Phenotype, genotype, and clinical outcome of Taiwanese with congenital nephrotic syndrome

BACKGROUND/PURPOSE

Congenital nephrotic syndrome (CNS) is one of the important causes of end-stage kidney disease in children. Studies on the genotype, phenotype, and clinical outcome in infants with CNS caused by genetic mutations are scarce.

METHODS

We analyzed the genetic background, clinical manifestations, treatment response, and prognosis of pediatric patients with CNS in Taiwan.

RESULTS

Fifteen infants with CNS were enrolled, and 11 patients of median age 21 (interquartile range 3∼44) days caused by genetic mutations from 10 unrelated families were included in the study. Of the eleven patients, 9 had extra-renal manifestations including microcephaly, facial dysmorphism, and skeletal anomalies. More than two-thirds of the patients had disease onset before 1 month of age. Diffuse meningeal sclerosis was the most common histological characteristic. Whole exome sequencing followed by direct Sanger sequence revealed mutations in OSGEP (R247Q), WT1 (R366H and R467Q), LAMB2 (Q1209∗ and c. 5432-5451 19 bp deletion), NUP93 (D302V), and LAGE3 (c.188+1G > A). Three of the variants were novel. Corticosteroids and/or immunosuppressants were administered in 2 patients, but both were refractory to treatment. During the mean 3.5 years of follow-up, all but two died of uremia and sepsis. The two survivors reached end-stage kidney disease and required peritoneal dialysis, and one of them underwent uneventful renal transplantation.

CONCLUSION

The majority of patients with CNS in Taiwan were caused by OSGEP followed by WT1 mutation. R247Q is the hotspot mutation of OSGEP in Taiwan. CNS patients in Taiwan suffer from significant morbidity and mortality.

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.

Atypical hemolytic uremic syndrome: Consensus of diagnosis and treatment in Taiwan

Atypical hemolytic uremic syndrome (aHUS), characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury, is a rare but life-threatening systemic disorder caused by the dysregulation of the complement pathway. Current advances in molecular analysis and pathogenesis have facilitated the establishment of diagnosis and development of effective complement blockade. Based on this recent consensus, we provide suggestions regarding the diagnosis and management of aHUS in Taiwan. The diagnosis of aHUS is made by the presence of TMA with normal ADAMTS13 activity without known secondary causes. Although only 60% of patients with aHUS have mutations in genes involving the compliment and coagulation systems, molecular analysis is suggestive for helping establish diagnosis, clarifying the underlying pathophysiology, guiding the treatment decision-making, predicting the prognosis, and deciding renal transplantation. Complement blockade, anti-C5 monoclonal antibody, is the first-line therapy for patients with aHUS. Plasma therapy should be considered for removing autoantibody in patients with atypical HUS caused by anti-CFH or complement inhibitor is unavailable.

Effects of erythropoietin in neonates with hypoxic-ischemic encephalopathy receiving therapeutic hypothermia

BACKGROUND

Minimizing multiple organ dysfunction-related mortality and morbidity is a critical issue for patients with hypoxic-ischemic encephalopathy (HIE) receiving therapeutic hypothermia (TH). Although erythropoietin (EPO) has demonstrated protective effects on various hypoxic-ischemic organs in animal studies and clinical trials in adults, its effects on neonates with HIE require further investigation.

METHODS

This study retrospectively analyzed the medical records of neonates with HIE who received TH with or without EPO (TH+EPO vs. TH groups) administration in a tertiary referral hospital from January 2016 to January 2021. Data regarding patient characteristics, medical treatment, and clinical (neurological, cardiac, respiratory, gastrointestinal, hepatic, and renal) function assessments were collected. To control for confounding factors and selection bias between the two groups, a 1:1 propensity matching method was applied.

RESULTS

A total of 45 neonates with HIE received TH during the study period, with 24 patients (53%) in the TH+EPO group. After matching, each group enrolled 13 cases. No significant difference in mortality or hospital stay between the two groups was noted. During the first 3 days, the patients in the TH+EPO group showed significantly higher blood pressure (BP) than those in the TH group (p < 0.05 on day 1). The TH+EPO group showed trends of higher blood hemoglobin (p > 0.05) and creatinine (p > 0.05) levels and lower estimated glomerular filtration rate (p > 0.05) and urine output (p > 0.05) during the first 2 weeks than TH group.

CONCLUSION

The use of EPO in addition to TH is safe for neonates with HIE. The neonates with moderate or severe HIE who received EPO may have a lesser risk of hypotension than those who received TH alone. Further clinical studies on renal and cardiac functions and long-term neurological effects of EPO are required.

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.

