Long-term survival of children with end-stage renal disease

Baseline characteristics of participants in the NAVKIDS2 trial: a patient navigator program in children with chronic kidney disease

BACKGROUND

Children with chronic kidney disease (CKD) require multidisciplinary care to meet their complex healthcare needs. Patient navigators are trained non-medical personnel who assist patients and caregivers to overcome barriers to accessing health services through care coordination. This trial aims to determine the effectiveness of a patient navigator program in children with CKD.

METHODS

The NAVKIDS² trial is a multi-center, waitlisted, randomized controlled trial of patient navigators in children with CKD conducted at five sites across Australia. Children (0-16 years) with CKD from low socioeconomic status rural or remote areas were randomized to an intervention group or a waitlisted control group (to receive intervention after 6 months). The study primary and secondary endpoints include the self-rated health (SRH) (primary), and utility-based quality of life, progression of kidney dysfunction of the child, SRH, and satisfaction with healthcare of the caregiver at 6 months post-randomization.

RESULTS

The trial completed recruitment in October 2021 with expected completion of follow-up by October 2022. There were 162 patients enrolled with 80 and 82 patients randomized to the immediate intervention and waitlisted groups, respectively. Fifty-eight (36%) participants were from regional/remote areas, with a median (IQR) age of 9.5 (5.0, 13.0) years, 46% were of European Australian ethnicity, and 65% were male. A total of 109 children (67%) had CKD stages 1-5, 42 (26%) were transplant recipients, and 11 (7%) were receiving dialysis.

CONCLUSION

The NAVKIDS² trial is designed to evaluate the effectiveness of patient navigation in children with CKD from families experiencing socioeconomic disadvantage. A higher resolution version of the Graphical abstract is available as Supplementary information.

Tertiary lymphoid tissues in kidney diseases: a perspective for the pediatric nephrologist

Chronic kidney disease (CKD) is a major public health problem worldwide. In the pediatric population, CKD is also an important health issue because it causes several comorbid conditions that can have long-term consequences beyond the pediatric age. Chronic inflammation is a common pathological feature of CKD, irrespective of etiology, and leads to maladaptive repair and kidney dysfunction. Tertiary lymphoid tissues (TLTs) are ectopic lymphoid structures that develop in non-lymphoid organs under chronic inflammation caused by pathological conditions, including infections, autoimmune diseases, and cancers. TLTs in the kidneys have been poorly researched due to the lack of an animal model. We have recently found that, in aged but not young mice, TLTs develop in multiple kidney injury models, and the analysis of age-dependent TLTs has brought about several novel insights into the development and pathogenic impacts of TLTs in the kidney. Age-dependent TLT formation is also observed in human kidneys. In addition to aged kidneys, TLT development is also reported in several human kidney diseases including kidney allografts, lupus nephritis, and IgA nephropathy in both adults and children. In this review, we describe the novel findings on TLTs in the kidney obtained mainly from the analysis of age-dependent TLTs and discuss the clinical relevance of TLTs in kidney diseases.

Health-related quality of life in adults after pediatric kidney failure in Switzerland

BACKGROUND

Little is known about health-related quality of life (HRQoL) in adults after kidney failure during childhood. In this study, we analyzed HRQoL of adults after pediatric kidney failure in Switzerland and investigated socio-demographic and clinical factors associated with HRQoL.

METHODS

In this cohort study, we sent questionnaires to 143 eligible patients registered in the Swiss Pediatric Renal Registry with continuous kidney replacement therapy starting before the age of 18 years. We assessed HRQoL using the Short-Form 36 version 1, compared HRQoL scores between our sample and the Swiss general population, and used linear regression models to examine socio-demographic and clinical factors associated with HRQoL.

RESULTS

We included 79 patients (response rate 55%) with a mean age of 38.6 years (range 19.4-63.1). Compared to the general population, HRQoL scores were lower for physical functioning (- 12.43, p < 0.001), role physical (- 13.85, p = 0.001), general health (- 14.42, p < 0.001), vitality (- 4.98, p = 0.035), and physical HRQoL (- 6.11, p < 0.001), but we found no difference in mental HRQoL (- 0.13, p = 0.932). The socio-demographic factors-lower education, unemployment, and not being in a relationship-were associated with lower HRQoL. The only clinical factor associated with HRQoL was the type of kidney disease. Patients with acquired kidney diseases had lower mental HRQoL than patients with congenital anomalies of the kidney and urinary tract (- 11.4, p = 0.007) or monogenetic hereditary diseases (- 9.5, p = 0.018).

CONCLUSIONS

Adults after pediatric kidney failure in Switzerland have lower physical, but similar mental HRQoL compared to the general population. Subgroups may require special attention with regard to their HRQoL. A higher resolution version of the Graphical abstract is available as Supplementary information.

Long-Term Survival and Kidney Function in Pediatric Patients Following Liver Transplantation: A 15-Year Retrospective Cohort Study

Long-term preservation of kidney function after liver transplantation (LT) has not been well studied. We thus evaluated the rates of kidney function preservation and long-term survival after pediatric LT. We also investigated the risk factors associated with the progression of chronic kidney disease (CKD). We conducted a retrospective study of 184 pediatric patients who had undergone LT from 2003 to 2018 at a university hospital. We collected demographics, primary indications for LT, liver disease scores, renal function test results, immunosuppressive drug prescriptions, and diagnosis of post-LT complications. The 15-year survival rate was 90.8%. Furthermore, the rate of kidney function preservation at 14 years post-LT in patients at high risk of renal disease was 79.3%, and that in those with less risk of kidney diseases was 96.0%. Arterial hypertension was an independent risk factor associated with CKD progression. However, when arterial hypertension was excluded, the use of cyclosporine and liver disease with renal involvement were risk factors for CKD progression. We found that kidney function after pediatric LT was well preserved. We encourage the early detection of underlying kidney involvement, routine monitoring of renal function for high-risk patients, active control of hypertension, and appropriate immunosuppressive regimens for pediatric patients with LT.

Urine Uromodulin Is Not Associated With Blood Pressure in the Chronic Kidney Disease in Children Cohort

BACKGROUND

Uromodulin regulates activity of the sodium-potassium-two-chloride transporter in the loop of Henle. In adults, higher urine uromodulin levels are associated with greater rise in blood pressure (BP) in response to salt intake. We hypothesized that higher urine uromodulin levels would be associated with higher BP in children with chronic kidney disease, and that there would be an interaction of dietary sodium on this association.

METHODS

In the chronic kidney disease in children Cohort, we utilized univariable and multivariable linear regression models to evaluate the relationship between baseline spot urine uromodulin levels indexed to urine creatinine (Umod/Cr mg/g) and 24-hour mean systolic and diastolic BP, as well as baseline clinic BP. We also tested whether sodium intake (g/day) modified these relationships.

RESULTS

Among 436 participants, the median age was 12.4 years (8.9-15.2), median estimated glomerular filtration rate was 50 mL/min per 1.73 m2 (36-62), and median 24-hour mean systolic BP was 112 mm Hg (104-119). The etiology of chronic kidney disease was glomerular disease in 27%. In univariable models, each 2-fold higher Umod/Cr ratio was associated with a 1.66 mm Hg (95% CI, -2.31 to -1.00) lower 24-hour mean systolic and a 1.71 mm Hg (-2.45 to -0.97) lower clinic systolic BP. However, there was no statistically significant association between Umod/Cr and either 24-hour or clinic BP in multivariable models. We did not find a significant interaction between uromodulin and sodium intake in their effect on BP (P>0.05 in all models).

CONCLUSIONS

Urine uromodulin levels are not associated with BP in the chronic kidney disease in children cohort. Further studies are needed to confirm this finding in healthy pediatric cohorts.

White Tongue Because of Uremic Stomatitis as a Sign of Advanced Kidney Disease

We present a case of a previously healthy adolescent male who initially presented to his primary care physician with the chief complaint of a "large and white tongue," who subsequently was diagnosed with end-stage kidney disease (ESKD) and associated uremic stomatitis. This patient required admission to a PICU for acute renal replacement therapy with intermittent hemodialysis, and his hospital course was complicated by generalized tonic-clonic seizures. ESKD is difficult to diagnose in the pediatric population because these patients are often asymptomatic in the early stages given the insidiousness of underlying disorders. Renal disease should be considered in the differential diagnosis of a child with a white tongue not being the result of oral candidiasis.

