Prevalence of reflux nephropathy in Iranian children with solitary kidney: results of a multi-center study.

BACKGROUND: Given the importance of the function of the remnant kidney in children with unilateral renal agenesis and the significance of timely diagnosis and treatment of reflux nephropathy to prevent further damage to the remaining kidney, we aimed to determine the prevalence of reflux nephropathy in this subgroup of pediatric patients. METHODS: In general, 274 children referred to pediatric nephrologists in different parts of Iran were evaluated, of whom 199 had solitary kidney and were included in this cross-sectional study. The reasons for referral included urinary tract infection (UTI), abnormal renal ultrasonography, being symptomatic, and incidental screening. Demographic characteristics, including age and gender were recorded. History of UTI and presence of vesicoureteral reflux (VUR) were evaluated. RESULTS: Of the 274 children evaluated in this study with the mean age (SD) of 4.71 (4.24) years, 199 (72.6%) had solitary kidney. Among these, 118 (59.3%) were male and 81 (60.7%) were female, 21.1% had a history of UTI, and VUR was present in 23.1%. The most common cause of referral was abnormal renal ultrasonography (40.2%), followed by incidental screening (21.1%), being symptomatic (14.1%), and UTI (5.5%). In 116 children (58.3%), the right kidneys and in 83 (41.7%) the left kidneys were absent. Besides, 14.6% of the participants had consanguineous parents and 3% had a family history of solitary kidney. Upon DMSA scan, the single kidney was scarred in 13.1%, of which only 7.5% were associated with VUR. In addition, proteinuria and hematuria were observed in 6.5% and 1.5% of children, respectively. CONCLUSIONS: The prevalence of reflux nephropathy was 7.5% in children with solitary kidney with a male predominance. Given the relatively high prevalence of reflux nephropathy in these children, screening for VUR in the remnant kidney appears to be essential in this population.

Usefulness of Doppler ultrasound for the early diagnosis of diabetic nephropathy in type 1 diabetes mellitus.

PURPOSE: Early diagnosis and management of diabetic nephropathy (DN) might prevent or delay its progression to end-stage renal disease. The purpose of this study was to investigate whether changes in the duplex Doppler resistivity index (RI) are useful for the early identification of renal involvement in children and adolescents with insulin-dependent diabetes mellitus and associated conditions. MATERIALS AND METHODS: A total of 49 diabetic patients (two groups: 21 with DN and 28 without DN) were included in this study. DN was defined as 30-300 mg/l of albumin excretion in a random urine sample. The RI of the main renal arteries and their intrarenal branches (arcuate, interlobar) were evaluated with duplex Doppler ultrasound and correlated with age, renal length, duration of diabetes, and laboratory examinations. RESULTS: The mean age did not significantly differ between the two groups. The patients with DN had a significantly longer duration of type 1 diabetes (p = 0.02). The majority of patients (90.5%) had mild renal involvement with microalbuminuria and normal renal function. The mean RI was normal in both groups of patients, with no significant difference between the two groups. CONCLUSION: The RI did not increase in the early clinical stage of DN and was not a reliable marker for the screening of DN in patients with type 1 diabetes mellitus.

Utility of Urine N-acetyl-ß-D-glucosaminidase for Prediction of Renal Damage in Obese Children.

The incidence of obesity has increased globally in children and adults. In addition, renal dysfunction is an important complication of childhood obesity. This study was performed to identify the diagnostic value of N-acetyl-ß-D-glucosaminidase (NAG), a renal injury marker, for the early determination of renal damage in childhood obesity. Totally, 115 obese children and 115 healthy normal weight controls were enrolled in a cross-sectional case-control study. Urine NAG was measured in sample urine and normalized by urine creatinine (CR). In addition, correlation of urine NAG with other variables such as blood pressure (BP), blood glucose, and urine albumin was evaluated. Mean systolic BP (P <0.001), serum glucose (P = 0.047), urine albumin/Cr (P = 0.049), and urine NAG/Cr (P = 0.037) were significantly higher in obese children, compared with normal healthy controls. There was no correlation between urine NAG and urine albumin excretion. Urinary NAG/Cr was a simple and safe screening test for early determination of renal damage in children with obesity.

Chronic Kidney Disease in Iran: First Report of the National Registry in Children and Adolescences.

