Determination of the clinical relevance of donor epitope-specific HLA-antibodies in kidney transplantation

In kidney transplantation, survival rates are still partly impaired due to the deleterious effects of donor specific HLA antibodies (DSA). However, not all luminex-defined DSA appear to be clinically relevant. Further analysis of DSA recognizing polymorphic amino acid configurations, called eplets or functional epitopes, might improve the discrimination between clinically relevant vs. irrelevant HLA antibodies. To evaluate which donor epitope-specific HLA antibodies (DESAs) are clinically important in kidney graft survival, relevant and irrelevant DESAs were discerned in a Dutch cohort of 4690 patients using Kaplan-Meier analysis and tested in a cox proportional hazard (CPH) model including nonimmunological variables. Pre-transplant DESAs were detected in 439 patients (9.4%). The presence of certain clinically relevant DESAs was significantly associated with increased risk on graft loss in deceased donor transplantations (p < 0.0001). The antibodies recognized six epitopes of HLA Class I, 3 of HLA-DR, and 1 of HLA-DQ, and most antibodies were directed to HLA-B (47%). Fifty-three patients (69.7%) had DESA against one donor epitope (range 1-5). Long-term graft survival rate in patients with clinically relevant DESA was 32%, rendering DESA a superior parameter to classical DSA (60%). In the CPH model, the hazard ratio (95% CI) of clinically relevant DESAs was 2.45 (1.84-3.25) in deceased donation, and 2.22 (1.25-3.95) in living donation. In conclusion, the developed model shows the deleterious effect of clinically relevant DESAs on graft outcome which outperformed traditional DSA-based risk analysis on antigen level.

Ellipro scores of donor epitope specific HLA antibodies are not associated with kidney graft survival

In kidney transplantation, donor HLA antibodies are a risk factor for graft loss. Accessibility of donor eplets for HLA antibodies is predicted by the ElliPro score. The clinical usefulness of those scores in relation to transplant outcome is unknown. In a large Dutch kidney transplant cohort, Ellipro scores of pretransplant donor antibodies that can be assigned to known eplets (donor epitope specific HLA antibodies [DESAs]) were compared between early graft failure and long surviving deceased donor transplants. We did not observe a significant Ellipro score difference between the two cohorts, nor significant differences in graft survival between transplants with DESAs having high versus low total Ellipro scores. We conclude that Ellipro scores cannot be used to identify DESAs associated with early versus late kidney graft loss in deceased donor transplants.

Long-term peridialytic blood pressure changes are related to mortality

BACKGROUND

In chronic haemodialysis (HD) patients, the relationship between long-term peridialytic blood pressure (BP) changes and mortality has not been investigated.

METHODS

To evaluate whether long-term changes in peridialytic BP are related to mortality and whether treatment with HD or haemodiafiltration (HDF) differs in this respect, the combined individual participant data of three randomized controlled trials comparing HD with HDF were used. Time-varying Cox regression and joint models were applied.

RESULTS

During a median follow-up of 2.94 years, 609 of 2011 patients died. As for pre-dialytic systolic BP (pre-SBP), a severe decline (≥21 mmHg) in the preceding 6 months was independently related to increased mortality [hazard ratio (HR) 1.61, P = .01] when compared with a moderate increase. Likewise, a severe decline in post-dialytic diastolic BP (DBP) was associated with increased mortality (adjusted HR 1.96, P < .0005). In contrast, joint models showed that every 5-mmHg increase in pre-SBP and post-DBP during total follow-up was related to reduced mortality (adjusted HR 0.97, P = .01 and 0.94, P = .03, respectively). No interaction was observed between BP changes and treatment modality.

CONCLUSION

Severe declines in pre-SBP and post-DBP in the preceding 6 months were independently related to mortality. Therefore peridialytic BP values should be interpreted in the context of their changes and not solely as an absolute value.

Responsiveness and minimal important change of seven PROMIS computerized adaptive tests (CAT) in patients with advanced chronic kidney disease

BACKGROUND

The Patient-Reported Outcomes Measurement Information System (PROMIS®) has the potential to harmonize the measurement of health-related quality of life (HRQL) across medical conditions. We evaluated responsiveness and minimal important change (MIC) of seven Dutch-Flemish PROMIS computerized adaptive tests (CAT) in Dutch patients with advanced chronic kidney disease (CKD).

