Mental health and professional outcomes in parents of children with chronic kidney disease

BACKGROUND

This study evaluated parenting stress, anxiety, and depression symptoms and their associated factors in parents of children with chronic kidney disease (CKD).

METHODS

This cross-sectional study compared parents of patients with CKD (0-18 years) with a matched control group of parents of healthy children. Both groups completed the Parenting Stress Index - Short Form, the Hospital Anxiety and Depression Scale, and a sociodemographic questionnaire.

RESULTS

The study group consisted of 45 parents (median age 39; 32 mothers) of CKD patients (median age 8; 36% female). Nearly 75% of children had CKD stages 2, 3, or 4, and 44.5% had congenital anomaly of the kidney and urinary tract. Five children (11%) were on dialysis, and 4 (9%) had a functioning kidney graft. Compared with parents of healthy children, more stress and anxiety symptoms were reported. Since the CKD diagnosis, 47% of parents perceived a deterioration of their own health, and 40% reduced work on a structural basis. Higher levels of stress, anxiety, and depression symptoms were associated with a more negative perception of own health, and more child medical comorbidities and school absence.

CONCLUSIONS

This study showed higher levels of parenting stress and anxiety symptoms in parents of children with CKD compared with parents of healthy children. This was associated with a less positive perception of their own health, especially if the child had more medical comorbidities or more absence from school. Psychosocial interventions to reduce the parental burden should be integrated in the standard care of pediatric nephrology departments.

Transition in enuresis patients: Identifying the gaps and opportunities for the future

BACKGROUND

Nocturnal enuresis is generally considered a children's condition, yet it may persist 1%-2% in adolescence and early adulthood. Refractory patients often demand follow-up by multidisciplinary teams, which is only restricted to some of the expert tertiary centers. However, there are no standardized transition programs/guidelines when follow-up must be passed from pediatric to adult healthcare providers.

AIM, MATERIALS & METHODS

To investigate this issue, we conducted a literature search on enuresis transition, which resulted in no articles. We, therefore, proceeded in a rescue search strategy: we explored papers on transition programs of conditions that may be related and/or complicated by enuresis, nocturia, or other urinary symptoms (chronic diseases, CKD, bladder dysfunction, kidney transplant, neurogenic bladder).

RESULTS

These programs emphasize the need for a multidisciplinary approach, a transition coordinator, and the importance of patient and parent participation, practices that could be adopted in enuresis. The lack of continuity in enuresis follow-up was highlighted when we investigated who was conducting research and publishing on enuresis and nocturia. Pediatric disciplines (50%) are mostly involved in children's studies, and urologists in the adult ones (37%).

DISCUSSION

We propose a stepwise approach for the transition of children with enuresis from pediatric to adult care, depending on the clinical subtype: from refractory patients who demand more complex, multidisciplinary care and would benefit from a transition coordinator up to children/young adults cured of enuresis but who persist in having or present lower urinary tract symptoms (LUTS)/nocturia later on. In any case, the transition process should be initiated early at the age of 12-14 years, with adequate information to the patient and parents regarding relapses or LUTS/nocturia occurrence and of the future treating general practitioner on the enuresis characteristics and comorbidities of the patient.

Time-Varying Determinants of Graft Failure in Pediatric Kidney Transplantation in Europe

BACKGROUND

Little is known about the time-varying determinants of kidney graft failure in children.

METHODS

We performed a retrospective study of primary pediatric kidney transplant recipients (younger than 18 years) from the Eurotransplant registry (1990-2020). Piece-wise exponential additive mixed models were applied to analyze time-varying recipient, donor, and transplant risk factors. Primary outcome was death-censored graft failure.

RESULTS

We report on 4528 kidney transplantations, of which 68% with deceased and 32% with living donor. One thousand six hundred and thirty-eight recipients experienced graft failure, and 168 died with a functioning graft. Between 2011 and 2020, the 5-year graft failure risk was 10% for deceased donor and 4% for living donor kidney transplant recipients. Risk of graft failure decreased five-fold from 1990 to 2020. The association between living donor transplantation and the lower risk of graft failure was strongest in the first month post-transplant (adjusted hazard ratio, 0.58; 95% confidence interval, 0.46 to 0.73) and remained statistically significant until 12 years post-transplant. Risk factors for graft failure in the first 2 years were deceased donor younger than 12 years or older than 46 years, potentially recurrent kidney disease, and panel-reactive antibody >0%. Other determinants of graft failure included dialysis before transplantation (until 5 years post-transplant), human leukocyte antigen mismatch 2-4 (0-15 years post-transplant), human leukocyte antigen mismatch 5-6 (2-12 years post-transplant), and hemodialysis (8-14 years post-transplant). Recipients older than 11 years at transplantation had a higher risk of graft failure 1-8 years post-transplant compared with other age groups, whereas young recipients had a lower risk throughout follow-up. Analysis of the combined effect of post-transplant time and recipient age showed a higher rate of graft failure during the first 5 years post-transplant in adolescents compared with young transplant recipients. In contrast to deceased donor younger than 12 years, deceased donor older than 46 years was consistently associated with a higher graft failure risk.

CONCLUSIONS

We report a long-term inverse association between living donor kidney transplantation and the risk of graft failure. The determinants of graft failure varied with time. There was a significant cumulative effect of adolescence and time post-transplant. The ideal donor age window was dependent on time post-transplant.

The development of the Belgian paediatric clinical trial network

Paediatric clinical trials are critical to ensure that medications prescribed to children are safe and effective. However, evidence-based dosing and labelling of such medications remain limited, and most clinical trials in paediatrics fail. Factors for lack of trial completion include performance at site level (limited patient recruitment, limited site staff experience and lack of infrastructure), the sponsor team (limited paediatric specific expertise in design, uncertainties on robustness of biomarkers or outcome variables) as well as regulatory and administrative burdens. As a result of the growing demand for site support, the Belgian Paediatric Clinical Research Network (BPCRN) established in 2009 has been relaunched in 2018 to improve paediatric clinical trials, with the support of innovative-medicines-initiative 2 (IMI2) pan-European network conect4children (c4c) and the transatlantic network I-ACT for Children (US).This paper highlights the formation of the BPCRN and the practical insights it offers for advancing paediatric clinical trials through national networks. A national network can improve trial quality, safety and efficiency, provide clinical research expertise, identify suitable sites, and help with troubleshooting of common trial issues. The BPCRN's centralized approach has advanced paediatric clinical trials by streamlining communication and standardizing trial conduct. Challenges and opportunities have arisen, including a relaunch in 2018, orphan medicine trials, and network sustainability. Collaboration between network activities, government support, site-level improvements, efficient communication, and interaction with industry are key to achieve lasting transformation in paediatric medicine research.

Population pharmacokinetics of lisinopril in hypertensive children and adolescents with normal to mildly reduced kidney function

AIMS

Lisinopril, an angiotensin-converting enzyme inhibitor, is a frequently prescribed antihypertensive drug in the paediatric population, while being used off-label under the age of 6 years in the USA and for all paediatric patients globally. The SAFEPEDRUG project (IWT-130033) investigated lisinopril pharmacokinetics in hypertensive paediatric patients corresponding with the day-to-day clinical population.

METHODS

The dose-escalation pilot study included 13 children with primary and secondary hypertension who received oral lisinopril once daily in the morning; doses ranged from 0.05 to 0.2 mg kg-1 . Patients were aged between 1.9 and 17.9 years (median 13.5 years) and weight ranged between 9.62 and 97.2 kg (median 53.2 kg). All data were analysed using Monolix version 2020R1 (Lixoft, France) and R version 3.6.2.

RESULTS

A 1-compartment model with first-order absorption and first-order elimination optimally describes the data. Parameter estimates of absorption rate constant (0.075 h-1 [0.062, 0.088], typical value [95% confidence interval]), volume of distribution (31.38 L 70 kg-1 [10.5, 52.3]) and elimination clearance (24.2 L h-1 70 kg-1 [19.5, 28.9]) show good predictive ability. Significant covariate effects include total body weight on elimination clearance, and distribution volume and estimated glomerular filtration rate (eGFR) on elimination clearance. The effects of eGFR on the elimination clearance are optimally described by a linear effect centred around 105 mL min-1  1.73 m-2 . The effects of body weight were implemented using fixed allometric exponents centred around an adult weight of 70 kg.

