Amniotic fluid peptides predict postnatal kidney survival in developmental kidney disease.

Although a rare disease, bilateral congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of end stage kidney disease in children. Ultrasound-based prenatal prediction of postnatal kidney survival in CAKUT pregnancies is far from accurate. To improve prediction, we conducted a prospective multicenter peptidome analysis of amniotic fluid spanning 140 evaluable fetuses with CAKUT. We identified a signature of 98 endogenous amniotic fluid peptides, mainly composed of fragments from extracellular matrix proteins and from the actin binding protein thymosin-ß4. The peptide signature predicted postnatal kidney outcome with an area under the curve of 0.96 in the holdout validation set of patients with CAKUT with definite endpoint data. Additionally, this peptide signature was validated in a geographically independent sub-cohort of 12 patients (area under the curve 1.00) and displayed high specificity in non-CAKUT pregnancies (82 and 94% in 22 healthy fetuses and in 47 fetuses with congenital cytomegalovirus infection respectively). Change in amniotic fluid thymosin-ß4 abundance was confirmed with ELISA. Knockout of thymosin-ß4 in zebrafish altered proximal and distal tubule pronephros growth suggesting a possible role of thymosin ß4 in fetal kidney development. Thus, recognition of the 98-peptide signature in amniotic fluid during diagnostic workup of prenatally detected fetuses with CAKUT can provide a long-sought evidence base for accurate management of the CAKUT disorder that is currently unavailable.

Escherichia coli-associated hemolytic uremic syndrome and severe chronic hepatocellular cholestasis: complication or side effect of eculizumab?

BACKGROUND: Liver lesions of hemolytic uremic syndrome due to Shiga-toxin-producing Escherichia coli (STEC-HUS) are uncommon. CASE-DIAGNOSIS/TREATMENT: We report three observations of severe STEC-HUS with delayed hepatic involvement. They presented with multiple organ failure and received eculizumab; 15 days after the onset of STEC-HUS, cholestasis appeared and cytolysis worsened. Abdominal ultrasonography showed vesicular sludge. Liver biopsy performed 3 to 6 months after the STEC-HUS found cholangiolar proliferation and inflammatory portal fibrosis. Despite renal recovery, cholestasis persisted and worsened in two cases, leading to biliary cirrhosis and subsequent liver transplantation. Pathological examination of one native liver found thrombotic microangiopathy. CONCLUSIONS: Even though the pathological examination performed on one native liver demonstrated areas of thrombotic microangiopathy, we cannot completely rule out that eculizumab may have worsened the liver lesions. Before the efficacy of eculizumab in STEC-HUS is formally demonstrated, physicians should stay cautious in its use.

Clinical and Genetic Spectrum of Bartter Syndrome Type 3.

Bartter syndrome type 3 is a clinically heterogeneous hereditary salt-losing tubulopathy caused by mutations of the chloride voltage-gated channel Kb gene (CLCNKB), which encodes the ClC-Kb chloride channel involved in NaCl reabsorption in the renal tubule. To study phenotype/genotype correlations, we performed genetic analyses by direct sequencing and multiplex ligation-dependent probe amplification and retrospectively analyzed medical charts for 115 patients with CLCNKB mutations. Functional analyses were performed in Xenopus laevis oocytes for eight missense and two nonsense mutations. We detected 60 mutations, including 27 previously unreported mutations. Among patients, 29.5% had a phenotype of ante/neonatal Bartter syndrome (polyhydramnios or diagnosis in the first month of life), 44.5% had classic Bartter syndrome (diagnosis during childhood, hypercalciuria, and/or polyuria), and 26.0% had Gitelman-like syndrome (fortuitous discovery of hypokalemia with hypomagnesemia and/or hypocalciuria in childhood or adulthood). Nine of the ten mutations expressed in vitro decreased or abolished chloride conductance. Severe (large deletions, frameshift, nonsense, and essential splicing) and missense mutations resulting in poor residual conductance were associated with younger age at diagnosis. Electrolyte supplements and indomethacin were used frequently to induce catch-up growth, with few adverse effects. After a median follow-up of 8 (range, 1-41) years in 77 patients, chronic renal failure was detected in 19 patients (25%): one required hemodialysis and four underwent renal transplant. In summary, we report a genotype/phenotype correlation for Bartter syndrome type 3: complete loss-of-function mutations associated with younger age at diagnosis, and CKD was observed in all phenotypes.

Renovascular hypertension: results in adulthood of renal autotransplantation performed in children.