METHODS

CKD patients (eGFR < 30 ml/min.1.73m²) completed at baseline and after 6 months seven PROMIS CATs (assessing physical function, pain interference, fatigue, sleep disturbance, anxiety, depression, and ability to participate in social roles and activities), Short Form Health Survey 12 (SF-12), PROMIS Pain Intensity single item, Dialysis Symptom Index (DSI), and Global Rating Scales (GRS) of change. Responsiveness was assessed by testing predefined hypotheses about expected correlations among measures, area under the ROC Curve, and effect sizes. MIC was determined with predictive modelling.

RESULTS

207 patients were included; 186 (90%) completed the follow-up. Most results were in accordance with expectations (70-91% of hypotheses confirmed), with some exceptions for PROMIS Anxiety and Ability to Participate (60% and 42% of hypotheses confirmed, respectively). For PROMIS Anxiety and Depression correlations with the GRS were too low (0.04 and 0.20, respectively) to calculate a MIC. MIC values, representing minimal important deterioration, ranged from 0.4 to 2.5 T-score points for the other domains.

CONCLUSION

We found sufficient responsiveness of PROMIS CATs Physical Function, Fatigue, Sleep Disturbance, and Depression. The results for PROMIS CATs Pain Interference were almost sufficient, but some results for Anxiety and Ability to Participate in Social Roles and Activities were not as expected. Reported MIC values should be interpreted with caution because most patients did not change.

Technique failure in peritoneal dialysis: Modifiable causes and patient-specific risk factors

BACKGROUND

Technique survival is a core outcome for peritoneal dialysis (PD), according to Standardized Outcomes in Nephrology-Peritoneal Dialysis. This study aimed to identify modifiable causes and risk factors of technique failure in a large Dutch cohort using standardised definitions.

METHODS

Patients who participated in the retrospective Dutch nOcturnal and hoME dialysis Study To Improve Clinical Outcomes cohort study and started PD between 2012 and 2016 were included and followed until 1 January 2017. The primary outcome was technique failure, defined as transfer to in-centre haemodialysis for ≥ 30 days or death. Death-censored technique failure was analysed as secondary outcome. Cox regression models and competing risk models were used to assess the association between potential risk factors and technique failure.

RESULTS

A total of 695 patients were included, of whom 318 experienced technique failure during follow-up. Technique failure rate in the first year was 29%, while the death-censored technique failure rate was 23%. Infections were the most common modifiable cause for technique failure, accounting for 20% of all causes during the entire follow-up. Leakage and catheter problems were important causes within the first 6 months of PD treatment (both accounting for 15%). APD use was associated with a lower risk of technique failure (hazard ratio 0.66, 95% confidence interval 0.53-0.83).

CONCLUSION

Infections, leakage and catheter problems were important modifiable causes for technique failure. As the first-year death-censored technique failure rate remains high, future studies should focus on infection prevention and catheter access to improve technique survival.

Nocturnal Hemodialysis Leads to Improvement in Physical Performance in Comparison with Conventional Hemodialysis

End-stage kidney disease patients treated with conventional hemodialysis (CHD) are known to have impaired physical performance and protein-energy wasting (PEW). Nocturnal hemodialysis (NHD) was shown to improve clinical outcomes, but the evidence is limited on physical performance and PEW. We investigate whether NHD improves physical performance and PEW. This prospective, multicenter, non-randomized cohort study compared patients who changed from CHD (2−4 times/week 3−5 h) to NHD (2−3 times/week 7−8 h), with patients who continued CHD. The primary outcome was physical performance at 3, 6 and 12 months, assessed with the short physical performance battery (SPPB). Secondary outcomes were a 6-minute walk test (6MWT), physical activity monitor, handgrip muscle strength, KDQOL-SF physical component score (PCS) and LAPAQ physical activity questionnaire. PEW was assessed with a dietary record, dual-energy X-ray absorptiometry, bioelectrical impedance spectroscopy and subjective global assessment (SGA). Linear mixed models were used to analyze the differences between groups. This study included 33 patients on CHD and 32 who converted to NHD (mean age 55 ± 15.3). No significant difference was found in the SPPB after 1-year of NHD compared to CHD (+0.24, [95% confidence interval −0.51 to 0.99], p = 0.53). Scores of 6MWT, PCS and SGA improved (+54.3 [95%CI 7.78 to 100.8], p = 0.02; +5.61 [−0.51 to 10.7], p = 0.03; +0.71 [0.36 to 1.05], p < 0.001; resp.) in NHD patients, no changes were found in other parameters. We conclude that NHD patients did not experience an improved SPPB score compared to CHD patients; they did obtain an improved walking distance and self-reported PCS as well as SGA after 1-year of NHD, which might be related to the younger age of these patients.