CONCLUSION

Lisinopril dose and regimen adjustments for paediatric patients should include eGFR on top of weight adjustments. An expanded model characterizing the pharmacodynamic effect is required to identify the optimal dose and dosing regimen.

Exploring lifelong overactive bladder: Transitions, evidence, and clinical implications; A modified Delphi process

INTRODUCTION

Overactive bladder (OAB) is a prevalent urological condition characterized by urinary urgency, with or without urgency urinary incontinence, accompanied by increased daytime frequency and nocturia. However, the current definition of OAB lacks a specified time frame, hindering our understanding of the temporal aspects and transitions that occur within the OAB spectrum.

METHODS

A modified Delphi study was conducted in three rounds, involving a panel of international experts in functional urology, urogynaecology, geriatrics, transitional medicine, and pediatric urology. The study took place between February 2023 and June 2023 and employed two sequential rounds of online surveys, followed by a final hybrid group discussion session in June 2023.

RESULTS

The Delphi process resulted in a consensus definition of lifelong OAB as a persistent and continuous condition that may manifest differently from birth and evolve over time, with varying levels of clinical perception. The course of its progression is influenced by transition periods and modifying factors, mainly anatomical, hormonal, and psychosocial/stressors. Three main transition periods were identified: achievement of daytime continence, adulthood to elderly, and transition to frail elderly. The panel also considered the therapeutic and diagnostic implications of lifelong OAB, as well as future research prospects in terms of importance and feasibility.

CONCLUSIONS

Future longitudinal research is needed to develop this concept and further identify transitions and temporal dynamics.

Development and performance of the c4c national clinical trial networks for optimizing pediatric trial facilitation

Introduction

The high failure rate of industry-driven pediatric clinical trials leads to insufficient timely labeling of drugs in children and a lack of scientific evidence, resulting in the persistently high off-label drug use. National clinical trial networks can facilitate collaboration between sites, investigators, and experts, increasing the likelihood of successful trials. Within the conect4children (c4c) network, an Innovative Medicines Initiative 2-funded project, National Hubs hosted by National Clinical Trials Networks were set up across 21 European countries to facilitate the setup and execution of pediatric clinical trials. In this paper, we aim to present the performance metrics of the trial feasibility process as well as learnings and challenges encountered by the Belgian and Dutch Networks in working within the European c4c project.

Method

The c4c National Hubs streamline pediatric clinical trials by initiating early country outreach, identifying overlapping studies, recommending quality trial sites, and supporting trial budgeting for both industry and academic settings. To show the impact of Pedmed-NL and Belgian Pediatric Clinical Research Network (BPCRN), internal metrics were collected from 2019 to 2022 on four industry-sponsored and three academic trials performed within the c4c network. Timelines and outcomes of the site identification were collected and analyzed for industry trials. A qualitative analysis was conducted through c4c platforms, sponsor interactions, and stakeholder engagement to evaluate the added value of a research network.

Results

In industry-sponsored trials, full feasibility questionnaires were completed within 2 weeks (n = 48), and inclusion rates were up to 80% of clinical sites. Before committing to c4c, 14% of sites were contacted by industry, leading to communication burdens. Utilizing national infrastructure knowledge and therapeutic environment insights helped optimize trial timelines and address feasibility challenges. In addition, national adaptations, such as bilingual staff and site development, played a role in streamlining trial operations in both academic and industry settings. Performance and experiences were similar for both networks.

Conclusion

The early-facilitation examples from the c4c trials demonstrated promising metrics for two National Hubs, including optimized start-up timelines and aiding site selection quality. The learnings and challenges of the Belgian and Dutch Networks provided insights for the development of clinical research networks.

First uninterrupted sleep period in children and adolescents with nocturnal enuresis: Added value in diagnosis and follow-up during therapy

BACKGROUND

The first uninterrupted sleep period (FUSP, time up to the first episode of enuresis/nocturia after falling asleep) is a frequently investigated parameter in adults with nocturia, as it correlates with quality of life. However, it has not been included in pediatric enuresis studies.

AIM

Investigate FUSP, circadian renal water and sodium handling, as well as sleep quality before and after desmopressin therapy in enuresis.

MATERIALS AND METHODS

We conducted a post hoc analysis of a prospective study in 30 treatment-naïve children with enuresis who underwent a video-polysomnography and a 24-h urine concentration profile before and after 6 months of desmopressin therapy. We analyzed FUSP, periodic limb movements in sleep (PLMS), and arousal indexes and their correlations with the urinary parameters.

RESULTS

Sixteen children with a mean age of 10.9 ± 3.1 years had full registrations and were included in this subanalysis. After therapy, FUSP was significantly longer (p < 0.001), and the PLMS index was lower (p = 0.023). Significant differences in the circadian rhythm of diuresis (night/day diuresis, p = 0.041), nocturnal urinary osmolality (p = 0.009), and creatinine (p = 0.001) were found, demonstrating the increase of urinary concentration overnight by desmopressin, as well as a significant antidiuretic effect (diuresis [p = 0.013] and diuresis rate (p = 0.008). There was no correlation between the difference of FUSP, PLMS index, and urinary parameters. Nevertheless, despite this study being underpowered, there are indications of a correlation between nocturnal diuresis and diuresis rate.

RESULTS

Our results support the need for further research regarding FUSP in children with enuresis, in accordance with nocturia studies in adults, as this parameter could be valuable in the follow-up and evaluation of therapeutic strategies for enuresis.

The role of renal circadian biorhythms in lifelong LUTS

INTRODUCTION

This article delves into the intricate relationship between kidney function, diuresis, and lower urinary tract symptoms (LUTS) throughout the transitions of the human lifespan. It explores circadian regulation of urine production, maturation of renal function from birth to adulthood, and effects of aging on kidney function and LUTS. The complex connections between these factors are highlighted, offering insights into potential interventions and personalized management strategies.

METHODS

An international panel of seven experts engaged in online discussions, focusing on kidney function, diuresis, and LUTS throughout life. This manuscript summarizes expert insights, literature reviews, and findings presented during a webinar and subsequent discussions.

RESULTS

Renal function undergoes significant maturation from birth to adulthood, with changes in glomerular filtration rate, diuresis, and tubular function. A circadian rhythm in urine production is established during childhood. Adolescents and young adults can experience persistent enuresis due to lifestyle factors, comorbidities, and complex physiological changes. In older adults, age-related alterations in kidney function disrupt the circadian rhythm of diuresis, contributing to nocturnal polyuria and LUTS.

CONCLUSION

The interplay between kidney function, diuresis, and LUTS is crucial in understanding lifelong urinary health. Bridging the gap between pediatric and adult care is essential to address enuresis in adolescents and young adults effectively. For older adults, recognizing the impact of aging on renal function and fluid balance is vital in managing nocturia. This holistic approach provides a foundation for developing innovative interventions and personalized treatments to enhance quality of life for individuals with LUTS across all stages of life.

Illness-related parental stress and quality of life in children with kidney diseases

BACKGROUND

This cross-sectional study investigated quality of life (QoL) and illness-related parental stress in children with kidney diseases by (1) comparing mean levels of these two variables between several kidney disease categories; (2) exploring correlations between QoL and parental stress; and (3) describing which disease category reports lowest QoL and highest parental stress.

METHODS

We included 295 patients with a kidney disease (0-18 years) and their parents, followed at 6 reference centers for pediatric nephrology. Children's QoL was assessed by the PedsQL™ 4.0 Generic Core Scales, and illness-related stress by the Pediatric Inventory for Parents. All patients were divided into 5 kidney disease categories according to the multidisciplinary care program criteria prescribed by the Belgian authorities: (1) structural kidney diseases, (2) tubulopathies and metabolic diseases, (3) nephrotic syndrome, (4) acquired diseases with proteinuria and hypertension, and (5) kidney transplantation.

RESULTS

Child self-reports showed no differences in QoL between kidney disease categories, in contrast to parent proxy reports. Parents of transplant patients reported lower QoL in their child and more parental stress compared with the 4 non-transplant categories. QoL and parental stress were negatively correlated. Lowest QoL and highest parental stress scores were mainly found in transplant patients.

