Growth in children on kidney replacement therapy: a review of data from patient registries.

Growth retardation is a major complication in children with chronic kidney disease (CKD) and on kidney replacement therapy (KRT). Conversely, better growth in childhood CKD is associated with an improvement in several hard morbidity-mortality endpoints. Data from pediatric international registries has demonstrated that improvements in the overall conservative management of CKD, the search for optimal dialysis, and advances in immunosuppression and kidney transplant techniques have led to a significant improvement of final height over time. Infancy still remains a critical period for adequate linear growth, and the loss of stature during the first years of life influences final height. Preliminary new original data from the European Society for Paediatric Nephrology/European Renal Association-European Dialysis and Transplant Association (ESPN/ERA-EDTA) Registry confirm an association between the final height and the height attained at 2 years in children on KRT.

Ten-year trends in epidemiology and outcomes of pediatric kidney replacement therapy in Europe: data from the ESPN/ERA-EDTA Registry.

BACKGROUND: For 10 consecutive years, the ESPN/ERA-EDTA Registry has included data on children with stage 5 chronic kidney disease (CKD 5) receiving kidney replacement therapy (KRT) in Europe. We examined trends in incidence and prevalence of KRT and patient survival. METHODS: We included all children aged <15 years starting KRT 2007-2016 in 22 European countries participating in the ESPN/ERA-EDTA Registry since 2007. General population statistics were derived from Eurostat. Incidence and prevalence were expressed per million age-related population (pmarp) and time trends studied with JoinPoint regression. We analyzed survival trends using Cox regression. RESULTS: Incidence of children commencing KRT <15 years remained stable over the study period, varying between 5.5 and 6.6 pmarp. Incidence by treatment modality was unchanged over time: 2.0 for hemodialysis (HD) and peritoneal dialysis (PD) and 1.0 for transplantation. Prevalence increased in all age categories and overall rose 2% annually from 26.4 pmarp in 2007 to 32.1 pmarp in 2016. Kidney transplantation prevalence increased 5.1% annually 2007-2009, followed by 1.5% increase/year until 2016. Prevalence of PD steadily increased 1.4% per year over the entire period, and HD prevalence started increasing 6.1% per year from 2011 onwards. Five-year unadjusted patient survival on KRT was around 94% and similar for those initiating KRT 2007-2009 or 2010-2012 (adjusted HR: 0.98, 95% CI:0.71-1.35). CONCLUSIONS: We found a stable incidence and increasing prevalence of European children on KRT 2007-2016. Five-year patient survival was good and was unchanged over time. These data can inform patients and healthcare providers and aid health policy makers on future resource planning of pediatric KRT in Europe.

Outcomes of renal replacement therapy in boys with prune belly syndrome: findings from the ESPN/ERA-EDTA Registry.

BACKGROUND: As outcome data for prune belly syndrome (PBS) complicated by end-stage renal disease are scarce, we analyzed characteristics and outcomes of children with PBS using the European Society for Pediatric Nephrology/European Renal Association-European Dialysis and Transplant Association (ESPN/ERA-EDTA) Registry data. METHODS: Data were available for 88 male PBS patients aged <20 years who started renal replacement therapy (RRT) between 1990 and 2013 in 35 European countries. Patient characteristics, survival, and transplantation outcomes were compared with those of male patients requiring RRT due to congenital obstructive uropathy (COU) and renal hypoplasia or dysplasia (RHD). RESULTS: Median age at onset of RRT in PBS was lower [7.0; interquartile range (IQR) 0.9-12.2 years] than in COU (9.6; IQR: 3.0-14.1 years) and RHD (9.4; IQR: 2.7-14.2 years). Unadjusted 10-year patient survival was 85% for PBS, 94% for COU, and 91% for RHD. After adjustment for country, period, and age, PBS mortality was similar to that of RHD but higher compared with COU [hazard ratio (HR) 1.96, 95% confidence interval (CI) 1.03-3.74]. Seventy-four PBS patients (84%) received a first kidney transplant after a median time on dialysis of 8.4 (IQR 0.0-21.1) months. Outcomes with respect to time on dialysis before transplantation, chance of receiving a first transplant within 2 years after commencing RRT, and death-censored, adjusted risk of graft loss were similar for all groups. CONCLUSIONS: This study in the largest cohort of male patients with PBS receiving RRT to date demonstrates that outcomes are comparable with other congenital anomalies of the kidney and urinary tract, except for a slightly higher mortality risk compared with patients with COU.

Mortality risk disparities in children receiving chronic renal replacement therapy for the treatment of end-stage renal disease across Europe: an ESPN-ERA/EDTA registry analysis.