Allele-specific RT-PCR for the rapid detection of recurrent SLC12A3 mutations for Gitelman syndrome

Recurrent mutations in the SLC12A3 gene responsible for autosomal recessive Gitelman syndrome (GS) are frequently reported, but the exact prevalence is unknown. The rapid detection of recurrent SLC12A3 mutations may help in the early diagnosis of GS. This study was aimed to investigate the prevalence of recurrent SLC12A3 mutations in a Taiwan cohort of GS families and develop a simple and rapid method to detect recurrent SLC12A3 mutations. One hundred and thirty independent Taiwan families with genetically confirmed GS were consecutively enrolled to define recurrent SLC12A3 mutations and determine their prevalence. Using TaqMan probe-based real-time polymerase chain reaction, we designed a mutation detection plate with all recurrent mutations. We validated this mutation detection plate and tested its feasibility in newly diagnosed GS patients. A total of 57 mutations in the SLC12A3 gene were identified and 22 including 2 deep intronic mutations were recurrent mutations consisting of 87.1% (242/278, 18 triple) of all allelic mutations. The recurrent mutation-based TaqMan assays were fully validated with excellent sensitivity and specificity in genetically diagnosed GS patients and healthy subjects. In clinical validation, recurrent mutations were recognized in 92.0% of allelic mutations from 12 GS patients within 4 h and all were confirmed by direct sequencing. Recurrent SLC12A3 mutations are very common in Taiwan GS patients and can be rapidly identified by this recurrent mutation-based SLC12A3 mutation plate.

Asian guidelines for urinary tract infection in children

The followings are the level of evidence (LE) and grade of recommendation (GR) on pediatric UTI in Asia. Classification according to the sites of infection (lower versus upper tract), the number of episode (first versus recurrent), the severity (simple versus severe), or the existence of complicating factor (uncomplicated versus complicated) is useful to differentiate children with UTI whether they are at risk of renal damage or not (LE: 2, GR: B). Diagnosis of UTI requires both urinalysis that suggests infection and positive urine culture (LE:3, GR B). For pre-toilet trained children, urine specimen for culture should be collected by urethral catheterization or suprapubic aspiration. For toilet trained children, midstream clean catch urine is reliable (LE: 3, GR: A). Urine culture is considered positive if it demonstrates growth of a single bacterium with the following colony counts: (1) any growth by suprapubic aspiration, (2) >5 × 104 CFU/ml by urethral catheterization, or (3) >105 CFU/ml by midstream clean catch (LE:3, GR: B). For children with febrile UTI, renal and bladder ultrasonography (RBUS) should be routinely performed as soon as possible (LE: 3, GR: C). RBUS should be followed up 6 months later in children with acute pyelonephritis and/or VUR (LE: 3, GR: C). Acute DMSA scan can be performed when severe acute pyelonephritis or congenital hypodysplasia is noted on RBUS or when the diagnosis of UTI is in doubt by the clinical presentation (LE: 3, GR: C). Late DMSA scan (>6 months after the febrile UTI) can be performed in children with severe acute pyelonephritis, high-grade VUR, recurrent febrile UTIs, or abnormal renal parenchyma on the follow-up RBUS (LE: 3, GR: C). Top-down or bottom-up approach for febrile UTI is suggested for the diagnosis of VUR. For top-down approach, VCUG should not be performed routinely for children after the first febrile UTI. VCUG is indicated when abnormalities are apparent on either RBUS or DMSA scan or both (LE: 2, GR: B). VCUG is also suggested after a repeat febrile UTI (LE:2, GR: B). Appropriate antibiotic should be given immediately after urine specimen for culture has been obtained (LE:2, GR: A). Initiating therapy with oral or parenteral antibiotics is equally efficacious for children (>3 months) with uncomplicated UTI (LE: 2: GR: A). The choice of empirical antibiotic agents is guided by the expected pathogen and the local resistance patterns (LE: 2, GR: A). For children with febrile UTI, the total course of antibiotic therapy should be 7-14 days (LE: 2, GR: B). Circumcision may, but not definitively, reduce the risk of febrile UTI in males and breakthrough febrile UTI in males with VUR. Circumcision should be offered to uncircumcised boys with febrile UTI and VUR in countries where circumcision is accepted by the general population (LE: 3, GR: B), while in countries where childhood circumcision is rarely performed, other measures for febrile UTI/VUR should be the preferred choice (LE: 4, GR: C). Bladder bowel dysfunction (BBD) is one of the key factors of progression of renal scarring (LE: 2). Early recognition and management of BBD are important in prevention of UTI recurrence (LE:2, GR: A). Antibiotic prophylaxis to prevent recurrent febrile UTI is indicated in children with moderate to high grade (III-V) VUR (LE: 1b, GR: A). Surgical intervention may be used to treat VUR in the setting of recurrent febrile UTI because it has been shown to decrease the incidence of recurrent pyelonephritis (LE: 2, GR: B).

