A prospective cohort study of incident maintenance dialysis in children: an NAPRTC study

Recessive variants in MYO1C as a potential novel cause of proteinuric kidney disease

BACKGROUND

Steroid-resistant nephrotic syndrome is the second leading cause of chronic kidney disease among patients < 25 years of age. Through exome sequencing, identification of > 65 monogenic causes has revealed insights into disease mechanisms of nephrotic syndrome (NS).

METHODS

To elucidate novel monogenic causes of NS, we combined homozygosity mapping with exome sequencing in a worldwide cohort of 1649 pediatric patients with NS.

RESULTS

We identified homozygous missense variants in MYO1C in two unrelated children with NS (c.292C > T, p.R98W; c.2273 A > T, p.K758M). We evaluated publicly available kidney single-cell RNA sequencing datasets and found MYO1C to be predominantly expressed in podocytes. We then performed structural modeling for the identified variants in PyMol using aligned shared regions from two available partial structures of MYO1C (4byf and 4r8g). In both structures, calmodulin, a common regulator of myosin activity, is shown to bind to the IQ motif. At both residue sites (K758; R98), there are ion-ion interactions stabilizing intradomain and ligand interactions: R98 binds to nearby D220 within the myosin motor domain and K758 binds to E14 on a calmodulin molecule. Variants of these charged residues to non-charged amino acids could ablate these ionic interactions, weakening protein structure and function establishing the impact of these variants.

CONCLUSION

We here identified recessive variants in MYO1C as a potential novel cause of NS in children.

Copy number variation analysis in 138 families with steroid-resistant nephrotic syndrome identifies causal homozygous deletions in PLCE1 and NPHS2 in two families

BACKGROUND

Steroid-resistant nephrotic syndrome (SRNS) is the second most common cause of kidney failure in children and adults under the age of 20 years. Previously, we were able to detect by exome sequencing (ES) a known monogenic cause of SRNS in 25-30% of affected families. However, ES falls short of detecting copy number variants (CNV). Therefore, we hypothesized that causal CNVs could be detected in a large SRNS cohort.

METHODS

We performed genome-wide single nucleotide polymorphism (SNP)-based CNV analysis on a cohort of 138 SRNS families, in whom we previously did not identify a genetic cause through ES. We evaluated ES and CNV data for variants in 60 known SRNS genes and in 13 genes in which variants are known to cause a phenocopy of SRNS. We applied previously published, predefined criteria for CNV evaluation.

RESULTS

We detected a novel CNV in two genes in 2 out of 138 families (1.5%). The 9,673 bp homozygous deletion in PLCE1 and the 6,790 bp homozygous deletion in NPHS2 were confirmed across the breakpoints by PCR and Sanger sequencing.

CONCLUSIONS

We confirmed that CNV analysis can identify the genetic cause in SRNS families that remained unsolved after ES. Though the rate of detected CNVs is minor, CNV analysis can be used when there are no other genetic causes identified. Causative CNVs are less common in SRNS than in other monogenic kidney diseases, such as congenital anomalies of the kidneys and urinary tract, where the detection rate was 5.3%. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

An ethical analysis of obesity as a contraindication of pediatric kidney transplant candidacy

The inclusion of body mass index (BMI) as a criterion for determining kidney transplant candidacy in children raises clinical and ethical challenges. Childhood obesity is on the rise and common among children with kidney failure. In addition, obesity is reported as an independent risk factor for the development of CKD and kidney failure. Resultantly, more children with obesity are anticipated to need kidney transplants. Most transplant centers around the world use high BMI as a relative or absolute contraindication for kidney transplant. However, use of obesity as a relative or absolute contraindication for pediatric kidney transplant is controversial. Empirical data demonstrating poorer outcomes following kidney transplant in obese pediatric patients are limited. In addition, pediatric obesity is distributed inequitably among groups. Unlike adults, most children lack independent agency to choose their food sources and exercise opportunities; they are dependent on their families for these choices. In this paper, we define childhood obesity and review (1) the association and impact of obesity on kidney disease and kidney transplant, (2) existing adult guidelines and rationale for using high BMI as a criterion for kidney transplant, (3) the prevalence of childhood obesity among children with kidney failure, and (4) the existing literature on obesity and pediatric kidney transplant outcomes. We then discuss ethical considerations related to the use of obesity as a criterion for kidney transplant.

Practice patterns and outcomes of maintenance dialysis in children < 2 years of age: a report of the North American Pediatric Renal Trials and Collaborative Studies (NAPRTCS)

BACKGROUND

Peritoneal dialysis (PD) is the preferred mode of kidney replacement therapy (KRT) in infants and young children with kidney failure. Hemodialysis (HD) is used less often due to the technical challenges and risk of complications in smaller patients. There are limited data on chronic HD in this patient population.

METHODS

This was a retrospective study of children younger than 24 months on HD and PD in the North American Pediatric Renal Trials and Collaborative Studies (NAPRTCS) registry between January 1992 and December 2018. We compared demographic, clinical, and laboratory data and outcomes, including patient survival and kidney transplantation.

RESULTS

We identified 1125 infants and toddlers younger than 2 years of age who initiated KRT from January 1992 to December 2018. Of those, 1011 (89.8%) initiated peritoneal dialysis and 114 (10.2%) initiated hemodialysis. Median (IQR) age at HD onset was 12 (5.6-18.7) months compared to 4.6 (0.8-11.7) months at PD onset (p < 0.001). The primary cause of kidney failure with replacement therapy was congenital anomalies of the kidney and urinary tract (56.2% of PD versus 39.5% of HD group). Patients on HD had superior growth and nutrition markers than those on PD. Patient survival was similar between the two groups.

CONCLUSIONS

While HD may not be the modality of choice for chronic KRT in younger children, 10% of children younger than 24 months of age receive maintenance HD and the numbers have increased over time. Patient survival on dialysis is similar irrespective of dialysis modality. A higher resolution version of the Graphical abstract is available as Supplementary information.

Understanding disparities and barriers associated with pediatric transplant evaluation and time to listing: Moving toward a more comprehensive picture

BACKGROUND

Delayed time to listing (TTL) for pediatric transplant patients is associated with increased risks of mortality and morbidity. The full range of health disparities, sociodemographic factors, and other barriers associated with delays in listing in the pediatric transplant candidate evaluation process has not been fully examined.

METHODS

Retrospective chart reviews were conducted for 183 kidney, liver, and heart transplant candidates ages 0-18 who were referred for evaluation during 2012-2015. Demographic information and potential barriers (e g., social/medical factors, financial concerns) were gathered from pre-transplant evaluations and included in a comprehensive model to evaluate mechanisms that explain differences in TTL. Descriptive statistics, logistic regression models, Cox proportional hazards models, and path analysis were used for analyses.

RESULTS

Candidates included 26.8% heart, 33.3% liver, and 39.9% kidney patients. The most common barrier to listing was financial (71.6%), followed by caregiver psychological or substance use (57.9%), and medical problems (49.7%). Higher age, kidney, and liver organ type (relative to the heart), and presence of social, medical, administrative/motivation, and financial barriers were all directly associated with longer TTL. Public insurance was indirectly associated with TTL through social, administrative/motivation, and financial barriers. Organ type was indirectly associated with TTL through financial barriers.

CONCLUSIONS

Results suggest social problems, administrative issues, and financial issues act as mechanisms through which insurance type and liver transplant candidates face increased risk of delays in transplant listing time. There are numerous clinical implications and interventions that are warranted to reduce TTL among pediatric transplant candidates with co-occurring barriers.

