Cardiovascular health in pediatric patients with X-linked hypophosphatemia under two years of burosumab therapy.

Introduction: X-linked hypophosphatemia (XLH) is caused by an inactivating mutation in the phosphate-regulating endopeptidase X-linked (PHEX) gene whose defective product fails to control phosphatonin fibroblast growth factor 23 (FGF23) serum levels. Although elevated FGF23 levels have been linked with detrimental cardiac effects, the cardiologic outcomes in XLH patients have been subject to debate. Our study aimed to evaluate the prevalence and severity of cardiovascular morbidity in pediatric XLH patients before, during, and after a 2-year treatment period with burosumab, a recombinant anti-FGF23 antibody. Methods: This prospective observational study was conducted in a tertiary medical center, and included 13 individuals with XLH (age range 0.6-16.2 years) who received burosumab every 2 weeks. Clinical assessment at treatment initiation and after .5, 1, and 2 years of uninterrupted treatment included anthropometric measurements and cardiologic evaluations (blood pressure [BP], electrocardiogram, conventional echocardiography, and myocardial strain imaging). Results: The linear growth of all patients improved significantly (mean height z-score: from -1.70 ± 0.80 to -0.96 ± 1.08, P=0.03). Other favorable effects were decline in overweight/obesity rates (from 46.2% to 23.1%) and decreased rates of elevated BP (systolic BP from 38.5% to 15.4%; diastolic BP from 38.5% to 23.1%). Electrocardiograms revealed no significant abnormality throughout the study period. Cardiac dimensions and myocardial strain parameters were within the normative range for age at baseline and remained unchanged during the study period. Conclusion: Cardiologic evaluations provided reassurance that 2 years of burosumab therapy did not cause cardiac morbidity. The beneficial effect of this treatment was a reduction in cardiovascular risk factors, as evidenced by the lower prevalence of both overweight/obesity and elevated BP.

Linear growth of children with X-linked hypophosphatemia treated with burosumab: a real-life observational study.

To assess the long-term efficacy of burosumab for pediatric patients with X-linked hypophosphatemia, focusing on linear growth. This multi-center retrospective study included 35 pediatric patients who began treatment with burosumab between January 2018 and January 2021. We collected clinical data, anthropometric measurements, laboratory results, and Rickets Severity Score (RSS), from 2 years prior to treatment initiation and up to 4 years after. Burosumab was initiated at a mean age of 7.5 ± 4.4 years (range 0.6-15.9), with a mean initial dose of 0.8 ± 0.3 mg/kg, which was subsequently increased to 1.1 ± 0.4 mg/kg. The patients were followed for 2.9 ± 1.4 years (range 1-4) after initiating burosumab. Serum phosphorus levels increased from 2.7 ± 0.8 mg/dl at burosumab initiation to 3.4 ± 0.6 mg/dl after 3 months and remained stable (p < 0.001). Total reabsorption of phosphorus increased from 82.0 ± 6.8 to 90.1 ± 5.3% after 12 months of treatment (p = 0.041). The RSS improved from 1.7 ± 1.0 at burosumab initiation to 0.5 ± 0.6 and 0.3 ± 0.6 after 12 and 24 months, respectively (p < 0.001). Both height z-score and weight z-score improved from burosumab initiation to the end of the study: from - 2.07 ± 1.05 to - 1.72 ± 1.04 (p < 0.001) and from - 0.51 ± 1.12 to - 0.11 ± 1.29 (p < 0.001), respectively. Eight children received growth hormone combined with burosumab treatment. Height z-score improved among those who received growth hormone (from - 2.33 ± 1.12 to - 1.94 ± 1.24, p = 0.042) and among those who did not (from - 2.01 ± 1.01 to - 1.66 ± 1.01, p = 0.001). CONCLUSION:  Burosumab treatment in a real-life setting improved phosphate homeostasis and rickets severity and enhanced linear growth. WHAT IS KNOWN: • Compared to conventional therapy, burosumab treatment has been shown to increase serum phosphate levels and reduce the severity of rickets. • The effect of burosumab on growth is still being study. WHAT IS NEW: • Height z-score improved between the start of burosumab treatment and the end of the study (-2.07 ± 1.05 vs. -1.72 ± 1.04, p < 0.001). • Eight children received burosumab combined with growth hormone treatment without side effects during the concomitant treatments.

