Epidemiology and clinicopathological characteristics of native kidney disease in children in Flanders, Belgium

BACKGROUND

The Flemish Collaborative Glomerulonephritis Group (FCGG) registry is a population-based kidney biopsy registry that has been including all native kidney biopsies performed in children in Flanders (Belgium), since 2017.

METHODS

From 2017 to 2020, 148 pediatric (< 18 years) native kidney biopsies were included. Each biopsy received a histopathological and final nephrological diagnosis, and concordance between both was assessed. Disease chronicity, summarized by the Mayo Clinic Chronicity Score, was determined on 122 biopsies with > 5 glomeruli.

RESULTS

Kidney biopsy rate was high (29.0 biopsies per million children per year), median age was 10.0 years (IQR 5.8-14.7), and boys predominated (56.1% males). A total of 140 biopsies (94.6%) showed a representative pathology result. Glomerular disease was most prevalent, with IgA nephropathy/IgA vasculitis (43 biopsies, 29.1%) and minimal change disease (MCD) (29 biopsies, 19.6%) being the overall most frequent diagnoses. In general, diagnostic concordance was high (80.7%). In Alport syndrome and focal segmental glomerulosclerosis (FSGS), concordance was lower, as the nephrological diagnosis was often determined by results of genetic analysis. Nephrotic syndrome was the most frequent indication for kidney biopsy (31.8%) and was mainly caused by MCD and FSGS. The degree of disease chronicity on kidney biopsies was generally low, although 27.3% of biopsies with a diagnosis of FSGS showed moderate-to-severe chronic damage.

CONCLUSIONS

The presented epidemiological findings validate data from previous European registry studies and may inspire kidney biopsy registries worldwide to implement novel features such as clinicopathological concordance and chronicity grading. A higher resolution version of the Graphical abstract is available as Supplementary information.

Clinicopathological characteristics and disease chronicity in native kidney biopsies in Flanders

Background

The Flemish Collaborative Glomerulonephritis Group (FCGG) registry provides complete population data on kidney disease epidemiology in the region of Flanders (Belgium), as it captures all native kidney biopsies performed in its population of 6.5 million inhabitants.

Methods

From 2017 until 2019, 2054 adult kidney biopsies were included from 26 nephrology centers (one biopsy per patient). Data on nephrotic and nephritic syndrome were available in 1992 and 2026 biopsies, respectively. In a subgroup of 898 biopsies containing ≥10 glomeruli from 2018 to 2019, disease chronicity was graded using the Mayo Clinic Chronicity Score (MCCS). The association between clinical variables and MCCS was determined using simple and multiple linear regression models.

Results

Nephrotic syndrome (present in 378 patients, 19.0%) was most frequently caused by minimal change disease in younger patients (18-44 years), membranous nephropathy in older patients (45-74 years) and amyloidosis in the elderly (>75 years). Nephritic syndrome (present in 421 patients, 20.8%) was most frequently caused by immunoglobulin A nephropathy (IgAN) in younger patients (18-64 years) and ANCA-associated vasculitis (AAV) in older patients (>64 years). AAV and IgAN were the most frequent underlying diagnoses in biopsies in which crescents were identified. In multivariable analysis, acute and chronic kidney disease and diagnoses of diabetic kidney disease, nephrosclerosis and hyperoxaluria/hypercalcemic nephropathy were associated with the highest MCCS increases.

Conclusions

The FCGG registry validates data from previous Western European registries and provides a snapshot of disease chronicity in the whole biopsied Flemish population.

Trends in Mortality Due to Myocardial Infarction, Stroke, and Pulmonary Embolism in Patients Receiving Dialysis

IMPORTANCE

During the past decades, improvements in the prevention and management of myocardial infarction, stroke, and pulmonary embolism have led to a decline in cardiovascular mortality in the general population. However, it is unknown whether patients receiving dialysis have also benefited from these improvements.

OBJECTIVE

To assess the mortality rates for myocardial infarction, stroke, and pulmonary embolism in a large cohort of European patients receiving dialysis compared with the general population.

DESIGN, SETTING, AND PARTICIPANTS

In this cohort study, adult patients who started dialysis between 1998 and 2015 from 11 European countries providing data to the European Renal Association Registry were and followed up for 3 years. Data were analyzed from September 2020 to February 2022.

EXPOSURES

Start of dialysis.

MAIN OUTCOMES AND MEASURES

The age- and sex-standardized mortality rate ratios (SMRs) with 95% CIs were calculated by dividing the mortality rates in patients receiving dialysis by the mortality rates in the general population for 3 equal periods (1998-2003, 2004-2009, and 2010-2015).

RESULTS

In total, 220 467 patients receiving dialysis were included in the study. Their median (IQR) age was 68.2 (56.5-76.4) years, and 82 068 patients (37.2%) were female. During follow-up, 83 912 patients died, of whom 7662 (9.1%) died because of myocardial infarction, 5030 (6.0%) died because of stroke, and 435 (0.5%) died because of pulmonary embolism. Between the periods 1998 to 2003 and 2010 to 2015, the SMR of myocardial infarction decreased from 8.1 (95% CI, 7.8-8.3) to 6.8 (95% CI, 6.5-7.1), the SMR of stroke decreased from 7.3 (95% CI, 7.0-7.6) to 5.8 (95% CI, 5.5-6.2), and the SMR of pulmonary embolism decreased from 8.7 (95% CI, 7.6-10.1) to 5.5 (95% CI, 4.5-6.6).

CONCLUSIONS AND RELEVANCE

In this cohort study of patients receiving dialysis, mortality rates for myocardial infarction, stroke, and pulmonary embolism decreased more over time than in the general population.

Epidemiology of native kidney disease in Flanders: results from the FCGG kidney biopsy registry

Background

The Flemish Collaborative Glomerulonephritis Group (FCGG) registry is the first population-based native kidney biopsy registry in Flanders, Belgium. In this first analysis, we report on patient demographics, frequency distribution and incidence rate of biopsied kidney disease in adults in Flanders.

Methods

From January 2017 to December 2019, a total of 2054 adult first native kidney biopsies were included. A ‘double diagnostic coding’ strategy was used, in which every biopsy sample received a histopathological and final clinical diagnosis. Frequency distribution and incidence rate of both diagnoses were reported and compared with other European registries.