Racial Disparities in Pediatric Kidney Transplantation under the New Kidney Allocation System in the United States

BACKGROUND AND OBJECTIVES

In December 2014, the Kidney Allocation System (KAS) was implemented to improve equity in access to transplantation, but preliminary studies in children show mixed results. Thus, we aimed to assess how the 2014 KAS policy change affected racial and ethnic disparities in pediatric kidney transplantation access and related outcomes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a retrospective cohort study of children <18 years of age active on the kidney transplant list from 2008 to 2019 using the Scientific Registry of Transplant Recipients. Log-logistic accelerated failure time models were used to determine the time from first activation on the transplant list and the time on dialysis to deceased donor transplant, each with KAS era or race and ethnicity as the exposure of interest. We used logistic regression to assess odds of delayed graft function. Log-rank tests assessed time to graft loss within racial and ethnic groups across KAS eras.

RESULTS

All children experienced longer wait times from activation to transplantation post-KAS. In univariable analysis, Black and Hispanic children and other children of color experienced longer times from activation to transplant compared with White children in both eras; this finding was largely attenuated after multivariable analysis (time ratio, 1.16; 95% confidence interval, 1.01 to 1.32; time ratio, 1.13; 95% confidence interval, 1.00 to 1.28; and time ratio, 1.17; 95% confidence interval, 0.96 to 1.41 post-KAS, respectively). Multivariable analysis also showed that racial and ethnic disparities in time from dialysis initiation to transplantation in the pre-KAS era were mitigated in the post-KAS era. There were no disparities in odds of delayed graft function. Black and Hispanic children experienced longer times with a functioning graft in the post-KAS era.

CONCLUSIONS

No racial and ethnic disparities from activation to deceased donor transplantation were seen before or after implementation of the KAS in multivariable analysis, whereas time on dialysis to transplantation and odds of short-term graft loss improved in equity after the implementation of the KAS, without compromising disparities in delayed graft function.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2021_12_07_CJN06740521.mp3.

Policy in pediatric nephrology: successes, failures, and the impact on disparities

Pediatric nephrology has a history rooted in pediatric advocacy and has made numerous contributions to child health policy affecting pediatric kidney diseases. Despite this progress, profound social disparities remain for marginalized and socially vulnerable children with kidney disease. Different risk factors, such as genetic predisposition, environmental factors, social risk factors, or health care access influence the emergence and progression of pediatric kidney disease, as well as access to life-saving interventions, leading to disparate outcomes. This review will summarize the breadth of literature on social determinants of health in children with kidney disease worldwide and highlight policy-based initiatives that mitigate the adverse social factors to generate greater equity in pediatric kidney disease.

Urologic issues in pediatric transplant recipients

The limited supply of kidneys for pediatric transplantation leads to a large number of children in waiting transplant list. These patients have to be properly evaluated and prepared before organ transplantation to increase its success. The aim of this review is focus on urologic issues of pediatric kidney transplants such as preoperative evaluation and urinary tract abnormalities correction, surgical technique, and postoperative complications. All children that are candidates for kidney transplantation should be submitted to abdominal ultrasound. If bladder dysfunction is suspected, a more detailed evaluation is mandatory, including a voiding cystourethrography and urodynamic study. Patients with a poor bladder capacity and compliance will require bladder augmentation. Whenever possible the native ureter is recommended for that. Regarding kidney transplantation, recipient surgery can be safely performed through an extraperitoneal access, even in children weighting less than 10 kilograms. It allows adequate access to iliac vessels, aorta and vena cava. Graft survival continued to improve over the past decade and it is around 80% in 5 years. Postoperative complications such as urinary fistula may occur in less than 5% of cases, while vascular complications are reported in 1% to 2% of cases.

Nephrotic Syndrome

Nephrotic syndrome is characterized by edema, proteinuria, hypoalbuminemia, and hyperlipidemia. Minimal change disease, the most common cause in childhood, generally responds to corticosteroids, although most patients experience disease relapses. Focal segmental glomerulosclerosis is usually resistant to corticosteroids and carries a significant risk of kidney failure, necessitating renal transplantation. Nephrotic syndrome may also be secondary to gene mutations and systemic diseases such as lupus. Clinical evaluation involves distinguishing primary and secondary causes and monitoring for disease complications, including blood clots and serious infections such as spontaneous bacterial peritonitis. Immunosuppressive medications are used to prevent relapses and treat corticosteroid-resistant disease.

Adrenocorticotropic Hormone for Childhood Nephrotic Syndrome: The ATLANTIS Randomized Trial

BACKGROUND AND OBJECTIVES

There is renewed interest in adrenocorticotropic hormone (ACTH) for the treatment of nephrotic syndrome. We evaluated the efficacy and safety of ACTH in children with frequently relapsing or steroid-dependent nephrotic syndrome in a randomized trial.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Participants aged 2-20 years old with frequently relapsing or steroid-dependent nephrotic syndrome were enrolled from 16 sites in the United States and randomized 1:1 to ACTH (repository corticotropin injection) or no relapse-preventing treatment. ACTH treatment regimen was 80 U/1.73 m2 administered twice weekly for 6 months, followed by 40 U/1.73 m2 administered twice weekly for 6 months. The primary outcome was disease relapse during the first 6 months. Participants in the control group were offered crossover to ACTH treatment if they relapsed within 6 months. Secondary outcomes were relapse after ACTH dose reduction and treatment side effects.

RESULTS

The trial was stopped at a preplanned interim analysis after enrollment of 31 participants because of a lack of discernible treatment efficacy. Fourteen out of 15 (93%) participants in the ACTH arm experienced disease relapse in the first 6 months, with a median time to first relapse of 23 days (interquartile range, 9-32), compared with 15 out of 16 (94%) participants and at a median of 21 days (interquartile range, 14-51) in the control group. There was no difference in the proportion of relapsed patients (odds ratio, 0.93; 95% confidence interval, 0.05 to 16.40; P>0.99) or time to first relapse (hazard ratio, 1.03; 95% confidence interval, 0.50 to 2.15; P=0.93). Thirteen out of 16 participants in the control group crossed over to ACTH treatment. Three out of 28 participants completed 12 months of ACTH treatment; the others exited the trial because of frequent relapses or side effects. There were no disease relapses after ACTH dose reduction among the three participants. Most side effects were mild and similar to side effects of corticosteroids.

CONCLUSIONS

ACTH at 80 U/1.73 m2 administered twice weekly was ineffective at preventing disease relapses in pediatric nephrotic syndrome.

Impact of Inflammation on Ferritin, Hepcidin and the Management of Iron Deficiency Anemia in Chronic Kidney Disease

Iron deficiency anemia (IDA) is a major problem in chronic kidney disease (CKD), causing increased mortality. Ferritin stores iron, representing iron status. Hepcidin binds to ferroportin, thereby inhibiting iron absorption/efflux. Inflammation in CKD increases ferritin and hepcidin independent of iron status, which reduce iron availability. While intravenous iron therapy (IIT) is superior to oral iron therapy (OIT) in CKD patients with inflammation, OIT is as effective as IIT in those without. Inflammation reduces predictive values of ferritin and hepcidin for iron status and responsiveness to iron therapy. Upper limit of ferritin to predict iron overload is higher in CKD patients with inflammation than in those without. However, magnetic resonance imaging studies show lower cutoff levels of serum ferritin to predict iron overload in dialysis patients with apparent inflammation than upper limit of ferritin proposed by international guidelines. Compared to CKD patients with inflammation, optimal ferritin levels for IDA are lower in those without, requiring reduced iron dose and leading to decreased mortality. The management of IDA should differ between CKD patients with and without inflammation and include minimization of inflammation. Further studies are needed to determine the impact of inflammation on ferritin, hepcidin and therapeutic strategy for IDA in CKD.