Access to kidney transplantation among pediatric candidates with prior solid organ transplants in the United States

BACKGROUND

Pediatric kidney transplant candidates require timely access to transplant to optimize growth and neurodevelopmental outcomes. We studied access to transplant for pediatric candidates with prior organ transplants.

METHODS

We used US registry data to identify pediatric kidney transplant candidates added to the waiting list 2015-2019 and used competing risk regression to study the association between prior transplant status and probability of receiving a kidney transplant, treating wait-list removal and death as competing events.

RESULTS

Of 4962 pediatric kidney transplant candidates included, 89% had no prior transplant and 11% had received a prior organ transplant (kidney 87%, liver 5%, heart 5%). Prior transplant recipients were older at listing (median 15 vs. 12 years) and more likely to have PRA≥98% (22% vs. 0.3%) (both p < .001). There was no significant difference in the proportion of candidates from each group who were preemptively wait-listed. Unadjusted competing risk regression showed a lower risk of kidney transplant after wait-listing among candidates with prior organ transplant (HR 0.52, 95%CI 0.47-0.59, p < .001). This association remained significant after adjusting for candidate characteristics (HR 0.73, 95%CI 0.63-0.83, p < .001). Among deceased donor kidney recipients, median KDPI was similar between groups, but recipients with prior transplants were more likely to receive kidneys from donors with hypertension (4% vs. 1%, p = .01) and donors after cardiac death (11% vs. 4%, p < .001).

CONCLUSIONS

Pediatric kidney transplant candidates with prior organ transplants have reduced access to transplant after wait-listing. Allocation system changes are needed to improve timely access to transplant for this vulnerable group.

Effects of Ramipril on Biomarkers of Endothelial Dysfunction and Inflammation in Hypertensive Children on Maintenance Hemodialysis: the SEARCH Randomized Placebo-Controlled Trial

BACKGROUND

Hypertension, endothelial dysfunction, and inflammation are associated with increased cardiovascular mortality in end-stage kidney disease. We evaluated the effects of ACE (angiotensin-converting enzyme) inhibition on biomarkers of endothelial dysfunction and inflammation in hypertensive children with end-stage kidney disease on maintenance hemodialysis.

METHODS

In a randomized, double-blind, placebo-controlled trial, 135 (72 males/63 females) children and adolescents (age 7-15 years) were randomly assigned to treatment with either 2.5 mg once daily ramipril (n=68) or placebo (n=67) for 16 weeks. Primary outcome were the serum concentrations of asymmetrical dimethylarginine, a marker of endothelial dysfunction and hs-CRP (high-sensitivity C-reactive protein), a marker of inflammation. Changes in IL-6 (interleukin-6), TNF-α (tumor necrosis factor-alpha), systolic (S), and diastolic (D) blood pressure were secondary outcomes. Change in potassium levels and incidence of hyperkalemia were among the safety parameters.

RESULTS

Ramipril, but not placebo, significantly reduced serum levels of asymmetrical dimethylarginine (-79.6%; P<0.001), hs-CRP (-46.5%; P<0.001), IL-6 (-27.1%; P<0.001), and TNF-α (-51.7%; P<0.001). Systolic blood pressure and diastolic blood pressure were significantly lowered in both groups with a greater reduction in children receiving ramipril (median between-group differences -12.0 [95% CI -18.0 to -9.5] and -9.0 [95% CI -12.0 to -4.5]; P<0.001, respectively). Changes in asymmetrical dimethylarginine, hs-CRP, IL-6, or TNF-α in the ramipril group did not significantly correlate with blood pressure reductions. No severe cases of hyperkalemia or other serious treatment-associated adverse events were observed.

CONCLUSIONS

Ramipril improves biomarkers of endothelial dysfunction and inflammation in hypertensive children on maintenance hemodialysis in addition to its efficacious and safe potential to lower blood pressure.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04582097.

The Role of Registries in Kidney Transplantation Across International Boundaries

Transplant professionals strive to improve domestic kidney transplantation rates safely, cost efficiently, and ethically, but to increase rates further may wish to allow their recipients and donors to traverse international boundaries. Travel for transplantation presents significant challenges to the practice of transplantation medicine and donor medicine, but can be enhanced if sustainable international registries develop to include low- and low-middle income countries. Robust data collection and sharing across registries, linking pretransplant information to post-transplant information, linking donor to recipient information, increasing living donor transplant activity through paired exchange, and ongoing reporting of results to permit flexibility and adaptability to changing clinical environments, will all serve to enhance kidney transplantation across international boundaries.

Transplantation Mediates Much of the Racial Disparity in Survival from Childhood-Onset Kidney Failure

BACKGROUND

The role of kidney transplantation in differential survival in Black and White patients with childhood-onset kidney failure is unexplored.

METHODS

We analyzed 30-year cohort data of children beginning RRT before 18 years of age between January 1980 and December 2017 (n=28,337) in the US Renal Data System. Cox regression identified transplant factors associated with survival by race. The survival mediational g-formula estimated the excess mortality among Black patients that could be eliminated if an intervention equalized their time with a transplant to that of White patients.

RESULTS

Black children comprised 24% of the cohort and their crude 30-year survival was 39% compared with 57% for White children (log rank P<0.001). Black children had 45% higher risk of death (adjusted hazard ratio [aHR], 1.45; 95% confidence interval [95% CI], 1.36 to 1.54), 31% lower incidence of first transplant (aHR, 0.69; 95% CI, 0.67 to 0.72), and 39% lower incidence of second transplant (aHR, 0.61; 95% CI, 0.57 to 0.65). Children and young adults are likely to require multiple transplants, yet even after their first transplant, Black patients had 11% fewer total transplants (adjusted incidence rate ratio [aIRR], 0.89; 95% CI, 0.86 to 0.92). In Black patients, grafts failed earlier after first and second transplants. Overall, Black patients spent 24% less of their RRT time with a transplant than did White patients (aIRR, 0.76; 95% CI, 0.74 to 0.78). Transplantation compared with dialysis strongly protected against death (aHR, 0.28; 95% CI, 0.16 to 0.48) by time-varying analysis. Mediation analyses estimated that equalizing transplant duration could prevent 35% (P<0.001) of excess deaths in Black patients.

CONCLUSIONS

Equalizing time with a functioning transplant for Black patients may equalize survival of childhood-onset ESKD with White patients.

Organ allocation in pediatric abdominal transplant

Pediatric patients constitute an important group within the general transplant population, given the opportunity to significantly extend their lives with successful transplantation. Children have historically received special consideration under the various abdominal solid organ allocation algorithms, but matching patients with size and weight restrictions with appropriate donors remains an ongoing issue. Here, we describe the historical trends in pediatric organ allocation policies for liver, kidney, intestine, and pancreas transplantation. We also review recent changes to these allocation policies, with particular attention to recent amendments to geographical prioritization, with the dissolution of donor service areas and United Network for Organ Sharing (UNOS) regions and the subsequent creation of acuity circles.

Overview of pediatric kidney transplantation

Kidney transplantation is the treatment of choice for pediatric patients with end-stage kidney disease. Unlike adult recipients undergoing transplantation, special considerations must be taken when transplanting children based on the underlying etiology of kidney disease, previous surgical procedures, anatomical limitations and necessary technical adjustments. Additionally, the choice of donor must be measured to ensure optimal graft survival given a longer post-transplant life expectancy. Those topics as well as frequently encountered postoperative complications are also discussed in this publication.

The causes and consequences of paediatric kidney disease on adult nephrology care

Adult nephrologists often look after patients who have been diagnosed with kidney disease in childhood. This does present unique challenges to the adult nephrologist, who may be unfamiliar with the underlying cause of kidney disease as well as the complications of chronic kidney disease (CKD) that may have accumulated during childhood. This review discusses common causes of childhood CKD, in particular congenital anomalies of the kidney and urinary tract (CAKUT), autosomal dominant tubulointerstitial kidney disease (ADTKD), polycystic kidney disease, hereditary stone disease, nephrotic syndrome and atypical haemolytic uraemic syndrome. The long-term consequences of childhood CKD, such as the cardiovascular consequences, cognition and education as well as bone health, nutrition and growth are also discussed.

