Characteristics and predictors of chronic kidney disease in children with myelomeningocele: a nationwide cohort study.

BACKGROUND: Myelomeningocele (MMC) is highly prevalent in developing countries, and MMC-related neurogenic bladder is an important cause of childhood chronic kidney disease (CKD). This nationwide study aimed to evaluate demographic and clinical features of pediatric patients with MMC in Turkey and risk factors associated with CKD stage 5. METHODS: Data from children aged 0-19 years old, living with MMC in 2022, were retrospectively collected from 27 pediatric nephrology centers. Patients > 1 year of age without pre-existing kidney abnormalities were divided into five groups according to eGFR; CKD stages 1-5. Patients on dialysis, kidney transplant recipients, and those with eGFR < 15 ml/min/1.73 m2 but not on kidney replacement therapy at time of study constituted the CKD stage 5 group. RESULTS: A total of 911 (57.8% female) patients were enrolled, most of whom were expectantly managed. Stages 1-4 CKD were found in 34.3%, 4.2%, 4.1%, and 2.4%, respectively. CKD stage 5 was observed in 5.3% of patients at median 13 years old (range 2-18 years). Current age, age at first abnormal DMSA scan, moderate-to-severe trabeculated bladder on US and/or VCUG, and VUR history were independent risk factors for development of CKD stage 5 (OR 0.752; 95%; CI 0.658-0.859; p < 0.001; OR 1.187; 95% CI 1.031-1.367; p = 0.017; OR 10.031; 95% CI 2.210-45.544; p = 0.003; OR 2.722; 95% CI 1.215-6.102; p = 0.015, respectively). Only eight CKD stage 5 patients underwent surgery related to a hostile bladder between 1 and 15 years old. CONCLUSION: MMC-related CKD is common in childhood in Turkey. A proactive approach to neurogenic bladder management and early protective surgery in selected cases where conservative treatment has failed should be implemented to prevent progressive kidney failure in the pediatric MMC population in our country.

Mutations in MAPKBP1 Cause Juvenile or Late-Onset Cilia-Independent Nephronophthisis.

Nephronophthisis (NPH), an autosomal-recessive tubulointerstitial nephritis, is the most common cause of hereditary end-stage renal disease in the first three decades of life. Since most NPH gene products (NPHP) function at the primary cilium, NPH is classified as a ciliopathy. We identified mutations in a candidate gene in eight individuals from five families presenting late-onset NPH with massive renal fibrosis. This gene encodes MAPKBP1, a poorly characterized scaffolding protein for JNK signaling. Immunofluorescence analyses showed that MAPKBP1 is not present at the primary cilium and that fibroblasts from affected individuals did not display ciliogenesis defects, indicating that MAPKBP1 may represent a new family of NPHP not involved in cilia-associated functions. Instead, MAPKBP1 is recruited to mitotic spindle poles (MSPs) during the early phases of mitosis where it colocalizes with its paralog WDR62, which plays a key role at MSP. Detected mutations compromise recruitment of MAPKBP1 to the MSP and/or its interaction with JNK2 or WDR62. Additionally, we show increased DNA damage response signaling in fibroblasts from affected individuals and upon knockdown of Mapkbp1 in murine cell lines, a phenotype previously associated with NPH. In conclusion, we identified mutations in MAPKBP1 as a genetic cause of juvenile or late-onset and cilia-independent NPH.

The relationship between body mass index and renal length in obese children.

BACKGROUND: Obesity in the pediatric population is a severe public health problem and is associated with various comorbidities. Renal length is an important clinical parameter for the diagnosis and follow-up of renal diseases. The aim of this study was to determine the relationship between renal length (measured ultrasonographically) and body mass index (BMI) in obese children, and to develop nomograms for renal length according to BMI. METHODS: Renal ultrasound was performed in 368 children without renal disease. Each child's age, gender, weight, height, and BMI (kg/m2) were recorded. The children were divided into three groups according to BMI percentiles: obese group: BMI ≥ 95th percentile; overweight group: BMI 85th-94th percentile; normal weight group: BMI 5th-84th percentile. RESULTS: Weight, height, BMI, and right and left renal length differed significantly between the three groups (p = 0.001). There were significant correlations between renal length with age, weight, height, and BMI. Measurement of renal length was independently associated with BMI, age, and height. BMI was used to create renal length nomograms for obese children, based on multiple regression analysis (R2 = 0.32 and p = 0.0001). Mean renal length was highest in the obese group (96.9 ± 13.4 mm) and lowest in the normal weight group (88.3 ± 12.9 mm). CONCLUSIONS: Ultrasonographic measurement of the renal length according to BMI in children can be a useful method in evaluating these children. Smaller-than-normal kidneys can easily remain undiagnosed in obese and overweight children and this nomogram offers an additional method to evaluate the renal size in obese children.