Care of the Pediatric Patient on Chronic Dialysis

Optimal care of the pediatric end-stage renal disease (ESRD) patient on chronic dialysis is complex and requires multidisciplinary care as well as patient/caregiver involvement. The dialysis team, along with the family and patient, should all play a role in choosing the dialysis modality which best meets the patient's needs, taking into account special considerations and management issues that may be particularly pertinent to children who receive peritoneal dialysis or hemodialysis. Meticulous attention to dialysis adequacy in terms of solute and fluid removal, as well as to a variety of clinical manifestations of ESRD, including anemia, growth and nutrition, chronic kidney disease-mineral bone disorder, cardiovascular health, and neurocognitive development, is essential. This review highlights current recommendations and advances in the care of children on dialysis with a particular focus on preventive measures to minimize ESRD-associated morbidity and mortality. Advances in dialysis care and prevention of complications related to ESRD and dialysis have led to better survival for pediatric patients on dialysis.

Effect of center practices on the choice of the first dialysis modality for children and young adults

BACKGROUND

Peritoneal dialysis (PD) remains the modality of choice in children, but there is no clear evidence to support a better outcome in children treated with PD. We aimed to assess factors that have an impact on the choice of dialysis modality in children and young adults in France and sought to determine the roles of medical factors and center practices.

METHODS

We included all patients aged <20 years at the start of renal replacement therapy (RRT), recorded in the French RRT Registry between 2002 and 2013. Hierarchical logistic regression models were used to study the association between the patient/center characteristics and the probability of receiving PD as the first dialysis modality.

RESULTS

We included 806 patients starting RRT in 177 centers, 23 of which were specialized pediatric centers. Six hundred and one patients (74.6 %) started with hemodialysis (HD), whereas 205 (25.4 %) started with PD. A greater probability of PD was found in younger children, whereas starting the treatment in an emergency setting was associated with a low use of PD. We found a significant variability among centers that accounted for 43 % of the total variability. The probability of PD was higher in adult centers and was proportional to the rate of PD in the center.

CONCLUSIONS

Center practices are a major factor in the choice of dialysis modality. This raises concerns about patient and family choices and to what extent doctors may influence the final decision. Further pediatric studies focusing on children's and parents' wishes are needed to provide care as close as possible to patients' and families' expectations.

Childhood Nephrotic Syndrome Management and Outcome: A Single Center Retrospective Analysis

There is a paucity of information on outpatient management and risk factors for hospitalization and complications in childhood nephrotic syndrome (NS). We described the management, patient adherence, and inpatient and outpatient usage of 87 pediatric NS patients diagnosed between 2006 and 2012 in the Atlanta Metropolitan Statistical Area. Multivariable analyses were performed to examine the associations between patient characteristics and disease outcome. We found that 51% of the patients were treated with two or more immunosuppressants. Approximately half of the patients were noted to be nonadherent to medications and urine protein monitoring. The majority (71%) of patients were hospitalized at least once, with a median rate of 0.5 hospitalizations per patient year. Mean hospital length of stay was 4.0 (3.8) days. Fourteen percent of patients experienced at least one serious disease complication. Black race, frequently relapsing/steroid-dependent and steroid-resistant disease, and the first year following diagnosis were associated with higher hospitalization rates. The presence of comorbidities was associated with longer hospital length of stay and increased risk of serious disease complications. Our results highlight the high morbidity and burden of NS and point to particular patient subgroups that may be at increased risk for poor outcome.

Chronic haemodialysis in small children: a retrospective study of the Italian Pediatric Dialysis Registry

BACKGROUND

Chronic haemodialysis (HD) in small children has not been adequately investigated.

METHODS

This was a retrospective investigation of the use of chronic HD in 21 children aged  <2 years (n = 12 aged <1 year) who were registered in the Italian Pediatric Dialysis Registry. Data collected over a period of >10 years were analysed.

RESULTS

The median age of the 21 children at start of HD was 11.4 [interquartile range (IQR) 6.2-14.6] months, and HD consisted mainly of haemodiafiltration for 3-4 h in  ≥4 sessions/week. A total of 51 central venous catheters were placed, and the median survival of tunnelled and temporary lines was 349 and 31 days, respectively (p  < 0.001). Eight children (38 %) showed evidence of central vein thrombosis. Although 19 % of patients received growth hormone and 63.6 % received enteral feeding, the weight and height of these patients remained suboptimal. During the HD period the haemoglobin level increased in all patients, but not to normal levels (from 8.5 to 9.6 g/dl) despite erythropoietin administration (503-600 U/kg/week). The hospitalisation rate was 1.94/patient-year. Seventeen patients underwent renal transplantation at a median age of 3.0 years. Four patients, all affected by severe comorbidities, died during follow-up (in 2 cases due to absence of a vascular access). The 5- and 10-year cumulative survival was 82.4 and 68.7 %, respectively.

CONCLUSIONS

Extracorporeal dialysis is feasible in children aged  <2 years, but comorbidities, vascular access, growth and anaemia remain major concerns.

Vitamin K antagonists in children with central venous catheter on chronic haemodialysis: a pilot study

BACKGROUND

To date, no study has investigated the use of vitamin K antagonists (VKA) in children undergoing chronic haemodialysis (HD) with a central venous catheter (CVC).

METHODS

Consecutive patients aged <18 years with a newly placed tunnelled CVC for chronic HD were enrolled over a 3-year period. Children with active nephrotic syndrome or a history of venous thrombosis received warfarin (VKA group) with therapeutic target international normalised ratios of between 2.0 and 3.0. Patients at standard risk of CVC malfunction were not treated with VKA (standard group). The primary end-point was overall CVC survival.

RESULTS

The VKA group consisted of nine patients (median age 10.6 years; range 1.2-15.3 years) with 11 CVC, and the standard group comprised eight patients (11.8 years; 6.1-17.3 years) with ten CVC. The 6- and 12-month CVC survival was significantly longer in the VKA group than in the standard group (100 vs. 60 % and 83.3 vs. 16.7 %, respectively; p < 0.05), with a median survival of 369 and 195 days, respectively (p < 0.05). None of the CVC in the VKA group required removal due to malfunction, as compared to four in the standard group. No major bleeding episodes occurred in either group.

CONCLUSIONS

Therapy with VKA would appear to be safe in children on chronic HD and may improve CVC survival in patients at increased risk of CVC thrombosis.

Impact of Pediatric Chronic Dialysis on Long-Term Patient Outcome: Single Center Study

Objective. Owing to a shortage of kidney donors in Israel, children with end-stage renal disease (ESRD) may stay on maintenance dialysis for a considerable time, placing them at a significant risk. The aim of this study was to understand the causes of mortality. Study Design. Clinical data were collected retrospectively from the files of children on chronic dialysis (>3 months) during the years 1995–2013 at a single pediatric medical center. Results. 110 patients were enrolled in the study. Mean age was 10.7 ± 5.27 yrs. (range: 1 month–24 yrs). Forty-five children (42%) had dysplastic kidneys and 19 (17.5%) had focal segmental glomerulosclerosis. Twenty-five (22.7%) received peritoneal dialysis, 59 (53.6%) hemodialysis, and 6 (23.6%) both modalities sequentially. Median dialysis duration was 1.46 years (range: 0.25–17.54 years). Mean follow-up was 13.5 ± 5.84 yrs. Seventy-nine patients (71.8%) underwent successful transplantation, 10 (11.2%) had graft failure, and 8 (7.3%) continued dialysis without transplantation. Twelve patients (10.9%) died: 8 of dialysis-associated complications and 4 of their primary illness. The 5-year survival rate was 84%: 90% for patients older than 5 years and 61% for younger patients. Conclusions. Chronic dialysis is a suitable temporary option for children awaiting renal transplantation. Although overall long-term survival rate is high, very young children are at high risk for life-threatening dialysis-associated complications.