Discussing results of patient-reported outcome measures (PROMs) between patients and healthcare professionals in routine dialysis care: a qualitative study

OBJECTIVES

Patient-reported outcome measures (PROMs) provide insight into patients' experienced health and needs, and can improve patient-professional communication. However, little is known about how to discuss PROM results. This study aimed to provide in-depth knowledge of patients' and healthcare professionals' experiences with and perspectives on discussing PROM results as part of routine dialysis care.

DESIGN

A qualitative study was performed using an interpretive description approach. Individual semistructured interviews were conducted with 22 patients and healthcare professionals. Interviews focused on general and specific situations (eg, addressing sensitive topics or when no medical treatment is available). Interviews were transcribed verbatim and analysed inductively using thematic analysis.

SETTING

Participants were purposively sampled from eight dialysis centres across the Netherlands.

PARTICIPANTS

Interviews were conducted with 10 patients receiving dialysis treatment and 12 healthcare professionals (nephrologists and nurses).

RESULTS

Patients and healthcare professionals provided practical guidance for optimal discussion about PROM results. First, patients and healthcare professionals emphasised that PROM results should always be discussed and indicated how to create a suitable setting, adequately prepare, deal with time constraints and use PROMs as a tool for personalised holistic consultations. Second, patients should actively participate and healthcare professionals should take a guiding role. A trusting patient-professional relationship was considered a prerequisite and patient-professional interaction was described as a collaboration in which both contribute their knowledge, experiences and ideas. Third, follow-up after discussing PROM results was considered important, including evaluations and actions (eg, symptom management) structurally embedded into the multidisciplinary treatment process. These general themes also applied to the specific situations, for example: results should also be discussed when no medical treatment is available. Though, healthcare professionals were expected to take more initiative and a leading role when discussing sensitive topics.

CONCLUSIONS

This study provides insight into how to organise and conduct conversations about PROM results and lays the foundation for training healthcare professionals to optimally discuss PROM results in routine nephrology care. Further research is needed to provide guidance on follow-up actions in response to specific PROM results.

Validity and reliability of Patient-Reported Outcomes Measurement Information System (PROMIS®) using Computerized Adaptive Testing (CAT) in patients with advanced chronic kidney disease

BACKGROUND

The Patient-Reported Outcomes Measurement Information System (PROMIS®) has been recommended for computerized adaptive testing (CAT) of health-related quality of life (HRQOL). This study compared the content, validity and reliability of seven PROMIS CATs to the 12-item Short-Form Health Survey (SF-12) in patients with advanced chronic kidney disease (CKD).

METHODS

Adult CKD patients with an eGFR < 30 ml/min.1.73m2 not receiving dialysis treatment completed seven PROMIS CATs (assessing physical function, pain interference, fatigue, sleep disturbance, anxiety, depression, and ability to participate in social roles and activities), the SF-12 and, additionally, the PROMIS Pain Intensity single item and Dialysis Symptom Index (DSI) at inclusion and 2-weeks. A content comparison was performed between PROMIS CATs and SF-12. Construct validity of PROMIS CATs was assessed using Pearson's correlations. Test-retest reliability of all patient-reported outcome measures (PROMs) was assessed by calculating the intra-class correlation coefficient (ICC) and minimal detectable change (MDC).

RESULTS

In total, 207 patients participated in the study. A median of 45 items (10 minutes) was completed for PROMIS CATs. All PROMIS CATs showed evidence for sufficient construct validity. PROMIS CATs, most SF-12 domains and summary scores, and DSI showed sufficient test-retest reliability (ICC ≥ 0.70). PROMIS CATs had a lower MDC compared to the SF-12 (5.7-7.4 compared to 11.2-21.7 across domains, respectively).

CONCLUSION

PROMIS CATs showed sufficient construct validity and test-retest reliability in patients with advanced CKD. PROMIS CATs required more items but showed better reliability than the SF-12. Future research is needed to investigate the feasibility of PROMIS CATs for routine nephrology care.

Differences in hospitalisation between peritoneal dialysis and haemodialysis patients

BACKGROUND

Dialysis is associated with frequent hospitalisations. Studies comparing hospitalisations between peritoneal dialysis (PD) and haemodialysis (HD) report conflicting results and mostly analyse data of patients that remain on their initial dialysis modality. This cohort study compares hospitalisations between PD and HD patients taking into account transitions between modalities.

METHODS

The Dutch nOcturnal and hoME dialysis Study To Improve Clinical Outcomes collected hospitalisation data of patients who started dialysis between 2012 and 2017. Primary outcome was hospitalisation rate, analysed with a multi-state model that attributed each hospitalisation to the current dialysis modality.

