Development of a tool for predicting HNF1B mutations in children and young adults with congenital anomalies of the kidneys and urinary tract.

BACKGROUND: We aimed to develop a tool for predicting HNF1B mutations in children with congenital abnormalities of the kidneys and urinary tract (CAKUT). METHODS: The clinical and laboratory data from 234 children and young adults with known HNF1B mutation status were collected and analyzed retrospectively. All subjects were randomly divided into a training (70%) and a validation set (30%). A random forest model was constructed to predict HNF1B mutations. The recursive feature elimination algorithm was used for feature selection for the model, and receiver operating characteristic curve statistics was used to verify its predictive effect. RESULTS: A total of 213 patients were analyzed, including HNF1B-positive (mut + , n = 109) and HNF1B-negative (mut - , n = 104) subjects. The majority of patients had mild chronic kidney disease. Kidney phenotype was similar between groups, but bilateral kidney anomalies were more frequent in the mut + group. Hypomagnesemia and hypermagnesuria were the most common abnormalities in mut + patients and were highly selective of HNF1B. Hypomagnesemia based on age-appropriate norms had a better discriminatory value than the age-independent cutoff of 0.7 mmol/l. Pancreatic anomalies were almost exclusively found in mut + patients. No subjects had hypokalemia; the mean serum potassium level was lower in the HNF1B cohort. The abovementioned, discriminative parameters were selected for the model, which showed a good performance (area under the curve: 0.85; sensitivity of 93.67%, specificity of 73.57%). A corresponding calculator was developed for use and validation. CONCLUSIONS: This study developed a simple tool for predicting HNF1B mutations in children and young adults with CAKUT.

Phenotypic Variability in Siblings With Autosomal Recessive Polycystic Kidney Disease.

Introduction: Autosomal recessive polycystic kidney disease (ARPKD) is a rare monogenic disorder characterized by early onset fibrocystic hepatorenal changes. Previous reports have documented pronounced phenotypic variability even among siblings in terms of patient survival. The underlying causes for this clinical variability are incompletely understood. Methods: We present the longitudinal clinical courses of 35 sibling pairs included in the ARPKD registry study ARegPKD, encompassing data on primary manifestation, prenatal and perinatal findings, genetic testing, and family history, including kidney function, liver involvement, and radiological findings. Results: We identified 70 siblings from 35 families with a median age of 0.7 (interquartile range 0.1-6.0) years at initial diagnosis and a median follow-up time of 3.5 (0.2-6.2) years. Data on PKHD1 variants were available for 37 patients from 21 families. There were 8 patients from 7 families who required kidney replacement therapy (KRT) during follow-up. For 44 patients from 26 families, antihypertensive therapy was documented. Furthermore, 37 patients from 24 families had signs of portal hypertension with 9 patients from 6 families having substantial hepatic complications. Interestingly, pronounced variability in the clinical course of functional kidney disease was documented in only 3 sibling pairs. In 17 of 20 families of our cohort of neonatal survivors, siblings had only minor differences of kidney function at a comparable age. Conclusion: In patients surviving the neonatal period, our longitudinal follow-up of 70 ARPKD siblings from 35 families revealed comparable clinical courses of kidney and liver diseases in most families. The data suggest a strong impact of the underlying genotype.

IgA vasculitis nephritis clinical course and kidney biopsy - national study in children.

The aim of the study was to investigate the relationship between the severity of typical clinical symptoms, severity of histopathological lesions in kidney biopsies in IgA vasculitis nephritis (IgAVN) and to propose indications for kidney biopsy in children. MATERIAL AND METHODS: This retrospective study enrolled 106 patients, included in the IgAVN registry of Polish children, diagnosed by kidney biopsy. Renal and extrarenal symptoms at onset of the disease were analyzed. Biopsy results were assessed using Oxford classifications (MEST-C). The patients were divided into 3 groups depending on the severity of proteinuria: A-nephrotic proteinuria with hematuria; B-non-nephrotic proteinuria with hematuria; C-isolated hematuria. RESULTS: The first symptoms of nephropathy were observed at the 0.7 (1-128.4) months from the onset of extrarenal symptoms. Kidney biopsy was performed on 39 (6-782) days after the onset of nephropathy symptoms. MEST-C score 4 or 5 was significantly more frequent in children from group A than in groups B and C. Significantly higher mean MEST-C score was found in patients with abdominal symptoms than without. In group A: S0 and T0 we found in significantly shorter time to kidney biopsy than in S1, T1-2 p < 0.05) and in group B the significantly shorter time in T0 compare to T1-2 p < 0.05). The ROC analysis shows that S1 changes appear in kidney biopsies in group A with cut off 21 days (AUC 0,702, p = 0.004, sensitivity 0.895 specificity 0.444) T1-2 changes after 35 days (AUC 0.685, p = 0.022, sensitivity 0.750, specificity 0.615), and in goupn B T1-2 cut off is 74 days (AUC 0,738, p = 0.002, sensitivity 0.667, specificity 0.833). CONCLUSIONS: In childhood IgAVN, the severity of changes in the urine is clearly reflected in the result of a kidney biopsy. The biopsy should be performed in patients with nephrotic proteinuria no later than 3 weeks after the onset of this symptom in order to promptly apply appropriate treatment and prevent disease progression. Accompanying abdominal symptoms predispose to higher MESTC score.