Results

The median age at biopsy was 61.1 years (interquartile range, 46.1–71.7); male patients were more prevalent (62.1%) and biopsy incidence rate was 129.3 per million persons per year. Immunoglobulin A nephropathy was the most frequently diagnosed kidney disease (355 biopsies, 17.3% of total) with a similar frequency as in previously published European registries. The frequency of tubulointerstitial nephritis (220 biopsies, 10.7%) and diabetic kidney disease (154 biopsies, 7.5%) was remarkably higher, which may be attributed to changes in disease incidence as well as biopsy practices. Discordances between histopathological and final clinical diagnoses were noted and indicate areas for improvement in diagnostic coding systems.

Conclusions

The FCGG registry, with its ‘double diagnostic coding’ strategy, provides useful population-based epidemiological data on a large Western European population and allows subgroup selection for future research.

Incidence of Kidney Replacement Therapy and Subsequent Outcomes Among Patients With Systemic Lupus Erythematosus: Findings From the ERA Registry

RATIONALE AND OBJECTIVE

There is a dearth of data characterizing patients requiring kidney replacement therapy (KRT) for kidney failure due to systemic lupus erythematosus (SLE) and their clinical outcomes. The aim of this study was to describe trends in incidence and prevalence of KRT among these patients as well as to compare their outcomes to patients treated with KRT for diseases other than SLE.

STUDY DESIGN

Retrospective cohort study based on kidney registry data.

SETTING & PARTICIPANTS

Patients recorded in 14 registries of patients receiving kidney replacement therapy that provided data to the European Renal Association (ERA) Registry between 1992 and 2016.

PREDICTOR

SLE as cause of kidney failure.

OUTCOMES

Incidence and prevalence of KRT, patient survival while receiving KRT, patient and graft survival after kidney transplantation, and specific causes of death.

ANALYTICAL APPROACH

Kaplan-Meier methods and Cox regression models were fit to compare patient survival between the SLE and non-SLE groups, overall KRT, dialysis and patient and graft survival after kidney transplantation.

RESULTS

In total, 1826 patients commenced KRT for kidney failure due to SLE, representing an incidence of 0.80 per million population (pmp) per year. The incidence remained stable during the study period (annual percent change=0.1 [95%CI: -0.6 ; 0.8]). Patient survival among patients with SLE receiving KRT was similar to survival within the comparator group (HR=1.11 [95%CI: 0.99-1.23]). After kidney transplantation, the risk of death was greater among patients with SLE than among patients within the comparator group (HR=1.25 [95%CI: 1.02-1.53]), while the risk of all-cause graft failure was similar (HR=1.09 [95%CI: 0.95-1.27]). Ten-year patient overall survival on KRT, and patient and graft survival after kidney transplantation improved over the study period (HR=0.71 [95%CI: 0.56-0.91], 0.43 [0.27-0.69] and 0.60 [0.43-0.84], respectively). Patients with SLE receiving KRT were significantly more likely to die from infections (24.8%) than patients in the comparator group (16.9%, p<0.001).

LIMITATIONS

No data were available on extrarenal manifestations of SLE, drug treatments, comorbidities, kidney transplant characteristics, or relapses of SLE.

CONCLUSION

The prognosis of patients with SLE receiving KRT has improved over time. Survival of patients with SLE requiring KRT was similar when compared to patients requiring KRT due to other causes of kidney failure. Survival following kidney transplantation was worse among patients with SLE.

Does kidney transplantation with a standard or expanded criteria donor improve patient survival? Results from a Belgian cohort

BACKGROUND

Changes in recipient and donor factors have reopened the question of survival benefits of kidney transplantation versus dialysis.

METHODS

We analysed survival among 3808 adult Belgian patients waitlisted for a first deceased donor kidney transplant from 2000 to 2012. The primary outcome was mortality during the median waiting time plus 3 years of follow-up after transplantation or with continued dialysis. Outcomes were analysed separately for standard criteria donor (SCD) and expanded criteria donor (ECD) kidney transplants. We adjusted survival analyses for recipient age (20-44, 45-64 and ≥65 years), sex and diabetes as the primary renal disease.

RESULTS

Among patients ≥65 years of age, only SCD transplantation provided a significant survival benefit compared with dialysis, with a mortality of 16.3% [95% confidence interval (CI) 13.2-19.9] with SCD transplantation, 20.5% (95% CI 16.1-24.6) with ECD transplantation and 24.6% (95% CI 19.4-29.5) with continued dialysis. Relative mortality risk was increased in the first months after transplantation compared with dialysis, with equivalent risk levels reached earlier with SCD than ECD transplantation in all age groups.

CONCLUSIONS

The results of this study suggest that older patients might gain a survival benefit with SCD transplantation versus dialysis, but any survival benefit with ECD transplantation versus dialysis may be small.

Effect of comorbidities on survival in patients >80 years of age at onset of renal replacement therapy: data from the ERA-EDTA Registry

BACKGROUND

The number of elderly patients on renal replacement therapy (RRT) is increasing. The survival and quality of life of these patients may be lower if they have multiple comorbidities at the onset of RRT. The aim of this study was to explore whether the effect of comorbidities on survival is similar in elderly RRT patients compared with younger ones.

METHODS

Included were 9333 patients ≥80 years of age and 48 352 patients 20-79 years of age starting RRT between 2010 and 2015 from 15 national or regional registries submitting data to the European Renal Association-European Dialysis and Transplantation Association Registry. Patients were followed until death or the end of 2016. Survival was assessed by Kaplan-Meier curves and the relative risk of death associated with comorbidities was assessed by Cox regression analysis.

RESULTS

Patients ≥80 years of age had a greater comorbidity burden than younger patients. However, relative risks of death associated with all studied comorbidities (diabetes, ischaemic heart disease, chronic heart failure, cerebrovascular disease, peripheral vascular disease and malignancy) were significantly lower in elderly patients compared with younger patients. Also, the increase in absolute mortality rates associated with an increasing number of comorbidities was smaller in elderly patients.

CONCLUSIONS

Comorbidities are common in elderly patients who enter RRT, but the risk of death associated with comorbidities is less than in younger patients. This should be taken into account when assessing the prognosis of elderly RRT patients.

Incidence, Characteristics, and Outcome of COVID-19 in Adults on Kidney Replacement Therapy: A Regionwide Registry Study

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection disproportionally affects frail, elderly patients and those with multiple chronic comorbidities. Whether patients on RRT have an additional risk because of their specific exposure and complex immune dysregulation is controversial.