Do children with end-stage renal disease live shorter? Analysis of mortality on the basis of data from the Polish Registry of Renal Replacement Therapy in Children

PURPOSE

The mortality of patients with end-stage renal disease (ESRD) is much higher than that of the general population. To date no data has been published on the mortality of children with ESRD in Poland. The aim of this study was to compare the risk of death for pediatric patients on renal replacement therapy (RRT) with that of the general pediatric population and to identify the risk factors of death.

MATERIAL/METHODS

Data of 779 children with ESRD registered in the Polish Registry of Children on RRT was analyzed. The relative risk of death was calculated as the ratio of the mortality rate in ESRD patients to the mortality rate in age-adjusted general population.

RESULTS

The mortality rate of children with ESRD was 74-fold higher than that of the age- and gender-adjusted general pediatric population (4.05 vs. 0.05/100 person-years). The highest mortality rate (4.53/100 patient-years) was found in the youngest age group. Younger age and duration of dialysis therapy were identified as mortality risk factors. The major causes of death in ESRD patients were infections and cardiovascular complications, whereas deaths in general child population were mainly due to accidents or congenital defects.

CONCLUSIONS

The mortality in Polish children with ESRD is 74-fold higher than that of the general pediatric population. Infections, followed by cardiovascular complications, constitute the main causes of mortality in children subjected to RRT. The risk of death is the highest among children who started RRT at a younger age and in those subjected to long-term dialysis treatment.

Mortality risk among children initially treated with dialysis for end-stage kidney disease, 1990-2010

IMPORTANCE

Most children with end-stage kidney disease (ESKD) are treated with dialysis prior to transplant. It is not known whether their outcomes have changed in recent years.

OBJECTIVE

To determine if all-cause, cardiovascular, and infection-related mortality rates for children and adolescents beginning dialysis improved between 1990 and 2010.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of patients younger than 21 years initially treated with dialysis for ESKD, recorded in the United States Renal Data System between 1990 and 2010. Children with a prior kidney transplant were excluded. We used Cox proportional hazard models to estimate the hazard ratios (HRs) for mortality associated with a 5-year increment in year of ESKD treatment initiation. Primary analyses censored observation at kidney transplant.

MAIN OUTCOMES AND MEASURES

All-cause, cardiovascular, and infection-related mortality.

RESULTS

A total of 3450 children younger than 5 years and 19,951 children 5 years or older started dialysis from 1990-2010. Of those younger than 5 years, 705 died during dialysis treatment (98.8/1000 person-years); mortality rates were 112.2 and 83.4 per 1000 person-years in those initiating dialysis in 1990-1994 and 2005-2010, respectively. Of those 5 years and older at treatment initiation, 2270 died during dialysis treatment (38.6/1000 person-years). Their mortality rates were 44.6 and 25.9 per 1000 person-years in those initiating dialysis in 1990-1994 and 2005-2010, respectively. Each 5-year increment in calendar year of dialysis initiation was associated with an adjusted HR of 0.80 (95% CI, 0.75-0.85) among children younger than 5 years at initiation and an HR of 0.88 (95% CI, 0.85-0.92) among those 5 years and older.

RESULTS

A total of 23,401 children and adolescents who initiated ESKD treatment with dialysis at younger than 21 years between 1990 and 2010 were identified. Crude mortality rates during dialysis treatment were higher among children younger than 5 years at the start of dialysis compared with those who were 5 years and older. Mortality rates for both children and adolescents being treated for ESKD with dialysis decreased significantly between 1990 and 2010.

CONCLUSIONS AND RELEVANCE

In the United States, there was a substantial decrease in mortality rates over time among children and adolescents initiating ESKD treatment with dialysis between 1990 and 2010. Further research is needed to determine the specific factors responsible for this decrease.

Prevalence and predictors of the sub-target Hb level in children on dialysis

BACKGROUND

Anaemia is a common and potentially treatable co-morbidity of end-stage renal disease. We aimed to determine the prevalence of the sub-target haemoglobin (Hb) level among European children on dialysis and to identify factors associated with a low Hb level.

METHODS

From the European Society for Paediatric Nephrology (ESPN)/European Renal Association-European Dialysis Transplant Association (ERA-EDTA) registry, data were available on 2351 children between 1 month and 18 years of age, totalling 5546 measurements from 19 countries.

RESULTS

The mean Hb level was 10.8 g/dL (5th-95th percentiles, 7.4-13.9). Among those above 2 years of age, the mean Hb level was 10.9 g/dL (11.4% below 8.5 g/dL), while it was 10.3 g/dL among those below 2 years (11.2% below 8.0 g/dL). A total of 91.2% of the patients were on an erythropoiesis-stimulating agent (ESA). Hb levels increased with age and were higher in peritoneal dialysis compared with haemodialysis patients. Patients with congenital anomalies of the kidney and urinary tract showed the highest Hb levels, and those with cystic kidney diseases or metabolic disorders the lowest ones. Ferritin levels between 25 and 50 ng/mL were associated with the highest Hb levels. We found a weak inverse association between parathyroid hormone (PTH) and Hb. Whereas standardized blood pressure (BP) was not elevated in patients with above-target Hb, elevated systolic BP z-score was noted in those with sub-target Hb levels.

CONCLUSIONS

Sub-target Hb levels remain common in children on dialysis, in spite of virtually all children being treated with ESA; although we cannot exclude under-dosing. Optimal ferritin levels seemed to be slightly lower in children (25-50 ng/mL) than those in adults. Other risk factors for sub-target Hb are dialysis modality and a high PTH level.

Vascular access: choice and complications in European paediatric haemodialysis units

BACKGROUND

European and U.S. guidelines emphasise that permanent vascular access in the form of arteriovenous fistulae (AVF) or grafts (AVG) are preferable to central venous catheters (CVC) in paediatric patients on long-term haemodialysis. We report vascular access choice and complication rates in 13 European paediatric nephrology units.

METHODS

A survey of units participating in the European Pediatric Dialysis Working Group requesting data on type of vascular access, routine care and complications in patients on chronic haemodialysis between March 2010 and February 2011.

RESULTS

Information was complied on 111 patients in 13 participating centres with a median age of 14 (range 0.25-20.2) years. Central venous catheters were used in 67 of 111 (60%) patients, with 42 patients (38%) having an AVF and two patients (2%) having an AVG. Choice of vascular access was significantly related to patient age, with patients with AVF/AVG having a median age of 16 years compared to 12 years for patients with CVCs (p < 0.001). Routine CVC exit site care and catheter lock solution use differed between centres. CVC infections requiring intravenous antibiotics were reported at a rate of 1.9 and exit site infections at a rate of 1.8 episodes/1000 catheter days. Overall infective complications necessitating CVC change occurred at a rate of 0.9 episodes/1000 catheter days. No infective complications were reported in patients with AVF/AVG access. The rate of CVC infections requiring intravenous antibiotics was significantly lower in patients in whom CVC exit sites were cleaned weekly as opposed to every dialysis session (relative risk with every session cleaning vs. weekly cleaning 2.58, 95% confidence interval 1.17-5.69). Catheter malfunction (inadequate blood flow) was a more prevalent complication necessitating 22.4 thrombolytic interventions/1000 catheter days and 2.1 CVC changes/1000 catheter days.