BACKGROUND: We explored the variation in country mortality rates in the paediatric population receiving renal replacement therapy across Europe, and estimated how much of this variation could be explained by patient-level and country-level factors. METHODS: In this registry analysis, we extracted patient data from the European Society for Paediatric Nephrology/European Renal Association-European Dialysis and Transplant Association (ESPN/ERA-EDTA) Registry for 32 European countries. We included incident patients younger than 19 years receiving renal replacement therapy. Adjusted hazard ratios (aHR) and the explained variation were modelled for patient-level and country-level factors with multilevel Cox regression. The primary outcome studied was all-cause mortality while on renal replacement therapy. FINDINGS: Between Jan 1, 2000, and Dec 31, 2013, the overall 5 year renal replacement therapy mortality rate was 15·8 deaths per 1000 patient-years (IQR 6·4-16·4). France had a mortality rate (9·2) of more than 3 SDs better, and Russia (35·2), Poland (39·9), Romania (47·4), and Bulgaria (68·6) had mortality rates more than 3 SDs worse than the European average. Public health expenditure was inversely associated with mortality risk (per SD increase, aHR 0·69, 95% CI 0·52-0·91) and explained 67% of the variation in renal replacement therapy mortality rates between countries. Child mortality rates showed a significant association with renal replacement therapy mortality, albeit mediated by macroeconomics (eg, neonatal mortality reduced from 1·31 [95% CI 1·13-1·53], p=0·0005, to 1·21 [0·97-1·51], p=0·10). After accounting for country distributions of patient age, the variation in renal replacement therapy mortality rates between countries increased by 21%. INTERPRETATION: Substantial international variation exists in paediatric renal replacement therapy mortality rates across Europe, most of which was explained by disparities in public health expenditure, which seems to limit the availability and quality of paediatric renal care. Differences between countries in their ability to accept and treat the youngest patients, who are the most complex and costly to treat, form an important source of disparity within this population. Our findings can be used by policy makers and health-care providers to explore potential strategies to help reduce these health disparities. FUNDING: ERA-EDTA and ESPN.

Timing of renal replacement therapy does not influence survival and growth in children with congenital nephrotic syndrome caused by mutations in NPHS1: data from the ESPN/ERA-EDTA Registry.

BACKGROUND: Congenital nephrotic syndrome (CNS) of the Finnish type, NPHS1, is the most severe form of CNS. Outcomes of renal replacement therapy (RRT) in NPHS1 patients in Europe were analysed using data from the ESPN/ERA-EDTA Registry. As NPHS1 is most prevalent in Finland and the therapeutic approach differs from that in many other countries, we compared outcomes in Finnish and other European patients. METHODS: NPHS1 mutations were confirmed in 170 children with CNS who initiated RRT (dialysis or renal transplantation) between 1991 and 2012. Finnish (n = 66) and non-Finnish NPHS1 patients (n = 104) were compared with respect to treatment policy, age at first RRT and renal transplantation (RTX), patient and graft survival, estimated glomerular filtration rate (eGFR) and growth. Age-matched patients with congenital anomalies of the kidney and urinary tract (CAKUT) served as controls. RESULTS: Finnish NPHS1 patients were significantly younger than non-Finnish patients, both at the start of RRT and at the time of RTX. We found similar overall 5-year patient survival on RRT (91 %) and graft survival (89 %) in both NPHS1 groups and CAKUT controls. At the start of RRT, height standard deviation score (SDS) was higher in Finnish patients than in non-Finnish patients (mean [95 % CI]: -1.31 [-2.13 to -0.49] and -3.0 [-4.22 to -1.91], p < 0.01 respectively), but not at 5 years of age. At 5 years of age height and body mass index (BMI) SDS were similar to those of CAKUT controls. CONCLUSIONS: Overall, 5-year patient and graft survival of both Finnish and non-Finnish NPHS1 patients on RRT were excellent and comparable with CAKUT patients with equally early RRT onset and was independent of the timing of RRT initiation and RTX.

Renal replacement therapy in Europe: a summary of the 2013 ERA-EDTA Registry Annual Report with a focus on diabetes mellitus.