Clinical characteristics, triggering etiologies, and response of plasmapheresis in thrombotic microangiopathy in Taiwan

Thrombotic microangiopathy (TMA) syndromes are extraordinarily diverse in clinical presentations and etiologies. However, there are still a limited number of large cohort studies focusing on the underlying causes, outcomes, and response to plasmapheresis.A retrospective study was designed to understand trigger etiologies, organ dysfunctions, clinical outcomes, and efficacy of plasmapheresis in patients with TMA. The whole population of Taiwan was set up into 2 cohorts: 875 patients with TMA in the 2006 cohort (2006-2010) and 1352 patients with TMA in the 2011 cohort (2011-2015). One hundred ninety-five patients in the 2006 cohort and 272 patients in the 2011 cohort were under plasmapheresis treatment.The common underlying etiologies were pregnancy, followed by systemic lupus erythematosus, rheumatoid arthritis, transplantation and drugs, which were significantly higher than the control group. Stroke, seizure, arterial thrombosis, vascular stenosis, hypertension, myocardial infarction, and pancreatitis were the main clinical signs and extra-renal involvements. In the multivariate regression analysis, stroke, arterial thrombosis, peripheral arterial disease, and uremia were significantly higher compared with the control group. The mortality rate in TMA under plasmapheresis was significantly higher than all TMA cases (39.33% vs 15.39% in the 2006 cohort and 39.27% vs 15.06% in the 2011 cohort).This study indicated the spectrum of underlying causes, extra-renal characteristics, and the response to plasmapheresis of patients with TMA in Taiwan. Of note, the poor clinical outcomes of plasmapheresis in patients with TMA might highlight the masked underlying etiology or worse disease condition that should be noticed.

Autosomal Recessive Renal Tubular Dysgenesis Caused by a Founder Mutation of Angiotensinogen

Introduction

Autosomal recessive renal tubular dysgenesis (ARRTD) caused by inactivation mutations in AGT, REN, ACE, and AGTR is a very rare but fatal disorder with an unknown prevalence.

Methods

We report 6 Taiwanese individuals with ARRTD from 6 unrelated families diagnosed by renal histology. Clinical features, outcome, and prevalence of carrier heterozygosity were examined.

Results

All patients exhibited antenatal oligohydramnios, postnatal anuria, pulmonary hypoplasia, and profound hypotension refractory to interventions. Angiotensinogen (AGT) protein levels were diminished in the liver, along with reduced serum AGT, angiotensin I (Ang I) and angiotensin II (Ang II) levels. Neonatal demise occurred in all but 1 case. All individuals carried the same homozygous E3_E4 del:2870bp deletion+9bp insertion in AGT, which led to a truncated protein (1-292 amino acid). The allelic frequency of this heterozygous AGT mutation was approximately 1.2% (6/500), suggesting that ARRTD may not be exceedingly rare in Taiwan. This mutation results in skipping of exons encoding the serpin domain of AGT, which is important for renin interaction and the generation of truncated protein. In silico modeling revealed a diminished interaction between mutant AGT and renin. One patient survived after responding to high-dose hydrocortisone therapy, with resolution of profound hypotension, accompanied by an increase in serum AGT, Ang I, and Ang II levels.

Conclusion

This AGT mutation may lead to the diminished interaction with renin and decreased Ang I and Ang II generation. Hydrocortisone may potentially rescue cases of ARRTD caused by this truncated AGT.

Clinical features, genetic background, and outcome in infants with urinary tract infection and type IV renal tubular acidosis

BACKGROUND

Type IV renal tubular acidosis (RTA) is a severe complication of urinary tract infection (UTI) in infants. A detailed clinical and molecular analysis is still lacking.

METHODS

Infants with UTI who exhibited features of type IV RTA were prospectively enrolled. Clinical, laboratory, and image characteristics and sequencing of genes responsible for phenotype were determined with follow-up.

RESULTS

The study cohort included 12 infants (9 males, age 1-8 months). All exhibited typical type IV RTA such as hyperkalemia with low transtubular potassium gradient, hyperchloremic metabolic acidosis with positive urine anion gap, hypovolemic hyponatremia with renal salt wasting, and high plasma renin and aldosterone levels. Seven had hyperkalemia-related arrhythmia and two of them developed life-threatening ventricular tachycardia. With prompt therapy, all clinical and biochemical abnormalities resolved within 1 week. Five had normal urinary tract anatomy, and three of them carried genetic variants on NR3C2. Three variants, c.1645T>G (S549A), c.538G>A (V180I), and c.1-2C>G, on NR3C2 were identified in four patients. During follow-up, none of them had recurrent type IV RTA, but four developed renal scaring.

CONCLUSIONS

Genetic mutation on NR3C2 may contribute to the development of type IV RTA as a complication of UTI in infants without identifiable risk factors, such as urinary tract anomalies.

Whole-exome sequencing detects mutations in pediatric patients with atypical hemolytic uremic syndrome in Taiwan

Although atypical hemolytic uremic syndrome (aHUS) is a genetic disorder, molecular defects are detected in only 60% of patients. We aim to dissect the genetic background by whole exome sequence and the clinical characteristics of pediatric patients with aHUS. Ten patients (6 male and 4 female) with mean age 5.2 ± 5.0 years were enrolled. The age at onset ranged from 2 days to 11 years. Eighteen different mutations (17 missense, 2 nonsense, and 11 novel) on 7 complement and 3 coagulation genes were detected in all patients. The majority of mutation was heterozygous and S1191L on CFH were the recurrent mutation. Sixty percent of patients had multiple genetic mutations. Nine mutations were associated with genes known to be implicated in aHUS (CFH, CFI, CD46, CFHR5, and DGKE), while 4 and 5 mutations were detected on complement- (C8B, C9, and MASP1) and coagulation-associated (VWF and CD36) genes, respectively. CD36 may be a candidate gene act as disease modifier for aHUS through the contribution of thrombosis by impairing the interaction with TSP-1 and ADAMTS 13 shown in simulation model. Genetic defects on both complement and coagulation pathways play pathogenic roles on aHUS. CD36 may be a novel candidate gene act as disease modifier of aHUS.