CONCLUSIONS

Central venous catheters remain the predominant choice of vascular access in Europe despite problems of malfunction and infection. AVF/AVG were predominantly used in adolescents without reported complications. More regular exit site cleaning may predispose to CVC infection, but this observation requires prospective evaluation.

Racial disparities in access to pediatric kidney transplantation since share 35

Share 35 was enacted in 2005 to shorten transplant wait times and provide high-quality donors to children with ESRD. To investigate the possible effect of this policy on racial disparities in access to pediatric transplantation, we analyzed data from the US Renal Data System before and after Share 35. Among 4766 pediatric patients with incident ESRD, the probability of receiving a deceased-donor kidney transplant increased 46% after Share 35, with Hispanics experiencing the greatest improvements (increases of 81% for Hispanics, 45% for blacks, and 37% for whites). On average, patients received a deceased-donor kidney transplant earlier after Share 35, but this finding varied by race: 63 days earlier for whites, 90 days earlier for blacks, and 201 days earlier for Hispanics. Furthermore, a shift from living- to deceased-donor sources occurred with Share 35 for all races, with a 25% reduction in living donors for whites compared with 48% and 46% reductions for Hispanics and blacks, respectively. In summary, Share 35 seems to have attenuated racial disparities in the time to and probability of children receiving a deceased-donor kidney transplant. These changes coincided with changes in the rates of living-donor sources, which vary by race. Future studies should explore how these changes may impact racial differences in long-term graft outcomes.

[Pediatric renal transplantation in France. Introduction]

Pediatric nephrology is a relatively recent medical speciality. The first French center opened in January 1969 at the Hospital des Enfants-Malades. In 2008, according to the Réseau Épidémiologie et Information en Néphrologie (REIN), the annual incidence of end stage renal disease (ESRD) was of 7,8 children/million children below the age of 20, which equals a prevalence of 49 pediatric ESRD patients/million inhabitants. The frequency of causative factors of ESRD varies according to the geographic and ethnic origin of the patients. Many challenges still lay ahead of ESRD management. The children's physical, psychological and social development has to be well taken care of until adulthood and the transition from pediatric to adult unit has to be handled with special care. The set up of pediatric nephrology departments helped to the access of patients to renal replacement therapy, in particular the pediatric priority for kidney donors below 30 years of age. In the 2000s period, the annual rate of pediatric renal transplantation was 70 to 75 grafts per year in France, half of which performed in the Paris area. This article presents the historical background of pediatric nephrology and pediatric renal transplantation in France.

Peritoneal dialysis in infants and young children

Although end-stage renal disease is rare in infants and young children, its development can be associated with significant morbidity and mortality and only through the provision of experienced, multidisciplinary care can a favorable outcome be anticipated. Peritoneal dialysis is the renal replacement modality of choice for this age group and serves as an essential bridge until successful renal transplantation can occur. In this review, we discuss the practice of peritoneal dialysis in infants including the unique ethical and technical considerations facing pediatric nephrologists and caregivers. In addition, we review current guidelines concerning nutrition, growth, and adequacy, as well as the literature on complications and outcomes.

Predictors and consequences of higher estimated glomerular filtration rate at dialysis initiation

There have been no studies in pediatric dialysis patients to evaluate the impact of higher estimated glomerular filtration rate (eGFR) at dialysis initiation on clinical outcomes. Baseline clinical and demographic information was collected for children aged 1-18 years undergoing incident dialysis from 1995-2002 within the United States Renal Data System. Baseline eGFRs calculated by the Schwartz formula were categorized as high (>15 ml/min/1.73 m(2)) or low (< or = 15 ml/min/1.73 m(2)). We determined predictors of eGFR at baseline, and associations between baseline eGFR and subsequent hospitalization for hypertension (HTN) or pulmonary edema (PE) in a longitudinal nonconcurrent pediatric end-stage renal disease (ESRD) cohort. Twenty percent of children had a high eGFR at initiation. Black children were less likely to initiate dialysis with a high eGFR [adjusted odds ratio (adjOR) 0.71, p < 0.001]. Girls were less likely to have a high eGFR at baseline (adjOR 0.71, p < 0.001). Children who received predialysis erythropoietin therapy were more likely to start dialysis with a high eGFR (adjOR 6.67, p < 0.001). Children with higher baseline eGFR were found to have a 21% decreased risk of hospitalization [adjusted hazard ratio (HR) 0.79, 95% confidence interval (CI) 0.65-0.96, p = 0.02]. It is not known whether this clinical benefit will result in decreased mortality and complication rates from cardiovascular disease.

Determinants of eGFR at start of renal replacement therapy in paediatric patients

BACKGROUND

Few studies have investigated the determinants of glomerular filtration rate (GFR) in paediatric patients starting on dialysis or with a transplant.

METHODS

Data were collected as part of the European Society of Paediatric Nephrology/European Renal Association-European Dialysis and Transplant Association registry from 14 European countries and referred to incident paediatric patients starting on renal replacement therapy (RRT) between 2002 and 2007 under the age of 18 years. Estimated glomerular filtration rate (eGFR) was calculated using the Schwartz formula. Data were adjusted for age, gender, treatment modality at start, primary cause of renal failure (PRD) and regions in Europe (eGFR(adj)).

RESULTS

Median eGFR in the 938 patients starting RRT was 10.4 mL/min/1.73 m(2) (5th and 95th percentile: 4.0-26.9). Twenty-six patients (2.8%), mainly infants with Finnish-type nephropathy, started with eGFR levels >50 mL/min/1.73 m(2). Younger age, female gender, starting on dialysis and having a short time between the first visit to a paediatric nephrologist (PN) and start of RRT were associated with lower eGFR at start of RRT. Gender differences were only present during adolescent age and disappeared when using the same K value for both genders. The various PRDs showed large differences in the rate of decline in eGFR between the first visit to a PN and start of RRT; however, this did not result in differences in eGFR(adj) at start of RRT.

CONCLUSIONS

The main determinants of eGFR at start of RRT were age, gender, treatment modality at start, and the time between the first visit to a PN and start of RRT. Research is needed to determine the consequences of these differences.

Interventions for bone disease in children with chronic kidney disease

BACKGROUND

Bone disease is common in children with chronic kidney disease (CKD) and when untreated may result in bone deformities, bone pain, fractures and reduced growth rates.

OBJECTIVES

To investigate the benefits and harms of interventions for preventing and treating bone disease in children with CKD.

SEARCH STRATEGY

The Cochrane Renal Group's specialised register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, reference lists and abstracts were searched without language restriction.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing different interventions used to prevent or treat bone disease in children with CKD stages 2-5D compared with placebo, no treatment or other agents were included. Studies examining different routes or frequency of treatment were also included.

DATA COLLECTION AND ANALYSIS

Data were extracted by two authors. The random-effects model was used and results were reported as risk ratios or risk differences for dichotomous outcomes and mean differences for continuous outcomes with 95% confidence intervals.