METHODS

To describe the incidence, characteristics, and outcomes of SARS-CoV-2 infection, we conducted a prospective, multicenter, region-wide registry study in adult patients on RRT versus the general population from March 2 to May 25, 2020. This study comprised all patients undergoing RRT in the Flanders region of Belgium, a country that has been severely affected by coronavirus disease 2019 (COVID-19).

RESULTS

At the end of the epidemic wave, crude and age-standardized cumulative incidence rates of SARS-CoV-2 infection were 5.3% versus 2.5%, respectively, among 4297 patients on hemodialysis, and 1.4% versus 1.6%, respectively, among 3293 patients with kidney transplants (compared with 0.6% in the general population). Crude and age-standardized cumulative mortality rates were 29.6% versus 19.9%, respectively, among patients on hemodialysis, and 14.0% versus 23.0%, respectively, among patients with transplants (compared with 15.3% in the general population). We found no excess mortality in the hemodialysis population when compared with mean mortality rates during the same 12-week period in 2015-2019 because COVID-19 mortality was balanced by lower than expected mortality among uninfected patients. Only 0.18% of the kidney transplant population died of SARS-CoV-2 infection.

CONCLUSIONS

Mortality associated with SARS-CoV-2 infection is high in patients on RRT. Nevertheless, the epidemic's overall effect on the RRT population remained remarkably limited in Flanders. Calculation of excess mortality and age standardization provide a more reliable picture of the mortality burden of COVID-19 among patients on RRT.

Variability in the incidence of renal replacement therapy over time in Western industrialized countries: A retrospective registry analysis

Introduction

A growing number of patients started renal replacement therapy (RRT) in Western industrialized countries between 1980 an early 2000s. Thereafter reports from national and international registries suggest a trend towards stabilization and sometimes a decrease in the incidence rate.

Aim

To investigate the differences in overall and age-specific incidence rates between industrialized countries from 1998 until 2013. Secondly, to investigate changes in incidence rates over time and their association with specific age categories.

Method

We extracted the unadjusted overall incidence of RRT and age-specific incidence rates from renal registry reports in Europe, the United States, Canada, Australia and New Zealand. Time trends in the incidence rate by country and age categories were analyzed by Joinpoint regression analysis.

Results

The incidence rate in 2013 ranged from 89 per million population (pmp) in Finland to 363 pmp in the US. Incidence rates in the lower age categories (20–64 year) were similar between countries and remained stable over time. Higher incidence countries were characterized by higher numbers of patients in both the 65–74 and ≥75 year categories starting RRT.

Joinpoint analysis confirmed that most countries had significant reductions in the incidence rate at the end of the study period. These reductions were explained by lower numbers of older patients starting RRT and were observed also in countries with lower overall incidence rates.

Conclusion

This study confirmed different incidence rates of RRT between industrialized countries worldwide. Countries with the highest overall incidence rates also had the highest incidence rates in the oldest age categories. Since the early 2000’s the number of older patients starting RRT is either stabilizing or even decreasing in most countries. This reduction is universal and is also observed in countries with previously low incidence rates.

The ERA-EDTA Registry Annual Report 2017: a summary

Background

This article presents a summary of the 2017 Annual Report of the European Renal Association–European Dialysis and Transplant Association (ERA-EDTA) Registry and describes the epidemiology of renal replacement therapy (RRT) for end-stage renal disease (ESRD) in 37 countries.

Methods

The ERA-EDTA Registry received individual patient data on patients undergoing RRT for ESRD in 2017 from 32 national or regional renal registries and aggregated data from 21 registries. The incidence and prevalence of RRT, kidney transplantation activity and survival probabilities of these patients were calculated.

Results

In 2017, the ERA-EDTA Registry covered a general population of 694 million people. The incidence of RRT for ESRD was 127 per million population (pmp), ranging from 37 pmp in Ukraine to 252 pmp in Greece. A total of 62% of patients were men, 52% were ≥65 years of age and 23% had diabetes mellitus as the primary renal disease. The treatment modality at the onset of RRT was haemodialysis for 85% of patients. On 31 December 2017, the prevalence of RRT was 854 pmp, ranging from 210 pmp in Ukraine to 1965 pmp in Portugal. The transplant rate in 2017 was 33 pmp, ranging from 3 pmp in Ukraine to 103 pmp in the Spanish region of Catalonia. For patients commencing RRT during 2008–12, the unadjusted 5-year patient survival probability for all RRT modalities combined was 50.8%.

P0114BENEFITS AND CHALLENGES OF A RENAL BIOPSY REGISTRY AND NETWORK - FCGG EXPERIENCE

Background and Aims

End December 2016, a renal biopsy network in the Flemish region (Belgium) was founded as a collaboration between the renal pathologists and nephrologists. This FCGG network introduced a uniform renal biopsy request form, a well-structured report form of the renal pathology examination and a comprehensive list of renal pathology diagnoses.

Method

Following informed consent [99.5%] and in compliance with GDPR, the registration of the renal biopsies consists of basic categorical renal data, structured renal pathology information and the final clinical renal disease.

Results

In 2017 and 2018, 1385 renal biopsies were registered – 10.5 per million inhabitants per year; in addition, 28 patients had a repeat biopsy in the same time frame (2%). Of the pediatric patients ( age &lt; 18 years; N=92; 6.6%), 23 had IgA nephropathy, 20 a minimal change disease and 15 another type of glomerulonephritis. The biopsy was reported as normal or non-diagnostic in 15 patients (16%) – the majority was clinically considered as glomerulonephritis. The spectrum of the adult population was quite similar across gender and age groups: 56% glomerulonephritis [= IgA nephropathy [19%] + FSGS [8%] + pauci-immune glomerulonephritis [7%] + other GN [22%] ), 10% tubulo-interstitial nephritis, 7% acute tubular necrosis [ATN], 7% diabetes mellitus, and 7% nephroangiosclerosis. Exceptions are pauci-immune glomerulonephritis as the most important renal disease in women aged 65 years and older, and lupus nephritis as the second most important glomerulonephritis in women aged 18-44 years. Only a small percentage of adult renal biopsies yielded no result (7%), clinically interpreted as glomerulonephritis in 50% of the cases.

Conclusion

The FCGG network has provided a more intense collaboration between renal pathologists and nephrologists mainly by standardizing the renal biopsy reading and reporting across all centers. More precise estimates of the prevalent renal diseases were provided for the first time; however, in order to get full information, renal diseases diagnosed by other techniques ( serology, genetic analysis ) should also be collected in the future. Efforts will be done to coordinate the clinical care of renal diseases, particularly the more rare renal diseases, and to offer access to new therapeutic molecules or new schemes, through this super-regional network.