CONCLUSIONS

This study showed lower QoL and higher parental stress in pediatric transplant patients compared with non-transplants, based on parent reports. Higher parental stress is associated with worse QoL in the child. These results highlight the importance of multidisciplinary care for children with kidney diseases, with special attention to transplant patients and their parents. A higher resolution version of the Graphical abstract is available as Supplementary information.

Circadian rhythm of water and solute excretion in nocturnal enuresis

BACKGROUND

Nocturnal polyuria (NP) due to a suppressed vasopressin circadian rhythm is a well-documented pathogenetic mechanism in enuresis, mainly studied in monosymptomatic enuresis. A substantial percentage of patients do not respond to desmopressin. This suggests that NP may not only be related to vasopressin, but that other kidney components play a role. Solute handling and osmotic excretion have been investigated in the past, especially in refractory patients. Nevertheless, data in treatment-naïve populations with information on timing overnight are sparse. This study aims to investigate the diuresis and solute excretion in treatment-naïve patients with or without NP, with emphasis on circadian rhythms.

METHODS

Retrospective analysis of 403 treatment-naïve children 5-18 years with severe enuresis (> 8 nights/2 weeks). Circadian rhythms were evaluated by a 24-h urine collection in 8 timed portions (4 day, 4 nighttime) at in-home settings. Urine volume, osmolality, and creatinine were measured. Patients were subdivided into three groups according to nocturnal diuresis (ND) and Expected Bladder Capacity (EBCage) ratio: (a) < 100%, (b) 100-129%, (c) > 130%.

RESULTS

All groups maintained circadian rhythm for diuresis and diuresis rates. Patients with higher ND (100-129% and > 130% EBCage) had higher daytime volumes and less pronounced circadian rhythm. In the ND group > 130% EBCage, the ND rate was higher during the first night collection and osmotic excretion was significantly higher overnight.

CONCLUSIONS

Overall 24-h fluid intake (reflected by 24-h diuresis) and nutritional intake (24-h osmotic excretion) might play a role in enuresis. Increased diuresis rate early in the night can be important in some patients, whereas the total night volume can be important in others. A higher resolution version of the Graphical abstract is available as Supplementary Information.

Definition, diagnosis and clinical management of non-obstructive kidney dysplasia: a consensus statement by the ERKNet Working Group on Kidney Malformations

Kidney dysplasia is one of the most frequent causes of chronic kidney failure in children. While dysplasia is a histological diagnosis, the term 'kidney dysplasia' is frequently used in daily clinical life without histopathological confirmation. Clinical parameters of kidney dysplasia have not been clearly defined, leading to imprecise communication amongst healthcare professionals and patients. This lack of consensus hampers precise disease understanding and the development of specific therapies. Based on a structured literature search, we here suggest a common basis for clinical, imaging, genetic, pathological and basic science aspects of non-obstructive kidney dysplasia associated with functional kidney impairment. We propose to accept hallmark sonographic findings as surrogate parameters defining a clinical diagnosis of dysplastic kidneys. We suggest differentiated clinical follow-up plans for children with kidney dysplasia and summarize established monogenic causes for non-obstructive kidney dysplasia. Finally, we point out and discuss research gaps in the field.

Nocturnal bladder emptying and Quality of Life in patients with spinal cord injury

BACKGROUND

Little is known about the relationship between sleep disruption due to nocturnal bladder emptying and Quality of Life in patients with spinal cord injury.

AIM

The aim of this study was to evaluate the possible influence of number of nocturnal bladder emptying, bladder emptying method and nocturnal incontinence on the Quality of Life of patients with spinal cord injury.

DESIGN

The design of this paper is a cross-sectional descriptive study.

SETTING

The setting is in- and outpatient.

POPULATION

Seventy-nine patients aged between 18 and 77 years with SCI in a first rehabilitation period or follow-up.

METHODS

Patients were asked to complete Short Form-36 and Incontinence Quality of Life questionnaires and a medical information form. Independent samples t-tests and ANOVA were used to compare scores between groups.

RESULTS

The response rate was 71 out of 79 (89%; 51 males and 20 females). 16 paraplegic and 4 tetraplegic patients were chronic, 29 paraplegic and 22 tetraplegic patients were in rehabilitation therapy or had finished this treatment recently. The paraplegic group had a significantly better Short Form-36 total score and emotional function score, while the tetraplegic group had a significantly better Incontinence Quality of Life total score and avoidance and limiting behavior score. The paraplegic patients with 0-1 nocturnal bladder emptying had better Short Form-36-derived Quality of Life than those with ≥2 emptying. Quality of Life score was not associated with gender, leg oedema, incontinence, or acute/chronic group. Incontinence Quality of Life score was significantly better for patients with incomplete spinal cord injury. Fully completed questionnaires were returned by 36 patients; at least 1 item was missing for 35 participants.

CONCLUSIONS

General Short Form-36-derived Quality of Life was better for the paraplegic population. Incontinence-related Quality of Life was better in tetraplegic patients, most of whom used suprapubic catheterization. Paraplegic patients had compromised sleep and Quality of Life when the patient had to wake up two or more times at night to empty the bladder by voiding or intermittent catheterization. The high number of incomplete responders indicates the shortcomings of Quality-of-Life questionnaires for wheelchair-bound patients with spinal cord injury.

CLINICAL REHABILITATION IMPACT

The use of suprapubic catheterization should be considered to improve Quality of Life for tetraplegic patients. For paraplegic patients, we must focus urological policy on aiming to reduce the number of nighttime bladder emptying to one or none.

Validity and reliability of the Dutch version of the PedsQL™ 3.0 End Stage Renal Disease Module in children with chronic kidney disease in Belgium

BACKGROUND

Children with chronic kidney disease (CKD) have a low quality of life (QoL). The PedsQL™ 4.0 Generic Core Scales are widely used to assess general QoL in children. The aim of this cross-sectional study was to translate the original version of the CKD-specific PedsQL™ 3.0 End Stage Renal Disease Module into a Dutch version and to evaluate its validity and reliability.

METHODS

The forward-backward translation method based on the guidelines from the original developer was used to produce the Dutch version of the PedsQL™ 3.0 ESRD Module. Fifty-eight CKD patients (aged 8-18 years) and their parents (n = 31) filled in both generic and disease-specific modules. The non-clinical control group consisted of the same number of healthy children (matched for gender and age) and their parents.

RESULTS

Cronbach's alpha coefficients (α's) for the PedsQL™ 3.0 ESRD Module demonstrated excellent reliability for the Total Scale scores. For all 7 subscales, α's were greater than 0.60, except for Perceived Physical Appearance. Overall, intercorrelations with the PedsQL™ 4.0 Generic Core Scales were in the medium to large range, supporting construct validity. Parent proxy reports showed lower generic QoL for all domains in CKD patients compared to healthy children. Child self-reports only demonstrated lower QoL on the domain School Functioning in children with CKD compared to healthy children.

CONCLUSIONS

This study shows good validity and reliability for the Dutch version of the PedsQL™ 3.0 ESRD Module. However, testing with a larger study group is recommended in order to make final conclusions about the psychometric qualities of this measure. A higher resolution version of the Graphical abstract is available as Supplementary information.

Mental Health Outcomes Among Parents of Children With a Chronic Disease During the COVID-19 Pandemic: The Role of Parental Burn-Out

Objective

The COVID-19 pandemic and associated quarantine measures highly impacted parental psychological well-being. Parents of children with chronic diseases might be specifically vulnerable as they already face multiple challenges to provide adequate care for their child. The research questions of the current study were twofold: (a) to examine whether parents of children with a chronic disease experienced more anxiety and depression compared to parents of healthy children and (b) to examine a series of risk factors for worsened well-being (i.e., depression, anxiety, and sleep problems), such as sociodemographic variables, COVID-19-specific variables (i.e., financial worries, living space, and perceived quality of health care), and parental psychological experiences (i.e., parental burn-out and less positive parenting experiences).

Methods

Parents of children with a chronic disease (i.e., the clinical sample; N = 599 and 507 for Research Questions 1 and 2, respectively) and parents of healthy children (i.e., the reference sample: N = 417) filled out an online survey.