Exstrophy-epispadias complex: are the kidneys and kidney function spared?

BACKGROUND: Exstrophy-epispadias complex (EEC) is a complex malformation of the lower abdominal wall, bladder, and pelvic floor, which necessitates multiple successive reconstruction procedures. Surgical and infectious complications are frequent. Our aim was to evaluate kidney function in these patients. METHODS: This cross-sectional study included patients with EEC, followed since birth in a pediatric urology clinic, who underwent nephrological evaluation (blood pressure (BP) measurement and blood and urine chemistries) and imaging studies (urinary tract ultrasound and DMSA kidney scan) during 2017-2020. RESULTS: Forty-three patients (29 males), median age 9 years (interquartile range 6-19), were included. Eleven (26%) used clean intermittent catheterization (CIC) for bladder drainage. At least one sign of kidney injury was identified in 32 (74%) patients; elevated BP, decreased kidney function (estimated glomerular filtration rate (eGFR) < 90 ml/min/1.73 m2), and proteinuria/albuminuria were detected in 29%, 12%, and 36% of patients, respectively. Urinary tract dilatation (UTD) was found in 13 (37%) ultrasound examinations. Parenchymal kidney defects were suspected in 46% and 61% of ultrasound and DMSA scintigraphy, respectively. UTD was significantly associated with DMSA-proven kidney defects (p = 0.043) and with elevated BP, 39% vs. 20% in those without UTD. Decreased eGFR and elevated BP were less frequent among patients on CIC than among patients who voided spontaneously: 10% vs. 14% and 18% vs. 36%, respectively. Recurrent UTIs/bacteriuria and nephro/cystolithiasis were reported by 44% and 29% patients, respectively. CONCLUSION: The high rate of signs of kidney injury in pediatric patients with EEC dictates early-onset long-term kidney function monitoring by joint pediatric urological and nephrological teams. A higher resolution version of the Graphical abstract is available as Supplementary information.

Monitoring oral propranolol for infantile hemangiomata.

Treating infantile hemangiomas with oral propranolol may be initiated in accordance with various protocols some require hospitalization. However, different adverse events have been reported during treatment, thus it is of special importance to find a protocol which is both safe and feasible. We performed a retrospective cohort study of all cases of infantile hemangiomas treated with oral propranolol at our institute between January 2010 and February 2020. Pretreatment evaluation consisted of pediatric cardiologist evaluation including electrocardiography and echocardiography. The propranolol starting dosage was 0.5 mg/kg bid; 2 weeks later the dosage was escalated to 1 mg/kg bid. During the initiation and escalation visits, heart rate and blood pressure were measured before and every hour for a total of 3 h, and blood glucose level was measured within the first hour of treatment. A total of 131 children were treated during the study period. Scalp, facial and genital region infantile hemangiomas were more prevalent in regard to their relative body surface area. No symptomatic bradycardia, hypotension, hypoglycemia, or any other adverse events were documented; few patients had asymptomatic bradycardia and hypotension, which were more common in infants below 6-months of age. Only one patient had asymptomatic hypoglycemia, not requiring any intervention. Initiation and escalation of propranolol treatment for infantile hemangiomas proved to be safe, and without symptomatic adverse effects. However, considering the young age of the patients and the possible asymptomatic adverse reactions, we recommend the following simple protocol as presented, for pretreatment evaluation and short monitoring during treatment initiation and dose escalation.

Asymptomatic bacteriuria and antibiotic resistance profile in children with neurogenic bladder who require clean intermittent catheterization.

