Prevalence and incidence of chronic kidney disease stage 3-5 - results from KidDiCo.

BACKGROUND: Chronic kidney disease (CKD) is a global challenge. CKD prevalence estimation is central to management strategies and prevention. It is necessary to predict end stage kidney disease (ESKD) and, subsequently, the burden for healthcare systems. In this study we characterize CKD stage 3-5 prevalence and incidence in a cohort covering the majority of the Region of Southern Denmark and investigate individuals' demographic, socioeconomic, and comorbidity status. METHODS: We used data from the Kidney Disease Cohort (KidDiCo) combining laboratory data from Southern Denmark with Danish national databases. Chronic kidney disease was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. RESULTS: The prevalence varied between 4.83 and 4.98% and incidence rate of CKD was 0.49%/year. The median age was 76.4 years. The proportion of individuals with CKD stage 3-5 in the entire population increased consistently with age. The percentage of women in the CKD 3-5 group was higher than in the background population. Diabetes mellitus, hypertension and cardiovascular disease were more prominent in patients with CKD. CKD stage 5 and ESKD were more frequent as incident CKD stages in the 18-49 year olds when compared to older individuals. CKD patients tended to have a lower socioeconomic status. CONCLUSION: Chronic kidney disease stage 3-5 is common, especially in the elderly. Patients with CKD stage 3-5 are predominantly female. The KidDiCo data suggests an association between lower socioeconomic status and prevalence of CKD.

Referral rate of chronic kidney disease patients to a nephrologist in the Region of Southern Denmark: results from KidDiCo.

Background: Data on the referral rate of chronic kidney disease (CKD) patients to specialists are sparse. Investigating referral rates and characterizing patients with kidney disease not followed by a nephrologist are relevant for future measures in order to optimize public health and guideline implementation. Methods: Data were extracted from the Kidney Disease Cohort of Southern Denmark (KidDiCo). Referral rates for all incident CKD patients below 60 mL/min/1.73 m² and referral rates according to the KDIGO guidelines based on glomerular filtration rates below 30 mL/min/1.73 m² were calculated. Information on contact with one of the nephrologist outpatient clinics in the Region of Southern Denmark was collected from the Danish National Patient Registry. The individual follow-up time for nephrology contact was 12 months. Additional data were accessed via the respective national databases. CKD patients on dialysis and kidney transplanted patients were excluded. Results: A total of 3% of patients with an eGFR <60 mL/min/1.73 m²-16% of patients with an eGFR <30 mL/min/1.73 m² and 35% of patients with an eGFR <15 mL/min/1.73 m² were in contact with a nephrologist in the outpatient settings. Younger age, male sex, diabetes, hypertension, higher education and proximity to a nephrology outpatient clinic increased the chance of nephrology follow-up. Conclusion: Only a small fraction of CKD patients are followed by a nephrologist. More studies should be performed in order to find out which patients will profit the most from renal referral and how to optimize the collaboration between nephrologists and general practitioners.

Rate and Risk Factors of Acute Myocardial Infarction after Debut of Chronic Kidney Disease-Results from the KidDiCo.