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.

Continuous low-dose everolimus shrinkage tuberous sclerosis complex-associated renal angiomyolipoma: a 48-month follow-up study

Tuberous sclerosis complex (TSC) is a rare disease that causes multisystem benign neoplasm, induced by dysregulation of the mammalian target of the rapamycin pathway (mTOR). This study aimed to examine the effects of continuous low-dose everolimus, a potent and selective inhibitor of mTOR, on the treatment of TSC-associated renal angiomyolipoma (AML). Between July 2013 and August 2017, 11 patients with TSC-AML were enrolled for an everolimus therapy protocol. An oral everolimus dose starting at 2.5 mg daily was gradually increased to 5.0 mg daily. All patients were evaluated using MRI or CT scanning at baseline, 12, 24, 36 and 48 months after the start of treatment for measuring changes of renal AML mass volume. Everolimus therapy resulted in significant shrinkage of TSC-AML volume after 48 months follow-up. Serum levels of everolimus were subdivided into group I (<8 ng/mL, n=6) and group II (>8 ng/mL, n=5). The volume reduction rates were 10.6%-65.2% in group I and 42.5%-70.6% in group II. To evaluate the response to treatment, three of six (50%) were responders in group I, and all the patients in group II (5/5, 100%) were responders. The differences in AML volume reduction between the groups were statistically significant at 12 months (p=0.011), 24 months (p=0006), 36 months (p=0.014) and 48 months (p=0.05). These results suggest that continuous low-dose everolimus therapy (2.5-5 mg daily) might be effective in shrinking TSC-AML volume and minimizes adverse effects and subsequent reducing medical costs.

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.

Management of nocturnal enuresis in Taiwan: Consensus statements of the Taiwan enuresis expert committee

Nocturnal enuresis causes significant psychological distress to affected children and their family and requires appropriate management. A 12-member expert committee of pediatric urologists and pediatric nephrologists in Taiwan with extensive experience in treating enuresis was established to develop consensus statements and a recommended treatment algorithm for the management of patients with nocturnal enuresis in Taiwan after careful consideration of current evidence, existing guidelines, and expert opinion as well as local practice and culture. The finalized consensus statements were reviewed by and have received endorsement from the Taiwan Urological Association and the Taiwan Pediatric Association. Patients with suspected enuresis should undergo a thorough initial assessment to fully evaluate urinary signs and symptoms and to rule out underlying causes of diurnal and nocturnal incontinence. Behavioral therapy is recommended throughout the course of management. Desmopressin in the fast-melting formulation is the recommended first-line pharmacological treatment. Combination therapy may be effective in patients who have failed first-line treatment. These consensus statements and a recommended treatment algorithm were created by the expert committee to provide practical support for clinical decision making by physicians in Taiwan.

Mutations in KEOPS-complex genes cause nephrotic syndrome with primary microcephaly

Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms.

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.

Detection of recurrent transmission of 17q12 microdeletion by array comparative genomic hybridization in a fetus with prenatally diagnosed hydronephrosis, hydroureter, and multicystic kidney, and variable clinical spectrum in the family

OBJECTIVE

This study was aimed at detection of recurrent transmission of the 17q12 microdeletion in a fetus with congenital anomalies of the kidney and urinary tract.

MATERIALS AND METHODS

A 35-year-old woman was referred to the hospital at 20 weeks' gestation because of hydronephrosis in the fetus. The mother was normal and healthy. Her second child was a girl who had bilateral dysplastic kidneys that required hemodialysis, and died at the age of 5 years. During this pregnancy, the woman underwent amniocentesis at 18 weeks' gestation because of advanced maternal age. Cytogenetic analysis revealed a karyotype of 46,XY. Prenatal ultrasound showed left hydronephrosis with a tortuous ureter, right hydronephrosis, and increased echogenicity of the kidneys. Fetal magnetic resonance imaging showed right dilated renal calyces, left hydronephrosis, hydroureter, and multicystic kidney. The pregnancy was subsequently terminated. Array comparative genomic hybridization (aCGH) and fluorescence in situ hybridization were applied for genetic analysis using umbilical cord, maternal blood, and cultured amniocytes.

RESULTS

aCGH analysis on umbilical cord detected a 1.75-Mb deletion at 17q12 including haploinsufficiency of LHX1 and HNF1B. aCGH analysis on maternal blood detected a 1.54-Mb deletion at 17q12 including haploinsufficiency of LHX1 and HNF1B. Metaphase fluorescence in situ hybridization analysis on cultured amniocytes and maternal blood lymphocytes using 17q12-specific bacterial artificial chromosome probe showed 17q12 microdeletion in the fetus and the mother.