Allergic sensitization in kidney transplanted patients - Is it a result of immunosuppressive agents or the sensitization of living donor?

BACKGROUND: Allergic sensitization has been reported increasingly in organ transplant recipients. However, the pathogenesis of this sensitization has still not been clearly understood. OBJECTIVE: The aim of this study was to evaluate allergic sensitization in kidney transplanted children and adolescents under immunosuppressive treatment. METHODS: Twenty seven kidney-transplanted subjects were studied by standardized interviews from the International Study of Asthma and Allergies in Childhood criteria, skin prick test (SPT) and measurement of specific immunoglobulin E (s-IgE). Patients were considered to have allergic sensitization when presenting a positive SPT and/or s-IgE >0.35 kUA/l to at least one of the tested allergens. Patients with a history of allergic diseases accompanied by sensitization were accepted as allergic. We also performed SPT on the living donors of the allergic groups. RESULTS: Seven patients (25.9%) were found to be sensitized to ≥1 common inhalant and 3 subjects (11.1%) additionally reported a corresponding present history of allergic diseases. All of the living donors' sensitized patients were allergic. New-onset post-transplantation food allergy was not documented in any patients. CONCLUSIONS: This study supports the concept that not only immunosuppressant agents but also sensitization of living donors could be a significant contributor to allergic sensitization in kidney recipients.

Whole exome sequencing identifies causative mutations in the majority of consanguineous or familial cases with childhood-onset increased renal echogenicity.

Chronically increased echogenicity on renal ultrasound is a sensitive early finding of chronic kidney disease that can be detected before manifestation of other symptoms. Increased echogenicity, however, is not specific for a certain etiology of chronic kidney disease. Here, we performed whole exome sequencing in 79 consanguineous or familial cases of suspected nephronophthisis in order to determine the underlying molecular disease cause. In 50 cases, there was a causative mutation in a known monogenic disease gene. In 32 of these cases whole exome sequencing confirmed the diagnosis of a nephronophthisis-related ciliopathy. In 8 cases it revealed the diagnosis of a renal tubulopathy. The remaining 10 cases were identified as Alport syndrome (4), autosomal-recessive polycystic kidney disease (2), congenital anomalies of the kidney and urinary tract (3), and APECED syndrome (1). In 5 families, in whom mutations in known monogenic genes were excluded, we applied homozygosity mapping for variant filtering and identified 5 novel candidate genes (RBM48, FAM186B, PIAS1, INCENP, and RCOR1) for renal ciliopathies. Thus, whole exome sequencing allows the detection of the causative mutation in 2/3 of affected individuals, thereby presenting the etiologic diagnosis, and allows identification of novel candidate genes.

Role of new biomarkers for predicting renal scarring in vesicoureteral reflux: NGAL, KIM-1, and L-FABP.

BACKGROUND: Reflux nephropathy is the most serious complication of vesicoureteral reflux (VUR). The aim of this study was to assess the role of urinary levels of neutrophil-gelatinase-associated lipocalin (NGAL),kidney injury molecule-1 (KIM-1), and liver-type fatty-acid-binding protein (L-FABP) in the early diagnosis of reflux nephropathy in patients with VUR. METHODS: This study assessed 123 patients with primary VUR and 30 healthy children as a control group. The children were divided into five groups: Group A, patients with VUR and renal parenchymal scarring (RPS); Group B, patients with VUR and without RPS; Group C, patients with RPS and resolved VUR; Group D, patients with resolved VUR and without RPS; Group E, healthy reference group. RESULTS: Median urinary NGAL (uNGAL)/Creatinine (Cr) was significantly higher in patients with than those without RPS and the control group (p = 0.0001). Median uKIM-1/Cr was similar in all groups (p = 0.417). Median uL-FABP/Cr was significantly higher in patients with RPS than in the reference group (p < 0.05). CONCLUSIONS: Urinary NGAL levels may be used as a noninvasive diagnostic marker for predicting renal scarring in reflux nephropathy.

Value of sonographic anterior-posterior renal pelvis measurements before and after voiding for predicting vesicoureteral reflux in children.