MAIN RESULTS

Fifteen RCTs (369 children) were identified. Compared with oral calcitriol, intraperitoneal calcitriol significantly reduced the level of serum parathyroid hormone (PTH) but there were no significant differences in bone histology or other biochemical measures (2 RCTs). There were no significant differences detected in growth, PTH, serum calcium or phosphorus between daily versus intermittent calcitriol (3 RCTs). Vitamin D therapy significantly reduced PTH levels compared with placebo or no treatment. The number of children with hypercalcaemia did not differ significantly between groups (4 RCTs). No significant differences were detected in growth rates, bone histology or biochemical parameters between calcitriol and either dihydrotachysterol or ergocalciferol (2 RCTs). Though fewer episodes of hypercalcaemia were reported with sevelamer, no significant differences were detected in serum calcium, phosphorus and PTH levels between calcium-containing phosphate binders and either aluminium hydroxide or sevelamer (4 RCTs).

AUTHORS' CONCLUSIONS

Bone disease, assessed by changes in PTH levels, is improved by all vitamin D preparations. However no consistent differences between routes of administration, frequencies of dosing or vitamin D preparations have been demonstrated. Though fewer episodes of high calcium levels occurred with the non calcium-containing binder, sevelamer, compared with calcium-containing binders, there were no differences in serum phosphorus and calcium overall and phosphorus values were reduced to similar extents. All RCTs were small with few data available on patient-centred outcomes (growth, bone deformities) and limited data on biochemical parameters resulting in considerable imprecision of results thus limiting the applicability to care of children with CKD.

Renal replacement therapy in infants with chronic renal failure in the first year of life

BACKGROUND AND OBJECTIVES

Although results of renal replacement therapy (RRT) in small children have improved during recent years, data about RRT in neonates are scarce.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a retrospective study, we analyzed the outcome of infants who had chronic kidney disease and started RRT within their first year of life. Between 1997 and 2008, all 29 infants who were younger than 1 yr, had end-stage renal failure, and underwent RRT (dialysis or transplantation) at Hannover Medical School were analyzed for up to 12 yr.

RESULTS

Twenty-seven of 29 infants with chronic kidney disease received peritoneal dialysis, starting at a mean age of 112 d; two children received preemptive renal transplantation (RTx). During follow-up, 21 of 29 children survived with RTx. The 5-yr patient and graft survival rate after RTx was 95.5%. Six of 29 children died, one with a functioning graft and five while on peritoneal dialysis. The main causes of death were severe cardiovascular and cerebral comorbidities. The mean GFR at last follow-up of patients who underwent RTx (mean time after RTx 5.1 yr) was 63.2 ml/min per 1.73 m(2).

CONCLUSIONS

RRT in infants who are younger than 1 year offers excellent chances of survival and should be offered to all infants who do not have severe, life-limiting extrarenal comorbidity. Contrary to previous observations, the long-term outcome of infants may be comparable to that of older children who undergo RRT.

Twenty-five years of infant dialysis: a single center experience

OBJECTIVE

To perform a retrospective analysis of the long-term outcome of infants with end-stage kidney disease (ESKD) treated at our center during the past 25 years.

STUDY DESIGN

The total cohort (n = 52) was divided into era 1 (1983-1995; n = 23) and era 2 (1996-2008; n = 29). Dialysis morbidity, transplantation, and long-term survival rates were assessed and compared between the 2 eras.

RESULTS

Average age at initiation of dialysis was 4.4 +/- 5.3 months (range, 0.5-18 months), with 96% begun on peritoneal dialysis. The predominant diagnoses were dysplasia/obstructive uropathy and autosomal recessive polycystic kidney disease. The overall survival rate is 46%, with current age of survivors ranging from 1.5 to 25 years. Mortality rates in the 2 eras were not significantly different. The predominant mortality occurred within the first year. Twenty-four patients received an initial renal transplant at 2.6 +/- 1.7 years of age. Six patients (25%) required a second renal allograft. Increased risk for mortality included African-American ethnicity, oligoanuria, autosomal recessive polycystic kidney disease, and co-morbid diagnoses.

CONCLUSIONS

Long-term survival is possible in infants with ESKD, although mortality and morbidity remain high. Technical innovations are needed to accommodate smaller infants undergoing dialysis. Early initiation of dialysis treatment is preferable because prognostic indicators remain poorly defined.

Long-term outcome of chronic dialysis in children

As the prevalence of children on renal replacement therapy (RRT) increases world wide and such therapy comprises at least 2% of any national dialysis or transplant programme, it is essential that paediatric nephrologists are able to advise families on the possible outcome for their child on dialysis. Most children start dialysis with the expectation that successful renal transplantation is an achievable goal and will provide the best survival and quality of life. However, some will require long-term dialysis or may return intermittently to dialysis during the course of their chronic kidney disease (CKD). This article reviews the available outcome data for children on chronic dialysis as well as extrapolating data from the larger adult dialysis experience to inform our paediatric practice. The multiple factors that may influence outcome, and, particularly, those that can potentially be modified, are discussed.

Survival advantage of pediatric recipients of a first kidney transplant among children awaiting kidney transplantation

The mortality rate in children with ESRD is substantially lower than the rate experienced by adults. However, the risk of death while awaiting kidney transplantation and the impact of transplantation on long-term survival has not been well characterized in the pediatric population. We performed a longitudinal study of 5961 patients under age 19 who were placed on the kidney transplant waiting list in the United States. Of these, 5270 received their first kidney transplant between 1990 and 2003. Survival was assessed via a time-varying nonproportional hazards model adjusted for potential confounders. Transplanted children had a lower mortality rate (13.1 deaths/1000 patient-years) compared to patients on the waiting list (17.6 deaths/1000 patient-years). Within the first 6 months of transplant, there was no significant excess in mortality compared to patients remaining on the waiting list (adjusted Relative Risk (aRR) = 1.01; p = 0.93). After 6 months, the risk of death was significantly lower: at 6-12 months (aRR = 0.37; p < 0.001) and at 30 months (aRR 0.26; p < 0.001). Compared to children who remain on the kidney transplant waiting list, those who receive a transplant have a long-term survival advantage. With the potential for unmeasured bias in this observational data, the results of the analysis should be interpreted conservatively.

Challenges in pediatric peritoneal dialysis in Turkey

Chronic peritoneal dialysis (CPD) is the modality of choice for children with end-stage renal disease in Turkey. CPD was first instituted in 1989 in Turkish pediatric patients by using imported basic equipment and solutions since then the number of patients on CPD increased gradually. Parallel to the developments in the PD industry, in 2002, the Turkish Pediatric Nephrology Association established the Turkish Pediatric Peritoneal Dialysis (TUPEPD) Study Group to study peritoneal dialysis in children and adolescents. Today in Turkey, almost all of the PD equipment and PD solutions are available. Turkish pediatric nephrologists now have a significant experience with PD. Physicians, parents, and the children prefer to start with CPD because of its advantages, such as a more liberal social life and better school attendance.