CONCLUSION

Prenatal diagnosis of recurrent renal and urinary tract abnormalities in the fetus should include a differential diagnosis of familial 17q12 microdeletion.

Urinary tract infections in infants: comparison between those with conjugatedvsunconjugated hyperbilirubinaemia

AIMS

The aim was to investigate conjugated and unconjugated hyperbilirubinaemia in association with urinary tract infection (UTI) in young infants.

METHODS

Fifty infants aged <3 mths who developed prolonged jaundice among 2128 infants with UTI from 1984 to 2004 were enrolled retrospectively. They were divided into conjugated (n=22) and unconjugated (n=28) hyperbilirubinaemia groups and the clinical variables between the two were compared.

RESULTS

Compared with the unconjugated group, the conjugated hyperbilirubinaemia group had statistically significantly lower haemoglobin (1.57 vs 1.80 micromol/L), higher aspartate aminotransferase (96 vs 32.5 U/L) and alanine aminotransferase (81.5 vs 16 U/L), were older on admission (48.0 vs 32.5 days), had a longer duration of jaundice before treatment (43.5 vs 30 days) and a higher incidence of E. coli infections (19/22 vs 15/28). The direct/total bilirubin ratio was linearly correlated with duration of jaundice before treatment (p=0.004). The most significant cut-off value for the duration of jaundice vis-à-vis the type of jaundice was 38 days (p=0.007). Patients who on presentation had had jaundice for >44 days (p=0.007) were unlikely to have unconjugated hyperbilirubinaemia.

CONCLUSIONS

Infants with UTI may present with unconjugated hyperbilirubinaemia in the early stage. After 6 weeks, it is always conjugated hyperbilirubinaemia and is frequently associated with anaemia, elevated hepatic aminotransferases and E. coli infections.

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.

Genotype, phenotype, and follow-up in Taiwanese patients with salt-losing tubulopathy associated with SLC12A3 mutation

CONTEXT AND OBJECTIVE

Genotype, phenotype, and follow-up analysis is rarely performed in a large number of patients with Gitelman's syndrome (GS) caused by mutations in SLC12A3 encoding the thiazide-sensitive NaCl cotransporter.

DESIGN, SETTING, AND PATIENTS

One hundred seventeen Taiwanese GS patients (70 males and 47 females, age 24 ± 10 yr) with SLC12A3 mutations belonging to 92 unrelated families were investigated. Genomic DNA and/or cDNA from blood leukocytes were analyzed for SLC12A3 mutations and haplotype analysis with intragenic and extragenic markers for recurrent SLC12A3 mutations. Clinical symptoms and biochemical studies at the first presentation as well as follow-up were examined.

RESULTS

Forty different SLC12A3 mutations were identified. Approximately 12% of patients had triple SLC12A3 mutations. Fourteen mutations were recurrent with only one founder effect (S710X). Typical hypocalciuria and hypomagnesemia were not found in seven and nine patients, respectively. In addition to male patients having an earlier age of onset, more severe hypokalemia, and significantly lower serum aldosterone concentration, patients with homozygous and deep mutations in intron 13 (c.1670-191C → T) had more severe phenotype. Seven and five patients had chronic kidney disease (stage III-IV) and type 2 diabetes at the follow-up, respectively.

CONCLUSION

Screening of recurrent hot spot SLC12A3 mutations may provide an early diagnosis of GS. Besides gender effect, the nature of homozygous and deep intronic mutations may influence the phenotype. Patients with GS may be at increased risk for the development of chronic kidney disease and type 2 diabetes.

Galloway-Mowat syndrome: prenatal ultrasound and perinatal magnetic resonance imaging findings

OBJECTIVE

To present prenatal ultrasound and perinatal magnetic resonance imaging (MRI) findings of Galloway-Mowat syndrome.

CASE REPORT

A 31-year-old woman, gravida 3, para 2, was referred for genetic counseling at 29 weeks of gestation because of abnormal ultrasound findings and a previous child with Galloway-Mowat syndrome. During this pregnancy, microcephaly, intrauterine growth restriction (IUGR), and oligohydramnios were first noted at 27 weeks of gestation. Repeated ultrasounds showed microcephaly, IUGR, and oligohydramnios. MRI performed at 32 weeks of gestation showed reduced sulcation of the brain, pachygyria, poor myelination of the white matter, and cerebellar atrophy. A diagnosis of recurrent Galloway-Mowat syndrome was made. At 40 weeks of gestation, a 2,496-g female baby was delivered with microcephaly, a narrow slopping forehead, epicanthic folds, microphthalmos, a highly arched palate, a small midface, a beaked nose, thin lips, large low-set floppy ears, clenched hands, and arachnodactyly. Postnatal MRI findings were consistent with the prenatal diagnosis. Renal ultrasound showed enlarged bilateral kidneys with increased echogenicity. At the age of 2 weeks, the infant became edematous and developed nephrotic syndrome.