BACKGROUND: This study describes the long-term results of renal autotransplantation for renovascular hypertension performed in children who are now 21 years of age or older. METHODS: Sixteen children (4 boys, 12 girls) with a mean age of 11.2 years at the time of the procedure underwent ex-vivo surgery at the university hospital of Saint-Etienne between 1992 and 2008. Acetylsalicylic acid was used for antiplatelet therapy in the postoperative period, without routine anticoagulation. The mean follow-up period was 15 years. The clinical course of these patients was retrospectively reviewed in adulthood and the results analyzed. RESULTS: The children were treated with a mean of 2.37 drugs per patient, and the mean preoperative blood pressure of the entire patient population was 151/89 mmHg. Mean preoperative creatinine clearance was 80 ml/min/1.73 m2. There was no postoperative death. One patient experienced a thrombosis immediately after the surgery, leading to a redo surgery. In this patient diuresis was restarted, but without efficient concentration and filtration, ultimately leading the patient to have a renal transplant after 1 year. At the end of the follow-up period, eight of the 16 patients (50%) were cured and the others were improved. At the last follow-up the mean blood pressure was 127/70 mmHg, and the mean number of drugs per patient was 0.68. The mean creatinine clearance at last follow-up was 104.3 ml/min/1.73 m2. Three patients had secondary procedures, with two undergoing percutaneous angioplasty (at postoperative months 9 and 12, respectively) and one having an hepatorenal bypass at postoperative year 4. Primary patency was 12/16 (75%); primary assisted patency was 15/16 (94%); secondary patency was 16/16 (100%). CONCLUSION: This study shows that renal autotransplantation has good and stable long-term results and is an effective conservative strategy for treating renovascular hypertension in children, thus avoiding nephrectomy.

Observations of a large Dent disease cohort.

Dent disease classically combines low-molecular-weight proteinuria, hypercalciuria with nephrocalcinosis, and renal failure. Nephrotic range proteinuria, normal calciuria, and hypokalemia have been rarely reported. It is unknown whether the changes in phenotype observed over time are explained by a decrease in glomerular filtration rate (GFR) or whether there is any phenotype-genotype relationship. To answer this we retrospectively analyzed data from 109 male patients with CLCN5 mutations (Dent-1) and 9 patients with mutation of the OCRL gene (Dent-2). In Dent-1 disease, the estimated GFR decreased with age, by 1.0 to 1.6 ml/min per 1.73 m(2)/yr in the absence and presence of nephrocalcinosis, respectively, with no significant difference. Median values of low-molecular-weight proteinuria were in the nephrotic range and remained at the same level even in late renal disease. End-stage renal disease occurred in 12 patients, at a median age of 40 years. Hypercalciuria decreased with glomerular filtration and was absent in 40% of the patients under 30 and 85% of those over the age of 30. Hypophosphatemia did not resolve with age and calcitriol concentrations were in the upper normal range. Kalemia decreased with age, with half of the patients over the age of 18 presenting with hypokalemia. Thus, no phenotype/genotype correlation was observed in this cohort of patients with Dent disease.

Mutation Update of the CLCN5 Gene Responsible for Dent Disease 1.

Dent disease is a rare X-linked tubulopathy characterized by low molecular weight proteinuria, hypercalciuria, nephrocalcinosis and/or nephrolithiasis, progressive renal failure, and variable manifestations of other proximal tubule dysfunctions. It often progresses over a few decades to chronic renal insufficiency, and therefore molecular characterization is important to allow appropriate genetic counseling. Two genetic subtypes have been described to date: Dent disease 1 is caused by mutations of the CLCN5 gene, coding for the chloride/proton exchanger ClC-5; and Dent disease 2 by mutations of the OCRL gene, coding for the inositol polyphosphate 5-phosphatase OCRL-1. Herein, we review previously reported mutations (n = 192) and their associated phenotype in 377 male patients with Dent disease 1 and describe phenotype and novel (n = 42) and recurrent mutations (n = 24) in a large cohort of 117 Dent disease 1 patients belonging to 90 families. The novel missense and in-frame mutations described were mapped onto a three-dimensional homology model of the ClC-5 protein. This analysis suggests that these mutations affect the dimerization process, helix stability, or transport. The phenotype of our cohort patients supports and extends the phenotype that has been reported in smaller studies.

Update of PAX2 mutations in renal coloboma syndrome and establishment of a locus-specific database.