The Role of Complement Component C3 Activation in the Clinical Presentation and Prognosis of IgA Nephropathy-A National Study in Children.

The aim of the study was to evaluate the influence of the intensity of mesangial C3 deposits in kidney biopsy and the serum C3 level on the clinical course and outcomes of IgAN in children. The study included 148 children from the Polish Pediatric IgAN Registry, diagnosed based on kidney biopsy. Proteinuria, creatinine, IgA, C3 were evaluated twice in the study group, at baseline and the end of follow-up. Kidney biopsy was categorized using the Oxford classification, with a calculation of the MEST-C score. The intensity of IgA and C3 deposits were rated from 0 to +4 in immunofluorescence microscopy. The intensity of mesangial C3 > +1 deposits in kidney biopsy has an effect on renal survival with normal GFR in children with IgAN. A reduced serum C3 level has not been a prognostic factor in children but perhaps this finding should be confirmed in a larger group of children.

Genome-Wide Survey for Microdeletions or -Duplications in 155 Patients with Lower Urinary Tract Obstructions (LUTO).

Lower urinary tract obstruction (LUTO) is, in most cases, caused by anatomical blockage of the bladder outlet. The most common form are posterior urethral valves (PUVs), a male-limited phenotype. Here, we surveyed the genome of 155 LUTO patients to identify disease-causing CNVs. Raw intensity data were collected for CNVs detected in LUTO patients and 4.392 healthy controls using CNVPartition, QuantiSNP and PennCNV. Overlapping CNVs between patients and controls were discarded. Additional filtering implicated CNV frequency in the database of genomic variants, gene content and final visual inspection detecting 37 ultra-rare CNVs. After, prioritization qPCR analysis confirmed 3 microduplications, all detected in PUV patients. One microduplication (5q23.2) occurred de novo in the two remaining microduplications found on chromosome 1p36.21 and 10q23.31. Parental DNA was not available for segregation analysis. All three duplications comprised 11 coding genes: four human specific lncRNA and one microRNA. Three coding genes (FBLIM1, SLC16A12, SNCAIP) and the microRNA MIR107 have previously been shown to be expressed in the developing urinary tract of mouse embryos. We propose that duplications, rare or de novo, contribute to PUV formation, a male-limited phenotype.

Refining genotype-phenotype correlations in 304 patients with autosomal recessive polycystic kidney disease and PKHD1 gene variants.

Autosomal recessive polycystic kidney disease (ARPKD) is a severe disease of early childhood that is clinically characterized by fibrocystic changes of the kidneys and the liver. The main cause of ARPKD are variants in the PKHD1 gene encoding the large transmembrane protein fibrocystin. The mechanisms underlying the observed clinical heterogeneity in ARPKD remain incompletely understood, partly due to the fact that genotype-phenotype correlations have been limited to the association of biallelic null variants in PKHD1 with the most severe phenotypes. In this observational study we analyzed a deep clinical dataset of 304 patients with ARPKD from two independent cohorts and identified novel genotype-phenotype correlations during childhood and adolescence. Biallelic null variants frequently show severe courses. Additionally, our data suggest that the affected region in PKHD1 is important in determining the phenotype. Patients with two missense variants affecting amino acids 709-1837 of fibrocystin or a missense variant in this region and a null variant less frequently developed chronic kidney failure, and patients with missense variants affecting amino acids 1838-2624 showed better hepatic outcome. Variants affecting amino acids 2625-4074 of fibrocystin were associated with poorer hepatic outcome. Thus, our data expand the understanding of genotype-phenotype correlations in pediatric ARPKD patients and can lay the foundation for more precise and personalized counselling and treatment approaches.

