificity and outcomes were all collected. 38 articles analysing 41 biomarkers were selected. The most frequent proteins investigated were neutrophil gelatinase-associated lipocalin (NGAL) (n=9; 23.7%), monocyte chemotactic peptide-1 (MCP1) (n=8; 21.1%), transforming growth factor β1 (TGFβ1) (n=7; 18.4%), epidermal growth factor (EGF) (n=6; 15.8%) and kidney injury molecule 1 (KIM 1) (n=6; 15.8%). Twenty-seven (71.1%) studies evaluated the effect of pyeloplasty on voided urine biomarker concentrations, comparing their values before and after surgery. Twelve (31.6%) studies investigated the correlation between preoperative biomarker concentration and the anterior posterior renal pelvis diameter (DAP) while 20 (52.6%) studies investigated the correlation between preoperative biomarker concentration with the split renal function (SRF) measured on nuclear medicine assessments. ROC curves were used to investigate the performance of urinary biomarkers in the total patient data set in 27 (71.1%) studies. Some biomarkers offer promising results. However, a critic analysis of the published studies demonstrates bias and lack of consistency suggesting that larger multicentre and carefully designed prospective studies are still needed to evaluate the clinical usefulness of urinary biomarkers in the diagnosis and follow-up of children with congenital obstructive hydronephrosis.

Value of urinary carbohydrate antigen 19-9 to predict failure of conservative management in children with ureteropelvic junction obstruction

OBJECTIVE

To assess the role of urinary carbohydrate antigen 19-9 (CA19-9) measurement in determining optimal management of ureteropelvic junction obstruction (UPJO) and predicting failure of conservative management.

PATIENTS AND METHODS

Children with UPJO diagnosed between December 2012 and April 2015 were included. Depending on clinical and para-clinical findings, patients were divided into three groups: Group 1 consisted of patients who were considered for non-operative management with improvement of the condition during the course of follow-up. Group 2 were suitable for observation; however due to deterioration of condition pyeloplasty was indicated after a period of observation. Group 3 patients required immediate pyeloplasty. Urinary CA19-9 was measured in all patients at baseline and compared between the study groups.

RESULTS

A total of 112 children (115 affected kidneys) with UPJO and mean age of 18.6 ± 3.3 months were assessed. Group 1, 2, and 3 consisted of 54(48.2%), 24(21.4%), and 34(30.4%) patients, respectively. Mean baseline urinary CA19-9 was 37.83 ± 5.20, 145.45 ± 18.38 and 244.62 ± 41.42 in groups 1, 2 and 3, respectively. Multivariate analysis showed that both CA19-9 and APD are independent predictors of need for surgery in patients on observation. ROC curve analysis revealed that urinary CA19-9 level at cut off value of 52.6 U/mL had sensitivity of 92.0% and specificity of 70.9% in predicting failure of non-operative management.

CONCLUSION

Higher urinary CA19-9 level is associated with failure of non-operative management in patients with UPJO. Such patients may require close follow-up and assessments to prevent irreversible damage to the kidney.

TYPE OF STUDY

Study of Diagnostic Test.

LEVEL OF EVIDENCE

Level II.

Identification of transcripts associated with renal damage due to ureteral obstruction as candidate urinary biomarkers

Renal obstruction is a common cause of renal failure in adults and children and is suspected when hydronephrosis is detected on imaging. Because not all cases of hydronephrosis are associated with renal damage, biomarkers are needed to guide intervention to relieve obstruction. We performed gene expression profiling on the kidneys from adult mice over a detailed time course after obstruction and compared these data with a neonatal model of bilateral high-grade obstruction induced by conditional deletion of the calcineurin β₁ gene. Having identified a set of 143 transcripts modulated in both adult and neonatal obstruction, we tested their expression in a model of short-term obstruction (1 day), where renal damage is transient and reversible, and long-term obstruction (5 days), where significant renal damage is permanent. A significant number of transcripts increased early after obstruction, and later normalized, while 26 transcripts remained elevated 10 and 28 days after relief of 5 days of ureteral obstruction. With the use of qPCR, elevated levels of several of these candidate RNA biomarkers of renal damage were detected in urine from obstructed mice. In addition, several of these candidate RNA biomarkers of damage resulting from obstruction were detectable in catheterized urine samples from children undergoing surgery for ureteropelvic junction obstruction. Measurement of urinary transcripts modulated in response to renal obstruction could serve as biomarkers of renal damage with important clinical applications.

The molecular biology of pelvi-ureteric junction obstruction

Over recent years routine ultrasound scanning has identified increasing numbers of neonates as having hydronephrosis and pelvi-ureteric junction obstruction (PUJO). This patient group presents a diagnostic and management challenge for paediatric nephrologists and urologists. In this review we consider the known molecular mechanisms underpinning PUJO and review the potential of utilising this information to develop novel therapeutics and diagnostic biomarkers to improve the care of children with this disorder.