Chronic kidney disease (CKD) is a known risk factor for cardiovascular disease, including acute myocardial infarction. However, whether this risk is only associated with severe kidney disease or is also related to mildly impaired kidney function is still under debate. The incidence rate and risk factors of incident acute myocardial infarction (AMI) in patients with CKD are sparse. Potential differences in risk factor profiles between CKD patients with incident AMI and CKD patients with a prior AMI have not been sufficiently investigated. Furthermore, important factors such as albuminuria and socio-economic factors are often not included. The primary aim of this study was to establish the incidence rate of AMI after CKD debut. Secondly, to evaluate the importance of different CKD stages and the risk of having an AMI. Finally, to identify individuals at risk for AMI after CKD debut adjusted for prevalent AMI. Based on data from the kidney disease cohort of Southern Denmark (KidDiCo), including 66,486 CKD patients, we established incidence rates and characteristics of incident AMI among patients within a 5-year follow-up period after CKD debut. A Cox regression was performed to compute the cause-specific hazard ratios for the different risk factors. The incidence rate for CKD stage G3−5 patients suffering acute myocardial infarction is 2.5 cases/1000 people/year. In patients without a previous myocardial infarction, the risk of suffering a myocardial infarction after CKD debut was only significant in CKD stage G4 (HR = 1.402; (95% CI: 1.08−1.81); p-value = 0.010) and stage G5 (HR = 1.491; (95% CI: 1.01−2.19); p-value = 0.042). This was not the case in patients who had suffered an acute myocardial infarction prior to their CKD debut. In this group, a previous myocardial infarction was the most critical risk factor for an additional myocardial infarction after CKD debut (HR = 2.615; (95% CI: 2.241−3.05); p-value < 0.001). Irrespective of a previous myocardial infarction, age, male sex, hypertension, and a low educational level were significant risk factors associated with an acute myocardial infarction after CKD debut. The incidence rate of AMI in patients with CKD stage G3−5 was 2.5 cases/1000 people/year. Risk factors associated with incident AMI in CKD stage G3−5 patients were CKD stage, age, and hypertension. Female sex and higher educational levels were associated with a lower risk for AMI. Prior AMI was the most significant risk factor in patients with and without previous AMI before fulfilling CKD stage G3−5 criteria. Only age, sex, and a medium-long educational level were significant risk factors in this group.

Hypertensive nephropathy is associated with an increased risk of myeloma, skin, and renal cancer.

Previous studies suggest an increased cancer risk in hypertension. Patients with hypertensive nephropathy have not been studied. A national registry study was performed to assess the presence and size of this association. Clinical data and cancer diagnoses for all patients with biopsy-proven hypertensive nephropathy between 1985 and 2015 in Denmark were extracted from four national registries and compared with age- and sex-adjusted national cancer rates. The risk of cancer was twice the background population. It was raised for renal cancer (odds ratio 10.4), myeloma (13.2), skin cancer (7.9), and other/unspecified (1.8). No increase in incidence was seen until 1 year before renal biopsy and then rose rapidly. It was again normal 5 years after biopsy. Hypertensive nephropathy is associated with an increased risk of myeloma, skin, renal, and other cancers. Screening of patients with hypertensive nephropathy, in the presence of reduced renal function or significant proteinuria, may be indicated.

FGF23 in hemodialysis patients is associated with left ventricular hypertrophy and reduced ejection fraction.

BACKGROUND: Fibroblast growth factor 23 (FGF23) is known to cause left ventricular hypertrophy (LVH), but controversy exists concerning its effect in dialysis. This study evaluated associations between FGF23 levels, echocardiography and prognosis in patients on hemodialysis (HD). METHODS: Patients >18 years on chronic HD were included in this cross-sectional study. Plasma C-terminal FGF23 concentration was measured with ELISA and transthoracic echocardiography was performed, both before and after HD treatment. RESULTS: 239 haemodialysis (HD) patients were included in the study. The FGF23 was median 3560RU/ml (IQR 1447-9952). The mean left ventricular mass index (LVMI) was 110.2±26.7g/m2 and the left ventricular ejection fraction (LVEF) was 52.7±9.9%. Defined by LVMI, LVH was found in 110 patients (46%), of which 92 (84%) had hypertension (p<0.01). Patients with LVH had FGF23 levels of 5319 RU/ml (IQR 1858-12,859) and those without 2496 RU/ml (IQR 1141-7028) (p<0.01). FGF23 was significant positive correlated with LVMI (p<0.01), and negatively to LVEF (p<0.01). In a multivariate analysis, FGF23 was correlated with LVEF (p<0.01), but only marginally to LVMI (p<0.01). Cardiovascular events in the follow up period was not correlated with FGF23. Furthermore, FGF23 was independently correlated with overall mortality (p<0.001). CONCLUSION: FGF23 was positively correlated with LVH and negatively to LVEF. FGF23 was an independent predictor for overall mortality.