Copy Number Variant Analysis and Genome-wide Association Study Identify Loci with Large Effect for Vesicoureteral Reflux.

BACKGROUND: Vesicoureteral reflux (VUR) is a common, familial genitourinary disorder, and a major cause of pediatric urinary tract infection (UTI) and kidney failure. The genetic basis of VUR is not well understood. METHODS: A diagnostic analysis sought rare, pathogenic copy number variant (CNV) disorders among 1737 patients with VUR. A GWAS was performed in 1395 patients and 5366 controls, of European ancestry. RESULTS: Altogether, 3% of VUR patients harbored an undiagnosed rare CNV disorder, such as the 1q21.1, 16p11.2, 22q11.21, and triple X syndromes ((OR, 3.12; 95% CI, 2.10 to 4.54; P=6.35×10-8) The GWAS identified three study-wide significant and five suggestive loci with large effects (ORs, 1.41-6.9), containing canonical developmental genes expressed in the developing urinary tract (WDPCP, OTX1, BMP5, VANGL1, and WNT5A). In particular, 3.3% of VUR patients were homozygous for an intronic variant in WDPCP (rs13013890; OR, 3.65; 95% CI, 2.39 to 5.56; P=1.86×10-9). This locus was associated with multiple genitourinary phenotypes in the UK Biobank and eMERGE studies. Analysis of Wnt5a mutant mice confirmed the role of Wnt5a signaling in bladder and ureteric morphogenesis. CONCLUSIONS: These data demonstrate the genetic heterogeneity of VUR. Altogether, 6% of patients with VUR harbored a rare CNV or a common variant genotype conferring an OR >3. Identification of these genetic risk factors has multiple implications for clinical care and for analysis of outcomes in VUR.

Health-related quality of life in children with immunoglobulin A nephropathy - results of a multicentre national study.

INTRODUCTION: Immunoglobulin A nephropathy (IgAN) may lead to end stage renal disease and severely affect patient functioning and wellbeing. The aim of the study was to evaluate health-related quality of life (HRQoL) in children and adolescents with IgAN, and compare HRQoL in relation to the disease course, social status and psychological factors, such as expressing anger and perceived personal competence. MATERIAL AND METHODS: The multicentre cross-sectional study included 51 patients ≥ 8 years from 7 paediatric nephrology centres in Poland. Psychometric analysis was performed using the Kidscreen-52 questionnaire to evaluate HRQoL, the Anger Expression Scale to evaluate the severity of anger and the Personal Competence Scale to measure general perception of personal competence. RESULTS: Mean age of patients was 14.54 ±3.69 years; duration since the diagnosis of IgAN was 4.98 ±3.9 years. Patients with IgAN rated their psychological wellbeing as significantly worse compared to healthy peers (p < 0.05). The presence of proteinuria was associated with significantly worse physical wellbeing (58.72 ±18.45 vs. 74.44 ±22.97; p < 0.05). Current therapy (steroids/immunosuppressive drugs) had no effect on HRQoL in the study group. Perceived personal competence was rated high by 49% of children in the study group. Children with IgAN were characterized by lower intensity of expressed anger (p < 0.001) and significantly higher intensity of suppressed anger (p < 0.01) compared to reference ranges. Severity of expressed anger correlated positively with the parent relations and school environment dimensions of HRQoL. CONCLUSIONS: We found lower HRQoL in regard to physical and psychological wellbeing in a group of Polish children with IgAN compared to healthy peers. HRQoL should be monitored in this patient group.

Heterozygous loss of WBP11 function causes multiple congenital defects in humans and mice.