P1630IS THERE ALWAYS A SURVIVAL BENEFIT WITH KIDNEY TRANSPLANTATION? RESULTS FROM A BELGIAN COHORT

Background and Aims

Older studies have shown a survival benefit with kidney transplantation compared to dialysis, even for patients older than 60 years. However, due to important evolutions such as older recipient age and the use of less-than-optimal quality donors, it is unclear if the survival benefit with transplantation still holds true nowadays.

Method

Patient survival was analyzed for 3808 Belgian patients waitlisted for a first deceased donor kidney transplant between 2000 to 2012. Patients were divided into age categories (20-44y, 45-64y, ≥65y). Primary outcome was the comparison of mortality during median waiting time plus 3 years follow-up, either after transplantation or when remaining on dialysis. Outcomes were analyzed separately for those receiving a standard criteria donor (SCD) or an expanded criteria donor (ECD) transplant. The survival analyses were adjusted for age, sex and primary renal disease.

Results

Among patients ≥ 65 years old, only SCD transplantation provided a significant survival benefit compared to dialysis: mortality was 16.3 % (95 % CI: 13.2–19.9 %) with SCD transplantation, 20.5 % (16.1–24.6 %) with ECD transplantation, and 24.6 % (19.5–29.5 %) when remaining on dialysis. Relative mortality risk was increased in the first months after transplantation compared to dialysis, with equal risk levels being reached earlier for SCD than ECD transplantations in all age groups.

Conclusion

This study suggests that older patients have a survival benefit with SCD transplantation versus dialysis, but the survival benefit with ECD transplantation versus dialysis may be small or non-existent.

Changes in co-morbidity pattern in patients starting renal replacement therapy in Europe-data from the ERA-EDTA Registry

Background

Patients starting renal replacement therapy (RRT) for end-stage renal disease often present with one or more co-morbidities. This study explored the prevalence of co-morbidities in patients who started RRT in Europe during the period from 2005 to 2014.

Methods

Using data from patients aged 20 years or older from all 11 national or regional registries providing co-morbidity data to the European Renal Association - European Dialysis and Transplant Association Registry, we examined the prevalence of the following co-morbidities: diabetes mellitus (DM) (primary renal disease and/or co-morbidity), ischaemic heart disease (IHD), congestive heart failure (CHF), peripheral vascular disease (PVD), cerebrovascular disease (CVD) and malignancy.

Results

Overall, 70% of 7578 patients who initiated RRT in 2014 presented with at least one co-morbidity: 39.0% presented with DM, 25.0% with IHD, 22.3% with CHF, 17.7% with PVD, 16.4% with malignancy and 15.5% with CVD. These percentages differed substantially between countries. Co-morbidities were more common in men than in women, in older patients than in younger patients, and in patients on haemodialysis at Day 91 when compared with patients on peritoneal dialysis. Between 2005 and 2014 the prevalence of DM and malignancy increased over time, whereas the prevalence of IHD and PVD declined.

Conclusions

More than two-thirds of patients initiating RRT in Europe have at least one co-morbidity. With the rising age at the start of RRT over the last decade, there have been changes in the co-morbidity pattern: the prevalence of cardiovascular co-morbidities decreased, while the prevalence of DM and malignancy increased.

The European Renal Association - European Dialysis and Transplant Association (ERA-EDTA) Registry Annual Report 2016: a summary

Background

This article summarizes the ERA-EDTA Registry’s 2016 Annual Report, by describing the epidemiology of renal replacement therapy (RRT) for end-stage renal disease (ESRD) in 2016 within 36 countries.

Methods

In 2017 and 2018, the ERA-EDTA Registry received data on patients undergoing RRT for ESRD in 2016 from 52 national or regional renal registries. In all, 32 registries provided individual patient data and 20 provided aggregated data. The incidence and prevalence of RRT and the survival probabilities of these patients were determined.

Results

In 2016, the incidence of RRT for ESRD was 121 per million population (pmp), ranging from 29 pmp in Ukraine to 251 pmp in Greece. Almost two-thirds of patients were men, over half were aged ≥65 years and almost a quarter had diabetes mellitus as their primary renal diagnosis. Treatment modality at the start of RRT was haemodialysis for 84% of patients. On 31 December 2016, the prevalence of RRT was 823 pmp, ranging from 188 pmp in Ukraine to 1906 pmp in Portugal. In 2016, the transplant rate was 32 pmp, varying from 3 pmp in Ukraine to 94 pmp in the Spanish region of Catalonia. For patients commencing RRT during 2007–11, the 5-year unadjusted patient survival probability on all RRT modalities combined was 50.5%. For 2016, the incidence and prevalence of RRT were higher among men (187  and 1381 pmp) than women (101 and 827 pmp), and men had a higher rate of kidney transplantation (59 pmp) compared with women (33 pmp). For patients starting dialysis and for patients receiving a kidney transplant during 2007–11, the adjusted patient survival probabilities appeared to be higher for women than for men.

Characteristics and Outcomes of Patients With Systemic Sclerosis (Scleroderma) Requiring Renal Replacement Therapy in Europe: Results From the ERA-EDTA Registry

RATIONALE & OBJECTIVE

Data for outcomes of patients with end-stage renal disease (ESRD) secondary to systemic sclerosis (scleroderma) requiring renal replacement therapy (RRT) are limited. We examined the incidence and prevalence of ESRD due to scleroderma in Europe and the outcomes among these patients following initiation of RRT.

STUDY DESIGN

Registry study of incidence and prevalence and a matched cohort study of clinical outcomes.

SETTING & PARTICIPANTS

Patients represented in any of 19 renal registries that provided data to the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry between 2002 and 2013.

PREDICTOR

Scleroderma as the identified cause of ESRD.

OUTCOMES

Incidence and prevalence of ESRD from scleroderma. Recovery from RRT dependence, patient survival after ESRD, and graft survival after kidney transplantation.

ANALYTICAL APPROACH

Incidence and prevalence were calculated using population data from the European Union and standardized to population characteristics in 2005. Patient and graft survival were compared with 2 age- and sex-matched control groups without scleroderma: (1) diabetes mellitus as the cause of ESRD and (2) conditions other than diabetes mellitus as the cause of ESRD. Survival analyses were performed using Kaplan-Meier analysis and Cox regression.