Central venous lines for chronic hemodialysis: survey of the Midwest Pediatric Nephrology Consortium

Central venous lines (CVL) continue to be the most commonly used vascular access device for children on hemodialysis (HD). Despite their frequent use, little is known regarding the frequency of CVL-related intradialytic complications that could interfere with delivery of effective dialysis. To better assess this, we conducted a cross-sectional study of ten HD centers within the Midwest Pediatric Nephrology Consortium. Vascular access was provided by CVL in 61 of the 83 patients (73%) included. CVL dysfunction (defined as reduced blood flows, need for reversed lines, or frequent intradialytic alarms) occurred in 46% in the prior month. Treatment for suspected clots occurred in 16 patients. Intraluminal tissue plasminogen activator (tPA) was the preferred treatment for a suspected clot. The survey also inquired about the preferred treatment for documented clots, and intraluminal tPA was most preferred, followed by CVL stripping, CVL removal, CVL brushing, and systemic tPA. As for preventative strategies, most HD centers locked the CVL with intraluminal heparin in concentrations ranging from 1,000 to 5,000 U/ml. In conclusion, catheter usage rates and complications were highly prevalent in pediatric HD units in this study. As treatment strategies varied greatly, future prospective studies are needed to determine the effectiveness of each individual therapy.

Hemodialysis in children weighing less than 15 kg: a single-center experience

Despite significant technical improvements, hemodialysis in infants with end-stage renal disease (ESRD) is still associated with significant morbidity and mortality. The files of patients weighing less than 15 kg with ESRD who were treated with hemodialysis at our institute between 1995 and 2005 were reviewed for background and treatment characteristics, morbidity and outcome. The study group included 11 patients aged 7-75 months (mean 34.2 months) weighing 7.2-14.9 kg (mean 10.9 kg). Mean duration of dialysis was 11.3 months. Vascular access posed the major problem. Ten patients were dialyzed through a central venous cuffed catheter and one through an arteriovenous fistula. An average of three different vascular accesses was required per patient (range 1-9). Mechanical difficulties were the most common cause of central-line removal (56.5%), followed by infections (15.6%). Major complications causing significant morbidity were intradialytic hemodynamic instability, hyperkalemia, coagulation within the dialysis set, anemia, hypertension, inadequate fluid removal, and recurrent hospitalizations. Analysis of outcome revealed that eight patients underwent successful transplantation, one returned for hemodialysis after 4.5 years due to graft failure, and two died. Hemodialysis is a suitable option for low-weight pediatric patients with ESRD awaiting transplantation when performed in highly qualified centers.

Validation of child serum creatinine-based prediction equations for glomerular filtration rate

Equations for estimating glomerular filtration rate (GFR) are vital in caring for patients with renal disease and the current standard, the Schwartz formula, lacks precision. We evaluated several child serum creatinine-based GFR prediction equations. Subjects aged 2-21 years who underwent iothalamate GFR (IoGFR) testing between 1999 and 2004 were studied retrospectively. GFR was estimated using: (1) Schwartz formula (SchwartzGFR), using a local k value; (2) Schwartz model (SchwartzMod) using regression-derived coefficients; (3) Leger GFR (LegerGFR) using original coefficients; and (4) Leger model (LegerMod) using regression-derived coefficients. Bias, precision, and diagnostic characteristics were evaluated. There were 195 subjects [61% male; mean (SD) age 12.4 (4.5) years; mean (SD) IoGFR 78.9 (33.4) ml/min per 1.73 m(2)]. Only the LegerGFR overestimated IoGFR (5.5 ml/min per 1.73 m(2)). Precision for all formulae was poor (95% limits of agreement approximately -40 to 40 ml/min per 1.73 m(2)), but >or=72% of estimates were within 30% of IoGFR. Sensitivities for detecting IoGFR <30 and 90 ml/min per 1.73 m(2) were highest using the SchwartzGFR (80%) and SchwartzMod (90%), respectively. The LegerGFR was most specific. Using local coefficients, the Schwartz and Leger models were imprecise estimates of GFR, but the Schwartz model was most unbiased and sensitive. Future research should derive more precise equations for GFR in children.

Vascular Access in Children: The Importance of Microsurgery for Creation of Autologous Arteriovenous Fistulae

Microsurgery gives much better immediate and long term results than classical surgery for the creation of direct arteriovenous fistulae, the best chronic access to blood in children.

Peritoneal dialysis in infants

The need for maintenance dialysis for infants is rare, but peritoneal dialysis has been the modality of choice in cases of end-stage renal failure, for technical reasons. Problems include higher mortality rates and an inferior long-term outcome compared with that in older children. Also, no internationally accepted guidelines exist for dialysis in infants. Many children on maintenance peritoneal dialysis in Finland have congenital nephrotic syndrome of the Finnish type (NPHS1), and dialysis is started during infancy. In this commentary we discuss our practice of performing peritoneal dialysis in infants and experiences gathered from the literature.

Sodium ferric gluconate complex maintenance therapy in children on hemodialysis

Intravenous iron therapy is recommended for children and adults who receive hemodialysis (HD) and recombinant human erythropoietin (rHuEPO). However, limited information exists on the use of any maintenance IV iron regimen in children. Therefore, we conducted a prospective, multicenter, open-label trial of maintenance therapy with sodium ferric gluconate complex (SFGC) in iron-replete pediatric HD patients receiving rHuEPO. Patients received SFGC weekly at an initial dose of 1.0 mg kg(-1) week(-1), not to exceed 125 mg. Doses could be adjusted based on iron indices. Twenty-three patients (mean age: 13.2+/-2.39 years) were enrolled and received at least one dose of SFGC, while twelve patients completed the study. After 12 weeks of treatment, the mean SFGC dose delivered was 1.0 mg/kg. Mean TSAT and serum ferritin levels remained within NKF-K/DOQI target ranges and the mean Hgb level remained unchanged from baseline. No unexpected or unusual safety risks were associated with SFGC use. In summary, this experience provides evidence for the safety and efficacy of intravenous SFGC and supports the recommendation that the maintenance SFGC starting dose should be 1.0 mg/kg, not to exceed 125 mg, with subsequent adjustments made according to TSAT and/or serum ferritin levels.

Glycation free adduct accumulation in renal disease: the new AGE

Glycation adducts formed in the later stages of protein glycation reactions, advanced glycation endproducts (AGEs), are a class of uraemic toxin. Protein glycation was viewed originally as a post-translational modification that accumulated mostly on extracellular proteins. We now know that AGE residues are also formed on short-lived cellular and extracellular proteins. Cellular proteolysis forms AGE free adducts from these proteins, which are released into plasma for urinary excretion. AGE free adducts are also absorbed from food. AGE free adducts are the major molecular form by which AGEs are excreted in urine. They normally have high renal clearance, but this declines markedly in chronic renal failure patients, leading to profound increases in plasma AGE free adducts. Accumulation of plasma AGE free adducts is increased further in end stage renal disease patients on peritoneal dialysis and haemodialysis by increased AGE formation. The impact of AGEs absorbed from food is probably most marked for undialysed patients with mild uraemia. The toxicity of AGEs has been associated with resistance of the extracellular matrix to proteolysis and AGE receptor-mediated responses. AGE free adducts may also contribute to vascular disease in uraemia. They represent an important new age for glycation research in nephrology.

