Antenatally detected urinary tract dilatation: long-term outcome.

This review provides updated knowledge on the long-term outcomes among children with antenatally diagnosed urinary tract dilatation (UTD), previously often referred to as antenatal hydronephrosis. Different definitions of UTD exist, which makes comparison between studies and generalized conclusions difficult. Roughly, one-third of antenatally diagnosed UTD, defined as a renal pelvis anterior posterior diameter (APD) of ≥ 4 mm in the second trimester and/or ≥ 7 mm in the third trimester, will resolve before birth, another third will resolve within the first years of life, and in the remaining cases, UTD will persist or a congenital abnormality (CAKUT) will be diagnosed postnatally. The risk of a postnatal CAKUT diagnosis increases with the degree of prenatal and postnatal dilatation, except for vesicoureteral reflux (VUR), which cannot be predicted from the degree of UTD. Urinary tract infections (UTIs) occur in 7-14% of children with UTD during the first years of life. The risk of UTI is higher in children with traditional risk factors for UTI, such as dilated VUR, hydroureteronephrosis, female gender, and intact foreskin. Continuous antibiotic prophylaxis may be considered in selected patients during the first years of life. In long-term follow-ups, permanent kidney damage is diagnosed in approximately 40% of children with moderate or severe UTD, but hypertension, proteinuria, and/or reduced eGFR are uncommon (0-5%). In children with mild UTD, the long-term outcome is excellent, and these children should not be subjected to unnecessary examinations and/or follow-up.

The role of dendrin in IgA nephropathy.

BACKGROUND: Immunoglobulin A nephropathy (IgAN) and its systemic variant IgA vasculitis (IgAV) damage the glomeruli, resulting in proteinuria, hematuria and kidney impairment. Dendrin is a podocyte-specific protein suggested to be involved in the pathogenesis of IgAN. Upon cell injury, dendrin translocates from the slit diaphragm to the nucleus, where it is suggested to induce apoptosis and cytoskeletal changes, resulting in proteinuria and accelerated disease progression in mice. Here we investigated gene and protein expression of dendrin in relation to clinical and histopathological findings to further elucidate its role in IgAN/IgAV. METHODS: Glomerular gene expression was measured using microarray on 30 IgAN/IgAV patients, 5 patients with membranous nephropathy (MN) and 20 deceased kidney donors. Dendrin was spatially evaluated on kidney tissue sections by immunofluorescence (IF) staining (IgAN patients, n = 4; nephrectomized kidneys, n = 3) and semi-quantified by immunogold electron microscopy (IgAN/IgAV patients, n = 21; MN, n = 5; living kidney donors, n = 6). Histopathological grading was performed according to the Oxford and Banff classifications. Clinical data were collected at the time of biopsy and follow-up. RESULTS: Dendrin mRNA levels were higher (P = .01) in IgAN patients compared with MN patients and controls and most prominently in patients with preserved kidney function and fewer chronic histopathological changes. Whereas IF staining did not differ between groups, immunoelectron microscopy revealed that a higher relative nuclear dendrin concentration in IgAN patients was associated with a slower annual progression rate and milder histopathological changes. CONCLUSION: Dendrin messenger RNA levels and relative nuclear protein concentrations are increased and associated with a more benign phenotype and progression in IgAN/IgAV patients.

Definition, diagnosis and management of fetal lower urinary tract obstruction: consensus of the ERKNet CAKUT-Obstructive Uropathy Work Group.