Renal coloboma syndrome, also known as papillorenal syndrome is an autosomal-dominant disorder characterized by ocular and renal malformations. Mutations in the paired-box gene, PAX2, have been identified in approximately half of individuals with classic findings of renal hypoplasia/dysplasia and abnormalities of the optic nerve. Prior to 2011, there was no actively maintained locus-specific database (LSDB) cataloguing the extent of genetic variation in the PAX2 gene and phenotypic variation in individuals with renal coloboma syndrome. Review of published cases and the collective diagnostic experience of three laboratories in the United States, France, and New Zealand identified 55 unique mutations in 173 individuals from 86 families. The three clinical laboratories participating in this collaboration contributed 28 novel variations in 68 individuals in 33 families, which represent a 50% increase in the number of variations, patients, and families published in the medical literature. An LSDB was created using the Leiden Open Variation Database platform: www.lovd.nl/PAX2. The most common findings reported in this series were abnormal renal structure or function (92% of individuals), ophthalmological abnormalities (77% of individuals), and hearing loss (7% of individuals). Additional clinical findings and genetic counseling implications are discussed.

School level of children carrying a HNF1B variant or a deletion.

The prevalence of neurological involvement in patients with a deletion of or a variant in the HNF1B gene remains discussed. The aim of this study was to investigate the neuropsychological outcomes in a large cohort of children carrying either a HNF1B whole-gene deletion or a disease-associated variant, revealed by the presence of kidney anomalies. The neuropsychological development-based on school level-of 223 children included in this prospective cohort was studied. Data from 180 children were available for analysis. Patients mean age was 9.6 years, with 39.9% of girls. Among these patients, 119 carried a HNF1B deletion and 61 a disease-associated variant. In the school-aged population, 12.7 and 3.6% of patients carrying a HNF1B deletion and a disease-associated variant had special educational needs, respectively. Therefore, the presence of a HNF1B deletion increases the risk to present with a neuropsychiatric involvement when compared with the general population. On the other hand, almost 90% of patients carrying a HNF1B disease-associated variant or deletion have a normal schooling in a general educational environment. Even if these findings do not predict the risk of neuropsychiatric disease at adulthood, most patients diagnosed secondary to kidney anomalies do not show a neurological outcome severe enough to impede standard schooling at elementary school. These results should be taken into account in prenatal counseling.

Long-term outcome of idiopathic steroid-resistant nephrotic syndrome: a multicenter study.

Long-term outcome of idiopathic steroid-resistant nephrotic syndrome was retrospectively studied in 78 children in eight centers for the past 20 years. Median age at onset was 4.4 years (1.1-15.0 years) and the gender ratio was 1.4. Median follow-up period was 7.7 years (1.0-19.7 years). The disease in 45 patients (58%) was initially not steroid-responsive and in 33 (42%) it was later non-responsive. The main therapeutic strategies included administration of ciclosporine (CsA) alone (n = 29; 37%) and CsA + mycophenolate mofetil (n = 18; 23%). Actuarial patient survival rate after 15 years was 97%. Renal survival rate after 5 years, 10 years and 15 years was 75%, 58% and 53%, respectively. An age at onset of nephrotic syndrome (NS) > 10 years was the only independent predictor of end-stage renal disease (ESRD) in a multivariate analysis using a Cox regression model (P < 0.001). Twenty patients (26%) received transplants; ten showed recurrence of the NS: seven within 2 days, one within 2 weeks, and two within 3-5 months. Seven patients lost their grafts, four from recurrence. Owing to better management, kidney survival in idiopathic steroid-resistant nephrotic syndrome (SRNS) has improved during the past 20 years. Further prospective controlled trials will delineate the potential benefit of new immunosuppressive treatment.

Implication of a healthcare worker with chronic skin disease in the transmission of an epidemic strain of methicillin-resistant Staphylococcus aureus in a pediatric intensive care unit.

This outbreak of colonization of neonates in a 10-bed pediatric intensive care unit illustrates the probable role of a healthcare worker (HCW) in the transmission of methicillin-resistant Staphylococcus aureus, despite good hygienic practices. It raises the issue of preventive exclusion of HCWs affected by chronic skin disease from high-risk units.

Severe cutaneous aspergillosis in a premature neonate linked to nonsterile disposable glove contamination?

After having eliminated a dysfunction of the hospital's ventilation system and any other possible environmental reservoir, the investigation of a fatal case of primary cutaneous aspergillosis in a neonate with extremely low birth weight led to the conclusion that nonsterile disposable gloves kept stored in their native packages were the likely source of contamination.

Prospective, randomized trial comparing short and long intravenous antibiotic treatment of acute pyelonephritis in children: dimercaptosuccinic acid scintigraphic evaluation at 9 months.