The genetic causes of multiple congenital anomalies are incompletely understood. Here, we report novel heterozygous predicted loss-of-function (LoF) and predicted damaging missense variants in the WW domain binding protein 11 (WBP11) gene in seven unrelated families with a variety of overlapping congenital malformations, including cardiac, vertebral, tracheo-esophageal, renal and limb defects. WBP11 encodes a component of the spliceosome with the ability to activate pre-messenger RNA splicing. We generated a Wbp11 null allele in mouse using CRISPR-Cas9 targeting. Wbp11 homozygous null embryos die prior to E8.5, indicating that Wbp11 is essential for development. Fewer Wbp11 heterozygous null mice are found than expected due to embryonic and postnatal death. Importantly, Wbp11 heterozygous null mice are small and exhibit defects in axial skeleton, kidneys and esophagus, similar to the affected individuals, supporting the role of WBP11 haploinsufficiency in the development of congenital malformations in humans. LoF WBP11 variants should be considered as a possible cause of VACTERL association as well as isolated Klippel-Feil syndrome, renal agenesis or esophageal atresia.

eGFR values and selected renal urine biomarkers in preterm neonates with uncomplicated clinical course.

BACKGROUND: Diagnosing acute kidney injury (AKI) in preterm newborns, who are particularly susceptible to renal damage, is a serious challenge as there is no definite consensus about the diagnostic criteria. OBJECTIVES: The objective of this study was to measure the values for selected urinary biomarkers and estimated glomerular filtration rate (eGFR) among a population of preterm infants with uncomplicated clinical course as well as to determine whether these markers depend on birth weight (BW), gestational age (GA), postnatal age (PNA), or gender. MATERIAL AND METHODS: The prospective study was carried out in neonatal intensive care unit (NICU). The evaluation included 57 children that were divided into 3 categories according to BW: low birth weight (LBW) - 1501-2500 g (22 infants); very low birth weight (VLBW) - 1000-1500 g (25 infants); and extremely low birth weight (ELBW) - 750-999 g (10 infants). Urine samples were collected daily between the 4th and 28th day of life for measurements of creatinine (Cr), neutrophil gelatinase-associated lipocalin (NGAL), osteopontin (OPN), and human kidney injury molecule 1 (hKIM1). RESULTS: The values of the 3 urine tubular biomarkers, serum creatinine and eGFR were taken in substantially healthy preterm infants with normal kidney function at 4 time intervals during the neonatal period. Their correlations were determined and a multivariable regression analysis was carried out with respect to BW, GA, PNA, and gender. Trends of the studied markers in terms of PNA and BW were also assessed with the Jonckheere-Terpstra test. CONCLUSIONS: Glomerular and tubular function in preterm neonates during the 1st month of life is significantly influenced by BW, GA, PNA, and gender.

Author Correction: The copy number variation landscape of congenital anomalies of the kidney and urinary tract.

In the version of this article initially published, affiliation 38 incorrectly read "ICNU-Nephrology and Urology Department, Barcelona, Spain"; "Renal Division, Hospital Clinic, IDIBAPS, University of Barcelona, Barcelona, Spain" is the correct affiliation. The error has been corrected in the HTML and PDF versions of the article.

Factors affecting mortality in children requiring continuous renal replacement therapy in pediatric intensive care unit.

BACKGROUND: Acute kidney injury (AKI) occurs in up to 30% of pediatric intensive care unit (PICU) patients and is associated with a high mortality rate. OBJECTIVES: The objective of the study was to evaluate factors associated with the outcome and to identify the prognostic factors in children receiving continuous renal replacement therapy (CRRT). MATERIAL AND METHODS: This was a retrospective, single-center study, including 46 patients. RESULTS: Logistic regression analysis demonstrated significant effects on patient survival exerted by the percentage of fluid overload (FO%) (odds ratio (OR): 1.030; p = 0.044). In the group of patients with FO% < 25%, the mortality was 33.3%, and in the FO% ≥ 25% group, the mortality was 67.9% (p < 0.001). The probability of death without multi-organ failure (MOF) was 13%, while with MOF it was 74%. There was no difference in the duration of hospitalization between the CRRT patients (mean: 21.9 days) and the general population of children hospitalized in PICU in the same period (n = 3,255; mean: 25.4 days); however, a significant difference was noted in mortality between the 2 groups of patients (54% vs 6.5%; p < 0.001). CONCLUSIONS: The mortality of PICU CRRT patients is more than 8-fold higher than the mortality of the total PICU population. Coexisting MOF increases the mortality almost 6 times. The mortality of children with FO% ≥ 25% was more than 2-fold higher than the mortality of children with FO% < 25%.

The copy number variation landscape of congenital anomalies of the kidney and urinary tract.

