P1627KIDNEY TRANSPLANT OUTCOMES FOR CHILDREN AND YOUNG ADULTS IN THE UK

Background and Aims

Multiple international studies report young adulthood is associated with kidney transplant loss. However, there are few published UK graft survival data for children and young adults. To our knowledge, no studies assess initial transplant function or examine declining function, when interventions may improve outcomes.

We aimed to report graft survival for UK children and young adults and to explore the importance of donor and recipient variables on graft loss and rate of decline.

Method

Retrospective cohort study using UK Renal Registry and NHS Blood and Transplant data, including patients aged <30 years who underwent kidney transplantation between 1998-2016. Univariate analyses included Kaplan-Meier survival curves and log-rank tests. Multivariable analyses used Cox proportional hazards to investigate variables associated with death-censored graft failure in a conditional risk-set model for multiple failure data. Age group was time-varying. We used the Efron method for ties, stratification by graft number and clustering at participant level.

We calculated estimated glomerular filtration rate (eGFR) using the Schwartz formula if aged <18 years and the 4-variable Modification of Diet in Renal Disease formula otherwise. For participants with ≥4 values outside the first 6 months, individual regressions of eGFR against time were performed. We undertook multivariable linear regression to establish associations with eGFR slope gradients.

Results

We studied 5121 individuals. Of these, 371 received a further transplant during the study period. There were 1371 graft failures and 145 deaths with a functioning graft over a 39541-year risk period. The cohort was 61% male and 80% white. Most (36%) had structural kidney problems, followed by glomerulonephritides (29%). Live donation occurred in 48%, donation after brainstem death in 46% and after circulatory death in 6%. Mean initial eGFR was 62 mls/min/1.73m2.

Median graft survival was 7 years. One-year survival was 94.4% (95% confidence interval (CI) 93.7, 95.0), 5-year survival 84.0% (95% CI 82.9, 85.0), 10-year survival 71.1% (95% CI 69.6, 72.5), 15-year survival 60.2% (95% CI 58.1, 62.3) and 20-year survival 51.2% (47.6, 54.7). Survival at 15 years was least at 54.4% (95% CI 49.9, 58.7) in those transplanted at age 15-19 years and most in those transplanted at age 0-4 years at 71.7% (95% CI 63.4, 78.5).

Figure 1 displays hazard ratios for graft loss. Protective associations were male gender (p=0.04), living donation (p=0.02) and higher initial eGFR (p<0.0001). Risk associations included adverse human leucocyte mismatches (p=0.001), black ethnicity (p=0.001), young adulthood and glomerulonephritides. Risk associations for faster eGFR decline included female gender (p<0.0001), age group 15-19 years (p=0.04), higher initial eGFR (p<0.0001), additional graft (p=0.003) and transplants during 2011-2014 (p=0.03).

Conclusion

This study reports long-term graft survival for UK children and young adults and evaluates associations with declining transplant function. It contributes up to 20 years of follow-up and considers initial graft function in addition to established co-variates. Graft survival was ≈60% at 15 years. The study highlights the changing survival by age group over time. Those aged <5 years at transplant had the least initial survival, but best long-term graft survival relative to other age groups. Initial transplant function is strongly associated with graft performance. Similar associations with gender, ethnicity and age group are seen compared with other studies. Young adulthood is a high-risk period for UK patients and interventions are needed to improve outcomes during transition and young adulthood.

The Incidence of Paediatric Acute Kidney Injury Identified Using an AKI E-Alert Algorithm in Six English Hospitals