CONCLUSION

Microcephaly, IUGR, and oligohydramnios are significant ultrasound triad of fetal Galloway-Mowat syndrome. Prenatal ultrasound diagnosis of microcephaly, IUGR, and oligohydramnios in late second trimester or in early third trimester should alert clinicians to the possibility of Galloway-Mowat syndrome and prompt a detailed search of abnormal sulcation, cortical gyral maldevelopment, and cerebellar atrophy by fetal ultrafast MRI.

Renal calcification in very low birth weight infants

BACKGROUND

Renal calcification in preterm infants has been described frequently. The etiologic factors have not yet been fully clarified. The objective of this study was to evaluate the incidence of and risk factors for renal calcification in our population.

METHODS

We retrospectively reviewed the charts of very low birth weight preterm infants during a 1-year period. Renal ultrasound scans were performed at term or before discharge and at a corrected age of 1 year.

RESULTS

Six infants (6%) had renal calcification at term or before discharge compared with 96 who did not. Factors significantly associated with renal calcification included gestational age (26 weeks vs. 29 weeks, p=0.006), birth weight (851 g vs. 1141 g, p=0.004), duration of mechanical ventilation (69 days vs. 29 days, p=0.002), length of intensive care (72 days vs. 41 days, p=0.013), furosemide therapy (33% vs. 3%, p=0.027), and dexamethasone therapy (50% vs. 2% p=0.001). Birth weight and dexamethasone therapy had significant independent association after stepwise logistic regression analysis. Sex, oliguria, acidosis, duration of oxygen therapy, length of hospital stay, nutrition status, and nephrotoxic drugs did not differ between the two groups. Three of the six infants had spontaneous remission of renal calcification, whereas two patients without the finding in neonatal stage had renal calcification at a corrected age of 1 year.

CONCLUSION

The incidence of renal calcification in very low birth weight infants in this study was relatively low, and the calcification was transient in one-half of the infants. Extremely premature, sick infants requiring long-term ventilation, and those receiving furosemide or dexamethasone were more likely to have renal calcification. Clinicians should be aware that renal calcification may develop beyond the neonatal stage.

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.

Chronic renal failure in a boy with classic Bartter's syndrome due to a novel mutation in CLCNKB coding for the chloride channel

BACKGROUND

Progressive renal failure in patients with classic Bartter's syndrome (cBS) due to inactivating mutations in CLCNKB gene is extraordinarily rare.

DISCUSSION

We describe a 17-year-old Chinese boy who presented with progressive muscle weakness and renal failure. He was diagnosed as BS of unknown type at the age of 9 months and treated with indomethacin (2 mg/kg/day) and potassium chloride (KCl) supplementation (1.5 mEq/kg/day) for hypokalemia (2.5 mmol/l). At the age of 12 years, serum K+ was 3.0 mmol/l and creatinine reached 2.0 mg/dl. On admission, his blood pressure was normal but volume status was depleted. Urinalysis was essentially normal. Biochemical studies showed hypokalemia (K+ 2.4 mmol/l) with a high transtubular K+ gradient (TTKG) 9.6, metabolic alkalosis (HCO3- 28.4 mmol/l), normomagnesemia (2.0 mg/dl), severe renal failure (BUN 94 mg/dl, Cr 6.3 mg/dl), and hypocalciuria (urine calcium/creatinine ratio 0.02 mg/mg). Abdominal sonography revealed bilateral small size kidneys without nephrocalcinosis or renal stones. After the withdrawal of indomethacin with regular KCl and adequate fluid supplementation for 1 year, serum creatinine and K+ levels have been maintained at 4.0 mg/dl and 3.3 mmol/l, respectively. Direct sequencing of NKCC2, ROMK, ClC-Kb, and NCCT in this patient disclosed a novel homozygous missense mutation (GGG to GAG, G470E) in CLCNKB. This G470E mutation was not identified in 100 healthy Chinese subjects. Long-term therapy of non-steroidal anti-inflammatory drugs (NSAIDs), prolonged hypokalemia, chronic volume depletion, and underlying genetic variety may contribute to the deterioration of his renal function. The cautious use of NSAIDs, aggressive correction of hypokalemia, and avoidance of severe volume depletion may prevent the irreversible renal damage in patients with BS due to a Cl- channel defect.

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.

Population-specific anthropometric cutoff standards improve the functionality of the Mini Nutritional Assessment without BMI in institutionalized elderly in Taiwan

OBJECTIVE

To assess the nutritional status of institutionalized Taiwanese elderly with the Mini Nutritional Assessment (MNA) without BMI and to determine whether the application of population-specific MAC and CC cutoff standards would improve the functionality of the tool.

DESIGN

Purposive sampling.

SETTING

A long-term care facility in central Taiwan.

PARTICIPANTS

Two hundred and eight > 65 y residents who were free of acute infection/diseases and were able to communicate.

MEASUREMENTS

A questionnaire survey to elicit personal data and administer the MNA and measurements of anthropometric and blood biochemical indicators.