BACKGROUND: This article provides a summary of the 2013 European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry Annual Report (available at http://www.era-edta-reg.org), with a focus on patients with diabetes mellitus (DM) as the cause of end-stage renal disease (ESRD). METHODS: In 2015, the ERA-EDTA Registry received data on renal replacement therapy (RRT) for ESRD from 49 national or regional renal registries in 34 countries in Europe and bordering the Mediterranean Sea. Individual patient data were provided by 31 registries, while 18 registries provided aggregated data. The total population covered by the participating registries comprised 650 million people. RESULTS: In total, 72 933 patients started RRT for ESRD within the countries and regions reporting to the ERA-EDTA Registry, resulting in an overall incidence of 112 per million population (pmp). The overall prevalence on 31 December 2013 was 738 pmp (n = 478 990). Patients with DM as the cause of ESRD comprised 24% of the incident RRT patients (26 pmp) and 17% of the prevalent RRT patients (122 pmp). When compared with the USA, the incidence of patients starting RRT pmp secondary to DM in Europe was five times lower and the incidence of RRT due to other causes of ESRD was two times lower. Overall, 19 426 kidney transplants were performed (30 pmp). The 5-year adjusted survival for all RRT patients was 60.9% [95% confidence interval (CI) 60.5-61.3] and 50.6% (95% CI 49.9-51.2) for patients with DM as the cause of ESRD.

Mineral metabolism in European children living with a renal transplant: a European society for paediatric nephrology/european renal association-European dialysis and transplant association registry study.

BACKGROUND AND OBJECTIVES: Data on mineral metabolism in pediatric renal transplant recipients largely arise from small single-center studies. In adult patients, abnormal mineral levels are related to a higher risk of graft failure. This study used data from the European Society for Paediatric Nephrology/European Renal Association-European Dialysis and Transplant Association Registry to study the prevalence and potential determinants of mineral abnormalities, as well as the predictive value of a disturbed mineral level on graft survival in a large cohort of European pediatric renal transplant recipients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This study included 1237 children (0-17 years) from 10 European countries, who had serum calcium, phosphorus, and parathyroid hormone measurements from 2000 onward. Abnormalities of mineral metabolism were defined according to European guidelines on prevention and treatment of renal osteodystrophy in children on chronic renal failure. RESULTS: Abnormal serum phosphorus levels were observed in 25% (14% hypophosphatemia and 11% hyperphosphatemia), altered serum calcium in 30% (19% hypocalcemia, 11% hypercalcemia), and hyperparathyroidism in 41% of the patients. A longer time since transplantation was associated with a lower risk of having mineral levels above target range. Serum phosphorus levels were inversely associated with eGFR, and levels above the recommended targets were associated with a higher risk of graft failure independently of eGFR. CONCLUSIONS: Abnormalities in mineral metabolism are common after pediatric renal transplantation in Europe and are associated with graft dysfunction.

Demographics of paediatric renal replacement therapy in Europe: a report of the ESPN/ERA-EDTA registry.

BACKGROUND: The ESPN/ERA-EDTA Registry collects data on European children with end-stage renal disease receiving renal replacement therapy (RRT) who are listed on national and regional renal registries in Europe. In this paper we report on the analysis of demographic data collected from 2009 to 2011. METHODS: Data on primary renal disease, incidence, prevalence, 4-year survival, transplantation rate and causes of death in paediatric patients receiving RRT were extracted from the ESPN/ERA-EDTA Registry for 37 European countries. RESULTS: The incidence of RRT in paediatric patients in Europe during the study period was 5.5 cases per million age-related population (pmarp) in patients aged 0-14 years and varied markedly between countries (interquartile range 3.4-7.0 years). The prevalence of RRT was 27.9 pmarp and increased with age, with 67 % of prevalent patients living with a functioning graft. The probability of receiving a transplant within 4 years was 76.9 % and was lowest in patients aged 0-4 years (68.9 %). Mortality in paediatric patients treated with RRT was 55-fold higher than that of the general EU paediatric population. Overall survival at 4 years was 93.7 %, with the poorest survival in patients aged 0-4 years and in patients starting on dialysis. Infections (19.9 %) were the primary cause of death in European paediatric RRT patients. CONCLUSION: Considerable variation exists in the current demographics of children treated with RRT across Europe.

Dyslipidaemia in children on renal replacement therapy.