PURPOSE: Voiding cystourethrography (VCUG) is the gold standard for diagnosing vesicoureteral reflux (VUR), but it is important to minimize the use of VCUG because of the urinary catheterization and radiation exposure required. Ultrasound (US) observations suggest that pelvicalyceal dilatation varies according to the degree of bladder fullness in children with urinary tract infection. The aim of this study was to assess whether anterior-posterior (AP) measurements of the renal pelvis on US before and after voiding can be used as a screening tool while predicting the presence of VUR in children. METHODS: The subjects were toilet-trained children older than 4 years who required VCUG. Two groups were established based on the VCUG results: a VUR group of 40 kidney units (each unit defined as calyces and ureter) that exhibited different severities of reflux, and a control group of 68 kidney units unaffected by VUR. Prior to VCUG, US AP measurements of the renal pelvis of each kidney unit were recorded when the urinary bladder was full and again after bladder emptying. The change in AP measurement from before to after voiding was compared between the two groups. RESULTS: The mean change in AP measurements from before to after voiding in the VUR group was significantly greater than that in the control group (p = 0.003). CONCLUSIONS: Comparing US AP measurements of the renal pelvis before and after voiding is useful for identifying children who are suspected to have VUR and thus require immediate VCUG.

Leptin and plasminogen activator inhibitor-1 levels in children on chronic dialysis.

PURPOSE: In this study, it is aimed to compare the serum leptin and PAI-1 levels and evaluate their relationship in children on hemodialysis (HD) and peritoneal dialysis (PD). METHOD: Thirty-six patients on HD (mean age: 15.0 ± 2.8 years), 19 patients on PD (mean age: 13.0 ± 3.5 years) and 15 healthy subjects (mean age: 14.5 ± 2.7 years) were included in the study. Laboratory investigations included blood count, biochemical parameters, serum iron, iron binding capacity, parathormone, erythrocyte sedimentation rate, C-reactive protein (CRP), prothrombin time (PT), partial thromboplastin time (PTT), fibrinogen, serum leptin and PAI-1 levels. RESULTS: Serum leptin levels were significantly higher in HD group than in control group when the effects of BMI and sex were controlled, while PD and control groups had similar leptin levels. PAI-1 levels were also significantly higher in HD group than in control group, while there was no statistically significant difference in PAI-1 levels of PD and control group. PAI-1 levels and leptin levels were significantly correlated, which was independent of the effect of BMI in both HD and PD groups when they are evaluated separately. CONCLUSION: Results of our study showed that HD patients had higher leptin and PAI-1 levels and leptin and PAI-1 levels were correlated significantly in both patient groups. The effect of elevated serum leptin and PAI-1 levels on the cardiovascular complications remains to be established.

Helicobacter pylori infection and gastroduodenal lesions in children with chronic kidney disease stage V.

BACKGROUND: This study aimed to investigate the dyspeptic symptoms, endoscopic findings, and frequency of Helicobacter pylori (Hp) infection in children with chronic kidney disease (CKD) stage V, and to compare findings in peritoneal dialysis (PD) and hemodialysis (HD) patients. METHODS: Sixty-five patients on PD (n = 36) or HD (n = 29) were included. Age, gender, duration and type of dialysis, and dyspeptic complaints were recorded. All patients underwent endoscopy. Rapid urease tests were performed in all patients and antral biopsy examinations done in suitable patients to investigate presence of Hp infection. RESULTS: The mean age of patients (55 % male) was 13.9 ± 3.6 years. Frequency of dyspepsia was 43 % and was similar in HD and PD groups. The most frequent dyspeptic symptoms were early satiety (21.5 %) and bloating (17 %). Abnormal endoscopic findings were present in 81.5 % of patients (similar in both groups), and the most common lesion was gastritis (35.5 %). Hp positivity was determined in 37 % of the patients, which was similar in both groups. No significant relationship was found between dyspeptic symptoms and Hp infection. Hp infection was found to be significantly higher in 41.5 % of the patients with gastroduodenal lesions. Abnormal endoscopic findings were significantly higher in severely dyspeptic patients (88.9 %). CONCLUSIONS: We think performing an upper gastrointestinal tract examination and Hp screening may be helpful in renal transplant candidates with severe dyspeptic symptoms.

Polyarteritis nodosa: a case presenting with renal mass.

An adolescent girl was hospitalized due to fever and abdominal flank pain. A left renal haematoma was detected on magnetic resonance imaging. Renal angiography demonstrated multiple microaneurysms at both hepatic arteries, intrarenal segments of the bilateral renal arteries, and inferior lobar segment of the left pulmonary artery, which is consistent with the diagnosis of polyarteritis nodosa. Vasculitic syndromes should be considered in patients with visceral haemorrhage.