Fetal lower urinary tract obstruction (LUTO) is associated with high mortality and postnatal morbidity caused by lung hypoplasia and impaired kidney function. Specific diagnostic features that can guide clinical approach and decisions are lacking; thus, the European Reference Network for Rare Kidney Diseases established a work group to develop recommendations regarding the clinical definition, diagnosis and management of prenatally detected LUTO. The work group recommends the use of antero-posterior diameter of renal pelvis as the most reliable parameter for suspecting obstructive uropathies and for suspecting prenatal LUTO in the presence of fetal megacystis. Regarding prenatal and postnatal prognosis of fetuses with LUTO, the risk of fetal and neonatal death depends on the presence of oligohydramnios or anhydramnios before 20 weeks' gestation, whereas the risk of kidney replacement therapy cannot be reliably foreseen before birth. Parents of fetuses with LUTO must be referred to a tertiary obstetric centre with multidisciplinary expertise in prenatal and postnatal management of obstructive uropathies, and vesico-amniotic shunt placement should be offered in selected instances, as it increases perinatal survival of fetuses with LUTO.

Kidney Transplantation in Small Children: Association Between Body Weight and Outcome-A Report From the ESPN/ERA-EDTA Registry.

BACKGROUND: Many centers accept a minimum body weight of 10 kg as threshold for kidney transplantation (Tx) in children. As solid evidence for clinical outcomes in multinational studies is lacking, we evaluated practices and outcomes in European children weighing below 10 kg at Tx. METHODS: Data were obtained from the European Society of Paediatric Nephrology/European Renal Association and European Dialysis and Transplant Association Registry on all children who started kidney replacement therapy at <2.5 y of age and received a Tx between 2000 and 2016. Weight at Tx was categorized (<10 versus ≥10 kg) and Cox regression analysis was used to evaluate its association with graft survival. RESULTS: One hundred of the 601 children received a Tx below a weight of 10 kg during the study period. Primary renal disease groups were equal, but Tx <10 kg patients had lower pre-Tx weight gain per year (0.2 versus 2.1 kg; P < 0.001) and had a higher preemptive Tx rate (23% versus 7%; P < 0.001). No differences were found for posttransplant estimated glomerular filtration rates trajectories (P = 0.23). The graft failure risk was higher in Tx <10 kg patients at 1 y (graft survival: 90% versus 95%; hazard ratio, 3.84; 95% confidence interval, 1.24-11.84), but not at 5 y (hazard ratio, 1.71; 95% confidence interval, 0.68-4.30). CONCLUSIONS: Despite a lower 1-y graft survival rate, graft function, and survival at 5 y were identical in Tx <10 kg patients when compared with Tx ≥10 kg patients. Our results suggest that early transplantation should be offered to a carefully selected group of patients weighing <10 kg.

Antenatally detected urinary tract dilatation: a 12-15-year follow-up.

BACKGROUND: Antenatally diagnosed urinary tract dilatation (UTD) still burdens healthcare providers and parents. This study was conducted to establish long-term outcome in an unselected group of children with antenatally detected UTD. METHODS: Seventy-one out of 103 children born in 2003-2005 and diagnosed with antenatal UTD agreed to participate in a 12-15-year follow-up including blood and urine samples, a kidney ultrasound exam, and kidney scintigraphy. The records were searched for previous urinary tract infections. RESULTS: Among children with an anteroposterior diameter (APD) ≤ 7 mm and no calyceal, kidney, ureteral, or bladder pathology in the early postnatal period, no one tested had reduced estimated glomerular filtration rate (eGFR), albuminuria, or UTD at the follow-up at a mean age of 13.6 years. One child had kidney damage not affecting kidney function. Among children with postnatal APD > 7 mm and/or kidney, calyceal, ureteral, or bladder pathology, 15% had persistent UTD and 32-39% (depending on the method used) had kidney damage. Major postnatal urinary tract ultrasound abnormalities and a congenital anomalies of the kidney and urinary tract (CAKUT) diagnosis were factors associated with an increased risk for permanent kidney damage (odds ratios 8.9, p = 0.016; and 14.0, p = 0.002, respectively). No one had reduced eGFR. One child (1/71, 1%) had a febrile urinary tract infection after the age of 2. CONCLUSIONS: We conclude that in children with postnatal APD ≤ 7 mm, no calyceal dilatation, normal bladder, ureters, and kidney parenchyma, the outcome is excellent. There is no need for long-term follow-up in these patients.