OBJECTIVE: We report a prospective, randomized, multicenter trial that compared the effect of 3 vs 8 days of intravenous ceftriaxone treatment on the incidence of renal scarring at 6 to 9 months of follow-up in 383 children with a first episode of acute pyelonephritis. METHODS: After initial treatment with intravenous netilmicin and ceftriaxone, patients were randomly assigned to either 5 days of oral antibiotics (short intravenous treatment) or 5 days of intravenous ceftriaxone (long intravenous treatment). Inclusion criteria were age 3 months to 16 years and first acute pyelonephritis episode, defined by fever of >38.5 degrees C, C-reactive protein level of >20 mg/L, and bacteriuria at >10(5)/mL. All patients underwent 99m technetium-dimercaptosuccinic acid scintigraphy 6 to 9 months after inclusion. A total of 548 children were included, 48 of whom were secondarily excluded and 117 of whom were lost to follow-up or had incomplete data; therefore, 383 children were eligible, 205 of them in the short intravenous treatment group and 178 in the long intravenous treatment group. RESULTS: At inclusion, median age was 15 months, median duration of fever was 43 hours, and median C-reactive protein level was 122 mg/L. A total of 37% (143 of 383) of patients had a vesicoureteral reflux grades 1 to 3. Patient characteristics at inclusion were similar in both groups, except for a significantly higher proportion of girls in the short intravenous treatment group. The frequency of renal scars at scintigraphy was similar in both groups. Multivariate analysis demonstrated that renal scars were significantly associated with increased renal height at initial ultrasound and with the presence of grade 3 vesicoureteric reflux. CONCLUSIONS: The incidence of renal scars was similar in patients who received 3 days compared 8 days of intravenous ceftriaxone. Increased renal height at initial ultrasound examination and grade 3 vesicoureteric reflux were significant risk factors for renal scars.

Surgery of the abdominal aorta and its branches in children: late follow-up.

BACKGROUND: The aim of this study was to evaluate the late results in adult patients who underwent surgery of the abdominal aorta as children. METHODS: During a 17-year period, eight children underwent surgery for lesions of the abdominal aorta. There were 6 boys and 2 girls, with an average age of 10 years. The presenting symptom that led to diagnosis of abdominal aortic lesions was hypertension in five cases and lower-limb claudication in three. The underlying disease was middle aortic syndrome in three cases, infrarenal aortic hypoplasia in two, infrarenal aortic aneurysm in two, and Takayasu's disease in one. Five children had associated renal artery lesions, including four with bilateral lesions and one with a unilateral lesion. Aortic bypass was used in all cases. A straight tube graft was placed between the distal descending thoracic or supraceliac aorta and the infrarenal aorta in six cases, and a bifurcated bypass was placed between the infrarenal aorta and the iliac arteries in two. Renal artery revascularization procedures (n = 9) included ex vivo repair with renal autotransplantation in five cases, direct reimplantation on the arch of Riolan in two, and direct reimplantation of the renal artery onto the aortic graft in two. RESULTS: One patient died on postoperative day 1. The remaining seven patients recovered uneventfully. Mean follow-up was 10.2 years. No patient was lost to follow-up. Further surgical intervention was required in three patients. The indications for additional surgery were fibrosis of a renal artery reimplanted onto the graft at 3 years, deterioration of the aortoaortic graft at 5 years, and false iliac aneurysm at 20 years. All seven patients had normal physical development. The average increase in height and weight were 28.5 cm and 26.2 kg, respectively. All patients had normal sexual function, and two are parents. All patients are currently asymptomatic. Short Form 36 scores for quality-of-life parameters were 78% to 83%. CONCLUSIONS: Late results of abdominal aortic surgery in children, in our experience, are encouraging. Quality of life in adulthood was excellent. Insofar as possible, correction should be deferred until the child is 8 to 10 years old so that a prosthesis of sufficient diameter can be used.

Prognosis of lupus membranous nephropathy in children.

The occurrence of membranous nephropathy in pediatric series of systemic lupus erythematosus has been reported only rarely, probably due to a very low frequency. One hundred fifty-four children who were seen in 100 French pediatric centers between January 2002 and April 2005 were included. Fifteen (12 girls and three boys) out of the 81 (18.5 %) children with renal involvement presented histological features of membranous nephropathy. Their ages ranged from six to 15 years old (mean=11.3) at the age of SLE diagnosis and 8/15 children were of African origin. Isolated membranous nephropathy was observed in nine patients, of whom five patients displayed a complete recovery following immunosuppressive treatment. Associated proliferative lesions were observed on the first kidney specimen in two patients and in a further renal biopsy in four other patients, leading to a less favorable course of lupus nephropathy.