Risk of death after first-time blood stream infection in incident dialysis patients with specific consideration on vascular access and comorbidity.

BACKGROUND: The mortality following blood stream infection (BSI) and risk of subsequent BSI in relation to dialysis modality, vascular access, and other potential risk factors has received relatively little attention. Consequently, we assessed these matters in a retrospective cohort study, by use of the Danish nation-wide registries. METHODS: Patients more than 17 years of age, who initiated dialysis between 1.1.2010 and 1.1.2014, were grouped according to their dialysis modality and vascular access. Survival was modeled in time-dependent Cox proportional hazard analyses. Potential risk factors confined by a modified Charlson comorbidity index (MCCI), were subsequently assessed in stepwise selection models. RESULTS: At baseline, 764 patients received peritoneal dialysis (PD), and 434, 479, and 782 hemodialysis (HD) patients were dialyzed by use of arteriovenous fistulas (AVFs), tunneled catheters (TCs), and non-tunneled catheters (NTCs), respectively. We identified 1069 BSIs with an overall incidence rate of 17.7 episodes per 100 person years, and 216 BSIs occurred more than one time in the same patient. HRs of post BSI mortality relative to PD were 3.20 (95% CI 1.86-5.50; p < 0.001) with NTCs; whereas no associations were found for AVF and TC. The risk of subsequent BSIs was higher with NTCs [HR 2.29 (95% CI 1.09-4.82), p = 0.030], and no significant difference was found for AVF and TC, in relation to PD. There was an increased risk of both outcomes with TC relative to AVF [death: 1.57 (95% CI 1.07-2.29, P < 0.021); BSI: 1.78 (95% CI 1.13-2.83, P < 0.014], and risk of death was reduced in patients who changed to AVF after first-time BSI. The MCCI was significantly associated with the risk of subsequent BSI and post BSI death; however, only some of the variables contained in the index were found to be significant risk predictors when analyzed in the fitted model. CONCLUSIONS: While NTC was the most predominant risk factor for subsequent BSI and post BSI mortality, AVF appeared protective.

Quantification of cancer risk in glomerulonephritis.

BACKGROUND: The association of increased cancer risk with glomerulonephritis (GN) is well known, but controversy exists concerning which types of GN are involved, and the size of the association. A national registry survey was performed to assess the size of this association, and the temporal relationship of cancer diagnosis to GN diagnosis. METHODS: All patients with biopsy-proven GN between 1985 and 2015 in Denmark were extracted from The Danish Renal Biopsy Registry and the National Pathology Data Bank. Incident cancer diagnoses between 10 years previous and 10 years subsequent to the GN diagnosis were extracted from the Danish Cancer Registry. Residence, birth and death data were obtained from the National Patient Register. Expected cancer incidence, classified according to cohort, age and sex were extracted from the Nordcan database. RESULTS: Nine hundred eleven cancers were diagnosed in 5594 patients. Thirty five percent were prevalent at renal biopsy. Prevalence at biopsy was 5.5% (expected 3.1%), but incidence was not increased < 1 year before biopsy. Increased cancer rates were seen for GN forms: minimal change, endocapillary, focal segmental glomerulosclerosis, mesangioproliferative, membranous, focal segmental, membranoproliferative, proliferative, ANCA-associated vasculitis, lupus nephritis and unclassified. Increased cancer rates were seen for lung, prostate, renal, non-Hodgkin lymphoma, myeloma, leukaemia and skin. The increased incidence was mainly limited to - 1 to 1 year after biopsy, but skin cancer showed an increased risk over time. Some diagnoses showed an increase 5-10 years after biopsy. Incidence was raised for patients with uraemia and nephrosis, but less for proteinuria or haematuria. Cancers in patients < 45 years were rare. The risk of developing cancer 0-3 years after biopsy for patients 45-64 years varied from 7.3% (minimal change) to 15.8% (unclassified GN); > 64 years from 11.8 (endocapillary GN) to 20.3% (unclassified). The diagnosis with the highest risk was membranoproliferative GN (8.6 & 19.6%). CONCLUSIONS: Cancer rates are increased for many cancer and most GN diagnoses. Cancer screening for patients < 45 years and for patients without nephrosis or uraemia may not be necessary. The findings suggest that screening programs for specific GN diagnoses can be extended to other GN forms.