Results

Findings demonstrated that the parents in the clinical sample reported higher levels of anxiety than parents in the reference sample. Analyses within the clinical sample indicated that COVID-19-specific stressors and parental psychological experiences were associated with higher levels of anxiety, depression, and sleep problems. Mediation analyses furthermore indicated that the association of COVID-19-specific stressors with all outcome measures was mediated by parental burn-out.

Conclusions

Parents of children with a chronic disease constitute a vulnerable group for worse well-being during the current pandemic. Findings suggest interventions directly targeting parental burn-out are warranted.

Towards an Algorithm-Based Tailored Treatment of Acute Neonatal Hyperammonemia

Acute neonatal hyperammonemia is associated with poor neurological outcomes and high mortality. We developed, based on kinetic modeling, a user-friendly and widely applicable algorithm to tailor the treatment of acute neonatal hyperammonemia. A single compartmental model was calibrated assuming a distribution volume equal to the patient's total body water (V), as calculated using Wells' formula, and dialyzer clearance as derived from the measured ammonia time-concentration curves during 11 dialysis sessions in four patients (3.2 ± 0.4 kg). Based on these kinetic simulations, dialysis protocols could be derived for clinical use with different body weights, start concentrations, dialysis machines/dialyzers and dialysis settings (e.g., blood flow QB). By a single measurement of ammonia concentration at the dialyzer inlet and outlet, dialyzer clearance (K) can be calculated as K = QB∙[(Cinlet - Coutlet)/Cinlet]. The time (T) needed to decrease the ammonia concentration from a predialysis start concentration Cstart to a desired target concentration Ctarget is then equal to T = (-V/K)∙LN(Ctarget/Cstart). By implementing these formulae in a simple spreadsheet, medical staff can draw an institution-specific flowchart for patient-tailored treatment of hyperammonemia.

Dietary fibre intake is low in paediatric chronic kidney disease patients but its impact on levels of gut-derived uraemic toxins remains uncertain

BACKGROUND

Chronic kidney disease (CKD) in children is a pro-inflammatory condition leading to a high morbidity and mortality. Accumulation of organic metabolic waste products, coined as uraemic toxins, parallels kidney function decline. Several of these uraemic toxins are protein-bound (PBUT) and gut-derived. Gut dysbiosis is a hallmark of CKD, resulting in a state of increased proteolytic fermentation that might be counteracted by dietary fibre. Data on fibre intake in children with CKD are lacking. We aimed to assess dietary fibre intake in a paediatric CKD cohort and define its relationship with PBUT concentrations.

METHODS

In this multi-centre, cross-sectional observational study, 61 non-dialysis CKD patients (9 ± 5 years) were included. Dietary fibre intake was assessed through the use of 24-h recalls or 3-day food records and coupled to total and free levels of 4 PBUTs (indoxyl sulfate (IxS), p-cresyl sulfate (pCS), p-cresyl glucuronide (pCG) and indole acetic acid (IAA).

RESULTS

In general, fibre intake was low, especially in advanced CKD: 10 ± 6 g/day/BSA in CKD 4-5 versus 14 ± 7 in CKD 1-3 (p = 0.017). Lower concentrations of both total (p = 0.036) and free (p = 0.036) pCG were observed in the group with highest fibre intake, independent of kidney function.

CONCLUSIONS

Fibre intake in paediatric CKD is low and is even worse in advanced CKD stages. Current dietary fibre recommendations for healthy children are not being achieved. Dietary management of CKD is complex in which too restrictive diets carry the risk of nutritional deficiencies. The relation of fibre intake with PBUTs remains unclear and needs further investigation. Graphical abstract.

Body mass index is associated with hyperparathyroidism in pediatric kidney transplant recipients

BACKGROUND

Hyperparathyroidism persists in up to 50% of pediatric kidney transplant recipients. The aims of this study were to describe the evolution of parathyroid hormone (PTH) in the first year after transplantation and to identify factors associated with hyperparathyroidism.

METHODS

This retrospective study included children who underwent kidney transplantation at the University Hospitals of Ghent, Leuven, Rotterdam, or Amsterdam. Data from 149 patients were collected before and up to 12 months after transplantation. Severe hyperparathyroidism was defined as PTH 2-fold above the reference value. Factors associated with hyperparathyroidism and severe hyperparathyroidism were identified using multivariate logistic regression analysis.

RESULTS

Before transplantation, 97 out of 137 patients (71%) had hyperparathyroidism. The probability of hyperparathyroidism and severe hyperparathyroidism declined from 0.49 and 0.17 to 0.29 and 0.09 at 3 and 12 months after transplantation, respectively. BMI SDS (β: 0.509; p = 0.011; 95% CI: 1.122-2.468), eGFR (β: - 0.227; p = 0.030; 95% CI: 0.649-0.978), and pre-transplant hyperparathyroidism (β: 1.149; p = 0.039; 95% CI: 1.062-9.369) were associated with hyperparathyroidism 12 months after transplantation. Pre-transplant hyperparathyroidism (β: 2.115; p = 0.044; 95% CI: 1.055-65.084), defined as intact parathormone (iPTH) levels > 65 ng/l (6.9 pmol/l) or 1-84 PTH > 58 ng/l (6.2 pmol/l), was associated with severe hyperparathyroidism at 3 months. Only eGFR (β: - 0.488; p = 0.010; 95% CI: 0.425-0.888) was inversely associated with severe hyperparathyroidism at 9 months after transplantation.

CONCLUSIONS

Allograft function remains the main determinant of severe hyperparathyroidism after transplantation. Our findings emphasize the importance of BMI and pre-transplant PTH control.

Pediatric Challenges in Robot-Assisted Kidney Transplantation

Kidney transplantation is universally recognized as the gold standard treatment in patients with End-stage Kidney Disease (ESKD, or according to the latest nomenclature, CKD stage 5). Robot-assisted kidney transplantation (RAKT) is gradually becoming preferred technique in adults, even if applied in very few centra, with potentially improved clinical outcomes compared with open kidney transplantation. To date, only very few RAKT procedures in children have been described. Kidney transplant recipient patients, being immunocompromised, might be at increased risk for perioperative surgical complications, which creates additional challenges in management. Applying techniques of minimally invasive surgery may contribute to the improvement of clinical outcomes for the pediatric transplant patients population and help mitigate the morbidity of KT. However, many challenges remain ahead. Minimally invasive surgery has been consistently shown to produce improved clinical outcomes as compared to open surgery equivalents. Robot-assisted laparoscopic surgery (RALS) has been able to overcome many restrictions of classical laparoscopy, particularly in complex and demanding surgical procedures. Despite the presence of these improvements, many challenges lie ahead in the surgical and technical–material realms, in addition to anesthetic and economic considerations. RALS in children poses additional challenges to both the surgical and anesthesiology team, due to specific characteristics such as a small abdominal cavity and a reduced circulating blood volume. Cost-effectiveness, esthetic and functional wound outcomes, minimal age and weight to undergo RALS and effect of RAKT on graft function are discussed. Although data on RAKT in children is scarce, it is a safe and feasible procedure and results in excellent graft function. It should only be performed by a RAKT team experienced in both RALS and transplantation surgery, fully supported by a pediatric nephrology and anesthesiology team. Further research is necessary to better determine the value of the robotic approach as compared to the laparoscopic and open approach. Cost-effectiveness will remain an important subject of debate and is in need of further evaluation as well.

Dietary Fibre Intake Is Associated with Serum Levels of Uraemic Toxins in Children with Chronic Kidney Disease

Imbalanced colonic microbial metabolism plays a pivotal role in generating protein-bound uraemic toxins (PBUTs), which accumulate with deteriorating kidney function and contribute to the uraemic burden of children with chronic kidney disease (CKD). Dietary choices impact the gut microbiome and metabolism. The aim of this study was to investigate the relation between dietary fibre and gut-derived PBUTs in paediatric CKD. Sixty-one (44 male) CKD children (9 ± 5 years) were prospectively followed for two years. Dietary fibre intake was evaluated by either 24-h recalls (73%) or 3-day food records (27%) at the same time of blood sampling for assessment of total and free serum levels of different PBUTs using liquid chromatography. We used linear mixed models to assess associations between fibre intake and PBUT levels. We found an inverse association between increase in fibre consumption (g/day) and serum concentrations of free indoxyl sulfate (−3.1% (−5.9%; −0.3%) (p = 0.035)), free p-cresyl sulfate (−2.5% (−4.7%; −0.3%) (p = 0.034)), total indole acetic acid (IAA) (−1.6% (−3.0%; −0.3%) (p = 0.020)), free IAA (−6.6% (−9.3%; −3.7%) (p < 0.001)), total serum p-cresyl glucuronide (pCG) (−3.0% (−5.6%; −0.5%) (p = 0.021)) and free pCG levels (−3.3% (−5.8%; −0.8%) (p = 0.010)). The observed associations between dietary fibre intake and the investigated PBUTs highlight potential benefits of fibre intake for the paediatric CKD population. The present observational findings should inform and guide adaptations of dietary prescriptions in children with CKD.