Epidemiology of pediatric chronic kidney disease/kidney failure: learning from registries and cohort studies

Although the concept of chronic kidney disease (CKD) in children is similar to that in adults, pediatric CKD has some peculiarities, and there is less evidence and many factors that are not clearly understood. The past decade has witnessed several additional registry and cohort studies of pediatric CKD and kidney failure. The most common underlying disease in pediatric CKD and kidney failure is congenital anomalies of the kidney and urinary tract (CAKUT), which is one of the major characteristics of CKD in children. The incidence/prevalence of CKD in children varies worldwide. Hypertension and proteinuria are independent risk factors for CKD progression; other factors that may affect CKD progression are primary disease, age, sex, racial/genetic factors, urological problems, low birth weight, and social background. Many studies based on registry data revealed that the risk factors for mortality among children with kidney failure who are receiving kidney replacement therapy are younger age, female sex, non-White race, non-CAKUT etiologies, anemia, hypoalbuminemia, and high estimated glomerular filtration rate at dialysis initiation. The evidence has contributed to clinical practice. The results of these registry-based studies are expected to lead to new improvements in pediatric CKD care.

Publication rate and research topics of studies in pediatric kidney transplantation

BACKGROUND

The quality of medical care for pediatric kidney transplant recipients depends on sound evidence from published clinical trials.

METHODS

We examined the publication rate, time to publication, and factors associated with publication of studies in pediatric kidney transplantation registered on ClinicalTrials.gov from 1999 to 2020.

RESULTS

We identified 136 studies with an overall enrollment of 36255 study participants, of which only 58.8% have been published yet. Unpublished studies included data from 14 350 participants. The median time to publication was 25 months (range, 0-117) with a significantly shorter time to publication in more recent years. The most frequently investigated research topic was immunosuppressants (49.3%), followed by perioperative management (11.0%) and infectiology (10.3%). The percentage of published studies was highest for the topic steroid withdrawal (87.5%), followed by infectiology (78.6%), and nutrition, sports and quality of life (71.4%). Studies, which were co-funded by industry, showed a significantly higher 5-year publication rate (p = 0.019).

CONCLUSIONS

In conclusion, nearly half of all studies in pediatric kidney transplantation remain unpublished. Non-publication of studies might lead to a publication bias with a negative impact on clinical decision-making.

Pediatric Kidney Transplantation: Frameshift in Medical and Surgical Management. Does the Perioperative Setting Have an Impact on Transplant Outcome? A Single-Center Experience

Introduction

Frameshift in medical management as well as in surgical thinking is putting the patient as a whole is the focus, rather than just the disease. To optimize the treatment of our pediatric transplant patients in our institution, we changed in 2013 the transplant program setting, treating, and operating all patients with pediatric transplant exclusively in a pediatric environment. The aim of this study was to analyze whether or not this change had an impact on patients safety, patient population, and patients and transplant outcome.

Methods

In the retrospective analysis, we compared transplant outcome of two eras. Era1 (2008–2012) solely included patients treated in the adult facilities, era 2 (2013–2017) patients were exclusively treated in the pediatric environment.

Results

There were 53 patients with renal transplant, with era 1 (28 patients) and era 2 (25 patients). Overall mortality was 5.6%. Median recipient age at transplantation was 13.2 years in era 1 and 8.59 years in era 2, median recipient weight at transplantation was 41.7 kg in era 1 vs. 26 kg in era 2, median size 149. 5 cm (era 1) vs. 123 cm in era2 (p = 0.05). The direct recipient/donor weight ratio remained stable in both eras, for recipients below 20 kg we saw a larger weight mismatch in era 1 (0.84 vs. 0.66). In the subgroup of patients with congenital anomalies of the kidney and urinary tract (CAKUT) those were significantly younger at onset of dialysis (p < 0.001) and at time of transplantation (p < 0.001), also they were less in body weight (p < 0.01), and body size (p < 0.001), this subgroup was larger in era 2. HLA mismatch data, serum creatinine, and GFR yield comparable results in both groups. Median time to detection of DSA was 46.2 month (3.8 years).

Conclusion

Since children with ESRD at the time of transplant trend to be younger and smaller, it is crucial to ensure a medical environment that is able to address their particular challenges. Even in this recipient cohort, renal transplantation can be performed safely as outlined by our data.

Psychological aspects in children and parents of children with chronic kidney disease and their families

Pediatric chronic kidney disease (CKD) is a chronic illness that affects the overall quality of life of patients during childhood. This article highlights the psychological and social burden of CKD in patients and their families. Patients with CKD and their families require comprehensive treatment for psychosocial problems. Therefore, it is crucial for pediatricians to screen for these issues and refer patients and their families for therapy. Tools that are short, easy to administer, and easy to score, such as the Pediatric Quality of Life Inventory or the Childhood Depression Inventory, can be utilized during routine clinical appointments. Reducing the negative impact of CKD on the family will improve the well-being and coping skills of patients and their families.

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.

Plasma Netrin-1 & cardiovascular risk in children with end stage renal disease

Background: Cardiovascular disease (CVD) is the most common cause of mortality and morbidity in children with end stage kidney disease (ESKD) which arises from the interaction of several risk factors. The aim of the study is to assess CV risk of ESKD children and outline the impact of KTX on this CV risk. Also valuate the relation between plasma Netrin-1, chronic inflammatory markers and CV risk. Methods: Sixty ESKD (30 on regular hemodialysis (HD), 30 recipients of kidney transplant (KTX)) were assessed using 24 hour AMBP assessment, laboratory (including lipid profile and markers of chronic inflammation namely N/L and HsCRP) and echocardiographic data. Plasma netrin-1 was assessed by ELISA technique for all patients. Results: showed significant higher prevalence of hypertension, higher number of patients with 24hrs BP> 95th percentile by ABPM, more prevalence of nocturnal non-dipping BP, higher percentage of obese and overweight patients, worse biochemical analysis, higher chance of medical calcification by higher Po4 and Ca X Po4, higher triglyceride level and lower HDL level and higher N/L in HD than KTX group. Significant inverse relation was detected between plasma netrin 1 and Hs CRP and between netrin 1 and N/L (p<0.001).

Pearls and Pitfalls in Pediatric Kidney Transplantation After 5 Decades

Worldwide, over 1,300 pediatric kidney transplantations are performed every year. Since the first transplantation in 1959, healthcare has evolved dramatically. Pre-emptive transplantations with grafts from living donors have become more common. Despite a subsequent improvement in graft survival, there are still challenges to face. This study attempts to summarize how our understanding of pediatric kidney transplantation has developed and improved since its beginnings, whilst also highlighting those areas where future research should concentrate in order to help resolve as yet unanswered questions. Existing literature was compared to our own data of 411 single-center pediatric kidney transplantations between 1968 and 2020, in order to find discrepancies and allow identification of future challenges. Important issues for future care are innovations in immunosuppressive medication, improving medication adherence, careful donor selection with regard to characteristics of both donor and recipient, improvement of surgical techniques and increased attention for lower urinary tract dysfunction and voiding behavior in all patients.

Cystinosis in Pediatric Renal Transplant Recipients: A Case-Control Study From Kuwait

OBJECTIVES

Cystinosis is the most frequent cause of the inherited renal Fanconi syndrome and is also potentially treatable. In this study, we have reported our single-center experience of the longterm outcomes of kidney transplant in patients with cystinosis.

MATERIALS AND METHODS

Pediatric patients with cystinosis (n = 17) were compared with a matched control group without cystinosis (n = 126). The 2 groups were compared with regard to demographic data, posttransplant complications, and graft and patient outcomes.

RESULTS

Most patients with cystinosis were male teenagers (52.9%) with comparable mean age (12.4 ± 4.1 vs 14 ± 3.1 years) versus the group without cystinosis. The 2 study groups were comparable with regard to type of dialysis, type of donor, blood group, and pretransplant comorbidities (P > .05). Patients with cystinosis received significantly more potent induction therapy (P < 0.05), but both groups were maintained on comparable immunosuppressive regimens (mostly tacrolimus based) (P > .05). Most grafts in both groups displayed immediate graft function. The percentage of patients with cystinosis with primary graft function was significantly higher than the percentage of those patients without cystinosis who had primary graft function (P = .024); this was associated with a relatively lower baseline creatinine level, although this was not significant (P > .05). Posttransplant complications, especially posttransplant diabetes, cytomegalovirus viremia, or BK nephropathy, were comparable (P > .05). Moreover, patient and graft survival rates were similar in the 2 groups (P > .05).