Is there a difference in fecal microbiota of children with and without voiding dysfunction?

OBJECTIVE: Voiding dysfunction (VD), which encompasses many urinary symptoms that are not caused by neurological or anatomical anomalies, is a frequently encountered functional urinary bladder disorder in children. It was reported that there was an association between lower urinary tract symptoms and fecal microbiota in adult patients. Therefore, we aimed to investigate the differences in fecal microbiota between children with or without VD. METHODS: Two patient groups, including 30 patients, were compared. Group 1 included patients with VD, while Group 2 consisted of healthy children. All study participants were asked to fill lower urinary tract and voiding dysfunction symptom score forms with the assistance of their parents. Subsequently, uroflowmetry tests and postvoiding residual urine measurements were performed. Fresh stool samples were collected from all children and analyzed by polymerase chain reaction. General bacterial load and presence of Roseburia intestinalis, Clostridium difficile, Fusobacterium nucleatum, and Bacteroides clarus were tested. RESULTS: The two groups were significantly different regarding general bacterial load; the presence of Fusobacterium nucleatum. Clostridium difficile and Bacteroides clarus was not detected in the fresh stool samples of the patients in Group 2; the counts of Roseburia intestinalis were less in Group 1 than in Group 2, although there was no statistically significant difference. There was a negative correlation between symptom scores, general bacterial load, and the presence of Fusobacterium nucleatum. However, there was no correlation between the presence of Roseburia intestinalis and symptom scores. CONCLUSIONS: There is a potential relationship between VD and a deviation in the fecal microbiota in the pediatric population.

Etiology and outcome of acute kidney injury in children.

The aim of this prospective, multicenter study was to define the etiology and clinical features of acute kidney injury (AKI) in a pediatric patient cohort and to determine prognostic factors. Pediatric-modified RIFLE (pRIFLE) criteria were used to classify AKI. The patient cohort comprised 472 pediatric patients (264 males, 208 females), of whom 32.6% were newborns (median age 3 days, range 1-24 days), and 67.4% were children aged >1 month (median 2.99 years, range 1 month-18 years). The most common medical conditions were prematurity (42.2%) and congenital heart disease (CHD, 11.7%) in newborns, and malignancy (12.9%) and CHD (12.3%) in children aged >1 month. Hypoxic/ischemic injury and sepsis were the leading causes of AKI in both age groups. Dialysis was performed in 30.3% of newborns and 33.6% of children aged >1 month. Mortality was higher in the newborns (42.6 vs. 27.9%; p < 0.005). Stepwise multiple regression analysis revealed the major independent risk factors to be mechanical ventilation [relative risk (RR) 17.31, 95% confidence interval (95% CI) 4.88-61.42], hypervolemia (RR 12.90, 95% CI 1.97-84.37), CHD (RR 9.85, 95% CI 2.08-46.60), and metabolic acidosis (RR 7.64, 95% CI 2.90-20.15) in newborns and mechanical ventilation (RR 8.73, 95% CI 3.95-19.29), hypoxia (RR 5.35, 95% CI 2.26-12.67), and intrinsic AKI (RR 4.91, 95% CI 2.04-11.78) in children aged >1 month.

Ambulatory blood pressure monitoring of healthy schoolchildren with a family history of hypertension.

Early detection of primary hypertension (HT) is essential to prevent the development of end organ damage, especially in patients with a family history of HT. Physicians must pay a great attention during the follow-up of these children. Our aim was to investigate whether children with hypertensive parents are under the risk of development of HT or not by using ambulatory blood pressure measurement (ABPM). Seventy-nine healthy children were enrolled in the study: 39 with positive familial history of primary HT (study group) and 40 without familial history of HT (control group). Complete blood count, urinalysis, and biochemical tests were performed in all children in the study group. Children in both groups were examined by casual BP measurement and ABPM. The study group had significantly higher levels of BP (p < 0.05) than the controls. In the study group systolic BP and diastolic BP loads were significantly higher than the controls (p < 0.000; p = 0.002, respectively). In conclusion, parental BP is a strong predictor of the future BP in their children. It is possible that early abnormalities of BP may escape from detection by casual office measurement, and ABPM is recommended especially to detect BP abnormalities before HT becomes clinically overt.

Parvovirus B19-induced multisystemic vasculitis and acute endocapillary proliferative glomerulonephritis in a child.