Management of BK-virus infection - Swedish recommendations.

BK-virus (BKV) associated nephropathy (BKVAN) and BKV associated haemorrhagic cystitis (HC) are complications of BKV infection/reactivation in renal and allogeneic haematopoietic stem cell transplantation (HSCT) patients, respectively. The task of how to manage these diseases was given to the chair by the Swedish Reference Group for Antiviral Therapy (RAV). After individual contributions by members of the working group, consensus discussions were held in a meeting on 23 January 2018 arranged by RAV. Thereafter, the recommendations were published in Swedish on November 2018. The current translation to English has been approved by all co-authors. High BKV serum levels suggest an increased risk for BKVAN and potential graft failure. For detection of BKVAN, careful monitoring of BKV DNA levels in serum or plasma is recommended the first year after renal transplantation and when increased creatinine serum levels of unknown cause are observed. Notably, a renal biopsy is mandatory for diagnosis. To reduce the risk for progression of BKVAN, there is no specific treatment, and tailored individual decrease of immunosuppression is recommended. For BKV-HC, BKV monitoring is not recommended, since BK-viruria frequently occurs in HSCT patients and the predictive value of BKV in plasma/serum has not been determined. However, the risk for BKV-HC is higher for patients undergoing myeloablative conditioning, having an unrelated, HLA-mismatched, or a cord blood donor, and awareness of the increased risk and early intervention may benefit the patients. Also for BKV-HC, no specific therapy is available. Symptomatic treatment, e.g. forced diuresis and analgesics could be of use.

Recovery of Kidney Function in Children Treated with Maintenance Dialysis.

BACKGROUND AND OBJECTIVES: Data on recovery of kidney function in pediatric patients with presumed ESKD are scarce. We examined the occurrence of recovery of kidney function and its determinants in a large cohort of pediatric patients on maintenance dialysis in Europe. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Data for 6574 patients from 36 European countries commencing dialysis at an age below 15 years, between 1990 and 2014 were extracted from the European Society for Pediatric Nephrology/European Renal Association-European Dialysis and Transplant Association Registry. Recovery of kidney function was defined as discontinuation of dialysis for at least 30 days. Time to recovery was studied using a cumulative incidence competing risk approach and adjusted Cox proportional hazard models. RESULTS: Two years after dialysis initiation, 130 patients (2%) experienced recovery of their kidney function after a median of 5.0 (interquartile range, 2.0-9.6) months on dialysis. Compared with patients with congenital anomalies of the kidney and urinary tract, recovery more often occurred in patients with vasculitis (11% at 2 years; adjusted hazard ratio [HR], 20.4; 95% confidence interval [95% CI], 9.7 to 42.8), ischemic kidney failure (12%; adjusted HR, 11.4; 95% CI, 5.6 to 23.1), and hemolytic uremic syndrome (13%; adjusted HR, 15.6; 95% CI, 8.9 to 27.3). Younger age and initiation on hemodialysis instead of peritoneal dialysis were also associated with recovery. For 42 patients (32%), recovery was transient as they returned to kidney replacement therapy after a median recovery period of 19.7 (interquartile range, 9.0-41.3) months. CONCLUSIONS: We demonstrate a recovery rate of 2% within 2 years after dialysis initiation in a large cohort of pediatric patients on maintenance dialysis. There is a clinically important chance of recovery in patients on dialysis with vasculitis, ischemic kidney failure, and hemolytic uremic syndrome, which should be considered when planning kidney transplantation in these children.

The FGF23-Klotho axis and cardiac tissue Doppler imaging in pediatric chronic kidney disease-a prospective cohort study.