120 High variation in prediction of developmental competence of bovine oocytes based on visual examination

The quality of an oocyte is often represented by its morphological characteristics. Stringent selection of bovine cumulus–oocyte complexes (COCs) for invitro embryo production (IVP) is regularly based on parameters such as colour and granulation of the ooplasm, density of the surrounding cumulus cells, brightness of the zona pellucida, among other less common parameters. The link between developmental competence and morphology of the COC has been demonstrated in literature in group culture system. However, this has not been yet examined in an individual invitro production system. This study investigates the ability of IVP researchers to predict whether an oocyte will develop into a blastocyst at Day 8 of invitro culture in an individual production system. A set of 29 pictures of immature bovine COCs was presented in duplicates to eight bovine IVP researchers with different institutional backgrounds. The observers were asked if they would select each oocyte for further IVP processing, assuming that only the oocytes with the highest developmental potential can proceed, and thus a stringent selection is warranted. These 29 immature oocytes were matured, fertilized, and cultured individually invitro (using conventional methods) so that their ability to develop into a blastocyst at Day 8 post-fertilization was known. The ability to reach the blastocyst stage was stated as the gold standard and compared with the answers of the observers using kappa statistics and sensitivity (Se) and specificity (Sp) tests. Kappa (κ) for interobserver agreement was κ=0.01 (Se=50%, Sp=53%; positive predictive value=14%, negative predictive value=87%) with 50% accuracy of prediction. The intraobserver agreement was κ=0.69, with κ=1 referring to 100% agreement (Se=87%, Sp=83%), with an accuracy of 85%. The ability of trained embryologists to predict the fate of oocytes’ developmental competence was accurate for only half of the presented oocytes. Additionally, the proportion of false positive (1 − Sp) and false negative (1−Se) predictions was equally distributed. The low positive predictive value might be due to the lower development rates in individual culture systems versus group culture systems, whereas observers are mainly trained to select oocytes for group culture. This study demonstrated the subjective nature of the oocyte selection process that is based on visual examination of COC morphology because interobserver agreement was almost nonexistent. Interpretation of the morphology within an observer remains consequent, represented by the high intraobserver agreement. Consequently, there is a need to develop a new model for the objective determination of oocyte quality for individual IVP. The implementation of machine learning algorithms could objectively enhance oocyte selection and artificial reproductive technologies in extension.

The long-term added value of voiding school for children with refractory non-neurogenic overactive bladder: an inpatient bladder rehabilitation program

INTRODUCTION & BACKGROUND

Despite adequate management, 20% of children with overactive bladder (OAB) syndrome fail to improve their bladder function. To approach the need for alternative strategies, an inpatient bladder rehabilitation 'voiding school' program was established.

OBJECTIVE

The objective of this study was to evaluate the short- and long-term (1-year follow-up) outcome of this voiding school program in children with refractory OAB. In addition, the authors aimed to identify which children achieved the best outcomes with this voiding school program.

STUDY DESIGN

The charts of all children (n = 357, mean age: 9.7 ± 2.0 years, 63.6% boys) with refractory OAB who attended voiding school between 2000 and 2010 were reviewed. A linear mixed model with random intercept was used to evaluate the incontinence (expressed by enuresis and daytime incontinence voiding scores) and maximal voiding volume (MVV).

RESULTS & DISCUSSION

This study demonstrated an overall beneficial long-term effect of the inpatient program on day- and night-time incontinence, in which 36.6% of children achieved dryness during day- and night-time. In addition, the mean overall decline in the number of wet nights and days declined with 4 extra dry days and/or nights per week, in comparison with the level of continence before attending the voiding school program. In contrast, only a temporary increase in MVV was seen, however, without relapse incontinence. At last, the authors identified the negative impact of decreasing age, male sex, dysfunctional voiding and nocturnal polyuria on the overall outcome of the inpatient program.

CONCLUSION

An inpatient rehabilitation 'voiding school' program is a successful and safe treatment modality for children with refractory OAB that results in long-term significant increase of continence, as well as amelioration in degree of severity. The worst outcomes of this voiding school program were detected in children with young age, who were boys, or had associated nocturnal polyuria, dysfunctional voiding, and/or faecal incontinence.

Management and treatment of nocturnal enuresis-an updated standardization document from the International Children's Continence Society

BACKGROUND

Enuresis is an extremely common condition, which, although somatically benign, poses long-term psychosocial risks if untreated. There are still many misconceptions regarding the proper management of these children.

AIM

A cross-professional team of experts affiliated with the International Children's Continence Society (ICCS) undertook to update the previous guidelines for the evaluation and treatment of children with enuresis.

METHODS

The document used the globally accepted ICCS terminology. Evidence-based literature served as the basis, but in areas lacking in primary evidence, expert consensus was used. Before submission, a full draft was made available to all ICCS members for additional comments.

RESULTS

The enuretic child does, in the absence of certain warning signs (i.e., voiding difficulties, excessive thirst), not need blood tests, radiology or urodynamic assessment. Active therapy is recommended from the age of 6 years. The most important comorbid conditions to take into account are psychiatric disorders, constipation, urinary tract infections and snoring or sleep apneas. Constipation and daytime incontinence, if present, should be treated. In nonmonosymptomatic enuresis, it is recommended that basic advice regarding voiding and drinking habits be provided. In monosymptomatic enuresis, or if the above strategy did not make the child dry, the first-line treatment modalities are desmopressin or the enuresis alarm. If both these therapies fail alone or in combination, anticholinergic treatment is a possible next step. If the child is unresponsive to initial therapy, antidepressant treatment may be considered by the expert. Children with concomitant sleep disordered breathing may become dry if the airway obstruction is removed.

Single-setting robot-assisted kidney transplantation consecutive to single-port laparoscopic nephrectomy in a child and robot-assisted living-related donor nephrectomy: initial Ghent experience

INTRODUCTION

Kidney transplantation (KT) is the gold-standard treatment for end-stage renal disease (ESRD) in children. Robot-assisted kidney transplantation (RAKT) in adults is becoming increasingly common with potentially improved morbidity compared with open KT. The study objective was to evaluate feasibility and outcomes of RAKT in children.

PATIENTS & METHODS

An 8-years-old boy with ESRD received a kidney transplant from his mother. Simultaneously in two operation theatres, the boy underwent single-port (GelPOINT®) right laparoscopic nephro-ureterectomy (LNU), and his mother underwent robot-assisted left donor nephrectomy (RADN).Two full surgical teams were operating at the same time. Subsequently, the boy underwent RAKT, introducing the graft through the GelPOINT®.

RESULTS

Total operative time for LNU, RADN, and RAKT was 180, 140, and 195 min, respectively, with warm, cold, and rewarming ischemia times 1.5, 200, and 47 min, respectively. Blood loss was 300, 20, and 50 cc, respectively. No intraoperative complications were noted. Convalescence of both donor and recipient was uneventful, with good kidney function at 1-year follow-up.

CONCLUSION

RAKT in children is technically feasible and safe, resulting in excellent graft function. Concomitant nephrectomy can be done laparoscopically through the single-site GelPOINT®. An experienced RAKT team with the full support of pediatric nephrologists is mandatory.

Concentrations of representative uraemic toxins in a healthy versus non-dialysis chronic kidney disease paediatric population

Background

Chronic kidney disease (CKD) in childhood is poorly explained by routine markers (e.g. urea and creatinine) and is better depicted in adults by other uraemic toxins. This study describes concentrations of representative uraemic toxins in non-dialysis CKD versus healthy children.