A 10-year-old girl was admitted with fever, cough, maculopapular rash, hemoptysis, dark-colored urine, edema, multiple lymphadenopathies, and hepatosplenomegaly. She developed acute glomerulonephritis during the course of these complex clinical features. Laboratory data showed hematuria, proteinuria, and hypocomplementemia. Serological tests showed positive human parvovirus B19 (HPVB19)-specific immunoglobin M (IgM) and HPVB19 DNA was detected in the patient's serum using polymerase chain reaction (PCR). Renal biopsy revealed acute endocapillary proliferative glomerulonephritis (AEPGN) with coarse granular C3 depositions in a "starry sky pattern," which is more peculiar to poststreptococcal glomerulonephritis. Electron microscopy showed subendothelial and small hump-shaped subepithelial electron-dense deposits in glomerular capillary walls. There was no evidence of either any mycobacterial, staphylococcal, or streptococcal infection, and the diagnosis of Goodpasture syndrome and connective tissue disorders was excluded during clinical and laboratory investigations. A diagnosis of HPVB19-induced pleuropneumonitis and glomerulonephritis was made. Through a literature search there was no documented pediatric case of AEPGN induced by HPVB19, and this case represents, to our knowledge, the first time that a direct relationship between parvovirus infection and AEPGN has been demonstrated in a child.

Unusual cause of acute neurologic deficit in childhood: primary central nervous system vasculitis presenting with basilar arterial occlusion.

INTRODUCTION: Primary central nervous system (CNS) vasculitis of childhood is a rare disorder. The most common signs and symptoms are acute severe headache and focal neurologic deficit. It should be suspected in children who have an acquired neurologic deficit that remains unexplained after an initial basic evaluation. Diagnosis usually depends on brain magnetic resonance imaging and conventional angiography of cerebral vasculature. Stenosis is the most common angiographic finding and it usually affects the middle cerebral artery and its branches. Anterior and posterior circulation is rarely involved. CASE REPORT: In this report, we describe an 8-year-old boy who presented with vertebrobasilar insufficiency symptoms and primary CNS vasculitis diagnosis was made later.

Acute, reversible nonoliguric renal failure in two children associated with analgesic-antipyretic drugs.

Analgesic-antipyretic agents and nonsteroidal anti-inflammatory drugs are the most commonly used medications worldwide for the treatment of pain and fever in children. Acute renal failure is commonly seen in adults after treatment with analgesic agents. This complication has rarely been reported in children. Here, we describe 2 patients admitted to our hospital with acute nonoliguric renal failure temporally associated with ingestion of analgesic-antipyretic drugs at therapeutic doses. The first case was a 16-year-old adolescent boy, who had taken acetaminophen (APAP) and mefenamic acid for the indication of upper respiratory tract infection with daily doses of 1500 and 500 mg, respectively. His serum urea nitrogen and creatinine values were 16 and 1.6 mg/dL. The second case was a 12-year-old boy, who had taken APAP with a daily dose of 500 mg for abdominal pain. His serum urea nitrogen and creatinine values were 21 and 2.29 mg/dL. Both of them recovered with appropriate hydration within a week. Over-the-counter analgesic-antipyretic agents seem innocent but carry the risk of acute renal failure even at therapeutic doses. We believe that increased caution and awareness of the toxic effects of APAP and nonsteroidal anti-inflammatory drugs are needed. We suggest that clinicians should be careful while using analgesic-antipyretic-anti-inflammatory drugs especially in children with subclinical dehydration.

Electronic microarray screening of podocin mutations: a single-center study.

BACKGROUND: Because of resistance to immunosuppressants in nephrotic syndrome and reduction of proteinuria relapses following renal transplantation, it seems that new horizons have arisen from mutational screening of the podocin gene. The aim of this study was to assess electronic microarray screening of the podocin mutation. METHODS: Twelve previously identified podocin mutations were screened by the electronic microarray method in known DNA samples and in patients (aged 5 months-18 years, n = 38) with steroid-resistant primary nephrotic syndrome, isolated proteinuria, end-stage renal disease secondary to idiopathic nephrotic syndrome, and proteinuria relapses following renal transplantation. RESULTS: DNA samples previously supplied to define the mutation profile for analysis and which were used as controls were completely and correctly detected by this method. None of the 12 mutations was detected in our patients. The duration of analysis for one mutation, including hybridization, was only 30 min for 38 cases. CONCLUSION: Electronic microarray screening for NPHS2 mutations is not only rapid but also accurate. Previous identification of the mutation profile most often encountered in the investigated population is needed, however.