PURPOSE: Knowing the epidemiological aspects of chronic kidney disease (CKD) in children is crucial for early recognition, identification of reversible causes, and prognosis. Here, we report the epidemiological characteristics of childhood CKD in Iran. MATERIALS AND METHODS: This cross-sectional study was conducted during 1991 - 2009. The data were collected using the information in the Iranian Pediatric Registry of Chronic Kidney Disease (IPRCKD) core dataset. RESULTS: A total of 1247 children were registered. The mean age of the children at registration was 0.69 ± 4.72 years (range, 0.25 -18 years), 7.79 ± 3.18 years for hemodialysis (HD), 4.24 ± 1.86 years for continuous ambulatory peritoneal dialysis (CAPD), and 3.4±1.95 years for the children who underwent the renal transplantation (RT) (P < .001). The mean year of follow-up was 7.19 ± 4.65 years. The mean annual incidence of CKD 2-5 stages was 3.34 per million age-related population (pmarp). The mean prevalence of CKD 2-5 stages was 21.95 (pmarp). The cumulative 1-, 5-, and 10-year patients' survival rates were 98.3%, 90.7%, and 84.8%, respectively. The etiology of the CKD included the congenital anomalies of the kidney and urinary tract (CAKUT) (40.01%), glomerulopathy (19.00%), unknown cause (18.28%), and cystic/hereditary/congenital disease (11.14%). CONCLUSION: The incidence and prevalence rate of pediatric CKD in Iran is relatively lower than those reported in Europe and other similar studies. CAKUT was the main cause of the CKD. Appropriate management of CAKUT including early urological intervention is required to preserve the renal function. Herein, the long-term survival rate was higher among the children with CKD than the literature.

Utility of Urine Interleukines in Children with Vesicoureteral Reflux and Renal Parenchymal Damage.

PURPOSE: Vesicoureteral reflux (VUR) is the most common risk factor of urinary tract infection in children. Currently, diagnosis of VUR depends on invasive imaging studies, with a high radiologic burden. Therefore, different biomarkers have been introduced for the evaluation of these patients. The objective of this study was to identify alteration of urinary interleukins (ILs) excretion in children with primary VUR and renal parenchymal damage, for further clinical application. MATERIALS AND METHODS: Urinary concentrations of IL-1α, IL-1ß, IL-6, and IL-8 were evaluated in 34 children with VUR (cases) and 36 without VUR (control), during 2018-2019. Urinary concentrations of IL-1, IL-1, IL-6 and IL-8 were measured, using polyclonal antibody ELISA kit, and standardized to urine creatinine (Cr). Patients with infectious or inflammatory disorders, urolithiasis, immune deficiency, acute or chronic kidney disease, and secondary VUR were excluded from the study. RESULTS: Mean age of cases (36.00 ± 27.66) had no significant difference with the control (32.86±29.31) group (p=0.44). The majority of patients had moderate VUR (58.8%), followed by severe (35.3%) and mild (5.9%) grades. Urinary concentration of all ILs/Cr were significantly higher in patients with VUR, compared with those without VUR. There was no significant correlation between urine ILs/Cr with age, gender, serum electrolytes, urine specific gravity, renal ultrasound, laterality or severity of VUR, and DMSA renal scan. All urine ILs/Cr had acceptable sensitivity and accuracy for workup of children with primary VUR. CONCLUSION: Urine IL-1α, IL-1ß, IL-6 and IL-8/Cr were sensitive and accurate additionary screening biomarkers in children with primary VUR.

Predictive Value of Serum Interleukins in Children with Idiopathic Nephrotic Syndrome.

Pro-inflammatory cytokines have been suggested in the pathogenesis of idiopathic nephrotic syndrome (INS), with conflicting results. This study was performed to identify alteration of different serum interleukins (ILs) in children with INS, and their predictive value in response to steroid treatment. Three groups of children (27; steroid-sensitive INS, 21; steroid-resistant INS, and 19 healthy controls) with normal serum C3, negative serologic tests of hepatitis B virus (HBV), hepatitis C virus (HCV), human immune deficiency virus (HIV), and parasitic infections were included in this study. Serum concentrations of IL-1ß, IL-2, IL-6, IL-8, IL-13, and IL-18 were measured, using quantitative colorimetric sandwich ELISA kits. Children with secondary nephrotic syndrome, inflammations, systemic disorders, and chronic kidney disease were excluded. The serum concentration of all ILs; except IL-13 and IL-18; was significantly higher in children with INS, compared with the healthy controls. Serum IL-2 had the highest sensitivity of (95.24%) in patients with INS. All of the serum ILs had acceptable accuracy in children with INS, compared with the control group. The serum concentration of IL-1ß, IL-6, and IL-8 was significantly higher in children with steroid-sensitive nephrotic syndrome (SSNS), compared with steroid-resistant nephrotic syndrome (SRNS). All of these ILs had acceptable accuracy for the prediction of steroid response in patients with INS. Our findings suggested the pathogenic role of pro-inflammatory cytokines in children with INS, of which IL-1ß, IL-6, and IL-8 were accurate biomarkers for the prediction of steroid response in these patients.

Validity of urine neutrophile gelatinase-associated lipocalin in children with primary vesicoureteral reflux.