Methods

In 50 healthy children and 57 children with CKD Stages 1-5 [median estimated glomerular filtration rate 48 (25th-75th percentile 24-71) mL/min/1.73 m2; none on dialysis], serum concentrations of small solutes [symmetric and asymmetric dimethyl-arginine (SDMA and ADMA, respectively)], middle molecules [β2-microglobuline (β2M), complement factor D (CfD)] and protein-bound solutes [p-cresylglucuronide (pCG), hippuric acid (HA), indole-acetic acid (IAA), indoxyl sulphate (IxS), p-cresyl sulphate (pCS) and 3-carboxy-4-methyl-5-propyl-furanpropionic acid (CMPF)] were measured. Concentrations in the CKD group were expressed as z-score relative to controls and matched for age and gender.

Results

SDMA, CfD, β2M, IxS, pCS, IAA, CMPF and HA concentrations were higher in the overall CKD group compared with controls, ranging from 1.7 standard deviations (SD) for IAA and HA to 11.1 SD for SDMA. SDMA, CfD, β2M, IxS and CMPF in CKD Stages 1-2 with concentrations 4.8, 2.8, 4.5, 1.9 and 1.6 SD higher, respectively. In contrast, pCS, pCG and IAA concentrations were only higher than controls from CKD Stages 3-4 onwards, but only in CKD Stage 5 for ADMA and HA (z-score 2.6 and 20.2, respectively).

Conclusions

This is the first study to establish reference values for a wide range of uraemic toxins in non-dialysis CKD and healthy children. We observed an accumulation of multiple uraemic toxins, each with a particular retention profile according to the different CKD stages.

Haemodiafiltration does not lower protein-bound uraemic toxin levels compared with haemodialysis in a paediatric population

Background

Haemodiafiltration (HDF) is accepted to effectively lower plasma levels of middle molecules in the long term, while data are conflicting with respect to the additive effect of convection on lowering protein-bound uraemic toxins (PBUTs). Here we compared pre-dialysis β2-microglobulin (β2M) and PBUT levels and the percentage of protein binding (%PB) in children on post-dilution HDF versus conventional high- (hf) or low-flux (lf) haemodialysis (HD) over 12 months of treatment.

Methods

In a prospective multicentre, non-randomized parallel-arm intervention study, pre-dialysis levels of six PBUTs and β2M were measured in children (5–20 years) on post-HDF (n = 37), hf-HD (n = 42) and lf-HD (n = 18) at baseline and after 12 months. Analysis of variance was used to compare levels and %PB in post-HDF versus conventional hf-HD and lf-HD cross-sectionally at 12 months and longitudinal from baseline to 12 months.

Results

For none of the PBUTs, no difference was found in either total and free plasma levels or %PB between post-HDF versus the hf-HD and lf-HD groups. Children treated with post-HDF had lower pre-dialysis β2M levels [median 23.2 (21.5; 26.6) mg/dL] after 12 months versus children on hf-HD [P&lt;0.01; 35.2 (29.3; 41.2) mg/dL] and children on lf-HD [P&lt;0.001; 47.2 (34.3; 53.0) mg/dL]. While β2M levels remained steady in the hf-HD and lf-HD group, a decrease in β2M was demonstrated for children on post-HDF (P&lt;0.01).

Conclusions

While post-HDF successfully decreased β2M, no additive effect on PBUT over 12 months of treatment was found. PBUT removal is complex and hampered by several factors. In children, these factors might be different from adults and should be explored in future research.

Drug-metabolizing enzymes CYP3A as a link between tacrolimus and vitamin D in renal transplant recipients: is it relevant in clinical practice?

CYP3A enzymes are involved in the metabolism of calcineurin inhibitor tacrolimus as well as vitamin D. In this review, we summarize the clinical aspects of CYP3A-mediated metabolism of tacrolimus and vitamin D with emphasis on the influence of single-nucleotide polymorphisms on tacrolimus disposition. We describe the utility of 4β hydroxycholesterol as a marker of CYP3A activity. Then, we discuss the possible interaction between calcineurin inhibitors and vitamin D in solid organ transplant recipients. Also, we review other mechanisms which may contribute to side effects of calcineurin inhibitors on bone. Lastly, suggestions for future research and clinical perspectives are discussed.

Intra-patient variability in tacrolimus exposure in pediatric liver transplant recipients: Evolution, risk factors, and impact on patient outcomes

BACKGROUND

This study aims to investigate the evolution and factors associated with TAC IPV and its impact on patient outcomes in pediatric LT recipients.

METHODS

This is a retrospective study including 41 children. The TAC IPV was expressed as the coefficient of variation and was calculated for years 1-5 following LT. The number of missed clinic appointments was used as a surrogate marker for therapy adherence.

RESULTS

We identified a decrease in the TAC IPV during the first 3 years after LT (P < 0.01). Serum albumin in the first year (P = 0.03), hematocrit (P = 0.02) and total bilirubin (P = 0.04) in the third year, and therapy adherence (P < 0.01) in the fifth year were associated with TAC IPV. High TAC IPV was associated with biopsy-proven acute allograft rejection (P = 0.04) and the need for biopsy during the first year (P = 0.02). There was a borderline association between TAC IPV and donor-specific antibodies (P = 0.08) and CMV viremia (P = 0.07). High TAC IPV was a predictor of need for liver biopsy and AR with an odds ratio of 1.04 (95% CI 1.0-1.1; P = 0.03) and 1.04 (95% CI 1.0-1.1; P = 0.05), respectively.

CONCLUSIONS

Our results highlight the impact of biological factors on TAC IPV during the early LT follow-up and later also therapy adherence. High TAC IPV may be associated with adverse patient outcomes.

A devastating case of diarrhea-associated hemolytic uremic syndrome associated with extensive cerebral infarction; why we need to do better

A 4-year-old girl with diarrhea-associated hemolytic uremic syndrome (D+HUS) was transferred to the PICU of our center due to deteriorating renal function and neurological involvement. On admission, a comatous child was seen with hypoventilation and she was placed on mechanical ventilation. Hemodialysis was commenced but plasma exchange was discontinued due to repeated hypersensitivity reactions. A trial of eculizumab was given in light of the worsening of her neurologic condition with development of a pyramidal syndrome and deepening of the coma. Hematological and renal improvement were noted but severe neurologic involvement persisted. MRI revealed extensive bilateral zones of corticocerebral infarction and neurological damage proved to be irreversible. Diarrhea-associated hemolytic uremic syndrome is a common cause of Acute Kidney Injury associated with severe short- and long-term complications. Neurologic involvement is frequent but often reversible. Currently, no effective treatment strategies are available and a paucity of data exists concerning the efficacy of potential treatment options such as early plasma exchange, eculizumab, and high dose corticosteroids. A concerted effort is needed to early identify patients at risk for poor outcome with trials aimed at evaluating the efficacy of potential treatment options for this subgroup.

Is eculizumab efficacious in Shigatoxin-associated hemolytic uremic syndrome? A narrative review of current evidence

Severe complications due to Shigatoxin-associated hemolytic uremic syndrome (STEC-HUS) currently present a serious challenge since no specific treatment for this condition is available. Eculizumab, a terminal complement inhibitor, has been used especially in STEC-HUS patients with severe neurological involvement, but the efficacy remains undetermined. In order to determine its efficacy, we searched the databases Pubmed, Web of Science, Embase, and LiLACS for reports describing outcomes of eculizumab administration in STEC-HUS. We retrieved 11 reports ranging from case reports to cohort studies with the largest study population emanating from the 2011 German outbreak. Outcomes were variable and difficult to interpret in light of the absence of high-quality studies but seemed to point towards potential efficacy of eculizumab if administered early in the course.

CONCLUSION

The efficacy of eculizumab in STEC-HUS could not be established nor disproven based on current data, and there is a desperate need for randomized controlled trials. What is known? • Eculizumab has been used in complicated cases of Shigatoxin-associated hemolytic uremic syndrome but the efficacy remains unknown? What is new? • Eculizumab might be efficacious if given early in selected cases of Shigatoxin-associated hemolytic uremic syndrome; however, randomized trials are needed to assess this.