CONCLUSIONS

Under standard immunosuppression, renal transplant and cysteamine therapy were safe with good long-term outcomes in patients with cystinosis. Studies that can include more patients and that have longer follow-up are needed to better understand the nature of this genetic disease and to discover the best treatment options.

Nationwide study of mortality and sudden cardiac death in young persons diagnosed with chronic kidney disease

AIMS

The aim of this study was to compare short- and long-term risk of sudden cardiac death (SCD) among persons aged 18-49 years with and without chronic kidney disease (CKD).

METHODS AND RESULTS

Using Danish nationwide health registries, all persons aged 18-49 years diagnosed with earlier stages of CKD or chronic kidney failure from 1 July 1995 through 2009 were identified. Non-exposed subjects matched on sex and birth-year were identified. All SCD in the Danish population aged 18-49 years in 2000-2009 have previously been identified using information from the Danish nationwide health registries, death certificates, and autopsy reports. In total, 9308 incident cases of earlier stage CKD and 1233 incident cases of chronic kidney failure were included. Among patients with earlier stage CKD, the absolute risk of SCD 1, 5, and 10 years after diagnosis was 0.14%, 0.37%, and 0.68%, respectively. Compared with age- and sex-matched subjects the corresponding relative risk (RR) was 20.3 [95% confidence interval (CI) 8.4-48.8], 7.1 (95% CI 4.2-12.0), and 6.1 (95% CI 3.8-9.7), respectively. Among patients with chronic kidney failure, the absolute 1-, 5-, and 10-year risk of SCD was 0.17%, 0.56%, and 2.07%, respectively. The corresponding RR was 12.5 (95% CI 1.4-111.6), 7.9 (95% CI 2.3-27.0), and 10.1 (95% CI 4.5-22.6).

CONCLUSION

Persons with earlier stage CKD and chronic kidney failure had increased risk of SCD compared with the background population with a 6- to 20-fold increased risk of SCD. These findings underline the importance of early cardiovascular risk monitoring and assessment in persons with CKD.

Social Deprivation Is Associated With Lower Access to Pre-emptive Kidney Transplantation and More Urgent-Start Dialysis in the Pediatric Population

Introduction

Socioeconomic status (SES) is recognized as an important determinant of kidney health. We aimed to evaluate the association of social deprivation with different indicators at kidney replacement therapy (KRT) initiation in the French pediatric metropolitan population.

Methods

All patients with end-stage kidney disease (ESKD) who started KRT before 20 years old in France between 2002 and 2015 were included. We investigated different indicators at KRT initiation, which are as follows: KRT modality (dialysis vs. pre-emptive transplantation), late referral to a nephrologist, and dialysis modality (hemodialysis [HD] vs. peritoneal dialysis [PD], urgent vs. planned start of dialysis, use of catheter vs. use of fistula for HD vascular access). An ecological index (European Deprivation Index [EDI]) was used as a proxy for social deprivation.

Results

A total of 1115 patients were included (males 59%, median age at dialysis 14.4 years, glomerular/vascular diseases 36.8%). The most deprived group represented 38.7% of the patients, suggesting pediatric patients with ESKD come from a more socially deprived background. The most deprived group was more likely to initiate KRT with dialysis versus kidney transplantation. Among patients on HD, the odds of starting treatment in emergency with a catheter was >2-fold higher for the most deprived compared with the least deprived children (adjusted odds ratio [aOR] 2.35, 95% CI 1.16-4.78).

Conclusion

Children from the most deprived area have lower access to pre-emptive transplantation, have lower access to PD, tend to be late referred to a nephrologist, and have more urgent initiation of HD with a catheter.

Low-density lipoprotein and blood pressure are important risk factors for vasculopathy in children on dialysis: a single center study

INTRODUCTION

We searched for risk factors of cardiovascular assessment among children on dialysis.

METHODS

This is a cross-sectional study of cardiovascular assessment of all patients on dialysis at xxx University Children's Hospital. Pediatric patients between the ages of 6 and 21 who were on hemodialysis and peritoneal dialysis treatment were included in the study. Cardiovascular evaluation included left ventricular mass index (LVMI), pulse wave velocity (PWV), and carotid intima-media thickness (cIMT) measurements.

RESULTS

Nineteen patients were included in this study. The LDL had a correlation with the cIMT z-score, but not to PWVz-score. Binary Logistic regression analysis found that only LDL was significantly associated to increased cIMT.

CONCLUSION

This study reports an association between high LDL and high blood pressure increased cIMT on dialyzed children. Strategies to reduce LDL and blood pressure in dialysis patients may prevent vasculopathy and long-term cardiovascular complications.

Is Preemptive Kidney Transplantation Associated With Improved Outcomes when Compared to Non-preemptive Kidney Transplantation in Children? A Systematic Review and Meta-Analysis

Main Problem: Preemptive kidney transplantation (PKT) is performed prior to dialysis initiation to avoid dialysis-related morbidity and mortality in children and adolescents. We undertook a systematic review to compare clinical outcomes in PKT versus kidney transplantation after dialysis initiation in paediatric patients.

Methods: The bibliographic search identified studies that compared paediatric recipients of a first or subsequent, living or deceased donor PKT versus non-preemptive kidney transplant. Methodological quality was assessed for all studies. Data were pooled using the random-effects model.

Results: Twenty-two studies (n = 22,622) were included. PKT reduced the risk of overall graft loss (relative risk (RR) .57, 95% CI: .49–.66) and acute rejection (RR: .81, 95% CI: .75–.88) compared to transplantation after dialysis. Although no significant difference was observed in overall patient mortality, the risk of patient death was found to be significantly lower in PKT patients with living donor transplants (RR: .53, 95% CI: .34–.83). No significant difference was observed in the incidence of delayed graft function.

Conclusion: Evidence from observational studies suggests that PKT is associated with a reduction in the risk of acute rejection and graft loss. Efforts should be made to promote and improve rates of PKT in this group of patients (PROSPERO).

Systematic Review Registration:https://clinicaltrials.gov/, CRD42014010565

Sociodemographic features and outcomes of peritonitis episodes in children on peritoneal dialysis

INTRODUCTION

Peritoneal dialysis (PD) is one of the most preferred kidney replacement therapies in children. However, it has an important complication such as peritonitis. This study was planned to investigate the causes and frequency of peritonitis in children with PD.

METHODS

The demographic features, peritonitis episodes and microbiological characteristics of PD patients followed up for 5 years.

RESULTS

Fifty pediatric PD patients who met the study criteria in a 5-year period were included in the study. Consanguineous marriage was 64% and 44% of the mothers was illiterate. Nineteen patients had no peritonitis episode and a total of 54 peritonitis episode were experienced. The overall peritonitis rate was one episode per 24.4 patient-months. Culture negativity rate was 44%.

CONCLUSION

Even though factors such as the education level of the parents, the number of people or rooms in the house, dialysis modality were thought to influence peritonitis episodes, they could not be shown statistically. This article is protected by copyright. All rights reserved.

Epidemiology of haemodialysis outcomes

Haemodialysis (HD) is the commonest form of kidney replacement therapy in the world, accounting for approximately 69% of all kidney replacement therapy and 89% of all dialysis. Over the last six decades since the inception of HD, dialysis technology and patient access to the therapy have advanced considerably, particularly in high-income countries. However, HD availability, accessibility, cost and outcomes vary widely across the world and, overall, the rates of impaired quality of life, morbidity and mortality are high. Cardiovascular disease affects more than two-thirds of people receiving HD, is the major cause of morbidity and accounts for almost 50% of mortality. In addition, patients on HD have high symptom loads and are often under considerable financial strain. Despite the many advances in HD technology and delivery systems that have been achieved since the treatment was first developed, poor outcomes among patients receiving HD remain a major public health concern. Understanding the epidemiology of HD outcomes, why they might vary across different populations and how they might be improved is therefore crucial, although this goal is hampered by the considerable heterogeneity in the monitoring and reporting of these outcomes across settings.