RESULTS

The MNA, without BMI, predicted 22.1% of participants malnourished and 61.1% at risk of malnutrition among residents of a long-term care facility in Taiwan. Replacing the population-specific cutoff standards of MAC and CC for the original cutoff standards in the MNA and increasing the weighted score of MAC and CC to replace for the weighted score of BMI preserved and improved the predicting ability of the MNA. The improvement was evidenced by the increase in the correlationships between the MNA scores and the anthropometric, biochemical or health status indicators.

CONCLUSION

The MNA predicted nutritional risk status of the institutionalized elderly Taiwanese. The study suggests that whenever possible population-specific anthropometric cutoff standards should be applied to improve the functionality of the MNA. It also appears possible to preserve or even improve the functionality of the MNA without BMI. The modifications indicate an improvement in the application of the MNA in long-term care patients.

Acute urinary retention in a 7-year-old girl: an unusual complication of cytomegalovirus cystitis

Acute urinary retention in children is rare. There are a variety of causes about the disease. We report a case of a 7-year-old girl with acute urinary retention and hematuria. Pelvic sonogram revealed an isoechoic mass in the urinary bladder that appeared as a lobulated filling defect over the bladder neck on intravenous urography and computed tomography studies. The surgical specimen from cystoscopic examination showed reactive changes on pathologic analysis. Cytomegalovirus was isolated from urine culture. The girl recovered after supportive treatment.

Ureteropelvic junction obstruction in children: 10 years' experience in one institution

We reviewed our experience over 10 years with pyeloplasty for ureteropelvic junction obstruction. Preoperative and postoperative isotope renal scans were performed to assess the surgical outcome, with particular emphasis on the postoperative change in renal function (RF). We retrospectively reviewed the medical records of 137 consecutive children with ureteropelvic obstruction operated between January 1994 and December 2003. A total of 109 kidneys in 102 patients were evaluated with renal echo and (99m)Tc-diethylenetriaminepentaacetic renography both before and after Anderson-Hynes dismembered pyeloplasty. The improvement of RF >5% was noted in 67 kidneys (61.5%), the function remained stable in 30 kidneys (27.5%), and it deteriorated (>5%) in 12 kidneys (11.0%). Five patients (4.6%) required repeat pyeloplasty for either prolonged urine leakage or reobstruction with deterioration in RF. Dismembered pyeloplasty in children with ureteropelvic junction obstruction is safe. The renal functional improvement can be expected in the majority of kidneys that have impaired function at presentation.

Intermittent hydronephrosis secondary to ureteropelvic junction obstruction: clinical and imaging features

OBJECTIVE

We sought to assess the clinical and imaging findings in intermittent hydronephrosis secondary to ureteropelvic junction obstruction, with particular emphasis on the characteristic ultrasonographic findings.

METHODS

This prospective, longitudinal, observational study included all children who had intermittent ureteropelvic junction obstruction and presented with abdominal pain over 6 years. Renal ultrasound was used as an initial screening tool to detect intermittent hydronephrosis. Renal ultrasonography was repeated every 1 to 2 days to record serial changes from the symptomatic to the asymptomatic stage. Their clinical manifestations and imaging findings were studied.

RESULTS

Eighteen patients (14 boys, 4 girls) were studied. Most had sharp pain that began acutely and typically lasted for <2 days. Most of the children (16 of 18) had nausea and vomiting that accompanied the pain. The acute episode generally resolved spontaneously and was followed by a pain-free interval that ranged from days to months. Factors that predisposed to an attack included increased water intake, vigorous exercise, or bladder distention. All patients had clearly demonstrable obstruction of the renal pelvis during an acute attack, a finding that diminished or resolved during the symptom-free intervals. During convalescence, all patients had renal pelvic wall thickening on ultrasonography. This finding appeared on the second or third day after a painful episode subsided, persisted for 6 to 9 days, and then disappeared in the symptom-free stage. Pyeloplasty was performed in 17 patients, none of whom had recurrent pain on follow-up. Extrinsic obstructions were found in 9 patients.

CONCLUSIONS

The keys to diagnosis are awareness of the syndrome, a detailed history, and immediate and serial imaging studies during painful crises. A thickened renal pelvic wall during convalescence is an important ultrasonic sign of intermittent hydronephrosis.

Urinary tract infections in young infants with prolonged jaundice

The incidence of urinary tract infections (UTIs) in young infants with jaundice is low, and prolonged jaundice in that setting is even rarer. In this study, we retrospectively reviewed the clinical features of 50 infants (seen from 1984 through 2004) 1 week to 3 months of age who had UTIs and prolonged jaundice and compared them with those of infants with UTIs in a similar age range at our hospital from a published study. The infants in our study had a lower incidence of high fever (12%), were less likely to have pyuria (29%), had fewer Escherichia coli but more Enterococcus species infections, and had more mixed infections (32%) than did the historical control. Klebsiella pneumoniae or Enterococcus species dominated in mixed infections (15/16) but the frequency of E. coli isolates did not differ significantly between mixed and single infections. We conclude that high fever and pyuria are unreliable criteria for screening for UTIs in young infants presenting with prolonged jaundice. Urine cultures should be obtained in such patients to determine whether a UTI is present. Mixed urinary infections, particularly K. pneumoniae and Enterococcus species, may play a key role in this entity.

