Esra Baskin

Acute Renal Failure in the Neonatal Period

Acute renal failure (ARF) is a common problem in the neonatal intensive care unit (NICU). In most cases, ARF is associated with a primary condition such as sepsis, metabolic diseases, perinatal asphyxia and/or prematurity. This retrospective study investigated the course of illness, therapeutic interventions, early prognosis and risk factors associated with development of ARF in the neonatal period. A total of 1311 neonates were treated in our NICU during the 42‐month study period, and 45 of these babies had ARF. This condition was defined as serum creatinine level above 1.5 mg/dL despite normal maternal renal function. The data collected for each ARF case were contributing condition, cause and clinical course of ARF, gestational age and birth weight, age at the time of diagnosis, treatment, presence of perinatal risk factors and need for mechanical ventilation. The frequency of ARF in the NICU during the study period was 3.4%. Premature newborns constituted 31.1% of the cases. The mean birth weight in the group was 2863 ± 1082 g, and the mean age at diagnosis was 6.2 ± 7.4 days. The causes of ARF were categorized as prerenal in 29 patients (64.4%), renal in 14 patients (31.1%) and postrenal in 2 patients (4.4%). Forty‐seven percent of the cases were nonoliguric ARF. Asphyxia was the most common condition that contributed to ARF (40.0%), followed by sepsis/metabolic disease (22.2%) and feeding problems (17.8%). Therapeutic interventions were supportive in 77.8% of the cases, and dialysis was required in the other 22.2%. The mortality rate in the 45 ARF cases was 24.4%. Acute renal failure of renal origin, need for dialysis, and need for mechanical ventilation were associated with significantly increased mortality (p < 0.05). There were no statistical correlations between mortality rate and perinatal risk factors, oliguria, prematurity or blood urea nitrogen and creatinine levels. The study showed that, at our institution, ARF in the neonatal period is frequently associated with preventable conditions, specifically asphyxia, sepsis and feeding problems. Supportive therapy is effective in most cases of neonatal ARF. Acute renal failure of renal origin, need for dialysis, and need for mechanical ventilation were identified as indicators of poor prognosis in these infants. Early recognition of risk factors and rapid effective treatment of contributing conditions will reduce mortality in neonatal ARF.

Spectrum of Steroid-Resistant and Congenital Nephrotic Syndrome in Children: The PodoNet Registry Cohort

BACKGROUND AND OBJECTIVES Steroid-resistant nephrotic syndrome is a rare kidney disease involving either immune-mediated or genetic alterations of podocyte structure and function. The rare nature, heterogeneity, and slow evolution of the disorder are major obstacles to systematic genotype-phenotype, intervention, and outcome studies, hampering the development of evidence-based diagnostic and therapeutic concepts. To overcome these limitations, the PodoNet Consortium has created an international registry for congenital nephrotic syndrome and childhood-onset steroid-resistant nephrotic syndrome. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Since August of 2009, clinical, biochemical, genetic, and histopathologic information was collected both retrospectively and prospectively from 1655 patients with childhood-onset steroid-resistant nephrotic syndrome, congenital nephrotic syndrome, or persistent subnephrotic proteinuria of likely genetic origin at 67 centers in 21 countries through an online portal. RESULTS Steroid-resistant nephrotic syndrome manifested in the first 5 years of life in 64% of the patients. Congenital nephrotic syndrome accounted for 6% of all patients. Extrarenal abnormalities were reported in 17% of patients. The most common histopathologic diagnoses were FSGS (56%), minimal change nephropathy (21%), and mesangioproliferative GN (12%). Mutation screening was performed in 1174 patients, and a genetic disease cause was identified in 23.6% of the screened patients. Among 14 genes with reported mutations, abnormalities in NPHS2 (n=138), WT1 (n=48), and NPHS1 (n=41) were most commonly identified. The proportion of patients with a genetic disease cause decreased with increasing manifestation age: from 66% in congenital nephrotic syndrome to 15%-16% in schoolchildren and adolescents. Among various intensified immunosuppressive therapy protocols, calcineurin inhibitors and rituximab yielded consistently high response rates, with 40%-45% of patients achieving complete remission. Confirmation of a genetic diagnosis but not the histopathologic disease type was strongly predictive of intensified immunosuppressive therapy responsiveness. Post-transplant disease recurrence was noted in 25.8% of patients without compared with 4.5% (n=4) of patients with a genetic diagnosis. CONCLUSIONS The PodoNet cohort may serve as a source of reference for future clinical and genetic research in this rare but significant kidney disease.