STUDY DESIGN: A retrospective cohort study. OBJECTIVES: To document the prevalence of asymptomatic bacteriuria and to characterize the resistance patterns to antibiotics among children with neurogenic bladder who require clean intermittent catheterization, with an emphasis on multidrug resistance. SETTING: A national referral pediatric and adolescent rehabilitation facility in Jerusalem, Israel. METHODS: Routine urine cultures were collected before urodynamic studies in suitable individuals during 2010-2018. None of them had symptoms of urinary tract infection at the time of specimen collection. Cultures were defined as being positive if a single bacterial species was isolated together with a growth of over 105 colony-forming units/ml. Resistance patterns were defined as extended-spectrum beta-lactamase (ESBL) and resistant to 3 antimicrobial groups (multi-drug resistant, MDR). RESULTS: In total, 281 urine cultures were available for 186 participants (median age 7 years, range 0.5-18). Etiologies for CIC included myelomeningocele (n = 137, 74%), spinal cord injury (n = 16, 9%) and caudal regression syndrome (n = 9, 5%). Vesicoureteral reflux was diagnosed in 36 participants (19%), 14 of whom were treated with prophylactic antibiotics. Asymptomatic bacteriuria was present in 217 specimens (77%, 95%CI [0.72-0.82]). The bacteria species were E. coli (71%), Klebsiella (13%), and Proteus (10%). ESBL was found in 11% of the positive cultures and MDR in 9%, yielding a total of 34 (16% of positive cultures) positive for ESBL and/or MDR bacteria. CONCLUSIONS: Asymptomatic bacteriuria and resistance to antimicrobials are common in pediatric individuals who require CIC.

[DISTENDED FETAL BLADDER].

INTRODUCTION: Distended fetal bladder, also known as fetal megacystis, usually points to lower urinary tract obstruction (LUTO) which is most commonly caused by posterior urethral valves (PUV) in the male fetus. We present a short case-series of fetal megacystis without oligohydramnion where primary vesicoureteral reflux (VUR) was the leading aetiology. These cases also displayed a high rate of kidney dysplasia with early-onset renal dysfunction. By contrast, late-onset diagnosis of isolated megacystis, i.e without significant renal parenchymal or upper urinary tract abnormalities, had a surprisingly benign postnatal course with spontaneous resolution after birth. Our case series also display the associated risk for extra-renal malformations and specifically neuro-cognitive developmental abnormalities which should be sought on genetic and imaging evaluation.

Body composition and cardiometabolic health of pediatric patients with X-linked hypophosphatemia (XLH) under burosumab therapy.

BACKGROUND: Burosumab, a recombinant anti-FGF23 monoclonal antibody, was recently introduced as a treatment for X-linked hypophosphatemia (XLH). Burosumab normalizes blood phosphate levels, thereby healing rickets, decreasing leg bowing, and reducing pain. We aimed to explore the body composition and cardiometabolic health of pediatric patients with XLH treated with burosumab. METHODS: This observational real-life study was conducted on growing children and adolescents. The outcome measures included changes in sex- and age-adjusted anthropometric and body composition parameters [fat mass (FM), fat-free mass (FFM), appendicular skeletal muscle mass (ASMM), muscle-to-fat ratio (MFR)], blood pressure, laboratory evaluation, and radiographic rickets severity [Thacher Rickets Severity Score (TRSS)]. Body composition was assessed by bioelectrical impedance analysis (BIA). Percentiles for FFM% and ASMM% were calculated according to BIA pediatric reference curves. The delta variable was calculated as the variable at 12 months minus the variable at baseline. RESULTS: A total of 15 pediatric patients with XLH are treated in our clinic; included in the analyses were 7 children and adolescents (3 males, mean age 8.7 ± 3.2 years) with XLH without comorbidities. Baseline BIA revealed an unfavorable physique, with increased body fat percentage in five patients and decreased muscle mass in six. Indices of lean body mass significantly increased after 6 and 12 months of treatment: FFM(kg) (p = 0.001, p = 0.046, respectively) and ASMM(kg) (p = 0.012, p = 0.034, respectively), without any significant change in FM(kg). The percentile of ASMM% increased significantly after 6 months of treatment (p = 0.006) and stabilized thereafter. TRSS improved significantly after 12 months of therapy (p = 0.005). Age was positively correlated with delta TRSS (r = 0.814, p = 0.026), and delta TRSS was negatively correlated with delta MFR (r = -0.826, p = 0.022). CONCLUSIONS: There was a heretofore unrecognized improvement in body composition of growing children and adolescents with XLH who were treated with burosumab. These findings highlight the need to initiate burosumab treatment at a younger age when rickets is less severe.

Long-term outcomes during 37 years of pediatric kidney transplantation: a cohort study comparing ethnic groups.