BACKGROUND: Chronic kidney disease-associated mineral bone disorder (CKD-MBD) is common in pediatric kidney disease patients and a risk factor for future cardiovascular disease (CVD). Fibroblast growth factor-23 (FGF23) and Klotho are novel key players in CKD-MBD, and has been suggested to be involved in the development of CVD. METHODS: This prospective cohort study included 74 pediatric patients; 31 with CKD (age range 0.8-18.8 years, glomerular filtration rate (GFR) range 9-68 mL/min/1.73 m2) and 43 transplanted patients (CKD-T; age range 3.3-17.7 years, GFR range 10-99 mL/min/1.73 m2) examined annually for 3 years. We assessed longitudinal patterns and predictors of FGF23 and soluble Klotho, as well as associations to cardiac remodeling and function using echocardiographic pulse wave Doppler (PWD) and color-coded tissue Doppler imaging (cc-TDI). RESULTS: The prevalence of high FGF23 levels (≥95th percentile) was 60% in CKD and 42% in CKD-T patients, despite a low prevalence of hyperphosphatemia and normal Klotho levels. Low GFR at baseline was a predictor for high mean log FGF23 during follow-up in CKD and CKD-T patients (ß = -0.2, p < 0.001). A high log FGF23 z-score longitudinally was borderline significantly associated with elevated left ventricular mass index (LVMI) in CKD patients (ß = 1.8, p = 0.06). In addition, high log FGF23 (ß = -0.43, p = 0.01) and low log Klotho (ß = 0.44, p = 0.006) over time were associated with a worse left ventricular diastolic function (cc-TDI e'/a') in CKD-T patients. CONCLUSIONS: In pediatric CKD and CKD-T patients, the FGF23 level increase and Klotho level decrease with progressing renal failure, despite well-controlled phosphate levels. Following adjustments, both high FGF23 and low Klotho levels were strongly associated with a worse left ventricular diastolic function longitudinally. The potential role of FGF23 and Klotho in cardiac morbidity in pediatric CKD requires further investigation.

Infants Requiring Maintenance Dialysis: Outcomes of Hemodialysis and Peritoneal Dialysis.

BACKGROUND: The impact of different dialysis modalities on clinical outcomes has not been explored in young infants with chronic kidney failure. STUDY DESIGN: Cohort study. SETTING & PARTICIPANTS: Data were extracted from the ESPN/ERA-EDTA Registry. This analysis included 1,063 infants 12 months or younger who initiated dialysis therapy in 1991 to 2013. FACTOR: Type of dialysis modality. OUTCOMES & MEASUREMENTS: Differences between infants treated with peritoneal dialysis (PD) or hemodialysis (HD) in patient survival, technique survival, and access to kidney transplantation were examined using Cox regression analysis while adjusting for age at dialysis therapy initiation, sex, underlying kidney disease, and country of residence. RESULTS: 917 infants initiated dialysis therapy on PD, and 146, on HD. Median age at dialysis therapy initiation was 4.5 (IQR, 0.7-7.9) months, and median body weight was 5.7 (IQR, 3.7-7.5) kg. Although the groups were homogeneous regarding age and sex, infants treated with PD more often had congenital anomalies of the kidney and urinary tract (CAKUT; 48% vs 27%), whereas those on HD therapy more frequently had metabolic disorders (12% vs 4%). Risk factors for death were younger age at dialysis therapy initiation (HR per each 1-month later initiation, 0.95; 95% CI, 0.90-0.97) and non-CAKUT cause of chronic kidney failure (HR, 1.49; 95% CI, 1.08-2.04). Mortality risk and likelihood of transplantation were equal in PD and HD patients, whereas HD patients had a higher risk for changing dialysis treatment (adjusted HR, 1.64; 95% CI, 1.17-2.31). LIMITATIONS: Inability to control for unmeasured confounders not included in the Registry database and missing data (ie, comorbid conditions). Low statistical power because of relatively small number of participants. CONCLUSIONS: Despite a widespread preconception that HD should be reserved for cases in which PD is not feasible, in Europe, we found 1 in 8 infants in need of maintenance dialysis to be initiated on HD therapy. Patient characteristics at dialysis therapy initiation, prospective survival, and time to transplantation were very similar for infants initiated on PD or HD therapy.