This Review examines the epidemiology of haemodialysis outcomes — clinical, patient-reported and surrogate outcomes — across world regions and populations, including vulnerable individuals. The authors also discuss the current status of monitoring and reporting of haemodialysis outcomes and potential strategies for improvement.

Nearly 4 million people in the world are living on kidney replacement therapy (KRT), and haemodialysis (HD) remains the commonest form of KRT, accounting for approximately 69% of all KRT and 89% of all dialysis.

Dialysis technology and patient access to KRT have advanced substantially since the 1960s, particularly in high-income countries. However, HD availability, accessibility, cost and outcomes continue to vary widely across countries, particularly among disadvantaged populations (including Indigenous peoples, women and people at the extremes of age).

Cardiovascular disease affects over two-thirds of people receiving HD, is the major cause of morbidity and accounts for almost 50% of mortality; mortality among patients on HD is significantly higher than that of their counterparts in the general population, and treated kidney failure has a higher mortality than many types of cancer. Patients on HD also experience high burdens of symptoms, poor quality of life and financial difficulties.

Careful monitoring of the outcomes of patients on HD is essential to develop effective strategies for risk reduction. Outcome measures are highly variable across regions, countries, centres and segments of the population. Establishing kidney registries that collect a variety of clinical and patient-reported outcomes using harmonized definitions is therefore crucial.

Evaluation of HD outcomes should include the impact on family and friends, and personal finances, and should examine inequities in disadvantaged populations, who comprise a large proportion of the HD population.

Trends in Survival for Pediatric Transplantation

OBJECTIVES

Progress in pediatric transplantation measured in the context of waitlist and posttransplant survival is well documented but falls short of providing a complete perspective for children and their families. An intent-to-treat analysis, in which we measure survival from listing to death regardless of whether a transplant is received, provides a more comprehensive perspective through which progress can be examined.

METHODS

Univariable and multivariable Cox regression was used to analyze factors impacting intent-to-treat survival in 12 984 children listed for heart transplant, 17 519 children listed for liver transplant, and 16 699 children listed for kidney transplant. The Kaplan-Meier method and log-rank test were used to assess change in waitlist, posttransplant, and intent-to-treat survival. Wait times and transplant rates were compared by using χ2 tests.

RESULTS

Intent-to-treat survival steadily improved from 1987 to 2017 in children listed for heart (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.96-0.97), liver (HR 0.95, 95% CI 0.94-0.97), and kidney (HR 0.97, 95% CI 0.95-0.99) transplant. Waitlist and posttransplant survival also improved steadily for all 3 organs. For heart transplant, the percentage of patients transplanted within 1 year significantly increased from 1987 to 2017 (60.8% vs 68.7%); however, no significant increase was observed in liver (68.9% vs 72.5%) or kidney (59.2% vs 62.7%) transplant.

CONCLUSIONS

Intent-to-treat survival, which is more representative of the patient perspective than individual metrics alone, steadily improved for heart, liver, and kidney transplant over the study period. Further efforts to maximize the donor pool, improve posttransplant outcomes, and optimize patient care while on the waitlist may contribute to future progress.

Long-term social outcome after pediatric kidney transplantation: a single-center experience

BACKGROUND

Patient and graft survival rates after pediatric kidney transplantation have improved recently. Therefore, the quality of life or social outcome after kidney transplantation has become important for patients and their families.

METHODS

Patients who underwent kidney transplantation at < 18 years old and were observed for > 10 years were included in this study. The median age at first kidney transplantation was 9.2 (interquartile range [IQR] = 5.6-13.0) years; there were 56 males and 50 females. The median age at last follow-up was 29.9 (IQR = 22.2-36.0) years. We evaluated the patients' renal function, growth, professional status, and marital status at the last follow-up.

RESULTS

The percentage of functioning grafts at the last follow-up was 81.1%; 73 patients (68.9%) had a first graft. The mean estimated GFR was 51.0 ± 20.5 mL/min/1.73 m². Twenty patients received dialysis for graft failure. The mean final heights of the males and females were 158.1 ± 9.2 cm (- 2.2 standard deviations) and 149.1 ± 6.4 cm (- 1.7 standard deviations), respectively. Excluding 23 students, 63 patients (75.9%) were employed. Office worker was the most common profession. Twelve patients (14.5%) were unemployed. Of patients > 20 years old, 14 (16.7%), three males and 11 females, were married. Five females had one child each.

CONCLUSIONS

The graft survival rate was favorable. The final height was short, particularly in male. The rate of employment was relatively high. The rate of marriage and having children were still low. Improving the social outcome is an important problem after pediatric kidney transplantation.

Cognitive and academic outcomes in children with chronic kidney disease

BACKGROUND

Few data exist on the cognitive and academic functioning of children with chronic kidney disease (CKD) over the trajectory of their illness. We aimed to determine the association between CKD stages and cognitive and academic performance in children over time.

METHODS

We included 53 participants (aged 6-18 years) with CKD stages 1-5 (n = 37), on dialysis (n = 3), or with functioning kidney transplant (n = 22) from three units in Australia from 2015 to 2019. Participants undertook a series of psychometric tests and were invited for repeated assessments annually. We used linear regression and linear mixed models to investigate the effect of CKD stage, adjusted for socioeconomic status.

RESULTS

At baseline, full-scale intelligence quotient (FSIQ) (95%CI) of children on kidney replacement therapy (KRT) was in the low average range (87: 78, 96) and average (101: 95, 108) for children with CKD 1-5. Mean (95%CI) FSIQ, word reading, numerical operations, and spelling scores for children on KRT were 14.3 (- 25.3, - 3.3), 11 (- 18.5, - 3.6), 8.5 (- 17.6, 0.76), and 10 (- 18.6, - 1.3) points lower than children with CKD Stages 1-5. Spelling and numerical operations scores declined by 0.7 (- 1.4, - 0.1) and 1.0 (- 2.0, 0.2) units per year increase in age, regardless of CKD stage.

CONCLUSIONS

Children treated with KRT have low average cognitive abilities and lower academic performance for numeracy and literacy compared to both children with CKD 1-5 and to the general population. However, the rate of decline in academic performance over time is similar for children across the full spectrum of CKD. A higher resolution version of the Graphical abstract is available as Supplementary information.

Biomarkers of alloimmune events in pediatric kidney transplantation

Alloimmune events such as the development of de novo donor-specific antibody (dnDSA), T cell-mediated rejection (TCMR), and antibody-mediated rejection (ABMR) are the primary contributors to kidney transplant failure in children. For decades, a creatinine-based estimated glomerular filtration rate (eGFR) has been the non-invasive gold standard biomarker for detecting clinically significant alloimmune events, but it suffers from low sensitivity and specificity, especially in smaller children and older allografts. Many clinically "stable" children (based on creatinine) will have alloimmune events known as "subclinical acute rejection" (based on biopsy) that merely reflect the inadequacy of creatinine-based estimates for alloimmune injury rather than a distinct phenotype from clinical rejection with allograft dysfunction. The poor biomarker performance of creatinine leads to many unnecessary surveillance and for-cause biopsies that could be avoided by integrating non-invasive biomarkers with superior sensitivity and specificity into current clinical paradigms. In this review article, we will present and appraise the current state-of-the-art in monitoring for alloimmune events in pediatric kidney transplantation. We will first discuss the current clinical standards for assessing the presence of alloimmune injury and predicting long-term outcomes. We will review principles of biomarker medicine and the application of comprehensive metrics to assess the performance of a given biomarker against the current gold standard. We will then highlight novel blood- and urine-based biomarkers (with special emphasis on pediatric biomarker studies) that have shown superior diagnostic and prognostic performance to the current clinical standards including creatinine-based eGFR. Finally, we will review some of the barriers to translating this research and implementing emerging biomarkers into common clinical practice, and present a transformative approach to using multiple biomarker platforms at different times to optimize the detection and management of critical alloimmune events in pediatric kidney transplant recipients.

The impact of donor and recipient sex on kidney allograft survival in pediatric transplant recipients

BACKGROUND

Transplantation is widely considered the gold standard method of kidney replacement therapy. Despite compelling evidence for biological sexual dimorphisms, the role of donor and recipient sex matching in transplantation is undefined.