RESULTS

342 patients with scleroderma (0.14% of all incident RRT patients) were included. Between 2002 and 2013, the range of adjusted annual incidence and prevalence rates of RRT for ESRD due to scleroderma were 0.11 to 0.26 and 0.73 to 0.95 per million population, respectively. Recovery of independent kidney function was greatest in the scleroderma group (7.6% vs 0.7% in diabetes mellitus and 2.0% in other primary kidney diseases control group patients, both P<0.001), though time required to achieve recovery was longer. The 5-year survival probability from day 91 of RRT among patients with scleroderma was 38.9% (95% CI, 32.0%-45.8%), whereas 5-year posttransplantation patient survival and 5-year allograft survival were 88.2% (95% CI, 75.3%-94.6%) and 72.4% (95% CI, 55.0%-84.0%), respectively. Adjusted mortality from day 91 on RRT was higher among patients with scleroderma than observed in both control groups (HRs of 1.25 [95% CI, 1.05-1.48] and 2.00 [95% CI, 1.69-2.39]). In contrast, patient and graft survival after kidney transplantation did not differ between patients with scleroderma and control groups.

LIMITATIONS

No data for extrarenal manifestations, treatment, or recurrence.

CONCLUSIONS

Survival of patients with scleroderma who receive dialysis for more than 90 days was worse than for those with other causes of ESRD. Patient survival after transplantation was similar to that observed among patients with ESRD due to other conditions. Patients with scleroderma had a higher rate of recovery from RRT dependence than controls.

Access to kidney transplantation in European adults aged 75-84 years and related outcomes: an analysis of the European Renal Association-European Dialysis and Transplant Association Registry

To what extent access to, and allocation of kidney transplants and survival outcomes in patients aged ≥75 years have changed over time in Europe is unclear. We included patients aged ≥75-84 years (termed older adults) receiving renal replacement therapy in thirteen European countries between 2005 and 2014. Country differences and time trends in access to, and allocation of kidney transplants were examined. Survival outcomes were determined by Cox regression analyses. Between 2005 and 2014, 1392 older adult patients received 1406 transplants. Access to kidney transplantation varied from ~0% (Slovenia, Greece and Denmark) to ~4% (Norway and various Spanish regions) of all older adult dialysis patients, and overall increased from 0.3% (2005) to 0.9% (2014). Allocation of kidney transplants to older adults overall increased from 0.8% (2005) to 3.2% (2014). Seven-year unadjusted patient and graft survival probabilities were 49.1% (95% confidence interval, 95% CI: 43.6; 54.4) and 41.7% (95% CI: 36.5; 46.8), respectively, with a temporal trend towards improved survival outcomes. In conclusion, in the European dialysis population aged ≥75-84 years access to kidney transplantation is low, and allocation of kidney transplants remains a rare event. Though both are increasing with time and vary considerably between countries. The trend towards improved survival outcomes is encouraging. This information can aid informed decision-making regarding treatment options.

Lifetime risk of renal replacement therapy in Europe: a population-based study using data from the ERA-EDTA Registry

Background

Upcoming KDIGO guidelines for the evaluation of living kidney donors are expected to move towards a personal risk-based evaluation of potential donors. We present the age and sex-specific lifetime risk of renal replacement therapy (RRT) for end-stage renal disease in 10 European countries.

Methods

We defined lifetime risk of RRT as the cumulative incidence of RRT up to age 90 years. We obtained RRT incidence rates per million population by 5-year age groups and sex using data from the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry, and used these to estimate the cumulative incidence of RRT, adjusting for competing mortality risk.

Results

Lifetime risk of RRT varied from 0.44% to 2.05% at age 20 years and from 0.17% to 1.59% at age 70 years across countries, and was twice as high in men as in women. Lifetime RRT risk decreased with age, ranging from an average of 0.77% to 0.44% in 20- to- 70-year-old women, and from 1.45% to 0.96% in 20- to- 70-year-old men. The lifetime risk of RRT increased slightly over the past decade, more so in men than in women. However, it appears to have stabilized or even decreased slightly in more recent years.

Conclusions

The lifetime risk of RRT decreased with age, was lower in women as compared with men of equal age and varied considerably throughout Europe. Given the substantial differences in lifetime risk of RRT between the USA and Europe, country-specific estimates should be used in the evaluation and communication of the risk of RRT for potential living kidney donors.

Impact of food processing and detoxification treatments on mycotoxin contamination

Mycotoxins are fungal metabolites commonly occurring in food, which pose a health risk to the consumer. Maximum levels for major mycotoxins allowed in food have been established worldwide. Good agricultural practices, plant disease management, and adequate storage conditions limit mycotoxin levels in the food chain yet do not eliminate mycotoxins completely. Food processing can further reduce mycotoxin levels by physical removal and decontamination by chemical or enzymatic transformation of mycotoxins into less toxic products. Physical removal of mycotoxins is very efficient: manual sorting of grains, nuts, and fruits by farmers as well as automatic sorting by the industry significantly lowers the mean mycotoxin content. Further processing such as milling, steeping, and extrusion can also reduce mycotoxin content. Mycotoxins can be detoxified chemically by reacting with food components and technical aids; these reactions are facilitated by high temperature and alkaline or acidic conditions. Detoxification of mycotoxins can also be achieved enzymatically. Some enzymes able to transform mycotoxins naturally occur in food commodities or are produced during fermentation but more efficient detoxification can be achieved by deliberate introduction of purified enzymes. We recommend integrating evaluation of processing technologies for their impact on mycotoxins into risk management. Processing steps proven to mitigate mycotoxin contamination should be used whenever necessary. Development of detoxification technologies for high-risk commodities should be a priority for research. While physical techniques currently offer the most efficient post-harvest reduction of mycotoxin content in food, biotechnology possesses the largest potential for future developments.

The Relative Impact of Presumed-Consent Legislation on Thoracic Organ Donation in the Eurotransplant Area

A country's organ donation rate and hence the availability of thoracic organs can be increased by organizational measures, by legislative incentives, and by increasing awareness among the public and healthcare professionals. We analyzed the relative impact of organ procurement legislation or policy on heart and lung donation rates per million population per year in the four countries participating in the Eurotransplant organization (population, 112.7 million) between January 1992 and December 1994. Within this organization, Austria and Belgium have presumed-consent legislation, whereas Germany and the Netherlands have an opting-in (explicit-consent) policy. Although practices vary even among countries with similar policies (eg, in Belgium, relatives of the donor retain the right to object to procurement of organs in the absence of an explicit consent from the deceased before death), rates of heart and lung donation were at least twice as high in the two countries with presumed-consent legislation as in the two countries that rely on a policy of explicit consent from the donor's next of kin.

