Kidney Cysts in Children With Alport Syndrome: A Report of 3 Cases.

Alport syndrome (AS) is a progressive hereditary kidney disease characterized by hematuria, proteinuria, and progressive kidney dysfunction accompanied by sensorineural hearing loss and ocular abnormalities. Pathogenic COL4A3-5 variants can result in different AS spectra. Further, kidney cysts have been reported in adults with AS. However, the relationship between kidney cysts and AS remains unclear. Here, we report 3 cases of AS in children that occurred with kidney cysts. The patient in case 1 was initially diagnosed with IgA nephropathy at the age of 8 years but later developed bilateral multiple kidney cysts at the age of 17 years, suggesting autosomal-dominant polycystic kidney disease. Whole-exome sequencing identified a pathogenic COL4A5 variant and confirmed the AS diagnosis. The patients in cases 2 and 3 had already been diagnosed with X-linked AS using kidney biopsy and genetic analysis. Initial kidney ultrasonography showed nephromegaly; however, kidney cyst formation was observed during their annual follow-up. Our study supports the association between AS and kidney cysts. Kidney cysts in adolescents with suspected AS should not discourage clinicians from testing for pathogenic COL4A3-COL4A5 variants. Early detection of kidney cysts is critical because it may indicate kidney disease progression.

Nephrocalcinosis in children who received high-dose vitamin D.

BACKGROUND: Vitamin D supplements are readily available as over-the-counter preparations. However, although rare, cases of vitamin D overdose still occur and are associated with nephrocalcinosis and life-threatening hypercalcemia. Errors in manufacturing of nutritional supplements may be a cause of vitamin D intoxication in children. This study aimed to identify factors associated with vitamin D overdose-related nephrocalcinosis in children due to manufacturing errors in supplements. METHODS: This retrospective study reviewed medical charts of pediatric patients with non-registered supplement-related vitamin D overdose at a tertiary referral hospital between 2006 and 2011. Clinical and laboratory characteristics of patients with or without nephrocalcinosis were evaluated. Receiver operating characteristics curve and area under the receiver operating characteristics curve were used to determine the most predictive value of each characteristic. RESULTS: A total of 44 patients (males: 29; age: 7-62 months) were included. Age ≤ 16.5 months, body weight ≤ 10.25 kg, body height ≤ 78.5 cm, body surface area (BSA) ≤ 0.475 m2, 25-hydroxyvitamin D3 ≥ 143 ng/mL, and calcium ≥ 10.65 mg/dL were predictive of developing nephrocalcinosis with a sensitivity and specificity of > 60%. Univariant analysis revealed that BSA was the most significant anthropometric prognostic factor (odds ratio: 12.09; 95% confidence interval: 2.61-55.72; P = 0.001). CONCLUSIONS: Children with smaller BSAs were more vulnerable to high-dose vitamin D3-related nephrocalcinosis. Physicians and parents should be aware of the potential adverse effects of vitamin D overdose in children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Zinner syndrome in children: clinical presentation, imaging findings, diagnosis, and outcome.

BACKGROUND: Zinner syndrome (ZS), the association of congenital seminal vesicle cyst (SVC) and ipsilateral kidney anomalies, is rarely diagnosed in childhood. This study aimed to assess presentation, imaging findings, management, and outcome of pediatric ZS. METHODS: Sixteen children with ZS were diagnosed and managed at our hospital from 2003 to 2021. We reviewed the medical records to collect data on initial symptoms, results of imaging studies, complications, operation, and follow-up. RESULTS: Ultrasound was used in all 16 cases as initial diagnostic tool. Fourteen patients were asymptomatic at diagnosis: these were transferred from obstetricians or pediatricians for evaluation of the prenatally or postnatally detected ultrasonic kidney anomalies. SVCs were incidentally noted on ultrasonography. The other two cases initially presented with urinary tract infection (UTI). Kidney anomalies included multicystic dysplastic kidney in 3 and kidney agenesis in 13 patients. Eleven (68.7%) patients had ipsilateral ectopic ureters entering SVC. Four (36.4%) patients had a reflux from urethra into SVC (urethro-cystic reflux) on voiding cystourethrography. Ten (62.5%) patients remained asymptomatic over a mean of 58 months (range, 7-216 months), two patients developed lower urinary tract dysfunction, and five patients had UTIs. Two boys needed SVC removal, and SVC had disappeared in two patients after 2.5-4 years of follow-up. CONCLUSIONS: Unilateral kidney hypodysplasia with ectopic ureter inserting into the ipsilateral SVC is a characteristic sign for diagnosis of ZS. In our case series, ZS was mainly asymptomatic. Urethro-cystic reflux was associated with UTIs in young infants. SVC removal was rarely required. A higher resolution version of the Graphical abstract is available as Supplementary information.