METHODS

The UK historical cohort study explores the impact of donor and recipient sex on allograft survival, in children receiving their first deceased donor transplant. Nationwide registry data were collected for 1316 transplant procedures performed from January 1, 1999, to December 31, 2019.

RESULTS

Male donor-male recipient transplantation occurred most frequently (35%), followed by female donor-male recipient (23%), male donor-female recipient (22%), and female donor-female recipient (20%). The median follow-up time was 7.03 years (IQR: 2.89-12.4 years), with a total of 10,326 person-years. Male donor-male recipients were associated with the highest 10-year kidney allograft survival (72.8% [95% CI 68.3-77.8]) and male donor-female recipients with the lowest (64% [95% CI 57.7-71.1]). Multivariable Cox regression demonstrated for male donor transplantation, the risk of kidney allograft failure was 1.46 times greater for female (compared to male) recipients, after adjusting for acquired recipient age, recipient/donor age at transplantation, mismatched HLA A/B/DR, waitlist time, cold ischemia time, CMV seropositivity, donor hypertension, and donor diabetes (HR 1.46 [95% CI. 1.06-2.01], p = 0.02). There was no evidence for an independent effect of donor or recipient sex in other combinations.

CONCLUSION

This study highlights the complex relationship between donor and recipient sex and pediatric kidney allograft survival, which require further mechanistic evaluation.

Follow-Up of Blood Pressure, Arterial Stiffness, and GFR in Pediatric Kidney Transplant Recipients

Pediatric renal transplant recipients (RTx) were studied for longitudinal changes in blood pressure (BP), arterial stiffness by pulse wave velocity (PWV), and graft function.

Patients and Methods: 52 RTx patients (22 males) were included; office BP (OBP) and 24 h BP monitoring (ABPM) as well as PWV were assessed together with glycemic and lipid parameters and glomerular filtration rate (GFR) at 2.4[1.0–4.7] (T₁) and 9.3[6.3–11.8] years (T₂) after transplantation (median [range]).

Results: Hypertension was present in 67 and 75% of patients at T₁ and T₂, respectively. Controlled hypertension was documented in 37 and 44% by OBP and 40 and 43% by ABPM. Nocturnal hypertension was present in 35 and 30% at T₁ and T₂; 24 and 32% of the patients had masked hypertension, while white coat hypertension was present in 16 and 21% at T₁ and T₂, respectively. Blood pressure by ABPM correlated significantly with GFR and PWV at T₂, while PWV also correlated significantly with T₂ cholesterol levels. Patients with uncontrolled hypertension by ABPM had a significant decrease in GFR, although not significant with OBP. Anemia and increased HOMAi were present in ~20% of patients at T₁ and T₂.

Conclusion: Pediatric RTx patients harbor risk factors that may affect their cardiovascular health. While we were unable to predict the evolution of renal function based on PWV and ABPM at T₁, these risk factors correlated closely with GFR at follow-up suggesting that control of hypertension may have an impact on the evolution of GFR.

Pediatric renal transplantation; 10 years experience

Objectives

Although renal transplantation (RT) is the first treatment option for children with end-stage renal failure, the number of transplanted chil- dren remains low compared to adults. Experience of the individual pediatric transplant center is very important in the prognosis of pediatric transplant recipients. In this study, our pediatric RT experience was presented.

Material and Methods

We retrospectively analyzed the data of 27 patients who had RT in our clinic between April 2009 and April 2019.

Results

Fifteen of the patients were males, and mean age of all patients was 12.36 ± 4.18 years (range 4-17 years). The most frequent etiology for end- stage renal disease (ESRD) was vesicourethral reflux. Eighteen (66.7%) of the transplanted kidneys came from cadaveric donors and 9 (33.3%) from live donors. One patient had preemptive RT and one patient had a re-RT. Twenty-two patients were on peritoneal dialysis program and four patients were on hemodialysis program. Mean dialysis time before transplantation was 29 (3-104) months. Bleeding was the most common surgical complication. Delayed graft function developed in four patients, and all of their grafts were from cadaveric donors. Rejection developed in 12 of our patients, graft loss was observed in only four of them. Considering all patients, graft survival rates were 100% in the 1st and 3rd years, and 92% in the 5th year.

Conclusion

Pediatric RT program is difficult to establish, maintain and develop. Complications after transplantation are not uncommon; therefore, early detection and appropriate management are needed. Strategies are still needed to increase post-transplant success.

Thromboprophylaxis after kidney transplantation in children: Ten-year experience of a single Brazilian center

BACKGROUND

Kidney transplantation is the gold standard treatment for children with end-stage chronic kidney disease. Graft thrombosis is an important cause of graft failure, with high morbidity, mortality, and impact on quality of life and to the health system. The role of thromboprophylaxis in this setting is still uncertain. We describe the demographic characteristics and thrombotic risk factors in pediatric renal transplant recipients, determining the rate of renal graft thrombosis, and discuss the role of thromboprophylaxis.

METHODS

This retrospective study reviewed 96 pediatric renal transplantations between 2008 and 2017 in a single hospital. Patients were assigned to one of two groups: children who did not receive thromboprophylaxis after transplantation and those who did. We reported their characteristics, comparing the incidence of graft thrombosis and hemorrhagic complications between the groups.

RESULTS

Forty-nine patients (51%) received thromboprophylaxis. Thrombosis occurred in 5 patients who did not receive thromboprophylaxis (5.2%) compared with none in the group that did (p = .025). In all patients, renal graft thrombosis resulted in early graft loss. Thirteen patients had hemorrhagic complications. Seven were unrelated to pharmacological thromboprophylaxis (2 major, 1 moderate, and 4 minor bleeding, which either did not receive thromboprophylaxis or had bleeding prior to thromboprophylaxis), while six occurred during heparinization (2 major, 1 moderate, and 3 minor bleeding). There was no significant difference in the rate of hemorrhagic complications between the groups (p = .105).

CONCLUSIONS

The rate of renal graft thrombosis was 5.2%. Thrombosis remains an important cause of early graft loss. Thromboprophylaxis was associated with a reduction in graft thrombosis without increased risk of bleeding.

Demographics and long-term outcomes of children with end-stage kidney disease: A 20-year territory-wide study

AIM

To evaluate the demographics and long-term patient outcomes of children with end-stage kidney disease in Hong Kong.

METHODS

We conducted a cohort study at the Paediatric Nephrology Centre, the designated site providing kidney replacement therapy (KRT) for children in Hong Kong. The clinical characteristics and outcomes of all children who initiated chronic KRT before 19 years, between 2001 and 2020, were analysed.

RESULTS

One hundred forty-seven children (50% male) received KRT at a mean age of 11.4 ± 5.7 years. The incidence of ESKD was 6.28 per million age-related population (pmarp). The leading cause of ESKD was congenital anomalies (33%). Ten children (7%) had pre-emptive kidney transplants, 104 (71%) and 33 (22%) patients received automated peritoneal dialysis and haemodialysis as initial KRT. The incidence of ESKD increased over time, and were 4.38, 5.07, 6.15 and 9.17 pmarp during 2001-2005, 2006-2010, 2011-2015 and 2016-2020, respectively (p = .005). Ninty-seven patients (66%) received kidney transplants and the median time to receive a kidney graft was 3.7 years (95% CI 3.1-4.3). Only 10 patients had pre-emptive kidney transplants. The mortality rate was 9.1 deaths per 1000-patient-years (95%CI 4.6-16.2). The survival probabilities at 1-, 5-, 10- and 15-year were 100%, 94.8% (95%CI 90.7-98.9%), 89.7% (95% CI 83.4%-95.9%), 87.1% (95% CI 79.3%-94.9%), respectively. Standardised mortality ratio was 54.5. 72% of deaths were due to infections. Young infants and those without kidney transplants were associated with worse survival (p < .01). Multivariate analysis demonstrated that dialysis was the only factor associated with significantly increased risk of death (HR_adj 12.9, 95% CI 2.7-63.2, p = .002).

CONCLUSION

We observed an increasing incidence of paediatric ESKD in Hong Kong with considerable waiting time to kidney transplant. Mortality risk is comparable to other developed countries and is highest among dialysis population. Efforts should be made to facilitate early access to paediatric kidney transplantation in Hong Kong.