BACKGROUND: This study aimed to evaluate short- and long-term outcomes of kidney transplantation over 37 years in a national referral center and compare outcomes between Israeli Jewish and Arab children. METHODS: Data on 599 pediatric transplantations performed in 545 children during 1981-2017, including demographic parameters, kidney failure disease profile, and pre-transplant dialysis duration, were retrieved from our computerized database and patient files. Patient and graft survival were estimated using the Kaplan-Meier method. RESULTS: Twenty-year patient survival was 91.4% for live donor (LD) and 80.2% for deceased donor (DD) kidney recipients. Respective 10-year and 20-year graft survival rates for first kidney-only transplants were 75.2% and 47.0% for LD and 60.7% and 38.4% for DD grafts. Long-term graft survival improved significantly (p < 0.001) over the study period for recipients of both LD and DD allografts and reached 7-year graft survival of 92.0% and 71.3%, respectively. The proportion of DD transplantations was higher in the Arab subpopulation: 73.8% vs. 48.4% (p < 0.001). Graft survival was not associated with age at transplantation and did not differ between the Arab (N = 202) and Jewish children (N = 343). Median (IQR) waiting time on dialysis did not differ significantly between the Arab and Jewish children: 18 (10-30) and 15 (9-30) months, respectively (p Mann-Whitney = 0.312). CONCLUSIONS: Good and progressively improving long-term results were obtained in pediatric kidney transplantation at our national referral center, apparently due to expertise gained over time and advances in immunosuppression. Equal access to DD kidney transplant and similar graft survival were found between ethnic groups.

Improving renal phenotype and evolving extra-renal features of 17q12 deletion encompassing the HNF1B gene.

BACKGROUND: HNF1B deletion/intragenic mutations are the most commonly identified genetic cause of congenital anomalies of the kidney and urinary tract (CAKUT) suggested by fetal ultrasound findings such as: parenchymal hyperechogenicity, overt cystic changes or gross morphological urinary system (UT) abnormalities. The postnatal evolution of these 17q12 deletions encompassing the HNF1B gene-associated findings has not been assessed in depth. METHODS: In this observational study, we present postnatal follow-up findings in 5 of 6 cases (one pregnancy was terminated on parental request) of fetal-onset cystic/hyperechogenic kidneys eventually diagnosed with 17q12 microdeletion encompassing the HNF1B gene between 2009 and 2017. RESULTS: Complete normalization of kidney parenchymal abnormalities and of depressed neonatal renal function was observed in 4/5 and 5/5 patients within 2-4.9 years and 1.5-8 months, respectively. All 5 patients had preserved normal renal function at 3-11 years of follow-up. The evolving later-onset renal features included: hypomagnesemia, hyperuricemia, urinary tract infection (UTI), and bilateral grade 3-4 vesicoureteral reflux and bladder diverticula in 3, 3, 2, and 1 patient, respectively. HNF1B gene deletion-associated extra-renal manifestations with delayed presentation were global developmental delay/autistic spectrum disorder (ASD), rolandic-type seizures, overweight, and borderline fasting hyperglycemia observed in 1-2 patients each. Family history was positive for small-size or asymptomatic cystic kidneys with normal function, diabetes mellitus, seizures, and mental/psychiatric problems in 3/6 cases. CONCLUSIONS: Fetal-onset HNF1B deletion-associated kidneys' parenchymal abnormalities confirmed postnatally with initially depressed renal function might undergo complete resolution within several years and few months, respectively. However, later-onset urinary tract, metabolic, and neurodevelopmental features of this mutation might appear over years. Therefore, genetic molecular evaluation/diagnosis and continuous follow-up for evolving features are mandatory in affected children.

Neonatal acute kidney injury: recording rate, course, and outcome: one center experience.