Comparison of Dual Energy X-ray Absorptiometry and Bioimpedance in Assessing Body Composition and Nutrition in Peritoneal Dialysis Patients.

OBJECTIVE: Peritoneal dialysis (PD) patients are characterized by protein malnutrition and muscle wasting. Reliable, easy, and cheap methods for evaluating nutrition are desirable. Three methods are commonly available: dual-energy X-ray absorptiometry (DXA), bioimpedance (BI), and subjective global assessment (SGA).The objective of the study was to compare the previously mentioned methods for assessment of body composition and nutritional status in PD patients. DESIGN: The study is cross-sectional and consisted of 72 PD patients from a single center PD ambulatorium. METHODS: Participants were measured twice by DXA, twice by BI, and once by SGA. Measurements included lean tissue mass (LTM), fat tissue mass (FT) and, for BI, overhydration (OH), intracellular water (ICW), and extracellular water (ECW). LTM and FT were indexed to body area (Lean Tissue Index [LTI] and Fat Tissue Index [FTI], respectively), and ICW for height (ICW/ht). We assessed conventional biochemical and clinical variables, using values for normal individuals as a reference. RESULTS: There was good overall agreement between BI and DXA but considerable intra-individual variation (1 standard deviation: FT 5.7 kg; LTM 5.6 kg). Factors affecting the differences were FT, ICW, LTM, and ICW. Obesity (DXA 43%; BI 54%) and muscle wasting (BI 28%; SGA 53%) were common. Agreement between BI and SGA was poor. Thirty-eight percent of patients judged malnourished by SGA also had a low LTI; 23% with normal SGA had low LTI. SGA was closer related to LTI (BI) than LTI (DXA). Plasma albumin was correlated to LTI, FTI, and ICW/ht, and comorbidity to OH, clinical malnutrition, reduced FTI, but not LTI. CONCLUSION: Agreement between DXA and BI was high on a population basis but not at an individual level. Obesity and muscle wasting were common in this population. OH might reduce DXA accuracy in PD patients. LTI and ICW may be useful measures to supplement SGA in assessing nutrition.

Chronic Kidney Disease-Mineral Bone Disorder in the Elderly Peritoneal Dialysis Patient.

PURPOSE: The purpose of this paper was to review the literature concerning the treatment of chronic kidney disease-mineral bone disorder (CKD-MBD) in the elderly peritoneal dialysis (PD) patient. RESULTS: Chronic kidney disease-mineral bone disorder is a major problem in the elderly PD patient, with its associated increased fracture risk, vascular calcification, and accelerated mortality fracture risk. Peritoneal dialysis, however, bears a lower risk than hemodialysis (HD). The approach to CKD-MBD prophylaxis and treatment in the elderly PD patient is similar to other CKD patients, with some important differences. Avoidance of hypercalcemia, hyperphosphatemia, and hyperparathyroidism is important, as in other CKD groups, and is generally easier to attain. Calcium-free phosphate binders are recommended for normocalcemic and hypercalcemic patients. Normalization of vitamin D levels to > 75 nmol/L (> 30 pg/L) and low-dose active vitamin D therapy is recommended for all patients. Hyperparathryoidism is to be avoided by using active vitamin D and cinacalcet. Particular attention should be paid to treating protein malnutrition. Fracture prophylaxis (exercise, use of walkers, dwelling modifications) are important. Hypomagnesemia is common in PD and can be treated with magnesium supplements. Vitamin K deficiency is also common and has been identified as a cause of vascular calcification. Accordingly, warfarin treatment for this age group is problematic. CONCLUSION: While treatment principles are similar to other dialysis patient groups, physicians should be aware of the special problems of the elderly group.