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.

Prognostic factors and biomarkers of congenital obstructive nephropathy

Congenital obstructive nephropathy (CON) is the leading cause of chronic kidney disease (CKD) in children. Anomalies of the urinary tract are often associated with abnormal nephrogenesis, which is compounded by obstructive injury and by maternal risk factors associated with low birth weight. Currently available fetal and postnatal imaging and analytes of amniotic fluid, urine, or blood lack predictive value. For ureteropelvic junction obstruction, biomarkers are needed for optimal timing of pyeloplasty; for posterior urethral valves, biomarkers of long-term prognosis and CKD are needed. The initial nephron number may be a major determinant of progression of CKD, and most patients with CON who progress to renal failure reach this point in adulthood, presumably compounded by episodes of acute kidney injury. Biomarkers of tubular injury may be of particular value in predicting the need for surgical intervention or in tracking progression of CKD, and must be adjusted for patient age. Discovery of new biomarkers may depend on "unbiased" proteomics, whereby patterns of urinary peptide fragments from patients with CON are analyzed in comparison to controls. Most promising are the analysis of urinary exosomes (restricting biomarkers to relevant tubular cells) and quantitative magnetic resonance imaging techniques allowing precise determination of nephron number and tubular mass. The greatest need is for large prospective multicenter studies with centralized biomarker sample repositories to follow patients with CON from fetal life through adulthood.

Proximal tubule proteins are significantly elevated in bladder urine of patients with ureteropelvic junction obstruction and may represent novel biomarkers: A pilot study

PURPOSE

Ureteropelvic junction obstruction (UPJO) is the major cause of hydronephrosis in children and may lead to renal injury and early renal dysfunction. However, diagnosis of the degree of obstruction and severity of renal injury relies on invasive and often inconclusive renal scans. Biomarkers from voided urine that detect early renal injury are highly desirable because of their noninvasive collection and their potential to assist in earlier and more reliable diagnosis of the severity of obstruction. Early in response to UPJO, increased intrarenal pressure directly impacts the proximal tubule brush border. We hypothesize that single-pass, apically expressed proximal tubule brush border proteins will be shed into the urine early and rapidly and will be reliable noninvasive urinary biomarkers, providing the tools for a more reliable stratification of UPJO patients.

MATERIALS AND METHODS

We performed a prospective cohort study at Connecticut Children's Medical Center. Bladder urine samples from 12 UPJO patients were obtained prior to surgical intervention. Control urine samples were collected from healthy pediatric patients presenting with primary nocturnal enuresis. We determined levels of NGAL, KIM-1 (previously identified biomarkers), CD10, CD13, and CD26 (potentially novel biomarkers) by ELISA in control and experimental urine samples. Urinary creatinine levels were used to normalize the urinary protein levels measured by ELISA.

RESULTS

Each of the proximal tubule proteins outperformed the previously published biomarkers. No differences in urinary NGAL and KIM-1 levels were observed between control and obstructed patients (p = 0.932 and p = 0.799, respectively). However, levels of CD10, CD13, and CD26 were significantly higher in the voided urine of obstructed individuals when compared with controls (p = 0.002, p = 0.024, and p = 0.007, respectively) (Figure).

CONCLUSIONS

Targeted identification of reliable, noninvasive biomarkers of renal injury is critical to aid in diagnosing patients at risk, guiding therapeutic decisions and monitoring treatment efficacy. Proximal tubule brush border proteins are reliably detected in the urine of obstructed patients and may be more effective at predicting UPJO.

Comparison Between Diuretic Urography (IVP) and Diuretic Renography for Diagnosis of Ureteropelvic Junction Obstruction in Children

Background:

Ureteropelvic junction obstruction (UPJO) is one of the most common causes of urinary tract obstruction in children. Several methods are used to diagnose upper urinary tract obstruction including renal ultrasonography (US), intravenous pyelogram (IVP), diuretic renography (DR), magnetic resonance urography (MRU) and antegrade or retrograde pyelography. Nowadays it is suggested to use diuretic renography as the best method for diagnosing of UPJO. There is no comparative study between IVP and DR scan for diagnosis of UPJO in children.

Objectives:

The aim of the present study was to compare IVP with furosemide injection and diuretic renography in diagnosis of clinically significant UPJO.

Patients and Methods:

This was a cross sectional study performed in 153 UPJO suspected children (121 boys, 32 girls) based on US findings in cases presented with urinary tract infection (UTI), prenatal hydronephrosis, abdominal/flank pain, abdominal mass and hematuria. Renal ultrasound was used as an initial screening tool for detection of urinary tract abnormality. Vesicoureteral reflux (VUR) was ruled out by voiding cystourethrography (VCUG). Serum creatinin, blood urea nitrogen, urinalysis and urine culture was screened in all cases. IVP with furosemide and DR were performed as soon as possible after the mentioned workup.