External Validation of a risk stratification model to assist shared decision making for patients starting renal replacement therapy

Background

Shared decision making is nowadays acknowledged as an essential step when deciding on starting renal replacement therapy. Valid risk stratification of prognosis is, besides discussing quality of life, crucial in this regard. We intended to validate a recently published risk stratification model in a large cohort of incident patients starting renal replacement therapy in Flanders.

Methods

During 3 years (2001–2003), the data set collected for the Nederlandstalige Belgische Vereniging voor Nefrologie (NBVN) registry was expanded with parameters of comorbidity. For all incident patients, the abbreviated REIN score(aREIN), being the REIN score without the parameter “mobility”, was calculated, and prognostication of mortality at 3, 6 and 12 month after start of renal replacement therapy (RRT) was evaluated.

Results

Three thousand four hundred seventy-two patients started RRT in Flanders during the observation period (mean age 67.6 ± 14.3, 56.7 % men, 33.6 % diabetes). The mean aREIN score was 4.1 ± 2.8, and 56.8, 23.1, 12.6 and 7.4 % of patients had a score of ≤4, 5–6, 7–8 or ≥9 respectively. Mortality at 3, 6 and 12 months was 8.6, 14.1 and 19.6 % in the overall and 13.2, 21.5 and 31.9 % in the group with age >75 respectively. In RoC analysis, the aREIN score had an AUC of 0.74 for prediction of survival at 3, 6 and 12 months. There was an incremental increase in mortality with the aREIN score from 5.6 to 45.8 % mortality at 6 months for those with a score ≤4 or ≥9 respectively.

Conclusion

The aREIN score is a useful tool to predict short term prognosis of patients starting renal replacement therapy as based on comorbidity and age, and delivers meaningful discrimination between low and high risk populations. As such, it can be a useful instrument to be incorporated in shared decision making on whether or not start of dialysis is worthwhile.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-016-0253-3) contains supplementary material, which is available to authorized users.

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.

The changing trends and outcomes in renal replacement therapy: data from the ERA-EDTA Registry

BACKGROUND

This study examines the time trends in incidence, prevalence, patient and kidney allograft survival and causes of death (COD) in patients receiving renal replacement therapy (RRT) in Europe.

METHODS

Eighteen national or regional renal registries providing data to the European Renal Association-European Dialysis and Transplant Association Registry between 1998 and 2011 were included. Incidence and prevalence time trends between 2001 and 2011 were studied with Joinpoint and Poisson regression. Patient and kidney allograft survival and COD between 1998 and 2011 were analysed using Kaplan-Meier and competing risk methods and Cox regression.

RESULTS

From 2001 to 2008, the adjusted incidence of RRT rose by 1.1% (95% CI: 0.6, 1.7) annually to 131 per million population (pmp). During 2008-2011, the adjusted incidence fell by 2.2% (95% CI: -4.2, -0.2) annually to 125 pmp. This decline occurred predominantly in patients aged 45-64 years, 65-74 years and in the primary renal diseases diabetes mellitus type 1 and 2, renovascular disease and glomerulonephritis. Between 2001 and 2011, the overall adjusted prevalence increased from 724 to 1032 pmp (+3.3% annually, 95% CI: 2.8, 3.8). The adjusted 5-year patient survival on RRT improved between 1998-2002 and 2003-2007 [adjusted hazard ratio (HRa) 0.85, 95% CI: 0.84, 0.86]. Comparing these time periods, the risk of cardiovascular deaths fell by 25% (HRa 0.75, 95% CI: 0.74, 0.77). However the risk of malignant death rose by 9% (HRa 1.09, 95% CI: 1.03, 1.16) in patients ≥65 years.

CONCLUSION

This European study shows a declining RRT incidence, particularly in patients aged 45-64 years, 65-74 years and secondary to diabetic nephropathy. Encouragingly, the adjusted RRT patient survival continues to improve. The risk of cardiovascular death has decreased, though the risk of death from malignancy has increased in the older population.

Renal replacement therapy in Europe: a summary of the 2012 ERA-EDTA Registry Annual Report

BACKGROUND

This article summarizes the 2012 European Renal Association-European Dialysis and Transplant Association Registry Annual Report (available at www.era-edta-reg.org) with a specific focus on older patients (defined as ≥65 years).

METHODS

Data provided by 45 national or regional renal registries in 30 countries in Europe and bordering the Mediterranean Sea were used. Individual patient level data were received from 31 renal registries, whereas 14 renal registries contributed data in an aggregated form. The incidence, prevalence and survival probabilities of patients with end-stage renal disease (ESRD) receiving renal replacement therapy (RRT) and renal transplantation rates for 2012 are presented.

RESULTS

In 2012, the overall unadjusted incidence rate of patients with ESRD receiving RRT was 109.6 per million population (pmp) (n = 69 035), ranging from 219.9 pmp in Portugal to 24.2 pmp in Montenegro. The proportion of incident patients ≥75 years varied from 15 to 44% between countries. The overall unadjusted prevalence on 31 December 2012 was 716.7 pmp (n = 451 270), ranging from 1670.2 pmp in Portugal to 146.7 pmp in the Ukraine. The proportion of prevalent patients ≥75 years varied from 11 to 32% between countries. The overall renal transplantation rate in 2012 was 28.3 pmp (n = 15 673), with the highest rate seen in the Spanish region of Catalonia. The proportion of patients ≥65 years receiving a transplant ranged from 0 to 35%. Five-year adjusted survival for all RRT patients was 59.7% (95% confidence interval, CI: 59.3-60.0) which fell to 39.3% (95% CI: 38.7-39.9) in patients 65-74 years and 21.3% (95% CI: 20.8-21.9) in patients ≥75 years.

New primary renal diagnosis codes for the ERA-EDTA

The European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry has produced a new set of primary renal diagnosis (PRD) codes that are intended for use by affiliated registries. It is designed specifically for use in renal centres and registries but is aligned with international coding standards supported by the WHO (International Classification of Diseases) and the International Health Terminology Standards Development Organization (SNOMED Clinical Terms). It is available as supplementary material to this paper and free on the internet for non-commercial, clinical, quality improvement and research use, and by agreement with the ERA-EDTA Registry for use by commercial organizations. Conversion between the old and the new PRD codes is possible. The new codes are very flexible and will be actively managed to keep them up-to-date and to ensure that renal medicine can remain at the forefront of the electronic revolution in medicine, epidemiology research and the use of decision support systems to improve the care of patients.