Protein-bound solute removal during extended multipass versus standard hemodialysis.

BACKGROUND: Multipass hemodialysis (MPHD) is a recently described dialysis modality, involving the use of small volumes of dialysate which are repetitively recycled. Dialysis regimes of 8 hours for six days a week using this device result in an increased removal of small water soluble solutes and middle molecules compared to standard hemodialysis (SHD). Since protein-bound solutes (PBS) exert important pathophysiological effects, we investigated whether MPHD results in improved removal of PBS as well. METHODS: A cross-over study (Clinical Trial NCT01267760) was performed in nine stable HD patients. At midweek a single dialysis session was performed with either 4 hours SHD using a dialysate flow of 500 mL/min or 8 hours MPHD with a dialysate volume of 50% of estimated body water volume. Blood and dialysate samples were taken every hour to determine concentrations of p-cresylglucuronide (PCG), hippuric acid (HA), indole acetic acid (IAA), indoxyl sulfate (IS), and p-cresylsulfate (PCS). Dialyser extraction ratio, reduction ratio, and solute removal were calculated for these solutes. RESULTS: Already at 60 min after dialysis start, the extraction ratio in the hemodialyser was a factor 1.4-4 lower with MPHD versus SHD, resulting in significantly smaller reduction ratios and lower solute removal within a single session. Even when extrapolating our findings to 3 times 4 h SHD and 6 times 8 h MPHD per week, the latter modality was at best similar in terms of total solute removal for most protein-bound solutes, and worse for the highly protein-bound solutes IS and PCS. When efficiency was calculated as solute removal/litre of dialysate used, MPHD was found superior to SHD. CONCLUSION: When high water consumption is a concern, a treatment regimen of 6 times/week 8 h MPHD might be an alternative for 3 times/week 4 h SHD, but at the expense of a lower total solute removal of highly protein-bound solutes.

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.

Mesangioproliferative glomerulonephritis: a 30-year prognosis study.

BACKGROUND: Diffuse mesangioproliferative glomerulonephritis (MesP) is the most commonly diagnosed type of glomerulonephritis (GN) in Denmark, with an incidence of 10.8 million per year. In the present study, the 30-year renal survival was estimated. METHODS: A retrospective cohort investigation of 140 patients with biopsy-proven MesP was performed between the period 1967-2006. Factors influencing renal survival were investigated using Cox regression analysis. RESULTS: Renal survival at 5, 10, 20 and 30 years was 87, 78, 59 and 50%, respectively. Female survival after 30 years was significantly better than male survival (70 vs. 40%, p = 0.049). Multivariate analysis, adjusted for age, estimated glomerular filtration rate (GFR) and nephrotic syndrome (NS) was performed for each sex individually. An increase in GFR was associated with a hazard risk (HR) of 0.98 (p = 0.02) in women and 0.99 (p = 0.006) in men. Older age was associated with a HR of 1.04 (p = 0.02) in women and 1.03 (p = 0.004) in men. NS had a poorer prognosis in men (HR 2.53, p = 0.01), but not in women (HR 0.54, p = 0.38). CONCLUSION: Increasing age and decreasing GFR were adversely associated with renal death. Renal prognosis was better for women after 30 years, and NS resulted in a poorer prognosis in men. This suggests that disease course and prognosis are different between men and women.

Indexing glomerular filtration rate to body surface area: clinical consequences.