Early Terminal Complement Blockade and C6 Deficiency Are Protective in Enterohemorrhagic Escherichia coli-Infected Mice.

Complement activation occurs during enterohemorrhagic Escherichia coli (EHEC) infection and may exacerbate renal manifestations. In this study, we show glomerular C5b-9 deposits in the renal biopsy of a child with EHEC-associated hemolytic uremic syndrome. The role of the terminal complement complex, and its blockade as a therapeutic modality, was investigated in a mouse model of E. coli O157:H7 infection. BALB/c mice were treated with monoclonal anti-C5 i.p. on day 3 or 6 after intragastric inoculation and monitored for clinical signs of disease and weight loss for 14 d. All infected untreated mice (15 of 15) or those treated with an irrelevant Ab (8 of 8) developed severe illness. In contrast, only few infected mice treated with anti-C5 on day 3 developed symptoms (three of eight, p < 0.01 compared with mice treated with the irrelevant Ab on day 3) whereas most mice treated with anti-C5 on day 6 developed symptoms (six of eight). C6-deficient C57BL/6 mice were also inoculated with E. coli O157:H7 and only 1 of 14 developed disease, whereas 10 of 16 wild-type mice developed weight loss and severe disease (p < 0.01). Complement activation via the terminal pathway is thus involved in the development of disease in murine EHEC infection. Early blockade of the terminal complement pathway, before the development of symptoms, was largely protective, whereas late blockade was not. Likewise, lack of C6, and thereby deficient terminal complement complex, was protective in murine E. coli O157:H7 infection.

Assessing longitudinal trends in cardiac function among pediatric patients with chronic kidney disease.

BACKGROUND: Left ventricular diastolic dysfunction (LVDD) is an early marker of cardiac disease in pediatric chronic kidney disease (CKD), but few studies have analyzed longitudinal trends. We conducted a prospective 3-year follow-up study in pediatric CKD and kidney transplant (CKD-T) patients. METHODS: The patient cohort comprised 30 CKD and 42 CKD-T patients. The results of annual clinical and echocardiographic analyses using tissue Doppler imaging (TDI) and pulse wave Doppler (PWD) were assessed, and associations to predictive risk factors were studied using multivariate modeling. RESULTS: The mean age of CKD and CKD-T patients at inclusion was 9.8 ± 4.4 and 11.8 ± 4.3 years, respectively; the glomerular filtration rate was 35.3 ± 18.3 and 60.3 ± 18.8 mL/min/1.73 m(2), respectively. The prevalence of left ventricular diastolic dysfunction (LVDD), as assessed using TDI (lateral z-score e') was 7.1 and 12.5 % in CKD and CKD-T patients, respectively; the corresponding values with PWD E were 3.3 and 2.4 %, respectively. In unadjusted analyses, both TDI and PWD markers of diastolic function worsened over the follow-up period; following adjustments, an elevated systolic ambulatory blood pressure was the most important predictor of cardiac disease. CONCLUSIONS: Children with CKD show early signs of LVDD, with TDI being more sensitive than PWD in terms of diagnostic potential. An increased ambulatory systolic blood pressure predicted progression in diastolic function, suggesting opportunities for future interventions.

Associations between lower urinary tract dysfunction and health-related quality of life in children with chronic kidney disease.

AIM: Little is known about the health-related quality of life (HRQoL) of children with lower urinary tract dysfunction (LUTD) and chronic kidney disease (CKD). We investigated LUTD and other possible predictors of impaired HRQoL in children with conservatively treated moderate-to-severe CKD or with a kidney transplant. METHODS: All 64 children with CKD or a kidney transplant treated at Karolinska University Hospital, Stockholm, Sweden, between June 2011 and December 2012 were approached and 59 children aged 8-18 were enrolled in the study. Lower urinary tract function was evaluated with voiding history, frequency and volume chart, uroflowmetry and postvoid ultrasound measurements. Self-reported HRQoL was assessed with validated generic instruments. RESULTS: The HRQoL of the study cohort was as good as the general paediatric population, apart from the physical and psychological well-being dimensions, and was no different to children with other chronic conditions. Urinary incontinence, but not LUTD in general, was associated with impaired HRQoL, as was having a kidney transplant and being female in some dimensions. CONCLUSION: LUTD was common in children with CKD or a kidney transplant but did not affect their general HRQoL. Predictors of impaired HRQoL included incontinence, having had a kidney transplant and being female.