Congenital anomalies of the kidney and urinary tract (CAKUT) are a major cause of pediatric kidney failure. We performed a genome-wide analysis of copy number variants (CNVs) in 2,824 cases and 21,498 controls. Affected individuals carried a significant burden of rare exonic (that is, affecting coding regions) CNVs and were enriched for known genomic disorders (GD). Kidney anomaly (KA) cases were most enriched for exonic CNVs, encompassing GD-CNVs and novel deletions; obstructive uropathy (OU) had a lower CNV burden and an intermediate prevalence of GD-CNVs; and vesicoureteral reflux (VUR) had the fewest GD-CNVs but was enriched for novel exonic CNVs, particularly duplications. Six loci (1q21, 4p16.1-p16.3, 16p11.2, 16p13.11, 17q12 and 22q11.2) accounted for 65% of patients with GD-CNVs. Deletions at 17q12, 4p16.1-p16.3 and 22q11.2 were specific for KA; the 16p11.2 locus showed extensive pleiotropy. Using a multidisciplinary approach, we identified TBX6 as a driver for the CAKUT subphenotypes in the 16p11.2 microdeletion syndrome.

[B-type natriuretic peptide as a marker of cardiac dysfunction in children with chronic kidney disease]. / Peptyd natriuretyczny typu B jako marker uszkodzenia serca u dzieci z przewlekla choroba nerek.

Left ventricular hypertrophy is the most common organ damage in children with chronic kidney disease (CKD). AIM: The aim of the study was to assess the usefulness of B-type natriuretic peptide (BNP) as a marker of heart injury in children with CKD. MATERIALS AND METHODS: We included 66 children (41 boys and 25 girls) aged 0.7 to 18.6 (median 11.6) years with CKD stage 1-5. The concentrations of urea, creatinine, cystatin C and BNP in blood serum were assessed, and the estimated glomerular filtration rate (eGFR) was calculated from the Schwartz and Filler formulas. Patients were divided into groups depending on the CKD stage [group 1: CKD stages 1 + 2 (GFR> 60 ml/min/1.73 m2), group 2: stage 3 (GFR = 30-59 ml/min/1.73 m2), group 3: CKD stage 4 (GFR 15-29 ml/min/ 1.73 m2), group 4 - stage 5 (dialyzed children)]. On the basis of echocardiography, the left ventricular mass (LVM) was calculated, which was indexed for height (left ventricular mass index, LVMI). Left ventricular hypertrophy (LVH) was diagnosed if the LVMI value was > 95th percentile for sex and age. RESULTS: Depending on the CKD stage the median BNP concentrations for group 1, group 2, group 3, and group 4 were 2.5 pg/ml, 6.0 pg/ml, 9.3 pg/ml and 18.0 pg/ml, and the LVH prevalence 27.3%, 33.3%, 60.0% and 63.6% , respectively. Significant correlations between BNP concentration and LVH expressed by LVMI (R=0.256, p=0.038), creatinine (R=0.453, p<0.001), cystatin (R=0.494, p<0.001) and eGFR (R=-0.473, p<0.001) were found. CONCLUSIONS: In children with chronic kidney disease, BNP is an indicator of heart failure correlating with renal function parameters and left ventricular mass index.

Long-term renal outcome in children with OCRL mutations: retrospective analysis of a large international cohort.

Background: Lowe syndrome (LS) and Dent-2 disease (DD2) are disorders associated with mutations in the OCRL gene and characterized by progressive chronic kidney disease (CKD). Here, we aimed to investigate the long-term renal outcome and identify potential determinants of CKD and its progression in children with these tubulopathies. Methods: Retrospective analyses were conducted of clinical and genetic data in a cohort of 106 boys (LS: 88 and DD2: 18). For genotype-phenotype analysis, we grouped mutations according to their type and localization. To investigate progression of CKD we used survival analysis by Kaplan-Meier method using stage 3 CKD as the end-point. Results: Median estimated glomerular filtration rate (eGFR) was lower in the LS group compared with DD2 (58.8 versus 87.4 mL/min/1.73 m2, P < 0.01). CKD stage II-V was found in 82% of patients, of these 58% and 28% had moderate-to-severe CKD in LS and DD2, respectively. Three patients (3%), all with LS, developed stage 5 of CKD. Survival analysis showed that LS was also associated with a faster CKD progression than DD2 (P < 0.01). On multivariate analysis, eGFR was dependent only on age (b = -0.46, P < 0.001). Localization, but not type of mutations, tended to correlate with eGFR. There was also no significant association between presence of nephrocalcinosis, hypercalciuria, proteinuria and number of adverse clinical events and CKD. Conclusions: CKD is commonly found in children with OCRL mutations. CKD progression was strongly related to the underlying diagnosis but did not associate with clinical parameters, such as nephrocalcinosis or proteinuria.