BACKGROUND: Kidney function is mostly expressed in terms of glomerular filtration rate (GFR). A common feature is the expression as ml/min per 1.73 m(2) , which represents the adjustment of the individual kidney function to a standard body surface area (BSA) to allow comparison between individuals. We investigated the impact of indexing GFR to BSA in cancer patients, as this BSA indexation might affect the reported individual kidney function. METHODS: Cross-sectional study of 895 adults who had their kidney function measured with (51) chrome ethylene diamine tetraacetic acid. Mean values of BSA-indexed GFR vs. mean absolute GFR were analyzed with a t-test for paired data. Bland-Altman plot was used to analyze agreement between the indexed and absolute GFR values. RESULTS AND CONCLUSION: BSA-GFR in patients with a BSA <1.60 m(2) overestimated GFR with a bias of 10.08 ml/min (11.46%) and underestimated GFR in those with a BSA >2 m(2) with a bias up to -20.76 ml/min (-23.59%). BSA is not a good normalization index (NI) in patients with extreme body sizes. Therefore, until a better NI is found, we recommend clinicians to use the absolute GFR to calculate individual drug chemotherapy dosage as well as express individual kidney function.

The use of absolute values improves performance of estimation formulae: a retrospective cross sectional study.

BACKGROUND: Estimation of Glomerular Filtration Rate (GFR) by equations such as Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) or Modification of Diet in Renal Disease (MDRD) is usually expressed as a Body Surface Area (BSA) indexed value (ml/min per 1.73 m²). This can have severe clinical consequences in patients with extreme body sizes, resulting in an underestimation in the case of obesity or an overestimation of GFR in the case of underweight patients. The aim of this study was to compare the performance of both estimation formula expressed in ml/min, instead of ml/min per 1.73 m², with a reference method. METHODS: Retrospective single centre cross sectional study of 185 patients. GFR was measured with 51Cr-EDTA and estimated with CKD-EPI and MDRD. Bias, precision and accuracy of absolute estimated GFR was calculated. RESULTS: Bias of CKD-EPI and MDRD formulae expressed as an absolute value was 0.49 and 0.27 ml/min respectively, which is lower than previously reported. Precision was 12.95 and 16.33 and accuracy expressed as P30 was over 92.43% for CKD-EPI. There were no significant differences in GFR between the reference method and the estimation formulae. CONCLUSIONS: The performance of CKD-EPI and MDRD formulae can be significantly improved in the individual patient if the absolute values are used by removing the BSA normalization factor. Absolute estimated GFR by CKD-EPI is comparable to measured GFR, improving the performance of this formula in the assessment of individual kidney function, thus providing clinicians with an alternative to reference methods.

Timing and outcome of renal replacement therapy in patients with congenital malformations of the kidney and urinary tract.

BACKGROUND AND OBJECTIVES: Congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of ESRD in children, but the proportion of patients with individual CAKUT entities progressing to ESRD during adulthood and their long-term clinical outcomes are unknown. This study assessed the age at onset of renal replacement therapy (RRT) and patient and renal graft survival in patients with CAKUT across the entire age range. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Patients with CAKUT were compared with age-matched patients who were undergoing RRT for other renal disorders on the basis of data from the European Renal Association-European Dialysis and Transplant Association Registry. Competing risk and Cox regression analyses were conducted. RESULTS: Of 212,930 patients commencing RRT from 1990 to 2009, 4765 (2.2%) had renal diagnoses consistent with CAKUT. The proportion of incident RRT patients with CAKUT decreased from infancy to childhood and then increased until age 15-19 years, followed by a gradual decline throughout adulthood. Median age at RRT start was 31 years in the CAKUT cohort and 61 years in the non-CAKUT cohort (P<0.001). RRT was started earlier (median, 16 years) in patients with isolated renal dysplasia than in those with renal hypoplasia and associated urinary tract disorders (median, 29.5-39.5 years). Patients with CAKUT survived longer than age- and sex-matched non-CAKUT controls because of lower cardiovascular mortality (10-year survival rate, 76.4% versus 70.7%; P<0.001). CONCLUSIONS: CAKUT leads to ESRD more often at adult than pediatric age. Treatment outcomes differ from those of acquired kidney diseases and vary within CAKUT subcategories.

Multipass haemodialysis: a novel dialysis modality.