Cardiovascular and noncardiovascular mortality among men and women starting dialysis

BACKGROUND AND OBJECTIVES

Although women have a survival advantage in the general population, women on dialysis have similar mortality to men. We hypothesized that this paired mortality risk during dialysis may be explained by a relative excess of cardiovascular-related mortality in women.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We compared 5-year age-stratified cardiovascular and noncardiovascular mortality rates, relative risks, and hazard ratios in a European cohort of incident adult dialysis patients (European Renal Association-European Dialysis and Transplant Association [ERA-EDTA] Registry) with the European general population (Eurostat). Cause of death was recorded by ERA-EDTA codes in dialysis patients and by International Statistical Classification of Diseases codes in the general population.

RESULTS

Overall, sex did not have a predictive effect on outcome in dialysis. Stratification into age categories and causes of death showed greater noncardiovascular mortality in young women (<45 years). In other age categories (45 to 55 and >55 years), women presented lower cardiovascular mortality. This cardiovascular benefit was, however, smaller than in the general population. Stratification by diabetic nephropathy showed that diabetic women in all age categories remained at increased mortality risk compared with men, an effect mainly attributed to the noncardiovascular component.

CONCLUSIONS

Mortality rates and causes of death in men and women on dialysis vary with age. Increased noncardiovascular mortality may explain the loss of the survival advantage of women on dialysis. Both young and diabetic women starting dialysis are at a higher mortality risk than equal men.

Simple assessment of patient's stage of chronic kidney disease using eGFR-MDRD nomograms

European as well as US guidelines recommend the Modification of Diet in Renal Disease (MDRD) formula to determine the glomerular filtration rate (GFR) and, based on this, the staging of chronic kidney disease (CKD). The diagnosis of CKD is only established when a reduced eGFR has been observed for 3 months or longer. Because the MDRD equation is very complex, the calculation of eGFR is not possible without help from calculators or computers. Therefore, we converted this equation into simple, easy to use colour nomograms. These were drawn separately for men and women, on one hand, and for whites and blacks, on the other. These nomograms allow the determination of a patient's eGFR in a quick and easy way and at any location.

Level of renal function in patients starting dialysis: an ERA-EDTA Registry study

BACKGROUND

The aims of this European study were (i) to compare the level of renal function at the start of dialysis between age groups, gender, primary renal disease, comorbid conditions, treatment modality, time periods and countries, and (ii) to determine which baseline characteristics are associated with the level of renal function at the start of dialysis.

METHODS

Renal registries participating in the European Renal Association-European Dialysis and Transplant Association Registry provided data on serum creatinine 0-4 weeks before the start of dialysis in incident dialysis patients in 1999 and 2003. Data were available in 11 472 patients from nine renal registries. Glomerular filtration rate (GFR) was estimated by the four-variable Modification of Diet in Renal Disease equation.

RESULTS

The unadjusted median eGFR at the start of dialysis was 7.0 mL/min/1.73 m(2) in the 1999 data (median serum creatinine 7.5 mg/dL) and 7.7 mL/min/1.73 m(2) in the 2003 data (serum creatinine 7.0 mg/dL). Using linear regression with adjustment for the other covariates, older patients, males, patients with diabetes mellitus, hypertension/renal vascular disease (HT/RVD) as primary renal disease (vs glomerulonephritis), ischaemic heart disease or peripheral vascular disease and patients starting on peritoneal dialysis (PD) initiated dialysis at higher levels of eGFR (range Δ eGFR: 0.1-1.2 mL/min/1.73 m(2)). Using the same analyses, eGFR differed between countries (range: 6.5-8.6 mL/min/1.73 m(2)).

CONCLUSIONS

During 2003, patients started dialysis at somewhat higher eGFR levels than those starting during 1999. There were also international differences in eGFR. Such differences may, at least in part, be explained by differences in creatinine measurement methods between countries and time periods. Finally, older patients, males, patients with HT/RVD or comorbidity and those starting on PD had slightly higher eGFR levels than younger patients, females, those with glomerulonephritis, without comorbidity and those starting on haemodialysis. Further research is needed into other, more clinically related factors affecting the decision to start dialysis.

Cardiovascular and noncardiovascular mortality among patients starting dialysis

CONTEXT

Cardiovascular mortality is considered the main cause of death in patients receiving dialysis and is 10 to 20 times higher in such patients than in the general population.

OBJECTIVE

To evaluate if high overall mortality in patients starting dialysis is a consequence of increased cardiovascular mortality risk only or whether noncardiovascular mortality is equally increased.

DESIGN, SETTING, AND PATIENTS

Using data from between January 1, 1994, and January 1, 2007, age-stratified mortality in a European cohort of adults starting dialysis and receiving follow-up for a mean of 1.8 (SD, 1.1) years (European Renal Association-European Dialysis and Transplant Association [ERA-EDTA] Registry [N = 123,407]) was compared with the European general population (Eurostat).

MAIN OUTCOME MEASURES

Cause of death was recorded by ERA-EDTA codes in patients and matching International Statistical Classification of Diseases, 10th Revision codes in the general population. Standardized cardiovascular and noncardiovascular mortality rates, their ratio, difference, and relative excess of cardiovascular over noncardiovascular mortality were calculated.

RESULTS

Overall all-cause mortality rates in patients and the general population were 192 per 1000 person-years (95% confidence interval [CI], 190-193) and 12.055 per 1000 person-years (95% CI, 12.05-12.06), respectively. Cause of death was known for 90% of the patients and 99% of the general population. In patients, 16,654 deaths (39%) were cardiovascular and 21,654 (51%) were noncardiovascular. In the general population, 7,041,747 deaths (40%) were cardiovascular and 10,183,322 (58%) were noncardiovascular. Cardiovascular and noncardiovascular mortality rates in patients were respectively 38.1 per 1000 person-years (95% CI, 37.2-39.0) and 50.1 per 1000 person-years (95% CI, 48.9-51.2) higher than in the general population. On a relative scale, standardized cardiovascular and noncardiovascular mortality were respectively 8.8 (95% CI, 8.6-9.0) and 8.1 (95% CI, 7.9-8.3) times higher than in the general population. The ratio of these rates, ie, relative excess of cardiovascular over noncardiovascular mortality in patients starting dialysis compared with the general population, was 1.09 (95% CI, 1.06-1.12). Relative excess in a sensitivity analysis in which unknown/missing causes of death were regarded either as noncardiovascular or cardiovascular varied between 0.90 (95% CI, 0.88-0.93) and 1.39 (95% CI, 1.35-1.43).