Background: Neonates, and particularly preterm newborns, are at increased risk for acute kidney injury (AKI) due to immature kidney function. While specific criteria have been defined for AKI in this particular population, this diagnosis is frequently overlooked, and consequently, is often not recorded in patients' medical files. AKI-associated short- and long-term morbidity and mortality underline the importance of this diagnosis Objective: To assess the recording rate of AKI in the neonatal intensive care unit (NICU), and to identify clinical features that may promote awareness to this condition. Study design: The database of one medical center was searched for serum creatinine values above 1 mg% among all the newborns (more than 48 hours old) who were hospitalized in the neonatal intensive care unit (NICU) during the years 2010-2015, and who underwent at least two blood tests during their hospitalization. The files of patients who met acute kidney injury (AKI) diagnostic criteria were searched for AKI diagnosis, maternal, fetal, and postnatal course and outcome. Results: Of 59 newborns who met AKI criteria, 51 (86%) were preterm and 8 term newborns. The respective mean gestational weeks at birth were: 28 ± 3 and 38.5 ± 1, and mean birth weights: 1002 ± 57 and 3157 ± 375 grams. Mortality rates were 14/51 (27%) versus 1/8 (12.5%). Of the 44 survivors, AKI was recorded in the medical files of 9/37 (24%) preterm versus 5/7 (71%) term-newborns. AKI associated with twin pregnancy in preterm neonates: 22 (43%) versus 1 (12.5%) in term-newborn. Unexpected high frequencies of maternal obstetrical problems and cesarean section delivery: 62.5 and 78%, respectively, along with persistently depressed 5-min Apgar 6.6 ± 3.5 were found in term newborns with AKI. Congenital anomalies of the urinary tract (CAKUT) were suspected prenatally on fetal ultrasound in 3 (6%) and 1 (12.5%) of the respective groups, a 10-fold higher rate than that observed in the general population. AKI recurred in 18 (35%) of the preterm and none of the term neonates. Mild AKI episodes (Stage 1-2) occurred in 30/37 (81%) by contrast to severe events (Stage 3) in 4/7 (57%) preterm and term survivors, respectively. Ventilation duration associated significantly with AKI recurrence, and sepsis with mortality: OR 1.25 (95%CI = 1.09-1.43) (p < .001) and OR = 4.65 (95%CI = 1.26-17.2) (p = .014), respectively. Conclusions: We demonstrated underreporting of AKI, particularly among preterm newborns, a population at high risk of developing recurrent episodes. Our data suggest different clinical profiles of AKI among preterm and term neonates: with later onset, milder but recurrent episodes in the former. Increased alertness for AKI diagnosis is needed for neonates with prolonged respiratory support, treated with diuretics and after sepsis. Newborns suspected of CAKUT (Congenital Anomalies of Kidneys and Urinary Tract) as per fetal ultrasound might need closer observation for AKI occurrence.

Long-term Outcome of 1-step Kidney Transplantation and Bladder Augmentation Procedure in Pediatric Patients.

BACKGROUND: Guidelines for bladder augmentation (BA) in kidney transplantation (KT) recipients are not well-defined. In our center, simultaneous BA with KT (BA-KT) is performed. We assessed transplantation outcomes of this unique extensive procedure. METHODS: A case-control single center retrospective study. Transplantation outcomes were compared with those of KT recipients who did not need BA. RESULTS: Compared with 22 patients who underwent KT only, for 9 who underwent BA-KT, surgical complications and the need for revision in the early posttransplantation period were similar; early graft function was better: estimated glomerular filtration rate, 96.5 ± 17.1 versus 79.4 ± 16.6 mL/min at 0 to 6 months (P = 0.02); posttransplantation clean intermittent catheterization was more often needed: by 78% (7/9) versus 13% (3/22); and asymptomatic bacteriuria was more common: 100% versus 9% during the first 6 months (P < 0.001), 55% versus 9% (P = 0.02) and 66.6% versus 9% during the first and second years, respectively (P = 0.004). Urinary tract infection (UTI) incidence was also higher: 100% versus 23% during the first 6 months and 44% versus 9% during the second year posttransplantation. Graft function deteriorated significantly in the BA-KT group by the fifth posttransplantation year: estimated glomerular filtration rate was 47.7 ± 39.7 mL/min versus 69 ± 21.3 mL/min, with only 6 (66%) of 9 functioning grafts versus 100% in the KT only group. Causes of graft loss were noncompliance with drug therapy in 2 patients and recurrent UTIs in 2 patients. CONCLUSIONS: Excellent short-term outcome for simultaneous BA-KT is threatened by graft loss due to a high prevalence of UTIs and patient noncompliance with the demanding complex posttransplantation therapy.

[SOLITARY KIDNEY - IS IT TOO LITTLE?]