INTRODUCTION: Most home haemodialysis (HD) modalities are limited to home use since they are based on a single-pass (SP) technique, which requires preparation of large amounts of dialysate. We present a new dialysis method, which requires minimal dialysate volumes, continuously recycled during treatment [multipass HD (MPHD)]. Theoretical calculations suggest that MPHD performed six times weekly for 8 h/night, using a dialysate bath containing 50% of the calculated body water, will achieve urea clearances equivalent to conventional HD 4 h thrice weekly, and a substantial clearance of higher middle molecules. METHODS: Ten stable HD patients were dialyzed for 4 h using standard SPHD (dialysate flow 500 mL/min). Used dialysate was collected. One week later, an 8-h MPHD was performed. The dialysate volume was 50% of the calculated water volume, the dialysate inflow 500 mL/min-0.5 × ultrafiltration/min and the outflow 500 mL/min + 0.5 × ultrafiltration/min. Elimination rates of urea, creatinine, uric acid, phosphate and ß2-microglobulin (B2M) and dialysate saturation were determined hourly. RESULTS: Three hours of MPHD removed 49, 54, 50, 51 and 57%, respectively, of the amounts of urea, creatinine, uric acid, phosphate and B2M that were removed by 4 h conventional HD. The corresponding figures after 8 h MPHD were 63, 78, 74, 78 and 111%. CONCLUSIONS: Clearance of small molecules using MPHD 6 × 8 h/week will exceed traditional HD 3 × 4 h/week. Similarly, clearance of large molecules will significantly exceed traditional HD and HD 5 × 2.5 h/week. This modality will increase patients' freedom of movement compared with traditional home HD. The new method can also be used in the intensive care unit and for automated peritoneal dialysis.

Anti-glomerular basement membrane glomerulonephritis and thrombotic microangiopathy in first degree relatives: a case report.

BACKGROUND: Anti-glomerular basement membrane glomerulonephritis and thrombotic microangiopathy are rare diseases with no known coherence. CASE PRESENTATION: A daughter and her biological mother were diagnosed with pregnancy-induced thrombotic microangiopathy and anti-glomerular basement membrane glomerulonephritis, respectively. Both developed end-stage renal disease. Exploration of a common aetiology included analyses of HLA genotypes, functional and genetic aspects of the complement system, ADAMTS13 activity and screening for autoantibodies.The daughter was heterozygous carrier of the complement factor I G261D mutation, previously described in patients with membranoproliferative glomerulonephritis and atypical haemolytic uremic syndrome. The mother was non-carrier of this mutation. They shared the disease associated complement factor H silent polymorphism Q672Q (79602A>G). CONCLUSION: An unequivocal functional or molecular association between these two family cases was not found suggesting that the patients probably share another, so far undiagnosed and unknown, predisposing factor. It seems highly unlikely that two infrequent immunologic diseases would occur by unrelated pathophysiological mechanisms within first degree relatives.

Vitamin d and stage 5 chronic kidney disease: a new paradigm?

Vitamin D receptor agonists (VDRA) are currently recommended for the treatment of secondary hyperparathyroidism in stage 5 CKD. They are considered to be contraindicated in the presence of low or normal (for a dialysis patient) levels of PTH due to the risk of developing adynamic bone disease, with consequent vascular calcification. However, these recommendations are increasingly at odds with the epidemiological evidence, which consistently shows a large survival advantage for patients treated with low-dose VDRAs, regardless of plasma calcium, phosphate, or PTH. A large number of pleiotropic effects of vitamin D have been described, including inhibition of renin activity, anti-inflammation, and suppression of vascular calcification stimulators and stimulation of vascular calcification inhibitors present in the uremic milieu. Laboratory studies suggest that a normal cellular vitamin D level is necessary for normal cardiomyocyte and vascular smooth muscle function. While pharmacological doses of VDRA can be harmful, the present evidence suggests that the level of 1,25-dihydroxycholecalciferol should also be more physiological in stage 5 CKD, and that widespread use of low-dose VDRA would be beneficial. A randomized controlled trial to test this hypothesis is warranted.

Uraemia progression in chronic kidney disease stages 3-5 is not constant.