Objective: Acute kidney injury (AKI) is a significant cause of morbidity and mortality among hospitalised patients. The objectives in this study were (i) to investigate the incidence of AKI using the National Health Services (NHS) AKI e-alert algorithm as a means of identifying AKI; and (ii) in a randomly selected sub-group of children with AKI identified using the algorithm, to evaluate the recognition and management of AKI. Patients and Methods: Retrospective cross-sectional study with initial electronic retrieval of creatinine measurements at six hospitals in England over a six-month period. Results were evaluated using the NHS AKI e-alert algorithm with recognition and management of AKI stages 1, 2 and 3 reviewed in a sub-set of randomly selected patient case notes. Patients aged 29 to 17 years were included. AKI stage 1 was defined as a rise of 1.5 - ≤2x baseline creatinine level; AKI stage 2 a rise of ≤ 2.0 and < 3.0; AKI stage 3 a rise of ≥ 3.0. Urine output was not considered for AKI staging. Results: 57,278 creatinine measurements were analysed. 5,325 (10.8%) AKI alerts were noted in 1,112 patients with AKI 1 (62%), AKI 2 (16%) and AKI 3 (22%). There were 222 (20%) <1y, 432 (39%) 1 ≤ 6y, 192 (17%) 6 ≤ 11y, 207 (19%) 11 ≤ 16y, and 59 (5%) 16-17y. Case notes of 123 of 1,112 [11.1%] children with AKI alerts were reviewed. Confirmed AKI was recognised with a documented management plan following its identification in n = 32 [26%] patients only. Conclusions: In this first multicentre study of the incidence of AKI in children admitted to selected hospitals across England, the incidence of AKI was 10.8% with most patients under the age of 6 years and with AKI stage 1. Recognition and management of AKI was seen in just over 25% children. These data highlight the need to improve recognition of AKI in hospitalised children in the UK.

International consensus statement on the diagnosis and management of autosomal dominant polycystic kidney disease in children and young people

These recommendations were systematically developed on behalf of the Network for Early Onset Cystic Kidney Disease (NEOCYST) by an international group of experts in autosomal dominant polycystic kidney disease (ADPKD) from paediatric and adult nephrology, human genetics, paediatric radiology and ethics specialties together with patient representatives. They have been endorsed by the International Pediatric Nephrology Association (IPNA) and the European Society of Paediatric Nephrology (ESPN). For asymptomatic minors at risk of ADPKD, ongoing surveillance (repeated screening for treatable disease manifestations without diagnostic testing) or immediate diagnostic screening are equally valid clinical approaches. Ultrasonography is the current radiological method of choice for screening. Sonographic detection of one or more cysts in an at-risk child is highly suggestive of ADPKD, but a negative scan cannot rule out ADPKD in childhood. Genetic testing is recommended for infants with very-early-onset symptomatic disease and for children with a negative family history and progressive disease. Children with a positive family history and either confirmed or unknown disease status should be monitored for hypertension (preferably by ambulatory blood pressure monitoring) and albuminuria. Currently, vasopressin antagonists should not be offered routinely but off-label use can be considered in selected children. No consensus was reached on the use of statins, but mTOR inhibitors and somatostatin analogues are not recommended. Children with ADPKD should be strongly encouraged to achieve the low dietary salt intake that is recommended for all children.

Association between timing of dialysis initiation and clinical outcomes in the paediatric population: an ESPN/ERA-EDTA registry study

BACKGROUND

There is no consensus regarding the timing of dialysis therapy initiation for end-stage kidney disease (ESKD) in children. As studies investigating the association between timing of dialysis initiation and clinical outcomes are lacking, we aimed to study this relationship in a cohort of European children who started maintenance dialysis treatment.

METHODS

We used data on 2963 children from 21 different countries included in the European Society of Pediatric Nephrology/European Renal Association-European Dialysis and Transplant Association Registry who started renal replacement therapy before 18 years of age between 2000 and 2014. We compared two groups according to the estimated glomerular filtration rate (eGFR) at start: eGFR ≥8 mL/min/1.73 m2 (early starters) and eGFR <8 mL/min/1.73 m2 (late starters). The primary outcomes were patient survival and access to transplantation. Secondary outcomes were growth and cardiovascular risk factors. Sensitivity analyses were performed to account for selection- and lead time-bias.

RESULTS

The median eGFR at the start of dialysis was 6.1 for late versus 10.5 mL/min/1.73 m2 for early starters. Early starters were older [median: 11.0, interquartile range (IQR): 5.7-14.5 versus 9.4, IQR: 2.6-14.1 years]. There were no differences observed between the two groups in mortality and access to transplantation at 1, 2 and 5 years of follow-up. One-year evolution of height standard deviation scores was similar among the groups, whereas hypertension was more prevalent among late initiators. Sensitivity analyses resulted in similar findings.

CONCLUSIONS

We found no evidence for a clinically relevant benefit of early start of dialysis in children with ESKD. Presence of cardiovascular risk factors, such as high blood pressure, should be taken into account when deciding to initiate or postpone dialysis in children with ESKD, as this affects the survival.

Improved blood pressure and left ventricular remodelling in children on chronic intermittent haemodialysis: a longitudinal study

OBJECTIVES

We aimed to examine longitudinal changes in left ventricular (LV) structure and function and evaluate factors associated with LV remodelling in children on chronic haemodialysis.