Renal sonographic findings of type I glycogen storage disease in infancy and early childhood

BACKGROUND

Type I glycogen storage disease (GSD-I) is an inherited disorder affecting glycogenolysis and gluconeogenesis. The characteristic manifestations are hepatomegaly, hypoglycemia, hyperlacticacidemia, hyperuricemia, and hyperlipidemia. Renal disease is regarded as a long-term complication and is reported mainly in older patients.

OBJECTIVE

We report the renal manifestations and renal ultrasonographic findings of GSD-I in infancy and early childhood in order to assess the role of renal sonography in the diagnosis of GSD-I.

MATERIALS AND METHODS

We retrospectively reviewed our hospital's database for patients with GSD-I from January 1993 to September 2004. The records of five patients were reviewed for this study. These five patients were diagnosed when they were younger than 3 years old. Data extracted from the charts included the initial extrarenal and renal manifestations, laboratory data, and imaging studies. We analyzed the indications for, and results of, renal sonography.

RESULTS

In addition to the clinical presentations and laboratory abnormalities, all five children had nephromegaly and increased echogenicity on ultrasonography on their first visit, although only a minor degree of tubular dysfunction was noted clinically. Three of these five patients had nephrocalcinosis or renal stones or both.

CONCLUSION

Hyperechoic large kidneys, nephrocalcinosis, and renal stones are common in GSD-I. They can be present in early infancy. Abnormalities on renal sonography might suggest GSD-I in a patient with suspected inborn errors of metabolism.

Diffuse xanthogranulomatous pyelonephritis in a child with severe complications

Xanthogranulomatous pyelonephritis is a rare disease in childhood. Because the symptoms and signs are chronic and non-specific, preoperative diagnosis is usually difficult. We report an 8-year-old boy who had an abdominal mass and anemia for more than 6 months. Fever and dyspnea occurred 4 days prior to admission. Ultrasonography revealed an enlarged right kidney with multiple parenchymal hypoechogenic areas, absence of normal parenchymal structures, and perinephric thickening with multiple calcifications. An abdominal computed tomogram demonstrated an irregular, enlarged right kidney with multiple low-density round areas consistent with hydronephrosis and calculi. Diminished excretion of contrast media and a severe perinephric inflammatory reaction were present. Poor right kidney function was demonstrated by Tc99m-diethylenetriamine penta-acetic acid split renal function examination. We diagnosed xanthogranulomatous pyelonephritis preoperatively based on the clinical and radiological features. The child first had drainage of an extrarenal abscess and antibiotic therapy, followed by definitive nephrectomy. The hospital course was complicated with pleural effusion, peritonitis, pelvic abscess, and sepsis. A two-stage nephrectomy requiring less radical resection and decreasing the surgical complications would have been preferable.

Kimura disease in a patient with renal allograft failure secondary to chronic rejection

Recent studies suggest that CD4(+ )T helper 2 (Th2) cell proliferation and overexpression of Th2 cytokines may play an important role in the development of Kimura disease. Chronic rejection of a renal allograft by the indirect allo recognition pathway is also induced by Th2 cytokines. We report a 12-year-old boy who had presented with nephrotic syndrome 10 years previously. He was found to have focal segmental glomerulosclerosis, which was attributed to vesicoureteral reflux, and he underwent renal transplantation at the age of 5 years. Allograft dysfunction secondary to chronic rejection was noted by 2 years post transplant, after which continuous ambulatory peritoneal dialysis was instituted. After discontinuation of immunosuppressive therapy, he progressively developed peripheral eosinophilia and eczema, followed by cervical lymphadenopathy and then epitrochlear lymphadenopathy. Kimura disease was diagnosed on lymph node biopsy. Our patient demonstrated that Kimura disease can occur after renal allograft failure secondary to chronic rejection. Both disorders involve the Th2-dominant immune response, according to previous observations.

Epstein-Barr virus-associated acute renal failure: diagnosis, treatment, and follow-up

We retrospectively reviewed our experience of Epstein-Barr virus (EBV)-associated acute renal failure. Of 165 previously healthy children hospitalized with serologically proven primary EBV infection, 8 had acute renal failure, of whom 5 (group A) did not have virus-associated hemophagocytic syndrome (VAHS), while 3 (group B) did have VAHS. All had complications in four or more organ systems. Two patients in group A had renal biopsies showing acute tubulointerstitial nephritis, and the clinical and laboratory findings in the other 3 group A patients were consistent with acute tubulointerstitial nephritis. Acyclovir was used in 1 patient, but she died of hepatic failure and pulmonary hemorrhage. The other 4 spontaneously recovered renal function after supportive care, including hemodialysis in 1 patient. Our experience does not support the routine use of corticosteroids or antiviral agents in these patients. Children in group B had a relatively normal urinalysis. Renal biopsies were not performed, but their presentations were compatible with acute tubular necrosis. We conclude that EBV should be considered as a possible etiological agent in all children presenting with acute renal failure of unknown cause. The diagnosis depends on a high index of suspicion and careful serological evaluation in atypical cases.