New standardized cystatin C and creatinine GFR equations in children validated with inulin clearance.

BACKGROUND: This study compares glomerular filtration rate (GFR) equations in children based on standardized cystatin C (CYSC) and creatinine (CREA) and their combinations with renal clearance of inulin (C-inulin). METHODS: A total of 220 children with different renal disorders were referred for C-inulin (median 84 ml/min/1.73 m(2)). Bias, precision (interquartile range, IQR), and accuracy (percentage of estimates ±30 % of C-inulin; P30) were evaluated for two cystatin C equations, CAPACYSC and BergCYSC, for creatinine equations, SchwartzCREA and GaoCREA, the arithmetic mean of CAPACYSC and SchwartzCREA (MEANCAPA+Schwartz), BergCYSC and SchwartzCREA (MEANBERG+SCHWARTZ) and the composite equation ChehadeCYSC+CREA. RESULTS: Overall results of CAPACYSC, BergCYSC, SchwartzCREA, GaoCREA, MEANCAPA+Schwartz, MEANBERG+SCHWARTZ and ChehadeCYSC+CREA were: median bias -7.6/-4.9/-3.7/-2.3/-4.6/-4.0/-10.1 %, IQR 20.0/19.9/21.7/22.4/21.0/20.9/23.3 ml/min/1.73 m(2) and P30 86/86/80/83/89/91/83 %. The cystatin C equations, MEANCAPA+Schwartz and MEANBERG+SCHWARTZ had a more stable performance across subgroups compared with SchwartzCREA, GaoCREA and ChehadeCYSC+CREA. CONCLUSIONS: Cystatin C was the preferred filtration marker for GFR estimation in children, while the benefit of combining cystatin C and creatinine deserves further investigations.

Efficacy and safety of eculizumab in atypical hemolytic uremic syndrome from 2-year extensions of phase 2 studies.

Atypical hemolytic uremic syndrome (aHUS) is a rare, possibly life-threatening disease characterized by platelet activation, hemolysis and thrombotic microangiopathy (TMA) leading to renal and other end-organ damage. We originally conducted two phase 2 studies (26 weeks and 1 year) evaluating eculizumab, a terminal complement inhibitor, in patients with progressing TMA (trial 1) and those with long duration of aHUS and chronic kidney disease (trial 2). The current analysis assessed outcomes after 2 years (median eculizumab exposure 100 and 114 weeks, respectively). At all scheduled time points, eculizumab inhibited terminal complement activity. In trial 1 with 17 patients, the platelet count was significantly improved from baseline, and hematologic normalization was achieved in 13 patients at week 26, and in 15 patients at both 1 and 2 years. The estimated glomerular filtration rate (eGFR) was significantly improved compared with baseline and year 1. In trial 2 with 20 patients, TMA event-free status was achieved by 16 patients at week 26, 17 patients at year 1, and 19 patients at year 2. Criteria for hematologic normalization were met by 18 patients at each time point. Improvement of 15 ml/min per 1.73 m(2) or more in eGFR was achieved by 1 patient at week 26, 3 patients at 1 year, and 8 patients at 2 years. The mean change in eGFR was not significant compared with baseline, week 26, or year 1. Eculizumab was well tolerated, with no new safety concerns or meningococcal infections. Thus, a 2-year analysis found that the earlier clinical benefits achieved by eculizumab treatment of aHUS were maintained at 2 years of follow-up.

Renal-limited vasculitis in children: a single-center retrospective long-term follow-up analysis.