National and international kidney failure registries: characteristics, commonalities, and contrasts

Registries are essential for health infrastructure planning, benchmarking, continuous quality improvement, hypothesis generation, and real-world trials. To date, data from these registries have predominantly been analyzed in isolated "silos," hampering efforts to analyze "big data" at the international level, an approach that provides wide-ranging benefits, including enhanced statistical power, an ability to conduct international comparisons, and greater capacity to study rare diseases. This review serves as a valuable resource to clinicians, researchers, and policymakers, by comprehensively describing kidney failure registries active in 2021, before proposing approaches for inter-registry research under current conditions, as well as solutions to enhance global capacity for data collaboration. We identified 79 kidney-failure registries spanning 77 countries worldwide. International Society of Nephrology exemplar initiatives, including the Global Kidney Health Atlas and Sharing Expertise to support the set-up of Renal Registries (SharE-RR), continue to raise awareness regarding international healthcare disparities and support the development of universal kidney-disease registries. Current barriers to inter-registry collaboration include underrepresentation of lower-income countries, poor syntactic and semantic interoperability, absence of clear consensus guidelines for healthcare data sharing, and limited researcher incentives. This review represents a call to action for international stakeholders to enact systemic change that will harmonize the current fragmented approaches to kidney-failure registry data collection and research.

Development of Physiologically Based Pharmacokinetic Model for Pregabalin to Predict the Pharmacokinetics in Pediatric Patients with Renal Impairment and Adjust Dosage Regimens: PBPK Model of Pregabalin in Pediatric Patients with Renal Impairment

Pregabalin (PGB) is widely used clinically; however, its pharmacokinetics (PK) has not been studied in pediatric patients with renal impairment (RI). To design optimized PGB regimens for pediatric patients with varying degrees of RI and predict exposure to PGB, physiologically based pharmacokinetic (PBPK) models of PGB were developed and verified, and its disposition was simulated in the healthy population and adults with RI. The simulated results from the PBPK models after single-dose and multi-dose administrations of PGB were consistent with the corresponding observed data based on the fold error values of less than 2. The area under curve ratios were 1.23 ± 0.06, 2.02 ± 0.10, 3.86 ± 0.21, and 9.92 ± 0.79 in pediatric patients with mild, moderate, severe, and end-stage RI, respectively. Based on the predictions for pediatric patients with moderate, severe, and end-stage RI, the maximum dose should not exceed 7, 3.5, and 1.4 mg/kg/day, respectively, among those weighing < 30 kg, and it should not exceed 5, 2.5, and 1 mg/kg/day, respectively, among those weighing > 30 kg. In conclusion, the developed PBPK model is a valuable tool for predicting PGB dosage for pediatric patients with RI.

Bacterial metabolites and cardiovascular risk in children with chronic kidney disease

Cardiovascular complications are the major cause of the marked morbidity and mortality associated with chronic kidney disease (CKD). The classical cardiovascular risk factors such as diabetes and hypertension undoubtedly play a role in the development of cardiovascular disease (CVD) in adult CKD patients; however, CVD is just as prominent in children with CKD who do not have these risk factors. Hence, the CKD-specific pathophysiology of CVD remains incompletely understood. In light of this, studying children with CKD presents a unique opportunity to analyze CKD-associated mechanisms of CVD more specifically and could help to unveil novel therapeutic targets.

Here, we comprehensively review the interaction of the human gut microbiome and the microbial metabolism of nutrients with host immunity and cardiovascular end-organ damage. The human gut microbiome is evolutionary conditioned and modified throughout life by endogenous factors as well as environmental factors. Chronic diseases, such as CKD, cause significant disruption to the composition and function of the gut microbiome and lead to disease-associated dysbiosis. This dysbiosis and the accompanying loss of biochemical homeostasis in the epithelial cells of the colon can be the result of poor diet (e.g., low-fiber intake), medications, and underlying disease. As a result of dysbiosis, bacteria promoting proteolytic fermentation increase and those for saccharolytic fermentation decrease and the integrity of the gut barrier is perturbed (leaky gut). These changes disrupt local metabolite homeostasis in the gut and decrease productions of the beneficial short-chain fatty acids (SCFAs). Moreover, the enhanced proteolytic fermentation generates unhealthy levels of microbially derived toxic metabolites, which further accumulate in the systemic circulation as a consequence of impaired kidney function. We describe possible mechanisms involved in the increased systemic inflammation in CKD that is associated with the combined effect of SCFA deficiency and accumulation of uremic toxins. In the future, a more comprehensive and mechanistic understanding of the gut–kidney–heart interaction, mediated largely by immune dysregulation and inflammation, might allow us to target the gut microbiome more specifically in order to attenuate CKD-associated comorbidities.

Mortality outcomes and clinical background of children on maintenance dialysis without receiving kidney transplantation

BACKGROUND

Some pediatric patients on maintenance dialysis may need end-of-life care in the future because of being excluded from the indication of kidney transplantation and experiencing difficulty in continuation of their dialysis. This study aimed to thoroughly elucidate mortality outcomes of children on maintenance dialysis including the cause of death and clinical background of exclusion from indication of transplantation.

PATIENTS AND METHODS

This single-center retrospective study enrolled 53 children who received kidney transplantation (5) or maintenance peritoneal dialysis (PD, 48) as initial renal replacement therapy (RRT). We examined the selected RRT modalities, mortality outcomes, clinical backgrounds of cause of death, and risk factors of excluding from future the indication of transplantation.

RESULTS

Nine (17%) of all 53 patients, all receiving PD (9/48, 19%), were finally excluded from next RRT indication-7 were excluded due to severe extrarenal complications that indicated high risk for transplantation and 2 were excluded due to severe psychomotor retardation and at the guardians' discretion. Patients who were excluded from the indication had a younger age at PD induction and higher proportion of cerebral and cardiac complications or psychomotor retardation than patients who were included in the indication. Of the nine patients, seven died; of which, one patient died due to fatal progression of extrarenal complications and six died due to infectious or noninfectious dialysis-related complications.

CONCLUSION

Patients with severe extrarenal complications or psychomotor retardation tend to be excluded from the indication of transplantation. Their condition becomes fatal because of the complications of long-term dialysis and progression in extrarenal complications.

Antenatal and postnatal management of posterior urethral valves: where do we stand?

Introduction

Posterior urethral valve (PUV) is the leading etiology of lower urinary tract obstruction (LUTO) in boys and is an important cause of end-stage renal disease (ESRD) in children. The aim of this article is to review the current status on antenatal intervention for PUV as well as postnatal medical and surgical management.

Main body

MEDLINE, EMBASE, Pubmed and Google Scholar search was conducted throughout December 2020 using the keywords: posterior urethral valves, congenital urinary obstruction, antenatal, valve bladder syndrome, medical, anticholinergics, alpha blocker, antibiotics, biofeedback, diversion, augmentation cystoplasty and renal transplantation. Only papers written in English were included. The relevant literature was summarized. Despite advances in antenatal intervention for fetal LUTO, it remains associated with considerable fetal and maternal morbidity. Patient selection criteria for antenatal intervention are greatly debated. Fetal intervention has resulted in improved perinatal survival in properly selected cases, with a questionable benefit to postnatal renal function. There is decent evidence supporting the use of anticholinergics in infants and young children following valve ablation, with less robust evidence advocating alpha blockers, overnight catheter drainage and biofeedback. The role of urinary diversion remains contentious. Optimizing bladder dynamics is crucial for successful renal transplantation outcomes.

Conclusion

While antenatal intervention has failed to improve renal function outcomes of PUV, patient-centered medical and sometimes surgical interventions can help delay the progression of chronic kidney disease. Lifelong monitoring and management of the associated bladder dysfunction is indispensable even after successful renal transplantation.

Incidence of malignancy after pediatric kidney transplantation: a single-center experience over the past three decades in Japan

BACKGROUND

Malignancy after kidney transplantation (KT) is one of the most serious post-transplant complications. This study aimed to investigate the incidence, type, and outcomes of malignancy after pediatric KT.

METHODS

We performed a retrospective cohort study on pediatric kidney transplant recipients aged 18 years or younger who received their first transplant between 1975 and 2009.