Antihypertensive treatment prescription in pediatric dialysis patients in Poland: A comparison between two nationwide studies 2003/2004-2013.

BACKGROUND: Blood pressure in pediatric dialyzed patients is under poor control. OBJECTIVES: The aim of the study was to assess the strategy and efficacy of antihypertensive drugs used for the treatment of hypertension in pediatric dialyzed patients in 2013 in comparison with the data collected in 2003/2004. The results have been viewed against present strategies of antihypertensive treatment in children. There is still limited data concerning the treatment of hypertension in dialyzed pediatric patients. MATERIAL AND METHODS: The study embraced 10 of 12 pediatric dialysis units in Poland treating 59 pediatric patients (mean age - 132 months). Collected information included present antihypertensive treatment with regard to drug classes and the dose of antihypertensive agent. The treatment was regarded as effective if both systolic and diastolic values of blood pressure were below 1.64 SDS. The results from 2013 were juxtaposed with previously analyzed data from a similar study on hypertension in dialyzed children conducted in 2003/2004. RESULTS: Forty subjects have been provided with antihypertensive treatment. In monotherapy and polytherapy 50% of the subjects were treated with ACEI (enalapril and ramipril), 67.5% with amlodipine, 50% with beta-blockers. Only 10% of the subjects were treated with angiotensin II receptor blocker (losartan). Thirty percent of the subjects received furosemide, whereas 5% were given doxazosin. Antihypertensive drugs regarded as the 2nd and 3rd choice in treating high blood pressure (doxazosin, beta-blockers and furosemide) were applied as monotherapy in 46% of the patients. Satisfactory control of treated blood pressure was reached in 45% of them. CONCLUSIONS: Antihypertensive treatment in dialyzed children did not change significantly during the last decade with regard to the groups of drugs being used. Despite a wider feasibility of antihypertensive substances, the effectiveness of this therapy was still unsatisfactory.

Evaluation of the effect of 3-month bladder basic advice in children with monosymptomatic nocturnal enuresis.

INTRODUCTION: Advice (BBA) into the standards of patients' care in both monosymptomatic and non-monosymptomatic nocturnal enuresis. Although the idea of this recommendation was clear and reflects clinical experience, duration and efficacy have not been definitely established. Recent data have demonstrated the lack of efficacy of BBA and a fierce discussion has ensued. The present study was aimed to assess the efficacy of BBA in a group of previously untreated children with primary monosymptomatic nocturnal enuresis (MNE). STUDY DESIGN: The study was a prospective interventional multicenter trial in a cohort of previously untreated MNE patients. Forty-nine children (36 males, 13 females, mean age 7.2 years) were included in the analysis. The treatment efficacy was assessed at the 30th, 60th, and 90th days of BBA. RESULTS: We discovered that the mean number of wet nights decreased significantly (p < 0.001) only after 3 months of BBA from 8.9 to 5.9 episodes every 2 weeks. BBA was fully successful in 2% o the children after 30 day, 12% after 60 days, and 18% after 90 days (Figure). Partial response (by ICCS) was assessed for 8%, 20%, and 34% of the patients. We noted a relatively high rate of non-responders that decreased from 90% to 47% after 90 days. We detected no differences in BBA efficacy between children with night-time polyuria or decreased maximal voided volume. A lower number of wet nights initially predicted the response to the BBA. DISCUSSION: Our study confirmed rather limited efficacy of BBA, similarly to previous observations, but provided more information on isolated MNE, because of a more specific study group and longer period of observation. The limitation of the study was lack of randomization. CONCLUSION: Our study revealed that in treatment-naïve children with monosymptomatic enuresis basic bladder training had a low (18%) and late effect, mostly pronounced after the third month of therapy. It seems that only if the patient presents with a favorable profile of bedwetting, occasionally and with a high maximum voided volume, it is worth maintaining BBA for a longer period of up to 3 months before initiating second-line therapy. In an unfavorable initial profile desmopressin or an alarm may be introduced much earlier.