Results:

During a five year period, 46 out of 153 patients were diagnosed as UPJO based on diuretic renography: the age ranged from 4 months to 13 years (mean: 3.1 ± 0.78 years). There was a significant higher (76%) proportion of UPJO in the boys and in the left side (78%). The sensitivity of IVP with furosemide injection in diagnosis of UPJO was 91.3% whereas DR was accepted as standard for diagnostic procedure in diagnosis of UPJO.

Conclusions:

Although DR is accepted as the best method for diagnosis of UPJO, we found a small sensitivity difference between IVP and DR in kidneys with normal or near normal function. In many settings such as small cities lacking facilities for advanced isotope imaging technology, use of IVP with diuretic maybe an acceptable procedure for diagnosis of UPJO.

Is urine intercellular adhesion molecule-1 a marker of renal disorder in children with ureteropelvic junction obstruction?

AIM

We aimed to investigate whether urine intercellular adhesion molecule-1 (ICAM-1) might serve as a marker of renal disorder in children with ureteropelvic junction obstruction.

MATERIAL AND METHODS

Twenty-nine children with severe hydronephrosis (HN) were compared with 23 participants with mild HN and with 19 healthy peers.

RESULTS

Urine ICAM-1/uCre levels were significantly higher in HN children than healthy controls (P<0.01), and in severe HN when compared with mild HN (p<0.05).

CONCLUSIONS

It seemed to us that uICAM-1 is a biomarker of renal disorder, and might have the potential to predict which patients will require surgery.

Urine exoglycosidases are potential markers of renal tubular injury in children with ureteropelvic junction obstruction

AIM

Hydronephrosis caused by ureteropelvic junction obstruction (UPJO) is an important problem in children and young adults. The aim of this pilot study was to determine the urine profiles of a number of lysosomal exoglycosidases to see whether they indicated tubular renal damage in children with UPJO.

METHODS

We measured lysosomal exoglycosidases urine activities in 32 patients with UPJO, dividing them into three groups. The surgical group comprised 16 children with severe hydronephrosis who required surgery, the nonsurgical group comprised 16 patients with mild hydronephrosis, and the reference group comprised 42 healthy children. The following indicators were measured: N-acetyl-β-hexosaminidase and its A and B isoenzymes, α-fucosidase, β-galactosidase, α-mannosidase and β-glucuronidase.

RESULTS

The urine activities of all exoglycosidases were significantly higher in children with UPJO than children in the reference group (p < 0.01). A strong positive correlation was also found between most of the urine exoglycosidases and the urine albumin/creatinine ratio (p < 0.01).

CONCLUSION

Our findings demonstrated that children with UPJO showed increased renal activities of assessed exoglycosidases, which correlated positively with the urine albumin/creatinine ratio. A larger multicentre study is required to confirm the clinical applications of these observations.

Role of urinary levels of endothelin-1, monocyte chemotactic peptide-1, and N-acetyl glucosaminidase in predicting the severity of obstruction in hydronephrotic neonates

Purpose

Antenatal hydronephrosis (AH) is found in 0.5%-1% of neonates. The aim of the study was to assess the urinary concentrations of 3 biomarkers, endothelin-1 (ET-1), monocyte chemotactic peptide-1 (MCP-1), and N-acetyl-glucosaminidase (NAG) in severely hydronephrotic neonates.

Materials and Methods

Neonates with a history of prenatal hydronephrosis were enrolled in the prospective study in 2 groups. Group 1 included neonates with severe forms of obstruction requiring surgical intervention and group 2 included neonates with milder forms of obstruction without any functional impairment. Fresh voided urinary levels of ET-1, MCP-1, and NAG were measured and their ratios to urinary Cr were calculated.

Results

Fourty-two neonates were enrolled into the 2 groups: group 1, 24 patients (21 male, 3 female); group 2, 18 neonates (16 male, 2 female). There were no statistically significant differences between urinary ET-1, NAG, MCP-1 values, and ET-1/Cr and NAG/Cr ratios in groups 1 and 2. The urinary MCP-1/Cr ratio was significantly higher in group 1 than in group 2. For comparison of groups 1 and 2, the cut-off values were measured as 0.5709 ng/mg (sensitivity, 75%; specificity, 67%; positive predictive value [PPV], 71%; negative predictive value [NPV], 71%), 0.927 ng/mg (sensitivity, 77%; specificity, 72%; PPV, 77%; NPV, 72%), and 1.1913 IU/mg (sensitivity, 62%; specificity, 67%; PPV, 68%; NPV, 60%) for ET-1/Cr, MCP-1/Cr, and NAG/Cr ratios, respectively.

