Renal replacement therapy for rare diseases affecting the kidney: an analysis of the ERA-EDTA Registry.

BACKGROUND: In recent years, increased efforts have been undertaken to address the needs of patients with rare diseases by international initiatives and consortia devoted to rare disease research and management. However, information on the overall prevalence of rare diseases within the end-stage renal disease (ESRD) population is limited. The aims of this study were (i) to identify those rare diseases within the ERA-EDTA Registry for which renal replacement therapy (RRT) is being provided and (ii) to determine the prevalence and incidence of RRT for ESRD due to rare diseases, both overall and separately for children and adults. METHODS: The Orphanet classification of rare disease was searched for rare diseases potentially causing ESRD, and these diagnosis codes were mapped to the corresponding ERA-EDTA primary renal disease codes. Thirty-one diagnoses were defined as rare diseases causing ESRD. RESULTS: From 1 January 2007 to 31 December 2011, 7194 patients started RRT for a rare disease (10.6% children). While some diseases were exclusively found in adults (e.g. Fabry disease), primary oxalosis, cystinosis, congenital anomalies of the kidney and urinary tract (CAKUT) and medullary cystic kidney disease affected young patients in up to 46%. On 31 December 2011, 20 595 patients (12.4% of the total RRT population) were on RRT for ESRD caused by a rare disease. The point prevalence was 32.5 per million age-related population in children and 152.0 in adults. Only 5.8% of these patients were younger than 20 years; however, 57.7% of all children on RRT had a rare disease, compared with only 11.9% in adults. CAKUT and focal segmental glomerulosclerosis were the most prevalent rare disease entities among patients on RRT. CONCLUSIONS: More than half of all children and one of nine adults on RRT in the ERA-EDTA Registry suffer from kidney failure due to a rare disease, potentially with a large number of additional undiagnosed or miscoded cases. Comprehensive diagnostic assessment and the application of accurate disease classification systems are essential for improving the identification and management of patients with rare kidney diseases.

Exploration of the difference in incidence of renal replacement therapy between Flanders and the Netherlands--investigation of explanatory variables.

AIM: This study investigates the difference in the incidence of renal replacement therapy (RRT) between Flanders and the Netherlands and possible explanations for this difference. METHODS: End-stage renal disease incidence data were obtained from the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA). Additional sources were the National Institute of Statistics (NIS), the Central Bureau of Statistics (CBS), the Organisation for Economic Cooperation and Development (OECD) health data and the WHO Health For All database (WHO-HFA). RESULTS: There is remarkable difference in incidence rate of RRT between Flanders and the Netherlands, with a higher rate in Flanders. This difference is already present in patients aged 45-64 years and increases with age, being >2-fold higher in subjects of ≥ 75 years. With respect to the renal diagnoses leading to need for RRT, a higher share of especially diabetes mellitus type 2 and renovascular disease was observed in Flanders. Remarkably, the difference in incidence rate of RRT is not associated with a difference in survival on RRT, not even in the elderly, arguing against a restricted access to RRT in the Netherlands. In the general population, the expected number of healthy life years at birth is lower in Belgium than in the Netherlands, and in Belgium, the hospital discharge rates for diabetes, acute myocardial infarction and cerebrovascular accident and the number of coronary bypass procedures and percutaneous coronary interventions per capitum is higher, as is the prevalence of obesity. CONCLUSION: Our data do not support the assumption that the differences in RRT incidence in the elderly between Flanders and the Netherlands are due to a more restricted access to RRT in the Netherlands but may be due to differences in underlying comorbidity and life style between the two populations.

No important influence of limited steroid exposure on bone mass during the first year after renal transplantation: a prospective, randomized, multicenter study.

BACKGROUND: Steroid-related bone loss is a recognized complication after renal transplantation. In a prospective, randomized, multicenter study we compared the influence of a steroid-free immunosuppressive regimen with a regimen with limited steroid exposure on the changes in bone mass after renal transplantation. METHODS: A total of 364 recipients of a renal transplant were randomized to receive either daclizumab (1 mg/kg on days 0 and 10 after transplantation; steroid-free group n=186) or prednisone (0.3 mg/kg per day tapered to 0 mg at week 16 after transplantation; steroids group n=178). All patients received tacrolimus, mycophenolate mofetil, and, during the first 3 days, 100 mg prednisolone intravenously. Changes in bone mineral density (BMD) were evaluated in 135 and 126 patients in the steroid-free and steroids group, respectively. RESULTS: The mean (+/- SD) BMD of the lumbar spine decreased slightly in both groups during the first 3 months after transplantation (steroid-free -1.3 +/- 4.0% [P<0.01]; steroids -2.3 +/-4.2% [P<0.01]). In the following months, lumbar BMD recovered in both groups (P<0.01), resulting in a lumbar BMD at 12 months after transplantation comparable with the baseline value. No difference between the groups was found at 3 months (steroid-free versus steroids +1.0%; 95% confidence interval -0.0%-+2.0%, P=0.060) and at 12 months after transplantation (steroid-free versus steroids +0.9%; 95% confidence interval -0.8%-+2.6%, NS). CONCLUSION: The use of a moderate dose of steroids during 4 months after transplantation has no important influence on bone mass during the first year after renal transplantation. On average, both regimens prevented accelerated bone loss.