INTRODUCTION: Solitary functioning kidney (SFK) occurs with unilateral renal agenesis (URA) in 1/2000 live births - or after uninephrectomy for tumor, trauma, uncontrolled infections or hypertension and post-kidney donation. URA-associated states include urological, cardiac, gastrointestinal and skeletal anomalies or it might be a component of a genetic syndrome. In 10% of cases of URA another family member is affected. In any case of SFK a compensatory process is triggered consisting of glomerular hypertension with hyperfiltration which achieves 75% of two kidneys' function. In the long-run this process might be detrimental causing further loss of functioning nephrons, inability to sustain functional compensation and progressive kidney function deterioration. The risk for this chain of events is determined in the first place by the number of nephrons in the SFK, which cannot be assessed in vivo. Hints for reduced nephron number in the single kidney include prematurity or SGA-small for date birth weight, urological anomalies with or without accompanying infections, lack of increased single kidney size - compensatory hypertrophy. Age of onset of the compensatory process and acquired factors including nephrotoxin exposure, overweight/obesity, excessive salt and/or protein intake contribute to the risk of progressive renal damage. Life-long follow-up of all subjects with SFK is recommended from early age for lifestyle education: recommended diet and tailored physical activity, nephrotoxin avoidance along with early detection of renal injury signs: albuminuria, hypertension or depressed kidney function - GFR (glomerular filtration rate) targeting timely intervention for preservation of functioning renal mass.

Impact of Pediatric Chronic Dialysis on Long-Term Patient Outcome: Single Center Study.

Objective. Owing to a shortage of kidney donors in Israel, children with end-stage renal disease (ESRD) may stay on maintenance dialysis for a considerable time, placing them at a significant risk. The aim of this study was to understand the causes of mortality. Study Design. Clinical data were collected retrospectively from the files of children on chronic dialysis (>3 months) during the years 1995-2013 at a single pediatric medical center. Results. 110 patients were enrolled in the study. Mean age was 10.7 ± 5.27 yrs. (range: 1 month-24 yrs). Forty-five children (42%) had dysplastic kidneys and 19 (17.5%) had focal segmental glomerulosclerosis. Twenty-five (22.7%) received peritoneal dialysis, 59 (53.6%) hemodialysis, and 6 (23.6%) both modalities sequentially. Median dialysis duration was 1.46 years (range: 0.25-17.54 years). Mean follow-up was 13.5 ± 5.84 yrs. Seventy-nine patients (71.8%) underwent successful transplantation, 10 (11.2%) had graft failure, and 8 (7.3%) continued dialysis without transplantation. Twelve patients (10.9%) died: 8 of dialysis-associated complications and 4 of their primary illness. The 5-year survival rate was 84%: 90% for patients older than 5 years and 61% for younger patients. Conclusions. Chronic dialysis is a suitable temporary option for children awaiting renal transplantation. Although overall long-term survival rate is high, very young children are at high risk for life-threatening dialysis-associated complications.

Focal segmental glomerulosclerosis in pediatric kidney transplantation: 30 years' experience.

From 1982 to 2011, 53 kidney transplantations (KT) for pediatric focal segmental glomerulosclerosis (FSGS) were recorded in the National Israeli Kidney Transplant Registry (NIKTR): 22-primary (1◦) FSGS, 25-proved/suspected genetic-secondary (2◦) FSGS, six lost/incomplete files/other. Half (56%) of 23 patients with 2◦ FSGS were Israeli-Arabs vs 29% of 1◦ FSGS KT recipients. 1◦ FSGS recurrence occurred in 64% (14/22) of 22 KT in 17 patients aged (median) 14 years vs 1/25 of 2◦ FSGS (P<.001). Early graft days/nonfunction occurred in 9/14 (64%), 2/8 (25%) and 2/25 (4%) of recurrent 1◦ FSGS (rFSGS), nonr1◦ FSGS and 2◦ FSGS, respectively. Twelve biopsies performed in nine of these grafts at (median) 8 days (range 5-60 days) post-KT showed: ATN-5, suspected rejection-4, rFSGS-2, normal kidney-1; rFSGS was diagnosed eventually in 8/9. Dialysis need during the first month post-KT was significantly associated with FSGS recurrence: 6/14 (43%) for rFSGS vs 2/8 (25%) for non-rFSGS. Plasmapheresis (PP) achieved complete and partial rFSGS remission in 5/9 and 2/9 grafts, respectively. Three grafts were excised during the first 60 days post-KT for: nonfunction (1) and bleeding (2). Remaining grafts' GFR was: 78, 42, and 91 mL/min (median) at 5.3, 4.75, and 8 years follow-up for non-rFSGS, rFSGS, and 2◦ FSGS grafts, respectively. CONCLUSIONS: Early PP implementation should be considered after KT for 1◦ FSGS patients with early graft dysfunction despite delayed proteinuria and nonspecific biopsy.