Conclusions

The urinary MCP-1/Cr ratio is significantly elevated in neonates with severe obstruction requiring surgical intervention. Based upon these results, urinary MCP-1/Cr may be useful in identification of severe obstructive hydronephrosis in neonates.

The role of urinary TIMP1 and MMP9 levels in predicting vesicoureteral reflux in neonates with antenatal hydronephrosis

BACKGROUND

Antenatal hydronephrosis (AH) is commonly found on evaluation of pregnant women and 20-30 % of neonates have vesicoureteral reflux (VUR). In order to diagnose VUR, we required invasive testing and exposure of the neonate to radiation. The concentrations of a matrix metalloproteinase, MMP9, and its inhibitor TIMP1, were analyzed in hydronephrotic newborns with VUR and were compared to those without reflux.

METHODS

The neonates with a history of prenatal hydronephrosis were enrolled in two groups based on imaging study results, the neonates with VUR and without VUR. Neonates with a normal prenatal history and postnatal ultrasound were placed in a third group. We measured the random urinary levels of MMP9, TIMP1, and creatinine, their cut-off values and the MMP9/Cr and MMP9/TIMP1/Cr ratio was calculated, and an ROC curve was drawn.

RESULTS

Sixty-nine neonates were enrolled in three groups; 27 patients (20 male, seven female) with AH and VUR were in group 1, 23 neonates (19 male, four female) without VUR were placed in group 2, and 19 (15 male, four female) acted as controls in group 3. The differences between the three groups and the normal and total hydronephrotic groups were statistically significant for MMP9, the MMP9/Cr, MMP9/TIMP1, and MMP9/TIMP1/Cr ratios. The urinary TIMP1 and TIMP1/Cr ratios were not significantly different between the groups. A cut-off value of MMP9 was measured as 358.5 ng/ml (sensitivity [sens] 74 %, specificity [spec] 78 %) and was used to compare groups 1 and 2. For groups 2 and 3, this cut-off was 181.00 pg/ml (sens 91 %, spec 89 %). The cut-off values measured for the MMP9/TIMP1 ratio were 30.32 (sens 70 %, spec 61 %) and 9.85 (sens 96 %, spec 89 %) to compare groups 1 and 2, and 2 and 3, respectively. We found no valuable cut-offs for the TIMP1 and TIMP1/Cr values. There was no difference between neonates with mild, moderate, and severe VUR according to urinary biomarker concentrations.

CONCLUSIONS

Evaluation of urinary levels of MMP9, or the MMP9/Cr, MMP9/TIMP1, or MMP9/TIMP1/Cr ratios may help us to differentiate the newborns with hydronephrosis and VUR from those without reflux.

Chemokines as potential markers in pediatric renal diseases

Glomerular diseases and obstructive uropathies are the two most frequent causes of chronic kidney disease (CKD) in children. Recently, biomarkers have become a focus of clinical research as potentially useful diagnostic tools in pediatric renal diseases. Among several putative biomarkers, chemokines emerge as promising molecules since they play relevant roles in the pathophysiology of pediatric renal diseases. The evaluation of these inflammatory mediators might help in the management of diverse renal diseases in children and the detection of patients at high risk to develop CKD. The aim of this paper is to revise general aspects of chemokines and the potential link between chemokines and the most common pediatric renal diseases by including experimental and clinical evidence.

Epidermal growth factor and monocyte chemotactic peptide-1: potential biomarkers of urinary tract obstruction in children with hydronephrosis

OBJECTIVE

Hydronephrosis is diagnosed in 0.5% of all newborns, and ureteropelvic junction obstruction (UPJO) is a common cause. The aim of this study was to test whether specific urinary cytokines can be used as UPJO biomarkers in children with hydronephrosis.

MATERIALS AND METHODS

Twenty-eight children referred for pyeloplasty due to UPJO and 13 controls were included in this prospective study. Kidney function was assessed and urine samples collected pre-, peri-, and post-operatively. Urine levels of epidermal growth factor (EGF), monocyte chemotactic peptide-1 (MCP-1), macrophage inflammatory protein-1α (MIP-1α), interferon-γ-inducible protein-10 (IP-10), and RANTES were measured simultaneously by using a bead-based multiplex sandwich immunoassay.

RESULTS

In hydronephrotic children, preoperative urine levels were significantly increased for EGF (median 7.4 [1.2-60.2] vs. median 4.0 [1.2-13.8] ng/mg creatinine) and MCP-1 (median 136.9 [47.7-545.5] vs. median 80.1 [28.8-149.9] pg/mg creatinine) compared to those of controls. Urine levels of EGF and MCP-1 were identical to controls at the postoperative 1-year follow-up exam.

CONCLUSION

Urine levels of EGF and MCP-1 were preoperatively increased and postoperatively normalized. This study demonstrates that urine-excreted kidney cytokines may be potential biomarkers of obstruction in children with hydronephrosis.

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.