METHODS

Retrospective longitudinal study including all children from the start of chronic haemodialysis with two or more m-mode 2D echocardiograms and tissue Doppler studies. Left ventricular mass (LVM) in g/m^2.7, geometry and LV function were compared at baseline (dialysis start) with follow-up studies at least 6 months following commencement. Left ventricular hypertrophy (LVH) was defined if greater than 95th percentile as per age-specific centiles. We also defined LVH as indexed LV mass index (LVMI) > 51 g/m^2.7 and using LV mass-for-height z-scores greater than the 95th percentile. Biochemical data, interdialytic weight change and blood pressure level were assessed for their association with change in indexed LVM.

RESULTS

Twenty-three of the 32 children < 18 years were included (n = 5, < 5 years) with last follow-up study performed following dialysis after a median (IQR) of 21 (10-34) months. The prevalence of LVH reduced significantly (69.6%, (n = 16/23) vs. 39.1% (n = 9/23), P = 0.002); LV geometry improved (13% concentric and 56.5% eccentric vs. 8.7% and 17.4% respectively) with mean ± SD reduction in indexed LVM (50.8 ± 23.1 g/m^2.7 vs. 38.6 ± 14.7 g/m^2.7, P = 0.002) and LV mass-for-height z-scores (0.67 ± 1.66 vs. - 0.46 ± 1.88, P = 0.002) from baseline to last follow-up respectively. There was no change in systolic function (LV fractional shortening, 37% vs. 38%, P = 0.39) and diastolic function (mean E/E' 10.8 vs. 9.0, P = 0.09). Multiple regression analysis identified improved systolic BP control (β = 0.41, P = 0.04) as an independent predictor for change in indexed LVM.

CONCLUSIONS

LV structure and function can improve in children despite long-term chronic intermittent haemodialysis. Cardiovascular health in this population does not always deteriorate but can be stabilised and indeed improved with optimal blood pressure management.

Effects of Hemodiafiltration versus Conventional Hemodialysis in Children with ESKD: The HDF, Heart and Height Study

BACKGROUND

Hypertension and cardiovascular disease are common in children undergoing dialysis. Studies suggest that hemodiafiltration (HDF) may reduce cardiovascular mortality in adults, but data for children are scarce.

METHODS

The HDF, Heart and Height study is a nonrandomized observational study comparing outcomes on conventional hemodialysis (HD) versus postdilution online HDF in children. Primary outcome measures were annualized changes in carotid intima-media thickness (cIMT) SD score and height SD score.

RESULTS

We enrolled 190 children from 28 centers; 78 on HD and 55 on HDF completed 1-year follow-up. The groups were comparable for age, dialysis vintage, access type, dialysis frequency, blood flow, and residual renal function. At 1 year, cIMT SD score increased significantly in children on HD but remained static in the HDF cohort. On propensity score analysis, HD was associated with a +0.47 higher annualized cIMT SD score compared with HDF. Height SD score increased in HDF but remained static in HD. Mean arterial pressure SD score increased with HD only. Factors associated with higher cIMT and mean arterial pressure SD-scores were HD group, higher ultrafiltration rate, and higher β2-microglobulin. The HDF cohort had lower β2-microglobulin, parathyroid hormone, and high-sensitivity C-reactive protein at 1 year; fewer headaches, dizziness, or cramps; and shorter postdialysis recovery time.

CONCLUSIONS

HDF is associated with a lack of progression in vascular measures versus progression with HD, as well as an increase in height not seen in the HD cohort. Patient-related outcomes improved among children on HDF correlating with improved BP control and clearances. Confirmation through randomized trials is required.

Renal disease in pregnancy: Fetal, neonatal and long-term outcomes

Renal disease in women of childbearing age is estimated to be approximately 3%; consequently, renal disease is not an uncommon comorbidity in pregnancy. There has been considerable evidence published over the last 20 years to suggest that renal disease in pregnancy is associated with higher maternal, fetal, and offspring morbidity. Studies published are largely heterogeneous; include unmatched cohort studies; and focus on early neonatal outcomes such as prematurity, small for gestational age, and neonatal unit admission. There appears to be an inverse relationship between maternal renal function and likelihood of neonatal morbidity using these outcome measures. Overall though, data regarding medium-to long-term outcomes for children born to mothers with renal disease are scarce. However, in view of emerging epidemiological evidence regarding cardiovascular programming in intrauterine life in those born premature or small for gestational age, it is likely that this population of children remain at high risk of cardiovascular disease as adults. The scope of this review is to amalgamate and summarize existing evidence regarding the outcomes of infants born to mothers with renal disease. Focus will be given to pregnancy-related acute kidney injury, chronic kidney disease, dialysis, and transplantation.