Post-Infectious Glomerulonephritis in Pediatric Patients over Two Decades: Severity-Associated Features.

BACKGROUND: The incidence of post-infectious glomerulonephritis (PIGN) has decreased over the last decades. As a result, recent epidemiological data from industrialized countries are scarce. OBJECTIVES: To evaluate patterns of PIGN in children and detect possible predictors of disease severity. METHODS: We collected clinical and laboratory data of patients with PIGN admitted to Schneider Children's Medical Center during 1994-2011. Diagnostic criteria included presence of hematuria with/without other features of nephritic syndrome along with hypocomplementemia and/or microbiological/serological evidence of streptococcal infection. Patients with other diseases (systemic lupus erythematosus, vasculitis, etc.) were excluded from the study. RESULTS: A total of 125 patients with a mean age of 5.8 ± 3.3 years (range 1.5-17.6), of whom 16% were < 3 years, matched the study criteria. Presenting features included hypertension in 103 (82.4%) patients, azotemia in 87 (70.2%), fever in 49 (40/6), and elevated C-reactive protein in 75 (81.5%). Isolated macrohematuria was found in 21 (16%). Full-blown nephritic syndrome was diagnosed in 51 patients (41.1%) and 28 (22.9%) had nephritic syndrome with nephrotic-range proteinuria. Depressed C3 complement levels were associated with the presence of nephritic syndrome (OR 0.73, 95% CI 0.60-0.88, P = 0.001) as well as older age (OR 1.24, Cl 1.08-1.43, P = 0.001). At last follow-up (mean 42 months) all examined patients (100 of 125) had normal renal function, 6 had hypertension, and 1 had proteinuria. CONCLUSIONS: PIGN remains an important cause of glomerular disease in children and may affect very young patients. Nephrotic-range proteinuria with hypoalbuminemia seems to be more frequent than previously reported. Hypocomplementemia is associated with a more severe disease course, namely, azotemia and nephritic syndrome.

High prevalence of elevated blood pressure among children with neurofibromatosis type 1.

BACKGROUND: Neurofibromatosis type 1 (NF1) is a common neurocutaneous disease characterized by café-au-lait spots, axillary and inguinal freckling, neurofibromas, and optic gliomas. Increased rates of hypertension (HTN) were reported among NF1 patients, however, the prevalence of HTN and pre-HTN in pediatric NF1 patients has not been clarified. METHODS: Blood pressure (BP) measurements, weight, and renal ultrasound were assessed in 224 NF1 pediatric patients followed in a specialized NF1 clinic. RESULTS: The cohort's mean age was 9.1 ± 4.1 years. Overweight and obesity were found in 12.9 and 10.3 % of them, respectively. BP was measured averagely 2.9 times per patient on different occasions. Blood pressure was in the pre-HTN and HTN ranges in 14.9 and 16.9 % of measurements, respectively. BP >95th was detected in 20.5 % at the first measurement. Of 114 children with at least three BP measurements, 18.4 % had two values in the HTN range and 6.14 % had at least three. Overweight was not associated with HTN among children with NF1. Urinary tract ultrasonographic abnormalities were detected in 6.8 % (11/161) of cases. CONCLUSIONS: The prevalence of increased BP in pediatric NF1 is much higher than in the general pediatric population. BP has to be regularly assessed and managed in this high-risk population.

Cardiovascular risk factors in children after kidney transplantation--from short-term to long-term follow-up.