Galloway-Mowat syndrome in Taiwan: OSGEP mutation and unique clinical phenotype.

BACKGROUND: Galloway-Mowat syndrome (GAMOS) is a rare autosomal recessive disease characterized by the combination of glomerulopathy with early-onset nephrotic syndrome and microcephaly with central nervous system anomalies. Given its clinical heterogeneity, GAMOS is believed to be a genetically heterogenous group of disorders. Recently, it has been reported that mutations in KEOPS-encoding genes, including the OSGEP gene, were responsible for GAMOS. RESULTS: Overall, 6 patients from 5 different Taiwanese families were included in our study; the patients had an identical OSGEP gene mutation (c.740G > A transition) and all exhibited a uniform clinical phenotype with early-onset nephrotic syndrome, craniofacial and skeletal dysmorphism, primary microcephaly with pachygyria, and death before 2 years of age. We reviewed their clinical manifestations, the prenatal and postnatal presentations and ultrasound findings, results of imaging studies, associated anomalies, and outcome on follow-up. All individuals were found to have an "aged face" comprising peculiar facial dysmorphisms. Arachnodactyly or camptodactyly were noted in all patients. Neurological findings consisted of microcephaly, hypotonia, developmental delay, and seizures. Brain imaging studies all showed pachygyria and hypomyelination. All patients developed early-onset nephrotic syndrome. The proteinuria was steroid-resistant and eventually resulted in renal function impairment. Prenatal ultrasound findings included microcephaly, intrauterine growth restriction, and oligohydramnios. Fetal MRI in 2 patients confirmed the gyral and myelin abnormalities. CONCLUSIONS: Our study suggests that a careful review of the facial features can provide useful clues for an early and accurate diagnosis. Prenatal ultrasound findings, fetal MRI, genetic counseling, and mutation analysis may be useful for an early prenatal diagnosis.

Retrograde Ureteral Catheterization: A Possible New Treatment for Renal Fungal Balls in Very Low Birth Weight Infants.

Invasive candidiasis is a serious pathogen of late-onset sepsis in very low birth weight infants. Kidney is the most common organ involved, and it causes morbidity and mortality, especially when fungal balls are formed. We report a 34-day-old female infant (born at 28 weeks' gestation, 1152 g) with systemic fungal infection complicated obstructive uropathy. On sonography, the fungal balls filled the entire pelvis without hydronephrosis. Percutaneous nephrostomy was not feasible. In addition to systemic antifungals, we successfully performed cystoscopy-assisted retrograde ureteral catheterization to decompress the pelvis, which also provided a route for local amphotericin B irrigation to achieve therapeutic concentration without nephrotoxicity.

Titanium Dioxide in Toothpaste Causing Yellow Nail Syndrome.