CONCLUSION

Patients starting dialysis have a generally increased risk of death that is not specifically caused by excess cardiovascular mortality.

Impact of Convective Flow on Phosphorus Removal in Maintenance Hemodialysis Patients

OBJECTIVE

Hyperphosphatemia leads to increased risk of death in maintenance hemodialysis patients (MHD). This study investigated phosphorus (P) removal, P reduction rate (PRR), and P rebound, comparing on-line, high-volume hemodiafiltration in postdilution (HDF) and high-flux hemodialysis (HD) in a setting of an equal amount of produced dialysate solution in both modalities.

METHODS

A total of 22 MHD patients, treated with regular 3 x 4 hours HDF weekly, were randomly dialyzed with one 4-hour session of HDF and of HD. In both modalities, an equal amount of produced dialysate solution of 800 mL/minute was used. The only variable was the fact that in HDF, 100 mL/min of this produced dialysate solution was used as replacement fluid. The other parameters were kept identical: blood flow rate, 350 mL/min; high-flux polysulfone F80 dialyzer; and 4800 E monitor, (Fresenius, Bad Homburg, Germany). The P removal was measured in total spent dialysate and ultrafiltrate volumes. Statistical analyses were done with the paired t-test.

RESULTS

The mean total P removed with HDF was 1159 +/- 296 mg, and 972 +/- 312 mg with HD (P < .001), ie, 19% higher in HDF; PRR was significantly higher in HDF (63.3%) versus HD (58.6%) (P = .014). The mean serum P did not differ: 5.3 mg/dL in HDF and 5.2 mg/dL in HD. There was a linear correlation between serum P and P removal. With a serum P level up to 5 to 5.5 mg/dL, HDF achieved a higher P removal compared with HD. The difference gradually decreased as the serum P value increased. Above 7 mg/dL, no difference in total P removal was observed. There was a high but equal rebound percentage at 60 minutes in HDF (42%) and HD (39%) (P = .42). With HDF, no predialysis metabolic acidosis was noted.

CONCLUSIONS

Treatment with on-line HDF in postdilution resulted in a higher P removal and higher PRR compared with HD. The long-term implementation of this modality may result in a more optimal serum P control, without an increase in the number of or lengthening of the dialysis sessions.

A prognostic model for predicting waiting-list mortality for a total national cohort of adult heart-transplant candidates

BACKGROUND

Current trends in medical management of advanced heart failure and transplant medicine and the enactment of a national transplant law forced a change toward allocation driven by disease severity.

OBJECTIVE

The aim of this study was to create a model for predicting waiting-list survival on the basis of simple clinical parameters.

METHODS

The clinical profiles of all patients registered for heart transplantation in Germany in 1997 (n=889) were used as a derivation set, and the total German 1998 cohort (n=897) was used as a validation set. The model was validated by the c statistic and by comparison of risk stratified mortality rates. The validated model was fine tuned by the appropriate calibration procedures. The data were first classified into physiologic subscores: an urgency score, a left ventricular heart failure score, a right ventricular heart failure score, and a systemic heart failure score. A stepwise modeling procedure was undertaken using these subscores as factors as well as the recipient's age, ABO blood group, and body surface area.

RESULTS

The urgency and the left ventricular subscore were found to be significantly associated with waiting-list mortality. A summary index termed German Transplant Society (GTS) score was then calculated on the basis of seven parameters contained in these two subscores. The GTS score was able to predict waiting-list mortality risks for the 1998 cohort: 1-year mortality before transplantation was 71%, 34%, 11% for the high, medium, and low risk groups, respectively.

CONCLUSION

The use of this continuous disease severity index may improve the selection of cardiac transplant candidates.

Renal transplantation of highly sensitised patients via prioritised renal allocation programs. Shorter waiting time and above-average graft survival

BACKGROUND

Highly sensitised renal transplant candidates (HSP) have a reduced chance of receiving a transplant. In Eurotransplant (ET), two special allocation programs have been made available for such patients: the Highly Immunised Tray (HIT) program and the Acceptable Mismatch program (AM), albeit with different inclusion and exclusion criteria (HIT, current PRA% >or=85%; AM, current and/or historical PRA% >or=85%). When a suitable kidney is available for a patient, included in these special programs, the kidney is mandatory offered. In contrast, in the point score system of the standard ET kidney allocation procedure (ETKAS), HSP (PRA >or=85%) only get a marginal bonus according to their current sensitisation. It was tested whether the allocation priority of the two special allocation programs is justified from the perspective of transplant outcome.

METHODS

The post- transplant outcomes of recent consecutive cohorts of AM, HIT and HSP-ETKAS transplants were compared. The end points were initial graft function, rejection episodes during the first three months post-transplant, and 1-year kidney graft outcome.

RESULTS

Between January 1, 1997 and June 30, 1998, 101 HSP received a kidney-only transplant: 29 via AM, 39 via HIT and 33 via ETKAS. HLA-A,B,DR matching was more favourable in the AM and HIT allocation groups and their waiting times till transplantation were much shorter than those of the HSP-ETKAS allocation group. The incidence of initial graft non-function was similar among the three HSP allocation groups, averaging 50%. Recovery of the initial non-function was more likely for AM and HIT transplants. No difference was present with regard to the percentage of patients who experienced at least one rejection episode during the first three months post-transplant, averaging 43%. However, the AM group had less severe and/or less recurrent rejection episodes. The 1-year kidney graft survival, censored for death with functional graft, was 96% for AM, 82% for HIT and 75% for HSP-ETKAS transplants (p = 0.04).

CONCLUSIONS

The two special allocation programs for HSP do yield adequate results and offer a shorter waiting time, compared to the standard kidney allocation procedure. The AM approach might be preferred because of the smoother post-transplant management and the better graft survival, keeping the HIT approach as a back up. Since the allocation priority is justified in view of efficiency, the renal transplant community should support the incorporation of a special allocation program for HSP in their respective organ exchange program.