Vitamin B6 blood concentrations in paediatric dialysis patients

OBJECTIVES

We investigated vitamin B6 blood concentrations in children on long-term dialysis at our centre.

METHODS

Retrospective cross-sectional review of vitamin B6 blood concentrations in children on maintenance dialysis [peritoneal dialysis (PD), intermittent haemodialysis (IHD)].

RESULTS

We reviewed 28 children (16 boys), 15 IHD and 13 PD with median (interquartile range, IQR) age of 9.4 (2.4, 14.3) years. The median (IQR) vitamin B6 concentration was 223.4 (74.2, 392.8) nmol/L measured a median (IQR) of 9 (4, 16.5) months following commencement of dialysis. None of the children had vitamin B6 deficiency. Vitamin B6 concentrations were raised in 17 (61%), eight of these received a supplement. Nineteen (68%) received vitamin B6 and/or a supplement containing vitamin B6 whilst 11 (39%) received an enteral feed and a supplement. In those with normal vitamin B6 concentrations who were not receiving an enteral feed or an oral nutritional supplement (n = 6), all achieved normal concentrations without need for vitamin B6 supplementation. There were no differences between those on PD versus IHD (269.2 nmol/L vs. 130 nmol/L, P = 0.65).

CONCLUSIONS

We report no children with vitamin B6 deficiency although > 50% had elevated vitamin B6 concentrations. We suggest if dietary assessment of vitamin B6 intake indicates insufficient intake, measurement of blood concentrations will help confirm if supplementation is required. Routine vitamin B6 supplementation and monitoring is currently not indicated in children on chronic dialysis.

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.

Trace element and vitamin concentrations in paediatric dialysis patients

BACKGROUND

There are few recent data regarding blood micronutrient concentrations and supplementation in children on maintenance dialysis. We investigated micronutrient concentrations following dialysis commencement.

METHODS

Retrospective review, including all children on maintenance dialysis (peritoneal dialysis, PD; intermittent haemodialysis, IHD), for nutritional blood concentrations measured over the first 12 months. Patients received pyridoxine and Dialyvit® daily with planned 3-monthly micronutrient concentration monitoring including selenium, manganese, copper, zinc, folate and vitamins A, D, B12 and E.

RESULTS

We reviewed 47 children (24 girls) including 19 PD and 28 IHD, median age (IQR) 11.4 (2.8,14.4) years. 33 were white, 5 Asian, 5 black and 4 of other ethnic origins. Vitamin A, B12 and E concentrations were within range in 6%, 20% and 13% respectively, with all others above normal range. Serum folate and vitamin D concentrations were within the desired range of 55%, with the rest above or below target. For trace elements, 37%, 60%, 65% and 89% achieved normal ranges for zinc, manganese, copper and selenium respectively. Deficiencies were seen for zinc (43%), copper (28%), folate (6%) and selenium (4%), whereas 7%, 7%, 20% and 40% had copper, selenium, zinc and manganese levels above normal ranges. Despite standard pyridoxine supplementation, only 6 children were monitored during the study period.

CONCLUSIONS

Concentrations of several trace elements and vitamins were outside reference ranges. Response to systematic monitoring and targeted supplementation should be evaluated in future studies. Paediatric dialysis centres should consider undertaking routine nutritional bloods monitoring, particularly for vitamin D, zinc and copper.

Hypertension in Coarctation of the Aorta: Challenges in Diagnosis in Children

Evidence indicates that patients with coarctation of the aorta (COA) suffer from increased cardiovascular morbidity and mortality in later life despite successful repair of COA in childhood. Systolic arterial hypertension is common, presenting in up to one-third of patients, and is regarded as the main driver of premature cardiovascular events in this group of patients. In this review, we discuss the prevalence and pathophysiology of hypertension in children following successful COA repair with no residual arch obstruction. The challenges in accurate blood pressure assessment at this early phase are considered and non-invasive measures of central blood pressure are discussed. Although the pathways for investigations in adults are well defined, we highlight the need to address the issues of cardiovascular surveillance in children and describe techniques which can provide complementary information for cardiovascular assessment in this group of patients such that timely treatment can occur.