Pauci-immune renal limited vasculitis (RLV) is a rare and aggressive autoimmune disease. We retrospectively analyzed the renal outcome of 6 children with biopsy proven RLV. Median age at diagnosis was 10.6 years (range 7.1 - 14.5) and the median follow-up was 4.4 years (range 2.3 - 6.6). At diagnosis, 5 patients were given induction therapy (methylprednisolone + cyclophosphamide pulses) followed by maintenance treatment (prednisolone + azathioprine) while 1 patient received maintenance treatment only. After induction, 4 patients either retained or recovered normal renal function, and 1 patient, in whom short-term plasma exchange was prescribed to try to rescue her renal function, became free from dialysis. Repeated biopsy showed no disease activity; however, renal scarring was evident in all renal specimens. At last follow-up, 2 patients had normal renal function, 3 patients had mild renal insufficiency, and 1 patient had advanced renal failure. In addition, 5 patients were treated for hypertension. Our case series suggests that an initial favorable response to immunosuppressive therapy might not necessarily prevent the occurrence of renal scarring and highlights the importance of regular follow-up.

Renal transplantation in infants and small children.

There are still concerns about renal transplantation in small children. The aim of this study was to identify prenatal data, underlying diseases, patient and graft survival, graft function and growth in young renal transplant recipients at our center. A retrospective analysis was performed on 50 kidney transplants performed during the period 1981-2008 in children weighing <13 kg. Their median age at transplantation was 1.4 (range 0.4-3.7) years and the median weight was 9.5 (3.4-12.1) kg. The underlying diseases were congenital in 88% of the patients and acquired in 12%. Ten-year patient survival was 88% (82% before 1998 and 95% since 1998). Ten-year graft survival was 82% (75 and 95%, respectively). Graft function (glomerular filtration rate) deteriorated from a mean of 75-48 ml/min/1.73 m(2) within 10 years. There was rapid catch-up growth within the first years post-transplant, from a median height of -2.44 standard deviation score (SDS) at transplantation to -0.74 SDS after 3 years. In small children, patient and graft survival were as good as those in older children. Renal function deteriorated during the first years post-transplant but stabilized within a few years. In most children, there was a substantial improvement in growth within the first years after transplantation.

Schwartz formula: is one k-coefficient adequate for all children?

BACKGROUND/OBJECTIVE: Plasma-creatinine-based equations to estimate the glomerular filtration rate are recommended by several clinical guidelines. In 2009, Schwartz et al. adapted the traditional Schwartz equation to children and adolescents but did not find different k-coefficients between children and adolescents (k = 36.5 for all patients). We reevaluated the coefficient of the 2009-Schwartz formula according to sex and age in a pediatric population. PATIENTS/METHODS: We used linear mixed-effects models to reestimate the 2009-Schwartz k-coefficient in 360 consecutive French subjects aged 1 to 18 years referred to a single centre between July 2003 and July 2010 (965 measurements). We assessed the agreement between the estimated glomerular filtration rate obtained with the new formula (called Schwartz-Lyon) and the rate measured by inulin clearance. We then compared this agreement to the one between the measured glomerular filtration rate and 2009-Schwartz formula, first in the French then in a Swedish cohort. RESULTS: In Schwartz-Lyon formula, k was estimated at 32.5 in boys <13 years and all girls and at 36.5 in boys aged ≥13 years. The performance of this formula was higher than that of 2009-Schwartz formula in children <13 years. This was first supported by a statistically significant reduction of the overestimation of the measured glomerular filtration rate in both cohorts, by better 10% and 30% accuracies, and by a better concordance correlation coefficient. CONCLUSIONS: The performance and simplicity of Schwartz formula are strong arguments for its routine use in children and adolescents. The specific coefficient for children aged <13 years further improves this performance.

Comparison of plasma clearance of iohexol and urinary clearance of inulin for measurement of GFR in children.