Filter Size Not the Anticoagulation Method is the Decisive Factor in Continuous Renal Replacement Therapy Circuit Survival.

BACKGROUND/AIM: As continuous renal replacement therapy (CRRT) has emerged as a standard therapy in pediatric intensive care units (PICU), many related issues that may have an impact on circuit survival have gained in importance. Objective of the study was an evaluation of factors associated with circuit survival, including anticoagulation (ACG). METHODS: Retrospective study that included 40 patients, who in total received 7636 hours of CRRT during 150 sessions (84 filters, 4260 hours with heparin anticoagulation (Hep-ACG); 66 filters, 3376 hours with regional citrate anticoagulation (RCA)). RESULTS: The Kaplan-Meier analysis of the total circuit survival time depending on the type of ACG did not demonstrate a significant difference between Hep-ACG and RCA. The percentage of clotted filters was significantly higher in case of smaller filters (HF20: 58.8%; ST60: 29.5%; ST100: 15.8%), and their lifetime was significantly lower regardless of ACG (the mean and median lifetime for HF20: 38.7/27.0 h; for ST60: 54.1/72.0 h., for ST100: 62.1/72.0 h, respectively). CONCLUSIONS: Irrespectively of filter size, filter clotting occurs within the first 24 hours after the initiation of CRRT. Most commonly, clotting affects small filters, and their lifetime is significantly shorter as compared to larger filters regardless of the type of the ACG.

The Phenotypic Spectrum of Nephropathies Associated with Mutations in Diacylglycerol Kinase ε.

The recent discovery of mutations in the gene encoding diacylglycerol kinase ε (DGKE) identified a novel pathophysiologic mechanism leading to HUS and/or MPGN. We report ten new patients from eight unrelated kindreds with DGKE nephropathy. We combined these cases with all previously published cases to characterize the phenotypic spectrum and outcomes of this new disease entity. Most patients presented with HUS accompanied by proteinuria, whereas a subset of patients exhibited clinical and histologic patterns of MPGN without TMA. We also report the first two patients with clinical and histologic HUS/MPGN overlap. DGKE-HUS typically manifested in the first year of life but was not exclusively limited to infancy, and viral triggers frequently preceded HUS episodes. We observed signs of complement activation in some patients with DGKE-HUS, but the role of complement activation remains unclear. Most patients developed a slowly progressive proteinuric nephropathy: 80% of patients did not have ESRD within 10 years of diagnosis. Many patients experienced HUS remission without specific treatment, and a few patients experienced HUS recurrence despite complete suppression of the complement pathway. Five patients received renal allografts, with no post-transplant recurrence reported. In conclusion, we did not observe a clear genotype-phenotype correlation in patients with DGKE nephropathy, suggesting additional factors mediating phenotypic heterogeneity. Furthermore, the benefits of anti-complement therapy are questionable but renal transplant may be a feasible option in the treatment of patients with this condition.

Reference ranges and impact of selected confounders on classic serum and urinary renal markers in neonatal period.

PURPOSE: Renal injury in term and pre-term neonates may be an antecedent to chronic kidney disease in the child's further life. The aim of the paper was to compile a reference range for selected serum and urinary renal markers in the neonatal period for full-term (FT) and pre-term (PT) newborns. MATERIAL AND METHODS: The prospective study included 23 FT infants (birth weight - BW≥2500g and gestational age - GA≥37Hbd) and 32 PT children (BW<2500g and GA<37Hbd) in good general condition, without acute kidney injury (AKI) or sepsis. Between the 4th and 28th DOL, urinary concentrations of the studied renal markers (uCr, uNa, uOsm) were determined on a daily basis, while serum creatinine (SCr) was assessed minimum every 48-72h. RESULTS: The mean GA and BW of the FT and PT infants were respectively as follows: 38.5±1.7Hbd; 3433±495.2g and 32.7±2.6Hbd; 1836.7±419.8g. For serum glomerular (SCr, eGFR) and tubular markers (FENa, RFI), the median values with normal ranges were compiled. For urinary renal markers (uCr, uNa, uOsm) and those values standardized for kg of body weight, percentile tables for 4-28DOL were elaborated. CONCLUSIONS: The study has resulted in determining the normal ranges of serum glomerular and tubular renal markers, as well as percentile tables of selected urinary renal parameters during the neonatal period. The percentile tables may prove to be helpful for further standardization of other urinary parameters per urinary creatinine in neonatal population.