Myocardial Deformation Measured by 3-Dimensional Speckle Tracking in Children and Adolescents With Systemic Arterial Hypertension

Systemic arterial hypertension predisposes children to cardiovascular risk in childhood and adult life. Despite extensive study of left ventricular (LV) hypertrophy, detailed 3-dimensional strain analysis of cardiac function in hypertensive children has not been reported. The aim of this study was to evaluate LV mechanics (strain, twist, and torsion) in young patients with hypertension compared with a healthy control group and assess factors associated with functional measurements. Sixty-three patients (26 hypertension and 37 normotensive) were enrolled (mean age, 14.3 and 11.4 years; 54% men and 41% men, respectively). All children underwent clinical evaluation and echocardiographic examination, including 3-dimensional strain. There was no difference in LV volumes and ejection fraction between the groups. Myocardial deformation was significantly reduced in those with hypertension compared with controls. For hypertensive and normotensive groups, respectively, global longitudinal strain was -15.1±2.3 versus -18.5±1.9 (P<0.0001), global circumferential strain -15.2±3 versus -19.9±3.1 (<0.0001), global radial strain +44.0±11.3 versus 63.4±10.5 (P<0.0001), and global 3-dimensional strain -26.1±3.8 versus -31.5±3.8 (P<0.0001). Basal clockwise rotation, apical counterclockwise rotation, twist, and torsion were not significantly different. After multivariate regression analyses blood pressure, body mass index and LV mass maintained a significant relationship with measures of LV strain. Similar ventricular volumes and ejection fraction were observed in hypertensive and normotensive children, but children with hypertension had significantly lower strain indices. Whether reduced strain might predict future cardiovascular risk merits further longitudinal study.

Mutations in KEOPS-complex genes cause nephrotic syndrome with primary microcephaly

Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms.

Prophylactic Ureteric Stents in Renal Transplant Recipients: A Multicenter Randomized Controlled Trial of Early Versus Late Removal

Prophylactic ureteric stenting in renal transplantation reduces major urological complications; however, morbidity is related to the indwelling duration of a stent. We aimed to determine the optimal duration for stents in this clinical setting. Patients (aged 2-75 years) from six UK hospitals who were undergoing renal transplantation were recruited and randomly assigned to either early stent removal at 5 days (without cystoscopy) or late removal at 6 weeks after transplantation (with cystoscopy). The primary outcome was a composite of stent-related complications defined as pain, visible hematuria, migration, fragmentation, and urinary tract infections (UTIs) within 3 mo of transplantation. Between May 2010 and Nov 2013, we randomly assigned 227 participants, with 205 included in the final analysis of the primary outcome. Stent-related complications were significantly higher in the late versus early stent removal groups (36 of 126 [28.6%] vs. 6 of 79 [7.6%]; p < 0.001). The majority of stent complications consisted of UTIs, with an incidence of 31 of 126 (24.6%) in the late group compared with 6 of 79 (7.6%) in the early group (p = 0.004). We found early stent removal on day 5 significantly reduced stent-related complications and improved quality of life in the first 3 mo after transplantation (ISRCTN09184595).

Fifteen-minute consultation: the child with systemic arterial hypertension

Hypertension in children is a relatively uncommon condition but its prevalence is increasing with the rising rates of excess weight during childhood. It is important that hypertension is diagnosed early in children, particularly in those with symptoms, in those with secondary causes and in those with target organ damage. This article presents a systematic approach to the evaluation of a child with arterial hypertension, highlighting important points on history and examination, out-of-office monitoring and baseline investigations before consideration for more detailed investigations and treatment.

Genomic and clinical profiling of a national nephrotic syndrome cohort advocates a precision medicine approach to disease management