The choice between deceased- vs living-donor renal transplantation in children: Analysis of data from a Belgian tertiary center

Pediatric renal transplantation with a living donor (LD) has superior outcome, but there is a paucity of studies analyzing the reasons for not undertaking living donation in West-European countries. The aim of this study was to retrospectively review the choice of donor source in our center. We also aimed to identify factors which prevented transplantation with a LD. This retrospective study was performed including children aged 2-19 years who underwent kidney transplantation (KT) at the Ghent University Hospital between 1996 and 2016. Relevant data were collected from medical files to identify the main medical, psychological, and socio-economic factors influencing the choice of the donor source. There were 48 patients (boys n = 33) who underwent KT. Thirty-nine patients received a deceased donor (DD) kidney and nine patients received a LD kidney. Sixteen of 48 transplantations were preemptive. The reasons for DD KT included socio-economic factors such as single caregiver families, one or both parents with a criminal record or convictions and religious or cultural constraints (n = 15), medical considerations (n = 13), refusal of the close relatives/parents to donate (n = 7), and acceptance of an organ from a DD while prospective donor was undergoing medical screening (n = 4). The low incidence of living kidney donation can be explained by socio-economic and medical factors. Refusal to donate is a potentially modifiable factor and strategies aimed at education and guidance of the families might contribute to a higher incidence of living donation in our setting.

Accumulation of uraemic toxins is reflected only partially by estimated GFR in paediatric patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) in childhood is characterised by the accumulation of uraemic toxins resulting in a multisystem disorder that has a negative impact on quality of life. Childhood CKD is predominantly defined by a decrease in glomerular filtration rate, estimated (eGFR) by a single serum measurement of endogenous biomarkers, e.g. creatinine. The objective of this study was to evaluate how accurately eGFR predicts the concentration of uraemic toxins in a paediatric CKD cohort.

METHODS

In 65 children (10.8 [5.1; 14.7] years) with CKD (eGFR 44 [20; 64] mL/min/1.73 m²), serum concentrations were determined of small solutes (uric acid [UA], urea, symmetric dimethylarginine [SDMA], asymmetric dimethylarginine [ADMA]), middle molecules (β2-microglobulin [β2M], complement factor D [CfD]) and protein-bound solutes (p-cresylglucuronide [pCG], hippuric acid, indole acetic acid, indoxyl sulphate [IxS], p-cresylsulfate [pCS] and 3-carboxy-4-methyl-5-propyl-furanpropionic acid [CMPF]). Spearman's correlation coefficients (r) were calculated to correlate uraemic toxin concentrations with three different eGFR equations, based on either serum creatinine or β2M.

RESULTS

Updated Schwartz eGFR was correlated reasonably well with concentrations of creatinine (r = -0.98), urea (r_s = -0.84), SDMA (r = -0.82) and middle molecules CfD and β2M (both r_s = -0.90). In contrast, poor correlation coefficients were found for CMPF (r_s = -0.32), UA (r_s = -0.45), ADMA (r_s = -0.47) and pCG (r_s = -0.48). The other toxins, all protein-bound, had r_s between -0.75 and -0.57. Comparable correlations were found between the three evaluated eGFR equations and uraemic toxin concentrations.

CONCLUSIONS

This study demonstrates that eGFR poorly predicts concentrations of protein-bound uraemic toxins, UA and ADMA in childhood CKD. Therefore, eGFR only partially reflects the complexity of the accumulation pattern of uraemic toxins in childhood CKD.

Children on dialysis as well as renal transplanted children report severely impaired health-related quality of life

Objectives

To assess health-related quality of life (HRQoL) across three renal replacement therapy modalities (preemptive transplant, non-preemptive transplant, and dialysis) in comparison with the healthy norm and other chronic health conditions, and to explore related patient factors.

Study design

All prevalent end-stage renal disease (ESRD) patients aged 8–18 years who spent at least 6 months on their current treatment modality in the Netherlands, Belgium, and part of Germany were approached to complete the Pediatric Quality of Life Inventory 4.0 (PedsQL™) questionnaire. We determined the differences between groups on PedsQL™ mean scores, the proportion of children with an impaired HRQoL (≥ 1 SD lower than the healthy norm), the proportion of problems on individual items of the PedsQL™, and the effect of time on current treatment. Linear regression models were used to explore determinants of HRQoL.

Results

192 out of 278 patients (20% preemptive transplant, 58% non-preemptive transplant, 22% dialysis) filled in the PedsQL™ (response rate 69%). Independent of treatment modality, patients had significantly lower mean scores and consequently higher proportions of impaired HRQoL on almost all domains compared to the healthy norm and other chronic health conditions. Patients with a preemptive transplant only reported higher scores on physical health compared to the other treatment modalities. Having comorbidities was the most important determinant associated with lower HRQoL scores.

Conclusion

Dialysis and renal transplantation both have a severe impact on the HRQoL of children with ESRD. Physicians should be aware of this continuous burden. Furthermore, to develop tailored interventions for children with ESRD, qualitative studies are needed to gain more insight in the determinants of HRQoL in the different treatment modalities.

Urinary potassium to urinary potassium plus sodium ratio can accurately identify hypovolemia in nephrotic syndrome: a provisional study

There is evidence pointing to a decrease of the glomerular filtration rate (GFR) in a subgroup of nephrotic children, likely secondary to hypovolemia. The aim of this study is to validate the use of urinary potassium to the sum of potassium plus sodium ratio (UK/UK+UNa) as an indicator of hypovolemia in nephrotic syndrome, enabling detection of those patients who will benefit from albumin infusion. We prospectively studied 44 nephrotic children and compared different parameters to a control group (36 children). Renal perfusion and glomerular permeability were assessed by measuring clearance of para-aminohippurate and inulin. Vaso-active hormones and urinary sodium and potassium were also measured. Subjects were grouped into low, normal, and high GFR groups. In the low GFR group, significantly lower renal plasma flow (p = 0.01), filtration fraction (p = 0.01), and higher UK/UK+UNa (p = 0.03) ratio were noted. In addition, non-significant higher plasma renin activity (p = 0.11) and aldosteron (p = 0.09) were also seen in the low GFR group.

CONCLUSION

A subgroup of patients in nephrotic syndrome has a decrease in glomerular filtration, apparently related to hypovolemia which likely can be detected by a urinary potassium to potassium plus sodium ratio > 0.5-0.6 suggesting benefit of albumin infusion in this subgroup. What is Known: • Volume status can be difficult to assess based on clinical parameters in nephrotic syndrome, and albumin infusion can be associated with development of pulmonary edema and fluid overload in these patients. What is New: • Urinary potassium to the sum of urinary potassium plus sodium ratio can accurately detect hypovolemia in nephrotic syndrome and thus identify those children who would probably respond to albumin infusion.

Epidemiology and outcome of acute kidney injury in children, a single center study

BACKGROUND

Information on the epidemiology of Acute Kidney Injury (AKI) in children is scarce. We performed a single center retrospective cohort study to analyze the incidence of AKI, the male/female ratio, the underlying etiology, and age at presentation. We also aimed to assess outcome measured by mortality, duration of PICU stay, and development of Chronic Kidney Disease (CKD).

METHODS

Records were searched for children presenting with or developing AKI between 1st January 2008 and 1st January 2015. AKI was classified according to the pediatric Rifle criteria while the cause of AKI was defined as the major underlying disease.

RESULTS

Of the 28,295 children admitted, 167 episodes of AKI were identified, equaling 5.9 cases per 1000 children. Patients classified as Failure at presentation according to pRifle criteria where significantly more likely to need dialysis (27/50, 54%) compared to those presenting with Injury (12/57, 21.1%) or Risk (6/60, 10 %). Diarrhea-associated Hemolytic Uremic Syndrome (D+HUS) was the most frequent cause (20.3 %) peaking during the summer months, followed by cardiac surgery (13.7%), medication-related nephrotoxicity (13.2%), and acute Glomerulonephritis (12%). The median age of children admitted with AKI was 6.1 years (range 0.1-17) and 50.8% of cases were male. Twenty five (15%) children died while 27 (16.1%) developed CKD.

CONCLUSIONS

Pediatric AKI poses a significant problem and strategies aimed at prevention, early detection, treatment, and adequate follow-up are needed. D+HUS is the most common underlying cause and effective surveillance of Enterohemorrhagic E. coli infections in association with additional measures is highly recommended.