The significance of antineutrophil cytoplasmic antibody in microscopic polyangitis and classic polyarteritis nodosa

AIMS To describe the distribution and features of classic polyarteritis nodosa (PAN) and microscopic polyarteritis (MPA) and the importance of antineutrophil cytoplasmic antibody (ANCA) in childhood PAN. METHODS Classic PAN was diagnosed in 15 patients based on the presence of aneurysms on angiography in 10 patients and of necrotising vasculitis in medium sized arteries in five. MPA was diagnosed in 10 patients, based on characteristic findings at renal biopsy in six and by the presence of small sized necrotising arteritis in four. Serum ANCA was detected initially by indirect immunofluorescence (IIF) followed by an immunoassay for myeloperoxidase (MPO) in each case. RESULTS The median age of the patients with classic PAN and MPA was 12 (range 8–17) and 9.5 (range 5–14) respectively. None of the patients with classic PAN had renal failure. Six of the patients with MPA presented with renal failure; four progressed to chronic renal failure. Clinically evident pulmonary–renal syndrome was present in three of the 10 patients with MPA. IIF for ANCA in classic PAN was negative in nine, showed mild staining patterns in six, and in one MPO-ELISA was mildly increased. IIF for ANCA in MPA revealed very strong perinuclear ANCA staining in nine and atypical staining in one. In MPA, median MPO-ELISA level was 42.5 EU/ml (range 20–250). Treatment of childhood PAN was satisfactory with effective treatment; however relapses did occur. CONCLUSION ANCA is useful in the diagnosis and follow up of MPA.

Genetic screening in adolescents with steroid-resistant nephrotic syndrome

Genetic screening paradigms for congenital and infantile nephrotic syndrome are well established; however, screening in adolescents has received only minor attention. To help rectify this, we analyzed an unselected adolescent cohort of the international PodoNet registry to develop a rational screening approach based on 227 patients with nonsyndromic steroid-resistant nephrotic syndrome aged 10-20 years. Of these, 21% had a positive family history. Autosomal dominant cases were screened for WT1, TRPC6, ACTN4, and INF2 mutations. All other patients had the NPHS2 gene screened, and WT1 was tested in sporadic cases. In addition, 40 sporadic cases had the entire coding region of INF2 tested. Of the autosomal recessive and the sporadic cases, 13 and 6%, respectively, were found to have podocin-associated nephrotic syndrome, and 56% of them were compound heterozygous for the nonneutral p.R229Q polymorphism. Four percent of the sporadic and 10% of the autosomal dominant cases had a mutation in WT1. Pathogenic INF2 mutations were found in 20% of the dominant but none of the sporadic cases. In a large cohort of adolescents including both familial and sporadic disease, NPHS2 mutations explained about 7% and WT1 4% of cases, whereas INF2 proved relevant only in autosomal dominant familial disease. Thus, screening of the entire coding sequence of NPHS2 and exons 8-9 of WT1 appears to be the most rational and cost-effective screening approach in sporadic juvenile steroid-resistant nephrotic syndrome.

Effect of obesity on inflammatory markers and renal functions

AIM To examine the relationship between inflammation criteria and body mass index in otherwise-healthy obese schoolchildren and to evaluate the effect of obesity on renal functions. METHODS Sixty-five otherwise-healthy obese children (median age 10.8 y, range 7.1-16.5 y; median body mass index 26.8 kg/m(2), range 19.9-38.7 kg/m(2)) and 20 healthy controls (median age 12.4 y, range 10.1-17.1 y; median body mass index 18.8 kg/m(2), range 17.3-23.1 kg/m(2)) were included. Blood and urine samples were taken from every child. RESULTS Children in the obese and control groups had similar age and sex distributions (p>0.05). Inflammatory mediators were higher in obese children (p<0.05). A significant positive correlation was found between glomerular filtration rate and body mass index in the whole study group (r=0.39, p=0.001). A positive correlation was found between body mass index standard deviation and inflammatory mediators and glomerular filtration rate. No significant difference existed regarding protein and microalbumin excretion in the urine. CONCLUSION Inflammatory mediators increased significantly in obese children, and the glomerular filtration rate increased as the body mass index increased. To prevent obesity-related complications in adulthood, it is important to take measures to prevent development of obesity during childhood.

Acute Renal Failure and Mortality After Open-Heart Surgery in Infants

Acute renal failure (ARF) is a major complication in infants who undergo cardiac surgery. The aim of this investigation was to identify possible risk factors for ARF and mortality in this patients group. Out of 64 patients, 21 (32.8%) cases developed acute renal failure and overall mortality rate was 25%. The mortality rate was higher in the infants who developed ARF than those who did not (66.7% and 4.7%, respectively, p < 0.05). Also, ARF was positively correlated with mortality (r:0.70, p < 0.0001). The nonsurvivors had lower mean serum albumin than did the survivors (p < 0.05), and serum albumin level was negatively correlated with mortality (r = − 0.34, p < 0.05). For the patients with serum albumin level < 3.5 g/dL, the unadjusted odds ratio for mortality was 4.3 (CI 95%:1.05 − 17.86). Total bypass time and aorta clamping time were significantly longer in the nonsurvivor group than in the survivor group (p < 0.05 for both). In conclusion, the significant risk factors for mortality in these patients were development of ARF, low serum albumin level, and long total bypass and aorta clamping times, which may be predictive of poor prognosis.