Cardiovascular-related mortality is 100-fold higher in pediatric renal transplant recipients than in the age-matched general population. Seventy-seven post-renal transplant children's charts were reviewed for cardiovascular risk factors at two and six months after transplantation (short term) and at two yr after transplantation and the last follow-up visit (mean 7.14 ± 3.5 yr) (long term). Significant reduction was seen in cardiovascular risk factors prevalence from two months after transplantation to last follow-up respectively: Hypertension from 52.1% to 14%, hypercholesterolemia from 48.7% to 33%, hypertriglyceridemia from 50% to 12.5%, anemia from 29.6% to 18.3%, hyperparathyroidism from 32% to 18.3% and hyperglycemia from 11.7% to 10%, and left ventricular hypertrophy from 25.8% at short term to 15%. There was an increase in the prevalence of obesity from 1.5% to 3.9% and of CKD 3-5 from 4.75% to 24%. The need for antihypertensive treatment decreased from 54% to 42%, and the percentage of patients controlled by one medication rose from 26% to 34%, whereas the percentage controlled by 2, 3, and 4 medications decreased from 21.9%, 5.5%, and 1.4% to 6%, 2%, and 0. Children after renal transplantation appear to have high rates of cardiovascular risk factors, mainly on short-term follow-up.

Renal hypodysplasia associates with a WNT4 variant that causes aberrant canonical WNT signaling.

Abnormal differentiation of the renal stem/progenitor pool into kidney tissue can lead to renal hypodysplasia (RHD), but the underlying causes of RHD are not well understood. In this multicenter study, we identified 20 Israeli pedigrees with isolated familial, nonsyndromic RHD and screened for mutations in candidate genes involved in kidney development, including PAX2, HNF1B, EYA1, SIX1, SIX2, SALL1, GDNF, WNT4, and WT1. In addition to previously reported RHD-causing genes, we found that two affected brothers were heterozygous for a missense variant in the WNT4 gene. Functional analysis of this variant revealed both antagonistic and agonistic canonical WNT stimuli, dependent on cell type. In HEK293 cells, WNT4 inhibited WNT3A induced canonical activation, and the WNT4 variant significantly enhanced this inhibition of the canonical WNT pathway. In contrast, in primary cultures of human fetal kidney cells, which maintain WNT activation and more closely represent WNT signaling in renal progenitors during nephrogenesis, this mutation caused significant loss of function, resulting in diminished canonical WNT/ß-catenin signaling. In conclusion, heterozygous WNT4 variants are likely to play a causative role in renal hypodysplasia.

Cryptosporidiosis in children following solid organ transplantation.

BACKGROUND: Cryptosporidium parvum is a common cause of diarrhea. In immunocompetent individuals, spontaneous recovery is the rule. In immunocompromised patients, it may cause a serious disease. Data on cryptosporidiosis in children after solid organ transplantation are few. We report on 6 pediatric solid organ recipients with gastroenteritis caused by Cryptosporidium. PATIENTS AND METHODS: All episodes of gastroenteritis in solid organ transplant recipients hospitalized in Schneider Children's Medical Center from January 2008 to August 2011 were identified. Data on the episodes with positive staining for Cryptosporidium antigen in stool were reviewed. RESULTS: Fifty-seven episodes of gastroenteritis were recorded. In 6 (11%) patients (4 kidney recipient, 1 liver and kidney recipient and 1 heart transplant recipient) Cryptosporidium antigen was detected in stool. Mean age at transplantation was 3.7 ± 2 years, mean time between transplantation and cryptosporidial disease was 39 ± 53.9 months. Symptoms included prolonged diarrhea, fever, abdominal pain and weight loss. Mean duration of symptoms before diagnosis was 10.5 ± 8.7 days. In 5 children, kidney function deteriorated, blood concentrations of tacrolimus increased in 5 patients and abnormal values of liver enzymes were detected in 4 patients. All patients were hospitalized and received intravenous fluid replacement and were treated with nitazoxanide for 5-21 days. Two patients had recurrence of symptoms after short course (5 days) therapy. All patients recovered eventually from the disease. CONCLUSION: Cryptosporidium should be routinely tested in solid organ transplant recipients with diarrhea. Delay in initiation of treatment can result in serious complications including acute renal failure. Long-term therapy with nitazoxanide (at least 14 days) may facilitate recovery.