Yellow nail syndrome (YNS) is an uncommon disorder, the classic triad of which consists of yellow nails, lymphedema, and respiratory symptoms. Few pediatric cases have been reported. We report a 9-year-old girl with yellowish nail discoloration for 1 year accompanied by respiratory symptoms, including chronic cough, recurrent pneumonia, bronchiectasis, and chronic sinusitis. The patient was diagnosed with YNS. Knowing that a relationship between YNS and titanium has been reported, we collected her nail clippings and detected titanium in them by energy dispersive radiograph fluorescence. This patient's titanium exposure may have come from her habit of swallowing children's toothpaste. With meticulous avoidance of swallowing toothpaste, she had amelioration of her yellow nail discoloration as well as diminution of her respiratory symptoms. We reevaluated her nail clippings for titanium 3 years later, and no titanium was detected. This observation suggests that avoiding titanium exposure could alleviate the symptoms of YNS. This is the first report of YNS in a pediatric patient that demonstrates a relationship between YNS and titanium. We review the previous reports of pediatric patients with YNS.

Potential Role of Tc-99m DTPA Diuretic Renal Scan in the Diagnosis of Calyceal Diverticulum in Children.

The aim of the study was to assess the usefulness of Technetium-99m diethylene triamine pentaacetic acid (Tc-99m DTPA) diuretic scan to diagnose calyceal diverticulum (CD). From January 2000 to June 2014, children with evidence of renal cystic lesions of undetermined diagnosis on ultrasound were enrolled. Computed tomography urography (CTU) and Tc-99m DTPA diuretic scan were performed to characterize the precise anatomy. The diagnosis of CD depended on visualization of a renal cystic lesion with filling of contrast material or radiotracer from the collecting system on CTU or diuretic renal scan. Children who had positive findings of CD on 1 or both imaging studies were selected and analyzed. Both CTU and Tc-99m DTPA diuretic renal scan were performed in 39 children. A total of 9 (23.1 %) children with CD were diagnosed. All 9 children had positive diagnosis of CD on diuretic renal scan. Only 6 (66.7%) children could be diagnosed by CTU, and CD was missed by CTU in 3 subjects. The differential renal functions in patients with CD were 46% to 55%. The time of radiotracer appearance in the CD ranged from the 8th to the 24th minute. Seven patients had persistent accumulation of radiotracer in their CD at the end of the study. Tc-99m DTPA diuretic renal scan seems to be more sensitive than CTU in diagnosing CD. The possible reasons of higher sensitivity are discussed. Additional advantages that Tc-99m DTPA diuretic renal scan provides include the following: continuous monitoring, less radiation doses, and information on renal function, making it an attractive alternative to CTU for diagnosis of CD.

Hemolytic uremic syndrome caused by enteroviral infection.

A 4-year-old boy presented with enteroviral infection complicated with atypical hemolytic uremic syndrome (aHUS). Enterovirus RNA was detected by reverse transcription polymerase chain reaction (RT-PCR) of both blood and kidney biopsy specimens. A survey of the complement system did not reveal a specific complement defect. Supportive therapy with blood components transfusion, plasma therapy, and immunosuppressants was administered, however, renal function did not recover. The results of this report demonstrate that the enterovirus is the cause of aHUS.

Screening high-grade vesicoureteral reflux in young infants with a febrile urinary tract infection.

BACKGROUND: The lack of good evidence for improved outcomes in children and young infants with febrile urinary tract infection (UTI) after aggressive treatment for vesicoureteral reflux (VUR) has raised doubts regarding the need for routine voiding cystourethrography (VCUG), and the appropriate imaging evaluation in these children remains controversial. OBJECTIVES: This prospective study aimed to determine whether abnormalities found on acute dimercaptosuccinic acid (DMSA) scan and ultrasound (US) can help indicate the necessity of voiding cystourethrography (VCUG) in young infants. METHODS: For 3.5 years, all infants younger than 3 months presenting with first febrile UTI were prospectively studied. All infants were hospitalized and investigated using US (<3 days after admission), DMSA scan (<5 days after admission), and VCUG (7-10 days after antibiotic treatment) after diagnosis. The association among findings of US, DMSA scan, and VCUG were evaluated. RESULTS: From 220 infants, there were abnormal results in 136 (61.8%) US and in 111 (50.5%) DMSA scans. By US, ten infants (4.5%) with abscess or structural abnormalities other than VUR were diagnosed. High-grade (III-V) VUR was present in 39 patients (17.7%). The sensitivities for high-grade VUR of renal US alone (76.9%) or DMSA scan alone (82.1%) were not as good as that of the "OR rule" strategy, which had 92.3% sensitivity and 94.3% negative predictive value. CONCLUSIONS: To screen high-grade VUR in young infants with febrile UTI, US and acute DMSA scan could be performed first. VCUG is only indicated when abnormalities are apparent on either US or DMSA scan or both.