INTRODUCTION: Chronic kidney disease (CKD) is a progressive disease leading to loss of glomerular filtration rate (ΔGFR, measured in ml/min/1.73 m(2)/year). ΔGFR is usually assumed to be constant, but the hyperfiltration theory suggests that it accelerates in severe uraemia. A retrospective analysis of estimated GFR (eGFR) calculated from the Modification of Diet in Renal Disease equation was performed to evaluate whether ΔGFR is constant or accelerating. METHODS: 1,441 patients attending a nephrology clinic over a 21-year period, with an initial eGFR <60 ml/min/1.73 m(2) and an observation period ≥2 years, were included. eGFR was calculated from all creatinine measurements. 420 patients developed end-stage renal disease (ESRD). First- and second-order polynomial regression analysis of eGFR against time was performed for each patient individually. Patients had accelerating uraemia progression if the second-order term coefficient was negative. RESULTS: The initial eGFR was 30.8 ±15.1 ml/min/1.73 m(2). The second-order coefficient was median -0.15 ml/min/1.73 m(2)/year(2) (interquartile range -0.92, +0.34). Significantly more patients had an accelerating loss (62%, p < 0.001). Acceleration was mainly seen when eGFR was <30 ml/min. ΔGFR was mean 1.47 ± 4.5 ml/min/1.73 m(2)/year (male 1.67, female 1.22). ESRD patients lost 5.4 ± 5.4 ml/min/year/1.73 m(2) during the last year before ESRD. Accelerating loss was seen for all diagnoses except polycystic disease. Diagnoses with higher ΔGFR were polycystic renal disease (3.3 ml/min/1.73 m(2)/year), hypertensive nephropathy (2.1 ml/min/1.73 m(2)/year) and diabetic nephropathy (2.6 ml/min/ 1.73 m(2)/year). There was no evidence of improvement in overall uraemia progression during the period of observation. CONCLUSIONS: Uraemia progression in CKD stages 3-5 is not linear, but shows an accelerating trend. This suggests that hyperfiltration mechanisms play a role in CKD progression. ESRD cannot thus be predicted from previous ΔGFR alone.

Case-control study of gadodiamide-related nephrogenic systemic fibrosis.

BACKGROUND: Nephrogenic systemic fibrosis may be caused by gadolinium (Gd)-containing magnetic resonance imaging contrast agents. Most reported cases were associated with one particular agent, gadodiamide. Yet, unidentified cofactors might explain why only a minority of renal failure patients exposed to gadodiamide develop nephrogenic systemic fibrosis. METHODS: We conducted a case-control study of 19 histologically verified cases and 19 sex- and age-matched controls. All subjects had chronic renal failure when exposed to gadodiamide. Clinical, biochemical and pharmacological data were retrieved from medical records. RESULTS: Cases had been exposed to a mean gadodiamide dose of 0.29 mmol/kg (range 0.18-0.50) shortly before first signs of nephrogenic systemic fibrosis. Controls had been exposed to 0.28 mmol/kg (0.13-0.49). Cumulative gadodiamide exposure while in chronic kidney disease stage 5 was significantly higher among cases compared with controls (0.41 vs 0.31 mmol/kg, P = 0.05) and among severe cases (n = 9) compared with non-severe cases (0.49 vs 0.33 mmol/kg, P = 0.02). Severe cases developed primarily among patients in regular haemodialysis therapy at exposure. Cases had higher serum concentrations of ionized calcium and phosphate than controls and tended to receive higher doses of epoietin-beta than controls at time of exposure. Severe cases were treated with higher doses of epoietin-beta than non-severe cases at exposure (10.8 vs 4.4 10(3) IU/week, P = 0.02). CONCLUSIONS: Increasing cumulative gadodiamide exposure, high-dose epoietin-beta treatment, and higher serum concentrations of ionized calcium and phosphate increase the risk of gadodiamide-related nephrogenic systemic fibrosis in renal failure patients. Severe cases seem to develop primarily among patients in regular haemodialysis therapy at exposure.