BACKGROUND: Very few studies have been published that compare plasma clearance of iohexol (Cio) with renal clearance of inulin (Cin). STUDY DESIGN: Diagnostic test study. SETTING & PARTICIPANTS: 60 children aged 11.6 ± 4.5 years with different kidney disorders were investigated. INDEX TEST: Plasma Cio calculated from the slope and a single point. REFERENCE TEST: Renal Cin with continuous infusion during water diuresis. Results were compared with the correlation coefficients, bias and precision, accuracy percentage, root mean square error, and intraclass correlation. OTHER MEASUREMENTS: Measured creatinine clearance and estimated glomerular filtration rate based on serum creatinine level and height. RESULTS: Mean Cin was 70.7 ± 41.3 (SD) mL/min/1.73 m². Mean differences between Cio and Cin were 2.65 and 2.00 mL/min/1.73 m² for the slope and single-point methods, respectively. Precision was ±16 mL/min/1.73 m² and intraclass correlation was 0.92 in both methods. Proportions of Cio within 30% of Cin were 83.3% and 86.7% for the slope and single-point methods, respectively. LIMITATIONS: A limited number of patients; no adults were studied. CONCLUSIONS: Plasma Cio shows good agreement with renal Cin.

The Swedish reflux trial in children: III. Urinary tract infection pattern.

PURPOSE: We evaluated the difference in the febrile urinary tract infection rate in small children with dilating vesicoureteral reflux randomly allocated to 3 management alternatives, including antibiotic prophylaxis, endoscopic treatment or surveillance only as the control. MATERIALS AND METHODS: At 23 centers a total of 203 children were included in the study, including 128 girls and 75 boys 1 to younger than 2 years. Vesicoureteral reflux grade III in 126 cases and IV in 77 was detected after a febrile urinary tract infection (194) after prenatal screening (9). Voiding cystourethrography and dimercapto-succinic acid scintigraphy were done before randomization and after 2 years. The febrile urinary tract infection rate was analyzed by the intent to treat principle. RESULTS: We noted a total of 67 febrile recurrences in 42 girls and a total of 8 in 7 boys (p = 0.0001). There was a difference in the recurrence rate among treatment groups in girls with febrile infection in 8 of 43 (19%) on prophylaxis, 10 of 43 (23%) with endoscopic therapy and 24 of 42 (57%) on surveillance (p = 0.0002). In girls the recurrence rate was associated with persistent reflux after 2 years (p = 0.0095). However, reflux severity (grade III or IV) at study entry did not predict recurrence. CONCLUSIONS: In this randomized, controlled trial there was a high rate of recurrent febrile urinary tract infection in girls older than 1 year with dilating vesicoureteral reflux at study entry but not in boys. Antibiotic prophylaxis and endoscopic treatment decreased the infection rate.

The Swedish reflux trial in children: I. Study design and study population characteristics.

PURPOSE: We compared the rates of febrile urinary tract infection, kidney damage and reflux resolution in children with vesicoureteral reflux treated in 3 ways, including antibiotic prophylaxis, endoscopic therapy and surveillance with antibiotics only for symptomatic urinary tract infection. MATERIALS AND METHODS: Children 1 to younger than 2 years with grade III-IV reflux were recruited into this prospective, open, randomized, controlled, multicenter study and followed for 2 years after randomization. The main study end points were recurrent febrile urinary tract infection, renal status on dimercapto-succinic acid scintigraphy and reflux status. Outcomes were analyzed by the intent to treat principle. RESULTS: During a 6-year period 128 girls and 75 boys entered the study. In 96% of cases reflux was detected after urinary tract infection. The randomization procedure was successful and resulted in 3 groups matched for relevant factors. Recruitment was slower than anticipated but after patients were entered adherence to the protocol was good. Of the children 93% were followed for the intended 2 years without a treatment arm change. All except 2 patients completed 2-year followup scintigraphy. CONCLUSIONS: Recruitment was difficult but a substantial number of children were entered and randomly assigned to 3 groups with similar basic characteristics. Good adherence to the protocol made it possible to address the central study questions.