Why is hypercalciuria absent at diagnosis in some children with ATP6V1B1 mutation?

We try to explain why hypercalciuria is absent at diagnosis in some children with an ATP6V1B1 mutation. A 5-month-old girl presented with distal renal tubular acidosis (dRTA) and sensorineural hearing loss. Direct sequencing of the ATP6V1B1 genes disclosed a new homozygous mutation (452 delT) in exon 13. In particular, an absence of hypercalciuria and a normal level of parathyroid hormones were noted. After alkaline therapy, the signs of nephrocalcinosis improved on ultrasound during follow-up. After a review of the literature regarding patients with ATP6V1B1 gene mutations, a young age seemed to be an important factor for normocalciuria. The probable mechanism of normocalciuria and a dynamic mode of calcium excretion in patients with dRTA is proposed. The determinant factors include the degree of systemic acidosis, urine pH, genetic polymorphisms, age, dietary factors, and volume status. Low sodium intake may be a major determinant of normocalciuria in these patients. It is suggested that hypercalciuria is usually absent at diagnosis of dRTA in young infants. Blood pH, plasma bicarbonate concentration, urinary citrate levels, and growth catch-up may be better indicators of adequate alkali therapy in normocalciuric children. Volume contraction, low salt content in infant formula, and alkaline urine in young infants are likely to account for the increased calcium reabsorption.

Rasburicase improves hyperuricemia in patients with acute kidney injury secondary to rhabdomyolysis caused by ecstasy intoxication and exertional heat stroke.

OBJECTIVE: To report the successful use of rasburicase in two children with hyperuricemia secondary to severe rhabdomyolysis. DESIGN: : Case report. SETTING: Pediatric intensive care unit in a freestanding quaternary hospital. PATIENTS: Two pediatric patients with severe rhabdomyolysis and hyperuricemia caused by ecstasy intoxication and exertional heat stroke. INTERVENTION: Use of a single low dose (6 mg) of rasburicase, a urate oxidase enzyme. MEASUREMENTS AND MAIN RESULTS: Rasburicase was administered on the first and second hospital days with a single low dose of 6 mg (0.086 mg/kg in patient A and 0.092 mg/kg in patient B). Within 24 hrs, the levels of serum uric acid in both patients decreased dramatically, and their creatinine levels decreased and urine output increased concurrently. Continuous improvements in the uric acid levels, creatinine levels, and urine output were noted during hospitalization. CONCLUSION: Rasburicase seems to be a safe and effective drug for improving hyperuricemia in patients with rhabdomyolysis and renal failure.

Segmental multicystic dysplastic kidney in children: clinical presentation, imaging finding, management, and outcome.

PURPOSE: The aim of the study was to assess the presentation, imaging findings, management, and outcome of segmental multicystic dysplastic kidney (MCDK) in children. MATERIALS AND METHODS: Six patients with segmental MCDK were diagnosed and observed at our hospital. We reviewed the medical records to collect data on initial symptoms, results of imaging studies, associated urinary tract anomalies, operation, and outcome. RESULTS: Three patients had abnormal prenatal ultrasound and were diagnosed by further postnatal imaging; they were asymptomatic after birth. The other 3 children presented with a renal mass, recurrent urinary tract infection, or urinary incontinence. Five patients had associated ipsilateral or contralateral urinary tract abnormalities, including vesicoureteral reflux, ureterocele, duplex collecting system, ureteropelvic junction stenosis, and ectopic ureter. Lower tract reconstruction was performed in 3, and open biopsy was done in 1 child. None underwent partial or total nephrectomy, and all had involution of the cysts for a mean of 40 months. CONCLUSIONS: Most of the cases occur in the upper pole of a duplex kidney and often involute spontaneously without significant complication. The clinical presentation and imaging findings depend on the associated anomalies and complications. Although the latter may require surgery to resolve, segmental MCDK itself rarely requires resection.