Steroid Resistant Nephrotic Syndrome (SRNS) in children and young adults has differing etiologies with monogenic disease accounting for 2.9-30% in selected series. Using whole exome sequencing we sought to stratify a national population of children with SRNS into monogenic and non-monogenic forms, and further define those groups by detailed phenotypic analysis. Pediatric patients with SRNS were identified via a national United Kingdom Renal Registry. Whole exome sequencing was performed on 187 patients, of which 12% have a positive family history with a focus on the 53 genes currently known to be associated with nephrotic syndrome. Genetic findings were correlated with individual case disease characteristics. Disease causing variants were detected in 26.2% of patients. Most often this occurred in the three most common SRNS-associated genes: NPHS1, NPHS2, and WT1 but also in 14 other genes. The genotype did not always correlate with expected phenotype since mutations in OCRL, COL4A3, and DGKE associated with specific syndromes were detected in patients with isolated renal disease. Analysis by primary/presumed compared with secondary steroid resistance found 30.8% monogenic disease in primary compared with none in secondary SRNS permitting further mechanistic stratification. Genetic SRNS progressed faster to end stage renal failure, with no documented disease recurrence post-transplantation within this cohort. Primary steroid resistance in which no gene mutation was identified had a 47.8% risk of recurrence. In this unbiased pediatric population, whole exome sequencing allowed screening of all current candidate genes. Thus, deep phenotyping combined with whole exome sequencing is an effective tool for early identification of SRNS etiology, yielding an evidence-based algorithm for clinical management.

Hypertension in autosomal dominant polycystic kidney disease: a meta-analysis

CONTEXT

Autosomal dominant polycystic kidney disease (ADPKD) is a common disorder that can cause hypertension during childhood, but the true prevalence of hypertension during childhood is not known.

OBJECTIVE

We undertook a systematic review and meta-analysis to determine the prevalence of hypertension in children with ADPKD.

DATA SOURCES

Systematic review of articles published between 1980 and 2015 in MEDLINE and EMBASE.

STUDY SELECTION

Studies selected by two authors independently if reporting data on prevalence of hypertension in children and young persons aged <21 years with a diagnosis of ADPKD. Observational series were included with study populations of >15 children. Articles were excluded if inadequate diagnostic criteria for hypertension were used. Studies with selection bias were included but analysed separately.

DATA EXTRACTION

Data extracted on prevalence of hypertension, proteinuria and reduced renal function using standardised form. Meta-analysis was performed to calculate weighted mean prevalence.

RESULTS

903 articles were retrieved from our search; 14 studies met the inclusion criteria: 1 prospective randomised controlled trial; 8 prospective observational studies; and 5 retrospective cross-sectional studies. From 928 children with clinically confirmed ADPKD, 20% (95% CI 15% to 27%) were hypertensive. The estimated prevalence of proteinuria in children with ADPKD is 20% (8 studies; 95% CI 9% to 40%) while reduced renal function occurred in 8% (5 studies; 95% CI 2% to 26%).

LIMITATIONS

Studies showed a high degree of methodological heterogeneity (I²=73.4%, τ²=0.3408, p<0.0001). Most studies did not use ambulatory blood pressure (BP) monitoring to diagnose hypertension.

CONCLUSIONS

In this meta-analysis we estimate 20% of children with ADPKD have hypertension. In the population, many children with ADPKD are not under regular follow-up and remain undiagnosed. We recommend that all children at risk of ADPKD have regular BP measurement.

A single-centre retrospective study of the safety and efficacy of mycophenolate mofetil in children and adolescents with nephrotic syndrome

Background

The aim of the study was to investigate the efficacy and side effect profile of mycophenolate mofetil (MMF) therapy in children with nephrotic syndrome (NS).

Methods

A retrospective case note review was performed on all patients with NS who were commenced on MMF between 1 January 2000 and 31 December 2009 and were followed up for a minimum of 1 year.

Results

The sample size was 73 patients. The duration of follow-up was for a median of 3.2 years, interquartile range (IQR) (1.7–4.7 years). The median age at diagnosis was 3.2 years, IQR (2.3–5.7 years). The median age of MMF commencement was 11 years, IQR (7.9–13.6 years). There were more boys (67%) than girls. The majority were Caucasian (77%), with 18% Asian 4%, Black Africans and 1% other ethnicities. At initial diagnosis, 61 (84%) were steroid sensitive, 9 (12%) steroid resistant, 3 (4%) steroid dependent (SD). Forty-five (74%) of the 61 steroid-sensitive patients became SD, 4 (7%) of them became steroid resistant, 1 (1%) remained steroid-sensitive and 11 (18%) became frequent relapsers. As to the previous use of second-line immunosuppressants, none were used in 5 (7%) patients, one agent in 17 (23%), two in 27 (37%) and three or more agents were used in 23 (32%) patients. MMF was effective in 45 (62%) patients. Of these, 38 (52%) of them were in remission for >2 years; and in 7 (10%) MMF worked for 1 to 2 years (MMF therapy electively stopped/ongoing). MMF therapy allowed 27 (37%) patients to wean steroids completely and 8 (11%) to achieve complete steroid and immunosuppressant withdrawal. A further 8 (11%) had steroids partially weaned. MMF failures were seen in 13 (18%) within the first year and 5 (7%) in the second year. MMF was stopped due to side effects in 4 (6%) and non-compliance in 4 (6%). The majority of patients had no side effects [51 (70%)]. Seven (9%) had gastrointestinal side effects (diarrhoea/abdominal pain); 5 (7%) had immunological side effects (leucopenia/infections); 3 (4%) had both immunological and gastrointestinal side effects; and 2 (3%) suffered arthralgia.

