Mode of initial renal replacement therapy and transplant outcomes in the chronic kidney disease in children (CKiD) study

Socioeconomic Position and Health Among Children and Adolescents With CKD Across the Life-Course

Children and adolescents in families of lower socioeconomic position (SEP) experience an inequitable burden of reduced access to healthcare and poorer health. For children living with chronic kidney disease (CKD), disadvantaged SEP may exacerbate their considerable disease burden. Across the life-course, CKD may also compromise the SEP of families and young people, leading to accumulating health and socioeconomic disadvantage. This narrative review summarizes the current evidence on relationships of SEP with kidney care and health among children and adolescents with CKD from a life-course approach, including impacts of family SEP on kidney care and health, and bidirectional impacts of CKD on SEP. It highlights relevant conceptual models from social epidemiology, current evidence, clinical and policy implications, and provides directions for future research. Reflecting the balance of available evidence, we focus primarily on high-income countries (HICs), with an overview of key issues in low- and middle-income countries (LMICs). Overall, a growing body of evidence indicates sobering socioeconomic inequities in health and kidney care among children and adolescents with CKD, and adverse socioeconomic impacts of CKD. Dedicated efforts to tackle inequities are critical to ensuring that all young people with CKD have the opportunity to live long and flourishing lives. To prevent accumulating disadvantage, the global nephrology community must advocate for local government action on upstream social determinants of health; and adopt a life-course approach to kidney care that proactively identifies and addresses unmet social needs, targets intervening factors between SEP and health, and minimizes adverse socioeconomic outcomes across financial, educational and vocational domains.

Development of an adaptive clinical web-based prediction tool for kidney replacement therapy in children with chronic kidney disease

Clinicians need improved prediction models to estimate time to kidney replacement therapy (KRT) for children with chronic kidney disease (CKD). Here, we aimed to develop and validate a prediction tool based on common clinical variables for time to KRT in children using statistical learning methods and design a corresponding online calculator for clinical use. Among 890 children with CKD in the Chronic Kidney Disease in Children (CKiD) study, 172 variables related to sociodemographics, kidney/cardiovascular health, and therapy use, including longitudinal changes over one year were evaluated as candidate predictors in a random survival forest for time to KRT. An elementary model was specified with diagnosis, estimated glomerular filtration rate and proteinuria as predictors and then random survival forest identified nine additional candidate predictors for further evaluation. Best subset selection using these nine additional candidate predictors yielded an enriched model additionally based on blood pressure, change in estimated glomerular filtration rate over one year, anemia, albumin, chloride and bicarbonate. Four additional partially enriched models were constructed for clinical situations with incomplete data. Models performed well in cross-validation, and the elementary model was then externally validated using data from a European pediatric CKD cohort. A corresponding user-friendly online tool was developed for clinicians. Thus, our clinical prediction tool for time to KRT in children was developed in a large, representative pediatric CKD cohort with an exhaustive evaluation of potential predictors and supervised statistical learning methods. While our models performed well internally and externally, further external validation of enriched models is needed.

Life Years Lost in Children with Kidney Failure: A Binational Cohort Study with Multistate Probabilities of Death and Life Expectancy

SIGNIFICANCE STATEMENT

In children with kidney failure, little is known about their treatment trajectories or the effects of kidney failure on lifetime survival and years of life lost, which are arguably more relevant measures for children. In this population-based cohort study of 2013 children who developed kidney failure in Australia and New Zealand, most children were either transplanted after initiating dialysis (74%) or had a preemptive kidney transplant (14%). Life expectancy increased with older age at kidney failure, but more life years were spent on dialysis than with a functioning transplant. The expected (compared with the general population) number of life years lost ranged from 16 to 32 years, with female patients and those who developed kidney failure at a younger age experiencing the greatest loss of life years.

BACKGROUND

Of the consequences of kidney failure in childhood, those rated as most important by children and their caregivers are its effects on long-term survival. From a life course perspective, little is known about the experience of kidney failure treatment or long-term survival.

METHODS

To determine expected years of life lost (YLL) and treatment trajectory for kidney failure in childhood, we conducted a population-based cohort study of all children aged 18 years or younger with treated kidney failure in Australia (1980-2019) and New Zealand (1988-2019).We used patient data from the CELESTIAL study, which linked the Australian and New Zealand Dialysis and Transplant registry with national death registers. We estimated standardized mortality ratios and used multistate modeling to understand treatment transitions and life expectancy.

RESULTS

A total of 394 (20%) of 2013 individuals died over 30,082 person-years of follow-up (median follow-up, 13.1 years). Most children (74%) were transplanted after initiating dialysis; 14% (18% of male patients and 10% of female patients) underwent preemptive kidney transplantation. Excess deaths (compared with the general population) decreased dramatically from 1980 to 1999 (from 41 to 22 times expected) and declined more modestly (to 17 times expected) by 2019. Life expectancy increased with older age at kidney failure, but more life years were spent on dialysis than with a functioning transplant. The number of YLL ranged from 16 to 32 years, with the greatest loss among female patients and those who developed kidney failure at a younger age.