Screening young children with a first febrile urinary tract infection for high-grade vesicoureteral reflux with renal ultrasound scanning and technetium-99m-labeled dimercaptosuccinic acid scanning.

OBJECTIVE: To evaluate the predictive value of renal ultrasound scanning and 99m-Technetium-dimercaptosuccinic acid (DMSA) scintigraphy for high-grade vesicoureteral reflux (VUR) in young children with a first urinary tract infection (UTI). STUDY DESIGN: The medical records of children who had been examined with renal ultrasound scanning, DMSA scanning, and voiding cystourethrography (VCUG) were reviewed. The findings of renal ultrasound scanning, DMSA scanning, and their predictive values were evaluated. RESULTS: Of 699 children, high-grade VUR (grades III-V) was diagnosed in 119 (17.0%). Signs of renal hypodysplasia (OR, 16.15), cyclic dilatation of pelvicaliceal system (OR, 11.73), hydroureter (OR, 4.00) with renal ultrasound scanning, and renal hypodysplasia (OR, 8.78), acute pyelonephritis (OR, 2.76) with DMSA scanning were associated with high-grade VUR. The sensitivities for high-grade VUR of ultrasound scanning alone (67.2%) or DMSA scanning alone (65.5%) were not as good as that of a both-test strategy, which had a sensitivity rate of 83.2%. The negative predictive value of the both-test strategy was 91.5%. CONCLUSION: Renal ultrasound scanning and DMSA scanning both should be routinely performed in children with a first febrile UTI. VCUG is only indicated when abnormalities are apparent on either ultrasound scanning or DMSA scanning or both.

Paecilomyces lilacinus peritonitis complicating peritoneal dialysis cured by oral voriconazole and terbinafine combination therapy.

Fungal peritonitis (FP) is a serious complication in patients on continuous ambulatory peritoneal dialysis (CAPD). We report a case of CAPD-related FP caused by Paecilomyces lilacinus in a 15-year-old uraemic boy. The infection was successfully treated by combination therapy consisting of oral voriconazole and terbinafine, which has not been previously reported in the treatment of FP.

Clinical differentiation of acute pyelonephritis from lower urinary tract infection in children.

BACKGROUND AND PURPOSE: To evaluate clinical variables for diagnosing childhood acute pyelonephritis (APN) when technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy is not available. METHODS: We retrospectively reviewed the records of 590 children with febrile UTI seen from January 1999 to February 2004. On the basis of DMSA scintigraphy performed within 7 days after admission, they were divided into APN (n = 237) or non-APN (n = 353) groups. Gender, age, clinical presentation, absolute neutrophil count, C-reactive protein (CRP), urinalysis, culture, and sonographic findings were recorded from charts. RESULTS: A CRP level of > or =66.4 mg/L, in patients with >2 days prior to admission had a sensitivity of 71.6% and a specificity of 72.5% for APN. Similarly, a CRP of >27.3 mg/L in patients with < or =2 days prior to admission and a white cell count of >14,990/mm3 had sensitivities of 68.6% and 62.0% and specificities of 66.1% and 63.0%, respectively. Combining two or more variables did not result in better discrimination. CONCLUSIONS: If a DMSA scan is not available, it is reasonable to treat a febrile UTI as APN if the CRP is >66.4 mg/L in a patient with >2 days of fever or if the CRP is >27.3 mg/L in a patient febrile for < or =2 days.