RESULTS

Among the 375 children who underwent KT, 212 were male (56.5%) and 163 were female (43.5%) (median age at KT, 9.6 years [interquartile range {IQR}] 5.8-12.9 years). The incidence of malignancy was 5.6% (n = 21). The cumulative incidences of cancer were 0.8%, 2.5%, 2.8%, 4.2%, 5.5%, and 15.6% at 1, 5, 10, 15, 20, and 30 years post-transplantation, respectively. Of 375 patients, 12 (3.2%) had solid cancer and nine (2.4%) had lymphoproliferative malignancy. The median age at the first malignancy was 21.3 years (IQR 11.5-33.3 years). The median times from transplant to diagnosis were 22.3 years (IQR 12.3-26.6 years) for solid cancer and 2.2 years (IQR 0.6-2.8) for lymphoproliferative malignancies. During follow-up, five recipients died due to malignancy. The causes of death were hepatocellular carcinoma in one patient, squamous cell carcinoma in the transplanted kidney in one patient, malignant schwannoma in one patient, and Epstein-Barr virus-related lymphoma in two patients. The mortality rate was 0.79 per 1000 person-years (95% confidence interval 0.38, 1.85).

CONCLUSIONS

Early diagnosis and treatment of malignancies in transplant recipients is an important challenge. Therefore, enhanced surveillance and continued vigilance for malignancy following KT are necessary.

[Epidemiology of pediatric chronic kidney disease]

Major advances have been made in the management of children with chronic kidney disease over the past 30 years. However, existing epidemiology data are primarily from kidney replacement therapy registries, and information available at earlier stages of chronic kidney disease is limited. The incidence and prevalence of chronic kidney disease stages 2 to 5 remain poorly understood. However, rare population-based studies suggest that the prevalence of all-stage chronic kidney disease may be as high as 1% of the pediatric population. Congenital disorders including congenital abnormalities of the kidney and urinary tract and hereditary nephropathies account for one-half to two-thirds of pediatric chronic kidney disease cases in middle and high-income countries, whereas acquired nephropathies seem to predominate in low-income countries. The progression of chronic kidney disease is slower in children with congenital disorders than in those with acquired nephropathy, particularly glomerular disease, resulting in a lower proportion of congenital abnormalities of the kidney and urinary tract as a cause of end-stage kidney disease compared to less advanced stages of chronic kidney disease. The incidence of kidney replacement therapy in the pediatric population ranged by country from 1 to 14 per million children of the same age in 2018 (approximately 8 per million children in France) in patients younger than 20 years. The prevalence of kidney replacement therapy in children under 20 years of age in 2018 ranged from 15-30 per million children in some Eastern European and Latin American countries to 100 per million children in Finland and the United States (56 per million children in France). Most children with end-stage kidney disease initiate kidney replacement therapy with dialysis (more frequently hemodialysis than peritoneal dialysis). In about 20% of cases, the initial kidney replacement therapy modality is a pre-emptive kidney transplantation. In high-income countries, 60-80% of prevalent children with end-stage kidney disease live with a functioning transplant (75% in France). While the survival of children with chronic kidney disease has continuously improved over time, mortality remains about 30 times higher than in the general pediatric population.

Longitudinal Follow-Up on Cardiopulmonary Exercise Capacity Related to Cardio-Metabolic Risk Factors in Children With Renal Transplants

Background: Children with chronic kidney disease, including those treated with kidney transplantation (KT), have an increased risk of cardiovascular disease. The aim of this study was to examine the cardiopulmonary exercise capacity after KT compared to matched controls, to relate the results to physical activity, blood pressure and biochemical findings and to follow exercise capacity over time.

Methods: Patients with KT (n = 38, age 7.7–18 years), with a mean time from transplantation of 3.7 years (0.9–13.0) and mean time in dialysis 0.8 years, were examined at inclusion and annually for up to three years. Healthy controls (n = 17, age 7.3–18.6 years) were examined once. All subjects underwent a cardiopulmonary exercise test, resting blood pressure measurement, anthropometry and activity assessment. Patients also underwent echocardiography, dual-energy X-ray absorptiometry (DXA), 24-h ambulatory BP measurements (ABPM), assessment of glomerular filtration rate (GFR) and blood sampling annually.

Results: As compared to healthy controls, KT patients showed decreased exercise capacity measured both as VO_2peak (34.5 vs. 43.9 ml/kg/min, p < 0.001) and maximal load (2.6 vs. 3.5 W/kg, p < 0.0001), similarly as when results were converted to z-scores. No significant difference was found in weight, but the KT patients were shorter and had higher BMI z-score than controls, as well as increased resting SBP and DBP z-scores. The patient or parent reported physical activity was significantly lower in the KT group compared to controls (p < 0.001) In the combined group, the major determinants for exercise capacity z-scores were activity score and BMI z-score (β = 0.79, p < 0.0001 and β = −0.38, p = 0.007, respectively). Within the KT group, low exercise capacity was associated with high fat mass index (FMI), low activity score, low GFR and high blood lipids. In the multivariate analysis FMI and low GFR remained predictors of low exercise capacity. The longitudinal data for the KT patients showed no change in exercise capacity z-scores over time.

Conclusion: Patients with KT showed decreased exercise capacity and increased BP as compared to healthy controls. Exercise capacity was associated to GFR, physical activity, FMI and blood lipids. It did not improve during follow-up.

Paediatric deceased donor kidney transplant in Australia: A 30-year review-What have paediatric bonuses achieved and where to from here?

BACKGROUND

In this 30-year national review, we describe trends in DD transplantation for paediatric recipients, assess the impact of paediatric allocation bonuses and identify outstanding areas of need for this population.

METHODS

A retrospective review of all DD kidney only transplants to paediatric recipients (<18 years old) in Australia between 1989 and 2018 was conducted using deidentified extracts from the ANZDATA.

RESULTS

Of the 1011 kidney only transplants performed in paediatric recipients during the study period, 426 (42%) were from deceased donors. Paediatric candidates on the DD waiting list had consistently higher rates of transplantation and shorter time from dialysis initiation to transplantation compared with adult candidates (median 372 vs 832 days in 2018, for example). Donor characteristics remained more favourable for paediatric recipients, despite a decline in the overall quality of the donor pool. The mean number of HLA antigen mismatches for paediatric recipients of DD transplants increased each decade (2.86 [1989-1998], 3.85 [1999-2008], 4.01 [2009-2018]). Both patient and graft survival have improved for paediatric DD transplant recipients in the most recent era (5-year graft and patient survival 85% vs 65% and 99% vs 94%, respectively, for 2009-2018 vs 1999-2008).

CONCLUSIONS

The current DD kidney allocation system in Australia provides rapid access to high-quality organs for paediatric recipients, and early graft loss has decreased significantly in recent years; however, additional targeted interventions to address HLA matching may improve long-term outcomes in this population.

Barriers to pre-emptive kidney transplantation in New Zealand children

AIM

Pre-emptive kidney transplantation (PKT) is generally considered the optimal treatment for kidney failure as it minimises dialysis-associated morbidity and mortality and is associated with improved allograft survival. This study aimed to determine rates of paediatric PKT in New Zealand, identify barriers to PKT and consider potential interventions to influence future rates of pre-emptive transplantation.

METHODS

Children commencing kidney replacement therapy between 2005 and 2017 in New Zealand were included. Descriptive analysis considered those referred late (referral <3 months prior to kidney replacement therapy initiation) or early based on referral timing to paediatric nephrology. Additional analysis compared characteristics of children receiving dialysis versus pre-emptive transplant as their first mode of kidney replacement therapy.

RESULTS

PKT occurred in 15 of 90 children (17%). One-third of all patients were referred late. No late referrals received a pre-emptive transplant. Pre-emptively transplanted children were referred younger (median age 0.49 years), lived in less deprived areas, were more likely to have congenital anomalies of the kidney and urinary tract and none were Māori or Pasifika ethnicity.

CONCLUSIONS

Late referral, higher deprivation levels and Māori and Pasifika ethnicity confer a greater risk of not receiving pre-emptive transplantation. Improved education amongst health professionals about recognition of paediatric chronic kidney disease and the importance of timely referral to paediatric nephrology is recommended to reduce rates of late referral. A modified approach including enhanced culturally appropriate support for those diagnosed with chronic kidney disease during transplant evaluation should be pursued to improve equity.