BACKGROUND: Vesicoureteral reflux (VUR) is the most common congenital urinary tract abnormality in children. The objective of this study was to evaluate the diagnostic value of urine neutrophil gelatinase-associated lipocalin (NGAL) in children with primary vesicoureteral reflux (VUR). MATERIALS AND METHODS: A total of 69 patients were evaluated in 2 groups with (32) and without (37) VUR. Patients with secondary VUR, infectious or inflammatory disorders, obstructive uropathies, and acute or chronic kidney disease were excluded. Urine NGAL level was measured by ELISA kit. RESULTS: Mean age of children with VUR was 36.84 ± 28.16, compared to those without VUR 32.32 ± 29.08, with no significant difference (p = 0.51). Mean urine NGAL (p = 0.012) and urine NGAL/Cr (p = 0.003) were higher in patients with VUR. In addition, urine NGAL/Cr increased significantly in patients with decreased parenchymal function, compared to those with normal DMSA scan. Using the cutoff value of 0.888, urine NGAL had 84% sensitivity and 81% specificity for diagnosis of VUR. Based on AUC (0.86), urine NGAL had acceptable diagnostic accuracy in children with VUR. CONCLUSION: The results of this study support the evidence that urine NGAL/Cr is a sensitive, specific and accurate biomarker for diagnosis of children with primary VUR.

Early prediction of renal parenchymal injury with serum procalcitonin.

INTRODUCTION: Urinary tract infection (UTI) is one of the most common bacterial infections in children that can be associated with renal parenchymal injuries and late scars. Dimercaptosuccinic acid (DMSA) renal scan is known as golden standard for detecting acute pyelonephritis (APN) that has a lot of difficulties and limitations. OBJECTIVES: we designed this study the accuracy of one inflammatory marker, serum procalcitonin (PCT) to identify as an early predictor of renal injuries. PATIENTS AND METHODS: A prospective study was carried out in 95 patients who admitted in the hospital with the first febrile UTI. Serum PCT of all patients was measured; sensitivity, specificity, positive and negative predictive value (PPV and NPV) of this marker was analyzed compared to DMSA scan. P value <0.05 was taken as significant. RESULTS: In total, 79 females and 16 males were investigated. There are 42 cases in group 1 with normal DMSA scan and 53 patients in group two with renal parenchymal injuries in their scans. Mann-Whitney test showed a meaningful relation between the two groups regarding PCT level (P<0.0001). Sensitivity, specificity, PPV and NPV of PCT reported in optimum cut off were 70%, 88.1%, 88.1% and 70%, respectively. The positive likelihood ratio (PLR) of PCT test was 5.8. CONCLUSION: In the current survey, PCT was the eligible inflammatory marker to predict renal parenchymal injuries in children with proper sensitivity, specificity, PPV and NPV that play also a pivotal role in the children aged less than 24 months, although, more studies should be undertaken to confirm.

Validity of Neutrophil Gelatinase Associated Lipocaline as a Biomarker for Diagnosis of Children with Acute Pyelonephritis.

PURPOSE: Novel biomarkers have been investigated for various renal disorders, including urinary tract infection (UTI). The aim of this study was to assess whether urine neutrophil gelatinase associated lipocaline (NGAL), could represent a reliable biomarker for diagnosis and treatment of children with acute pyelonephritis (APN). MATERIALS AND METHODS: A total of 37 children (32 females, 5 males) with APN were included in this prospective study. Urine NGAL was measured before and 5-7 days after antibiotic treatment in the UTI group, using ELISA kit and compared with 26 (8 females, 18 males) control group children admitted for other bacterial infections. RESULTS: Mean age of the UTI group was 39 ± 28 months, compared to 43.6 ± 31.5 months for the control group with no statistically significant difference. Median urine NGAL level was significantly higher in patients with APN than the other subjects [0.48 (interquartile range (IQR): 0.15-0.72) vs. 0.065 (0.01-0.24), P = .001], and decreased significantly after antibiotic treatment (P = .002). Using a cutoff of 0.20 ng/mL, sensitivity and specificity of urine NGAL were 76% and 77% for prediction of APN, respectively. The area under the ROC curve (AUC) for urine NGAL was 0.75 (CI= 0.61-0.88), suggesting urine NGAL as a relatively good predictive biomarker of APN. CONCLUSION: Urine NGAL is a good biomarker for diagnosis and treatment monitoring of APN in children. .

Urine Neutrophil Gelatinase Associated Lipocalin to Creatinine Ratio: A Novel Index for Steroid Response in Idiopathic Nephrotic Syndrome.

OBJECTIVE: To find the value of urine neutrophil gelatinase associated lipocalin (NGAL) in differentiating steroid response in children with idiopathic nephrotic syndrome (INS). METHODS: A total of 52 children with INS (n = 27, steroid resistant; n = 25, steroid responsive) aged 1-16 y, along with 18 healthy control children were enrolled in this study. Urine NGAL as well as urine protein, and serum creatinine were analyzed during active phase of INS. RESULTS: Serum creatinine (P 0.032), and urine NGAL/Cr (P 0.001) were significantly higher in steroid resistant than steroid sensitive patients. The optimal cutoff value for urine NGAL/Cr with the highest sensitivity and specificity was 0.46 ng/mg and cut off value of 0.01 and 1.15 ng/mg had maximum sensitivity and specificity, respectively. CONCLUSIONS: Urine NGAL/Cr could be considered as a marker of steroid resistance in children with idiopathic nephrotic syndrome.