CONCLUSIONS

Children with kidney failure lose a substantial number of their potential life years. Female patients and those who develop kidney failure at younger ages experience the greatest burden.

A systematic review of social determinants of health in pediatric organ transplant outcomes

BACKGROUND

Equitable access to pediatric organ transplantation is critical, although risk factors negatively impacting pre- and post-transplant outcomes remain. No synthesis of the literature on SDoH within the pediatric organ transplant population has been conducted; thus, the current systematic review summarizes findings to date assessing SDoH in the evaluation, listing, and post-transplant periods.

METHODS

Literature searches were conducted in Web of Science, Embase, PubMed, and Cumulative Index to Nursing and Allied Health Literature databases.

RESULTS

Ninety-three studies were included based on pre-established criteria and were reviewed for main findings and study quality. Findings consistently demonstrated disparities in key transplant outcomes based on racial or ethnic identity, including timing and likelihood of transplant, and rates of rejection, graft failure, and mortality. Although less frequently assessed, variations in outcomes based on geography were also noted, while findings related to insurance or SES were inconsistent.

CONCLUSION

This review underscores the persistence of SDoH and disparity in equitable transplant outcomes and discusses the importance of individual and systems-level change to reduce such disparities.

Chronic Kidney Disease in Children

Chronic kidney disease (CKD) in children occurs mostly due to congenital anomalies of kidney and urinary tract and hereditary diseases. For advanced cases, a multidisciplinary team is needed to manage nutritional requirements and complications such as hypertension, hyperphosphatemia, proteinuria, and anemia. Neurocognitive assessment and psychosocial support are essential. Maintenance dialysis in children with end-stage renal failure has become the standard of care in many parts of the world. Children younger than 12 years have 95% survival after 3 years of dialysis initiation, whereas the survival rate for children aged 4 years or younger is about 82% at one year."

Differences in medication adherence between preemptive and post-dialysis young kidney transplant recipients

BACKGROUND

The mechanisms underlying the superior graft survival associated with preemptive kidney transplantation, compared with transplantation following a period of dialysis, are unknown. We aimed to compare medication adherence between preemptively transplanted young kidney transplant recipients and those who received a transplant after an interval of dialysis.

METHODS

This was a secondary analysis of the Teen Adherence in Kidney transplant Effectiveness of Intervention Trial (TAKE-IT), in which adherence was assessed with electronic monitoring over 15 months among 11-24-year-old transplant recipients. Adherence scores were calculated for each day as 0%, 50%, or 100% (intake of none, half, or all prescribed doses). We used ordinal logistic regression, with generalized estimating equations to account for repeated measures within each participant, to estimate the association between preemptive transplantation and adherence. The model was adjusted for sex, age at transplant, time since transplant, primary kidney disease, race, donor source, medication insurer, household income, and adherence intervention.

RESULTS

There were 43 preemptive transplant recipients and 103 who had been treated with dialysis. The median adherence score was 85.1% (IQR 81.3-88.9) for those preemptively transplanted, and 80.0% (IQR 76.7-83.4) for those transplanted after dialysis. Preemptively transplanted recipients had significantly higher odds of adherence than those dialyzed before transplantation (adjusted OR 1.76 95% CI 1.21-2.55; p = 0.003).

CONCLUSIONS

Preemptively transplanted patients showed significantly better adherence than those treated with dialysis before transplantation. This suggests that the superior outcomes observed among preemptive kidney transplant recipients may reflect selection of patients more likely to adhere to therapy. A higher resolution version of the Graphical abstract is available as Supplementary information.

The Relationship Between Neighborhood Disadvantage and Kidney Disease Progression in the Chronic Kidney Disease in Children (CKiD) Cohort

RATIONALE & OBJECTIVE

To examine the relationship between neighborhood poverty and deprivation, chronic kidney disease (CKD) comorbidities, and disease progression in children with CKD.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

Children with mild to moderate CKD enrolled in the CKiD (Chronic Kidney Disease in Children) study with available US Census data.

EXPOSURE

Neighborhood poverty and neighborhood disadvantage.

OUTCOME

Binary outcomes of short stature, obesity, hypertension, and health care utilization for cross-sectional analysis; a CKD progression end point (incident kidney replacement therapy [KRT] or 50% loss in estimated glomerular filtration rate), and mode of first KRT for time-to-event analysis.

ANALYTICAL APPROACH

Cross-sectional analysis of health characteristics at time of first Census data collection using logistic regression to estimate odds ratios. Risk for CKD progression was analyzed using a Cox proportional hazard model. Multivariable models were adjusted for race, ethnicity, sex, and family income.

RESULTS

There was strong agreement between family and neighborhood socioeconomic characteristics. Risk for short stature, hospitalization, and emergency department (ED) use were significantly associated with lower neighborhood income. After controlling for race, ethnicity, sex, and family income, the odds of hospitalization (OR, 1.71 [95% CI, 1.08-2.71]) and ED use (OR, 1.56 [95% CI, 1.02-2.40]) remained higher for those with lower neighborhood income. The hazard ratio of reaching the CKD progression outcome for participants living in lower income neighborhoods was significantly increased in the unadjusted model only (1.38 [95% CI, 1.02-1.87]). Likelihood of undergoing a preemptive transplant was decreased with lower neighborhood income (OR, 0.47 [95% CI, 0.24-0.96]) and higher neighborhood deprivation (OR, 0.31 [95% CI, 0.10-0.97]), but these associations did not persist after controlling for participant characteristics.