Effect of Congenital Heart Disease on Renal Function in Childhood

Background: Nephropathy is a well-known complication of congenital heart disease (CHD), and the risk of developing renal impairment is particularly high in patients with cyanotic CHD. Most investigations of renal impairment in CHD have involved patients 20 years and older. This study investigated renal tubule function in pediatric patients with CHD, and compared findings in cyanotic and acyanotic groups. Methods: Twenty children with acyanotic CHD, 23 children with cyanotic CHD, and 13 healthy children were enrolled. Blood and early morning urine samples were collected from each subject to measure urinary concentrations of sodium, microalbumin, creatinine, β2-microglobulin, and N-acetyl-β-D-glucosaminidase (NAG). Results: The age and sex distributions in the three groups were similar. Median fractional excretion of sodium (FeNa) and urinary NAG/creatinine were significantly higher in the cyanotic group than in the control group (p = 0.022 and p = 0.002, respectively). There were no statistically significant differences among the groups with respect to urinary β2-microglobulin/creatinine, urinary microalbumin/creatinine or glomerular filtration rate. Conclusion: Tubular injury can be detected before glomerular injury occurs even within the first decade of life in patients with cyanotic CHD.

Rituximab for post-transplant recurrences of FSGS.

Abstract:  A 14‐yr‐old boy whose primary kidney disease was FSGS developed severe recurrence of proteinuria immediately after a second living‐related kidney transplant. Despite pre‐ and post‐operative PP and immunosuppressive treatment consisting of steroids, CycA, daclizumab, and MMF, daily protein excretion and serum creatinine increased. We therefore administered rituximab on the fourth day of transplantation. He received four weekly doses of rituximab (375 mg/m2/dose), which resulted in a rapid clearing of circulating CD19‐positive B cells, and remission of proteinuria was achieved six wk after the first rituximab treatment. Graft function was excellent six months after transplantation with proteinuria of 8 mg/m2/h. We conclude that rituximab may be an effective treatment for post‐transplant recurrence of FSGS.

Cardiovascular Phenotypes in Children with CKD: The 4C Study

BACKGROUND AND OBJECTIVES Cardiovascular disease is the most important comorbidity affecting long-term survival in children with CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS The Cardiovascular Comorbidity in Children with CKD Study is a multicenter, prospective, observational study in children ages 6-17 years old with initial GFR of 10-60 ml/min per 1.73 m2. The cardiovascular status is monitored annually, and subclinical cardiovascular disease is assessed by noninvasive measurements of surrogate markers, including the left ventricular mass index, carotid intima-media thickness, and central pulse wave velocity. We here report baseline data at study entry and an explorative analysis of variables associated with surrogate markers. RESULTS A total of 737 patients were screened from October of 2009 to August of 2011 in 55 centers in 12 European countries, and baseline data were analyzed in 688 patients. Sixty-four percent had congenital anomalies of the kidney and urinary tract; 26.1% of children had uncontrolled hypertension (24-hour ambulatory BP monitoring; n=545), and the prevalence increased from 24.4% in CKD stage 3 to 47.4% in CKD stage 5. The prevalence of left ventricular hypertrophy was higher with each CKD stage, from 10.6% in CKD stage 3a to 48% in CKD stage 5. Carotid intima-media thickness was elevated in 41.6%, with only 10.8% of patients displaying measurements below the 50th percentile. Pulse wave velocity was increased in 20.1%. The office systolic BP SD score was the single independent factor significantly associated with all surrogate markers of cardiovascular disease. The intermediate end point score (derived from the number of surrogate marker measurements >95th percentile) was independently associated with a diagnosis of congenital anomalies of the kidney and urinary tract, time since diagnosis of CKD, body mass index, office systolic BP, serum phosphorus, and the hemoglobin level. CONCLUSIONS The baseline data of this large pediatric cohort show that surrogate markers for cardiovascular disease are closely associated with systolic hypertension and stage of CKD.

Effect of iron deficiency anemia on renal tubular function in childhood

Abstract.Little is known about renal function in children with iron deficiency anemia. The purpose of this study was to investigate renal tubular function in these children. We compared renal tubular function in 20 children with iron deficiency anemia with 20 healthy age-matched controls. Blood and urine samples were obtained for hematological and biochemical analysis. Mean fractional excretion of sodium and mean urinary N-acetyl-β-D-glucosaminidase/creatinine were significantly higher in the children with iron deficiency anemia than in controls (P<0.05). Hemoglobin levels were negatively correlated with urinary N-acetyl-β-D-glucosaminidase/creatinine (r= -0.44, P=0.015), but were not correlated with fractional excretion of sodium (r= -0.29, P=0.13). There was no correlation between urinary N-acetyl-β-D-glucosaminidase/creatinine and fractional excretion of sodium (r=0.32, P=0.09). The results suggest that children with iron deficiency anemia have impaired renal tubular function.