Risk factors for peritonitis in pediatric peritoneal dialysis: a single-center study

Recent US registry data and a European multicenter study described increased risk of peritonitis in young children on peritoneal dialysis (PD). No underlying age-specific risk factors could be defined in these reports. Therefore, we analyzed risk factors for peritonitis in children treated by PD as primary renal replacement therapy at the Kinderdialyse, Vienna, and particularly searched for age-specific aspects. Thirty children (15 boys, mean age 4.6 years) received PD [21 automated peritoneal dialysis (APD), nine continuous ambulatory peritoneal dialysis (CAPD)] for 13 months (3-49 months). During the total observation period of 395 dialysis months, 27 peritonitis episodes were diagnosed (1:14.6 months or 0.82/patient per year). Of our population, 43% remained peritonitis free; seven patients suffered from more than one peritonitis episode. Ten potential risk factors [age, gender, PD modality, duration of PD, exit-site status, urine volume, residual glomerular filtration rate (GFR), Kt/V, normalized protein catabolic rate (nPCR), albumin] and four indices of peritonitis outcome (peritonitis incidence, peritonitis burden, risk of suffering more than one episode of peritonitis and chance of staying free from peritonitis) were analyzed. Our study identified six risk factors in univariate analysis, namely age, APD treatment, exit-site infections, low urinary volume, low residual GFR and low nPCR, which were significantly correlated with two or more of the outcome indices. Multivariate analysis identified exit-site infection and residual urine volume as strong independent predictors. In summary, our study identified several age-dependent and age-independent risk factors for peritonitis in pediatric PD. These data demonstrate that the risk for peritonitis in small children is not pre-determined but might be open to therapeutic interventions, such as optimizing exit-site care, dialysis prescription and nutrition management.

Home nocturnal hemodialysis in children

OBJECTIVE

To describe the effect of home nocturnal hemodialysis (NHD) in North American children.

STUDY DESIGN

Four teenagers underwent NHD for 8 hours, 6 to 7 nights/week, using either central venous lines or fistulae for periods of 6 to 12 months. Blood flow approximated 200 mL/min, and dialysate flow was 300 mL/min; the dialysate contained potassium and phosphate. The procedure was remotely monitored.

RESULTS

The children had unrestricted diets and fluid allowance and did not require phosphate binders. Persistent relative hypotension developed in 2 of 4 children. Weekly Kt/V urea values were consistently >10; other biochemical measures varied. Quality of life and school attendance improved in 3 of 4 children. The workload and reported emotional burden of NHD was substantial. No significant complications occurred. Dialysate losses of calcium, phosphate and carnitine required supplementation. The annual cost per patient was dollar 64,000 Canadian, which represented a 27% savings compared with thrice weekly in-center hemodialysis.

CONCLUSIONS

NHD is feasible in selected children, allows free dietary and fluid intake, and improves patient wellbeing. The burden on the family is substantial, and NHD requires support of a dedicated multidisciplinary team.

Chronic peritoneal dialysis in Turkish children: a multicenter study

Chronic peritoneal dialysis (CPD) has been utilized in the treatment of children since 1989 in Turkey. The aims of this study were to summarize our experience with CPD in children and to establish a pediatric registry data system in Turkey. Standard questionnaires were sent to all pediatric CPD centers. 514 patients treated between 1989 and 2002 in 12 pediatric centers were enrolled in the study. Reflux nephropathy was the most common (18.1%) cause of renal failure. Mean age at dialysis initiation was 10.1+/-4.6 years. Mean duration of dialysis was 24.1+/-20.5 months. Continuous ambulatory peritoneal dialysis (CAPD) was the first CPD modality for 476 (92.6%) patients, 142 of whom switched to automated peritoneal dialysis (APD) during follow-up. Currently, 47.3% of the patients are still on CPD, 15.4% were transplanted, 13.2% switched to hemodialysis, 16.7% died. The patient and technique survivals were 90% and 95% at one year and 70% and 69% at five years, respectively. The survival was significantly shorter in the youngest age group (0-24 months) compared to those in older age groups (p=0.000). We herein report the first results of the TUPEPD study providing information on demographic data and survival of pediatric CPD patients. As opposed to clear recommendations in favor of APD, there is a clear preponderance of CAPD in our pediatric CPD population. That vesicoureteral reflux (VUR) is still the leading cause of renal failure is a distressing finding. Remarkably lower survival rates and transplantation ratios are as striking and distressing as the high incidence of VUR among the causes of ESRD. We conclude that we must make a great effort to achieve better results and to change these undesirable events.

Continuous Hemodiafiltration in Pediatric Critical Care Patients

Continuous hemodiafiltration (CHDF) is an essential procedure in critical care. However, application of this therapy to pediatric patients is associated with several problems derived from their smaller body size and weight compared with adults. We have successfully conducted CHDF in pediatric patients including newborns by taking such problems into consideration and carefully coping with them. The present study consisted of 60 pediatric patients treated with CHDF. Clinical efficacy and safety of CHDF in pediatric patients were assessed in these patients by reviewing patient clinical records. The 60 patients treated with CHDF included 27 males and 33 females. Their body weight ranged from 700 g to 53.0 kg. The mean CHDF duration was 6.80 +/- 6.94 days. Blood access was provided in a veno-venous mode in 42 patients, and an arterio-venous mode in 18 patients. Of the 60 pediatric patients receiving CHDF, 31 patients survived without serious complications, achieving a survival rate of 51.7%. Successful CHDF in pediatric patients was achieved by careful and exact execution of the following countermeasures to overcome problems specific to application of this therapy to pediatric patients: minimization of the priming volume; use of colloid solutions or whole blood as priming solution; maintaining secure blood access; selection of an appropriate anticoagulant; temperature control of both the patient's body and components of the hemofiltration circuit. In pediatric critical care, CHDF is safely applicable to the critically ill and expected to produce a wide spectrum of clinical efficacy just as in adults.

Effect of Adventitial Dissection in Brachiobasilic Arteriovenous Fistulae Opened in Children as Vascular Access for Hemodialysis on Patency and Maturation of Fistulae

Background

Recently, therapy of pediatric patients with chronic renal failure has been carried out using hemodialysis, peritoneal dialysis, or renal transplant. In this study, we prospectively investigated the role of adventitial dissection (performed on brachiobasilic arteriovenous fistulae in the antecubital area) in the patency rate, maturation, and early initiation of dialysis among pediatric cases undergoing chronic hemodialysis.

Methods

Thirty children (7 male and 23 females) were included in this study. They were operated on at the Department of Cardiovascular Surgery of Alsancak State Hospital and Dokuz Eylul University between March 2001 and June 2003. Their mean age was 12.3 ± 2.9 years (range 7–17 years), and their mean weight was 25.5 ± 7.9 kg (range 16–44 kg). Children who underwent only brachiobasilic arteriovenous fistula operation were included. Group 1 ( n = 15) consisted of those who underwent adventitial dissection, and group 2 ( n = 15) consisted of those not receiving the adventitial dissection procedure.

Results

The procedure was conducted by the same surgeon, and follow-up examinations were done at the Department of Pediatric Nephrology by investigators masked to treatment groups.

Conclusion

There were no significant differences in age, sex, existence of preoperative hypertension, diameter of vein measured preoperatively, and first day of dialysis between the groups. In 29 cases, a palpable thrill was noted at the operation site. Hemodialysis had been initiated after the fourth week, when the fistulae had matured. The mean duration of follow-up was 12.53 ± 8.98 months in group 1 and 11.85 ± 7.55 months in group 2 ( p = .880). In group 1, one case developed fistula infection in the second month and one case developed lymphatic drainage. In group 2, one case developed early thrombosis, one case developed hematoma, and one case developed transient ischemia owing to arterial spasm in the ipsilateral limb. One case in each group developed minimal edema in the forearm, which was treated conservatively. The primary patency rate was 93.3% in both groups, whereas the secondary patency rate was 100% in group 1. Adventitial dissection performed on the vein during arteriovenous fistula formation does not result in any additional benefit with respect to fistula maturation, early initiation of dialysis, and patency. Among pediatric patients with chronic renal failure, in cases of inappropriate forearm veins, brachial arteriovenous fistulae performed with a meticulous surgical technique should be the procedure of choice because it is associated with minimal complications and a high patency rate.