BACKGROUND: Information on lipid abnormalities in end-stage renal disease (ESRD) mainly originates from adult patients and small paediatric studies. We describe the prevalence of dyslipidaemia, and potential determinants associated with lipid measures in a large cohort of paediatric ESRD patients. METHODS: In the ESPN/ERA-EDTA registry, lipid measurements were available for 976 patients aged 2-17 years from 19 different countries from the year 2000 onwards. Dyslipidaemia was defined as triglycerides >100 mg/dL (2-9 years) or >130 mg/dL (9-17 years), high-density lipoprotein (HDL) cholesterol <40 mg/dL or non-HDL cholesterol >145 mg/dL. Missing data were supplemented using multiple imputation. RESULTS: The prevalence of dyslipidaemia was 85.1% in peritoneal dialysis (PD) patients, 76.1% in haemodialysis (HD) patients and 55.5% among renal allograft recipients. Both low and high body mass index (BMI) were associated with a less favourable lipid profile. Younger age was associated with a worse lipid profile among PD patients. HDL levels significantly improved after transplantation, whereas no significant improvements were found for triglyceride and non-HDL levels. In transplant recipients, use of cyclosporin was associated with significantly higher non-HDL and HDL levels than tacrolimus usage (P < 0.01). In transplant patients with eGFR < 29 mL/min/1.73 m(2), the mean triglyceride level was 137 mg/dL (99% confidence interval (CI): 119-159) compared with 102 mg/dL among those with eGFR > 90 mL/min/1.73 m(2) (P < 0.0001). CONCLUSIONS: Dyslipidaemia is common among paediatric ESRD patients in Europe. Young age and PD treatment are associated with worse lipid profiles. Although lipid levels generally improve after transplantation, dyslipidaemia may persist due to decreased graft function, high BMI or to the use of certain immunosuppressants.

Renal replacement therapy in Europe: a summary of the 2011 ERA-EDTA Registry Annual Report.

BACKGROUND: This article provides a summary of the 2011 ERA-EDTA Registry Annual Report (available at www.era-edta-reg.org). METHODS: Data on renal replacement therapy (RRT) for end-stage renal disease (ESRD) from national and regional renal registries in 30 countries in Europe and bordering the Mediterranean Sea were used. From 27 registries, individual patient data were received, whereas 17 registries contributed data in aggregated form. We present the incidence and prevalence of RRT, and renal transplant rates in 2011. In addition, survival probabilities and expected remaining lifetimes were calculated for those registries providing individual patient data. RESULTS: The overall unadjusted incidence rate of RRT in 2011 among all registries reporting to the ERA-EDTA Registry was 117 per million population (pmp) (n = 71.631). Incidence rates varied from 24 pmp in Ukraine to 238 pmp in Turkey. The overall unadjusted prevalence of RRT for ESRD on 31 December 2011 was 692 pmp (n = 425 824). The highest prevalence was reported by Portugal (1662 pmp) and the lowest by Ukraine (131 pmp). Among all registries, a total of 22 814 renal transplantations were performed (37 pmp). The highest overall transplant rate was reported from Spain, Cantabria (81 pmp), whereas the highest rate of living donor transplants was reported from Turkey (39 pmp). For patients who started RRT between 2002 and 2006, the unadjusted 5-year patient survival on RRT was 46.8% [95% confidence interval (CI) 46.6-47.0], and on dialysis 39.3% (95% CI 39.2-39.4). The unadjusted 5-year patient survival after the first renal transplantation performed between 2002 and 2006 was 86.7% (95% CI 86.2-87.2) for kidneys from deceased donors and 94.3% (95% CI 93.6-95.0) for kidneys from living donors.

Whole body composition analysis by the BodPod air-displacement plethysmography method in children with phenylketonuria shows a higher body fat percentage.

BACKGROUND: Phenylketonuria (PKU) causes irreversible central nervous system damage unless a phenylalanine (PHE) restricted diet with amino acid supplementation is maintained. To prevent growth retardation, a protein/amino acid intake beyond the recommended dietary protein allowance is mandatory. However, data regarding disease and/or diet related changes in body composition are inconclusive and retarded growth and/or adiposity is still reported. The BodPod whole body air-displacement plethysmography method is a fast, safe and accurate technique to measure body composition. AIM: To gain more insight into the body composition of children with PKU. METHODS: Patients diagnosed with PKU born between 1991 and 2001 were included. Patients were identified by neonatal screening and treated in our centre. Body composition was measured using the BodPod system (Life Measurement Incorporation©). Blood PHE values determined every 1-3 months in the year preceding BodPod analysis were collected. Patients were matched for gender and age with data of healthy control subjects. Independent samples t tests, Mann-Whitney and linear regression were used for statistical analysis. RESULTS: The mean body fat percentage in patients with PKU (n = 20) was significantly higher compared to healthy controls (n = 20) (25.2% vs 18.4%; p = 0.002), especially in girls above 11 years of age (30.1% vs 21.5%; p = 0.027). Body fat percentage increased with rising body weight in patients with PKU only (R = 0.693, p = 0.001), but did not correlate with mean blood PHE level (R = 0.079, p = 0.740). CONCLUSION: Our data show a higher body fat percentage in patients with PKU, especially in girls above 11 years of age.