Evidence for Bone and Mineral Metabolism Alterations in Children With Autosomal Dominant Polycystic Kidney Disease

CONTEXT

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease. Hypophosphatemia was demonstrated in adult patients with preserved renal function, together with high fibroblast growth factor 23 (FGF23) and low soluble Klotho levels. The latter explained the relative FGF23 hyporesponsiveness in this cohort.

OBJECTIVE

Evaluating phosphate and bone mineral metabolism in children with ADPKD compared with what is known in adult ADPKD patients.

DESIGN

Observational cross-sectional study.

SETTING

Multicenter study via ambulatory care in tertiary centers.

PARTICIPANTS

Ninety-two children with ADPKD (52 males; mean ± standard deviation age, 10.2 ± 5.0 years) and 22 healthy controls (HCs, 10 males; mean ± standard deviation age, 10.3 ± 4.1 years).

MAIN OUTCOME MEASURES

The predictor was early ADPKD stage. Bone mineral metabolism and renal phosphate handling were the main outcome measures. Performed measurements were serum phosphate, tubular maximum phosphorus reabsorption per glomerular filtration rate, FGF23, soluble Klotho, sclerostin, and bone alkaline phosphatase.

RESULTS

ADPKD children had significantly lower serum phosphate levels compared with HC. Low tubular maximum phosphorus reabsorption per glomerular filtration rate was observed in 24% of patients, although not significantly different from HC. Serum FGF23 and soluble Klotho levels were comparable between patients and HC. In addition, we showed decreased bone alkaline phosphatase levels in ADPKD children, suggesting suppressed bone formation.

CONCLUSIONS

This report demonstrates hypophosphatemia and suppressed bone formation in a pediatric ADPKD cohort, with preserved renal function, compared with HC. Although FGF23 levels were not different from controls, they should be considered inappropriate, given the concomitant hypophosphatemia. Further studies are required to elucidate underlying pathophysiology and potential clinical consequences.

Blood urea nitrogen to serum creatinine ratio is an accurate predictor of outcome in diarrhea-associated hemolytic uremic syndrome, a preliminary study

Diarrhea-associated hemolytic uremic syndrome (D+HUS) is a common thrombotic microangiopathy during childhood and early identification of parameters predicting poor outcome could enable timely intervention. This study aims to establish the accuracy of BUN-to-serum creatinine ratio at admission, in addition to other parameters in predicting the clinical course and outcome. Records were searched for children between 1 January 2008 and 1 January 2015 admitted with D+HUS. A complicated course was defined as developing one or more of the following: neurological dysfunction, pancreatitis, cardiac or pulmonary involvement, hemodynamic instability, and hematologic complications while poor outcome was defined by death or development of chronic kidney disease. Thirty-four children were included from which 11 with a complicated disease course/poor outcome. Risk of a complicated course/poor outcome was strongly associated with oliguria (p = 0.000006) and hypertension (p = 0.00003) at presentation. In addition, higher serum creatinine (p = 0.000006) and sLDH (p = 0.02) with lower BUN-to-serum creatinine ratio (p = 0.000007) were significantly associated with development of complications. A BUN-to-sCreatinine ratio ≤40 at admission was a sensitive and highly specific predictor of a complicated disease course/poor outcome.

CONCLUSION

A BUN-to-serum Creatinine ratio can accurately identify children with D+HUS at risk for a complicated course and poor outcome. What is Known: • Oliguria is a predictor of poor long-term outcome in D+HUS What is New: • BUN-to-serum Creatinine ratio at admission is an entirely novel and accurate predictor of poor outcome and complicated clinical outcome in D+HUS • Early detection of the high risk group in D+HUS enabling early treatment and adequate monitoring.

Desmopressin (melt) therapy in children with monosymptomatic nocturnal enuresis and nocturnal polyuria results in improved neuropsychological functioning and sleep

BACKGROUND

There is a high comorbidity between nocturnal enuresis, sleep disorders and psychological problems. The aim of this study was to investigate whether a decrease in nocturnal diuresis volume not only improves enuresis but also ameliorates disrupted sleep and (neuro)psychological dysfunction, the major comorbidities of this disorder.

METHODS

In this open-label, prospective phase IV study, 30 children with monosymptomatic nocturnal enuresis (MNE) underwent standardized video-polysomnographic testing and multi-informant (neuro)psychological testing at baseline and 6 months after the start of desmopressin treatment in the University Hospital Ghent, Belgium. Primary endpoints were the effect on sleep and (neuro)psychological functioning. The secondary endpoint was the change in the first undisturbed sleep period or the time to the first void.

RESULTS

Thirty children aged between 6 and 16 (mean 10.43, standard deviation 3.08) years completed the study. The results demonstrated a significant decrease in periodic limb movements during sleep (PLMS) and a prolonged first undisturbed sleep period. Additionally, (neuro)psychological functioning was improved on several domains.

CONCLUSIONS

The study demonstrates that the degree of comorbidity symptoms is at least aggravated by enuresis (and/or high nocturnal diuresis rate) since sleep and (neuro)psychological functioning were significantly ameliorated by treatment of enuresis. These results indicate that enuresis is not such a benign condition as has previously been assumed.

Review: Lisinopril in paediatric medicine: a retrospective chart review of long-term treatment in children

Objective. To investigate the antihypertensive efficacy, dosing, tolerability and effects on growth of lisinopril (off label-use) in paediatric patients during long-term treatment.

Design. We conducted a retrospective analysis of data from 123 patients treated with lisinopril in a paediatric nephrology clinic over a 9.3-year period. Patients were categorised by age group and predominant clinical diagnosis: hypertension (n=59), renal parenchymal disease (n=27), diabetes mellitus (n=33) and miscellaneous (n=4).

Results. The vast majority were Caucasian (93%) and boys (66%). Mean duration of treatment was 2.0 years. Age at start of treatment ranged from two months to 17.7 years. Mean lisinopril starting and final doses were 0.105 mg/kg/day for hypertensive patients and 0.108 mg/kg/day for patients with renal disease, respectively. The most common adverse event was hypotension (8.6% of the patients). Haematology and serum biochemistry profiles were unaffected by lisinopril. Growth was not different from data recorded by Belgian population studies. In 29 of the 47 hypertensive patients who received lisinopril monotherapy, comparing blood pressure (BP) at baseline and after six months' treatment, mean reductions in systolic/diastolic BP were 19/18 mmHg.

Conclusions. Lisinopril was well tolerated in paediatric patients. Doses of 0.1 mg/kg/day produced clinically significant BP reduction in hypertensive patients.

Heterozygous Loss-of-Function SEC61A1 Mutations Cause Autosomal-Dominant Tubulo-Interstitial and Glomerulocystic Kidney Disease with Anemia

Autosomal-dominant tubulo-interstitial kidney disease (ADTKD) encompasses a group of disorders characterized by renal tubular and interstitial abnormalities, leading to slow progressive loss of kidney function requiring dialysis and kidney transplantation. Mutations in UMOD, MUC1, and REN are responsible for many, but not all, cases of ADTKD. We report on two families with ADTKD and congenital anemia accompanied by either intrauterine growth retardation or neutropenia. Ultrasound and kidney biopsy revealed small dysplastic kidneys with cysts and tubular atrophy with secondary glomerular sclerosis, respectively. Exclusion of known ADTKD genes coupled with linkage analysis, whole-exome sequencing, and targeted re-sequencing identified heterozygous missense variants in SEC61A1-c.553A>G (p.Thr185Ala) and c.200T>G (p.Val67Gly)-both affecting functionally important and conserved residues in SEC61. Both transiently expressed SEC6A1A variants are delocalized to the Golgi, a finding confirmed in a renal biopsy from an affected individual. Suppression or CRISPR-mediated deletions of sec61al2 in zebrafish embryos induced convolution defects of the pronephric tubules but not the pronephric ducts, consistent with the tubular atrophy observed in the affected individuals. Human mRNA encoding either of the two pathogenic alleles failed to rescue this phenotype as opposed to a complete rescue by human wild-type mRNA. Taken together, these findings provide a mechanism by which mutations in SEC61A1 lead to an autosomal-dominant syndromic form of progressive chronic kidney disease. We highlight protein translocation defects across the endoplasmic reticulum membrane, the principal role of the SEC61 complex, as a contributory pathogenic mechanism for ADTKD.