Conclusions

MMF is well tolerated and effective as a second-line agent in treating steroid-sensitive NS. The drug permitted prolonged remission and steroid weaning or other second-line agent withdrawal in a majority of cases.

Early Requirement for RRT in Children at Presentation in the United Kingdom: Association with Transplantation and Survival

BACKGROUND AND OBJECTIVES

We evaluated rates and factors associating with late referral (LR) and describe association of LR with access to renal transplantation and patient survival in children in the United Kingdom. Early requirement of RRT within 90 days of presentation to a pediatric nephrologist was classed as a LR, and those >90 days as an early referral (ER).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We included patients who commenced RRT, aged ≥3 months and <16 years, from 1996 to 2012.

RESULTS

Of 1603 patients, 25.5% (n=408) were LR, of which 75% commenced RRT in <30 days following presentation. Those with LR were more likely to be older at presentation, female, and black. The primary renal disease in LR was more likely to be glomerular disease (odds ratio [OR], 1.6; 95% confidence interval [95% CI], 1.12 to 2.29), renal malignancy and associated diseases (OR, 4.11; 95% CI, 1.57 to 10.72), tubulo-interstitial diseases (OR, 2.37; 95% CI, 1.49 to 3.78), or an uncertain renal etiology (OR, 5.75; 95% CI, 3.1 to 10.65). Significant differences in rates of transplantation between LR and ER remained up to 1-year following commencement of dialysis (21% versus 61%, P<0.001) but with no differences for donor source (33.3% and 35.3% living donor in LR and ER respectively, P=0.55). The median (interquartile range) follow-up time was 4.8 years (2.9-7.6). There were 55 deaths with no statistically significant difference in survival in the LR group compared with the ER group (hazard ratio, 1.30; 95% CI, 0.7 to 2.3; P=0.40).

CONCLUSIONS

We found that 25% of children starting RRT in the United Kingdom receive a LR to pediatric renal services, with little change observed over the past two decades. Those with LR are unable to benefit from pre-emptive transplantation and require longer periods of dialysis before transplantation. There is an urgent need to understand causes of avoidable LR and develop strategies to improve kidney awareness more widely among health care professionals looking after children.

UK Renal Registry 18th Annual Report: Chapter 10 Clinical, Haematological and Biochemical Parameters in Patients Receiving Renal Replacement Therapy in Paediatric Centres in the UK in 2014: National and Centre-specific Analyses

The median height z-score for paediatric patients on dialysis was −2.1 and for those with a functioning transplant −1.3. Children transplanted before the age of 12 years improved their height z-score over the subsequent five years, whereas those older than 12 maintained their height z-score, with all transplanted patients having a similar median height z-score after five years of starting renal replacement therapy (RRT). The median weight z-score for children on dialysis was −1.4 whereas children with a functioning transplant had a near normal weight for age and sex with a median z-score of −0.3. Of those with data, 75% of the prevalent paediatric RRT population had one or more ‘traditional’ risk factors for cardiovascular disease, with 1 in 10 having all three risk factors present. For the 10 centres reporting quarterly laboratory data, the average creatinine in transplant patients was 79 mmol/L; dialysis patients had normal average anaemia and acidosis markers and evidence of secondary hyperparathyroidism with an average PTH of 17.3 pmol/L. For transplant patients, 80% achieved the systolic blood pressure (SBP) standard and 93% achieved the haemoglobin standard. For haemodialysis patients, 57% achieved the SBP standard, 62% achieved the haemoglobin standard, 82% achieved the calcium standard, 51% achieved the phosphate standard and 39% achieved the parathyroid hormone (PTH) standard. For peritoneal dialysis patients, 70% achieved the SBP standard, 77% achieved the haemoglobin standard, 72% achieved the calcium standard, 54% achieved the phosphate standard and 33% achieved the PTH standard.