LIMITATIONS

Limited generalizability, as only those with consistent longitudinal nephrology care were studied.

CONCLUSIONS

Neighborhood-level socioeconomic status (SES) was associated with poorer health characteristics and CKD progression in univariable analysis. However, the relationships were attenuated after accounting for participant-level factors including race. A persistent association of neighborhood poverty with hospitalizations and ED suggests an independent effect of SES on health care utilization, the causes for which deserve additional study.

Paediatric nephrology in under-resourced areas

BACKGROUND

Nearly 50% of the world population and 60% of children aged 0 to 14 years live in low- or lower-middle-income countries. Paediatric nephrology (PN) in these countries is not a priority for allocation of limited health resources. This article explores advancements made and persisting limitations in providing optimal PN services to children in such under-resourced areas (URA).

METHODS

Medline, PubMed and Google Scholar online databases were searched for articles pertaining to PN disease epidemiology, outcome, availability of services and infrastructure in URA. The ISN and IPNA offices were contacted for data, and two online questionnaire surveys of IPNA membership performed. Regional IPNA members were contacted for further detailed information.

RESULTS

There is a scarcity of published data from URA; where available, prevalence of PN diseases, managements and outcomes are often reported to be different from high income regions. Deficiencies in human resources, fluoroscopy, nuclear imaging, immunofluorescence, electron microscopy and genetic studies were identified. Several drugs and maintenance kidney replacement therapy are inaccessible to the majority of patients. Despite these issues, regional efforts with support from international bodies have led to significant advances in PN services and infrastructure in many URA.

CONCLUSIONS

Equitable distribution and affordability of PN services remain major challenges in URA. The drive towards acquisition of regional data, advocacy to local government and non-government agencies and partnership with international support bodies needs to be continued. The aim is to optimise and achieve global parity in PN training, investigations and treatments, initially focusing on preventable and reversible conditions.

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.

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

Kidney Disease Progression in Children and Young Adults With Pediatric CKD: Epidemiologic Perspectives and Clinical Applications

Chronic kidney disease (CKD) progression is typically characterized as either time to a clinically meaningful event (such as dialysis or transplant), or longitudinal changes in kidney function. This review describes pediatric kidney disease progression using these two distinct frameworks by reviewing and discussing data from the Chronic Kidney Disease in Children study. We first describe new equations to estimate glomerular filtration rate (GFR) for patients younger than age 25 years, and how the average of serum creatinine-based and cystatin C-based GFR equations yield valid estimates than either alone. Next, we present a life course description of CKD onset to kidney replacement therapy, prediction models based on clinical measurements, and show the importance of diagnosis (broadly classified as nonglomerular and glomerular in origin), GFR level, and proteinuria on progression. Literature on longitudinal GFR in children and young adults are reviewed and new data are presented to characterize nonlinear changes in estimated GFR in patients younger than age 25 years. These models showed accelerated progression associated with glomerular diagnosis, lower GFR level, and higher proteinuria, which was congruent with time-to-event analyses. Descriptions of online tools for GFR estimation and risk stratification for clinical applications are presented and we offer key epidemiologic considerations for the analysis of longitudinal pediatric CKD studies.

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.

Preemptive Kidney Transplantation is Associated With Transplantation Outcomes in Children: Results From the French Kidney Replacement Therapy Registry

BACKGROUND

Kidney transplantation (KT) is the optimal treatment for children with end-stage kidney disease (ESKD). The aim of this study was to evaluate the impact of PKT and of pretransplant dialysis duration on graft survival among French pediatric kidney transplant recipients.

METHODS

We analyzed all first pediatric kidney-only transplantations performed in France between 1993 and 2012. A Cox multivariable model was used to investigate the association of PKT and pretransplant dialysis time with the hazard of graft failure defined as death, return to dialysis or retransplant, whichever occurred first.

RESULTS

1911 patients were included, of which 380 (19.8%) received a PKT. Median time of follow-up was 7.0 years. PKT was associated with a 55% reduction of the hazard of graft failure at any time after KT compared to patients transplanted after dialysis (HR 0.45; 95%CI 0.33-0.62), after adjustment for recipient sex and age, primary kidney disease, donor age and type (living or deceased donor), number of HLA mismatches, cold ischemia time and year of transplantation. A reduction of the hazard of graft failure was found in PKT whatever the compared duration of dialysis, even when less than 6 months and whatever the dialysis modality. Results were similar in multiple sensitivity analyses.

CONCLUSIONS

In France, PKT among pediatric patients is associated with a better graft survival when compared to KT after dialysis, even when less than 6 months. Based on these findings, we suggest that PKT should be considered as the treatment of choice for children with ESKD.