RESULTS

In total, 695 patients (252 PD, 443 HD) treated in 31 Dutch hospitals were included. The crude hospitalisation rate for PD was 2.3 ( ± 5.0) and for HD 1.4 ( ± 3.2) hospitalisations per patient-year. The adjusted hazard ratio for hospitalisation rate was 1.1 (95%CI 1.02-1.3) for PD compared with HD. The risk for first hospitalisation was 1.3 times (95%CI 1.1-1.6) higher for PD compared with HD during the first year after dialysis initiation. The number of hospitalisations and number of hospital days per patient-year were significantly higher for PD. The most common causes of PD and HD hospitalisations were peritonitis (23%) and vascular access-related problems (33%).

CONCLUSION

PD was associated with higher hospitalisation rate, higher risk for first hospitalisation and higher number of hospitalisations compared with HD. Since the PD hospitalisations were mainly caused by peritonitis, more attention to infection prevention is necessary for reducing the number of hospitalisations in the future.

Reconsidering the Edelman equation: impact of plasma sodium concentration, edema and body weight

BACKGROUND

Guidelines recommend treatment of dysnatremias to be guided by formulas based on the Edelman equation. This equation describes the relation between plasma sodium concentration and exchangeable cations. However, this formula does not take into account clinical parameters that have recently been associated with local tissue sodium accumulation, which occurs without concurrent water retention. We investigated to what extent such clinical factors affect the Edelman equation and dysnatremia treatment.

METHODS

We performed a post-hoc analysis with original data of the Edelman study. Linear regression was used to examine the effect of age, sex, weight, edema, total body water (TBW) and heart and kidney failure on the Edelman equation. With attenuated correction, we corrected for measurement errors of both variables. Using piecewise regression, we analyzed whether the Edelman association differs for different plasma sodium concentrations.

RESULTS

Data was available for 82 patients; 57 males and 25 females with a mean (SD) age of 57 (15) years. The slope of the Edelman equation was significantly affected by weight (p=0.01) and edema (p=0.03). Also, below and above plasma sodium levels of 133 mmol/L the slope of the Edelman equation was significantly different (1.25 x0025vs 0.58x0025, p<0.01).

CONCLUSION

Edelman's equation's coefficients are significantly affected by weight, edema and plasma sodium, possibly reflecting differences in tissue sodium accumulation capacity. The performance of Edelman-based formulas in clinical settings may be improved by taking these clinical characteristics into account.

Symptom dimensions of anxiety and depression in patients receiving peritoneal dialysis compared to haemodialysis

BACKGROUND

Differences in symptom burden, treatment satisfaction and autonomy between patients receiving peritoneal dialysis and haemodialysis could be reflected by a difference in symptom dimensions of anxiety and depression. The aim of this study is to assess differences in prevalence and symptom dimensions of anxiety and depression between patients receiving peritoneal dialysis and haemodialysis.

METHODS

Baseline data from the Depression Related Factors and Outcomes in Dialysis Patients With Various Ethnicities and Races Study were used. Symptoms of anxiety and depression were measured with the Beck Anxiety Inventory and Beck Depression Inventory- second edition. Linear and logistic regression models were used to compare anxiety and depression total scores and somatic and subjective/cognitive symptom dimension scores between patients receiving peritoneal dialysis and haemodialysis, adjusted for potential confounders.

RESULTS

In total, 84 patients receiving peritoneal dialysis and 601 patients receiving haemodialysis were included. Clinically significant symptoms of anxiety and depression were present in respectively 22% and 43% of the patients, with no differences between dialysis modality. Both modalities scored high on the somatic symptom dimensions and on individual somatic items. Almost all patients reported symptoms related to loss of energy and sleep.

CONCLUSION

No differences in symptom dimensions of anxiety and depression were found between patients receiving peritoneal dialysis and haemodialysis. The high prevalence of somatic symptom dimensions in both groups underscores the possible interaction between somatic and psychiatric symptoms in dialysis patients and the need for early recognition and treatment of symptoms of anxiety and depression regardless of treatment modalities.

Itching in dialysis patients: impact on health-related quality of life and interactions with sleep problems and psychological symptoms – results from the RENINE/PROMs registry

Background

Itching (pruritus) is common in dialysis patients, but little is known about its impact on health-related quality of life (HRQOL), sleep problems and psychological symptoms. This study investigates the impact of itching in dialysis patients by looking into the persistence of itching, the effect of itching on the course of HRQOL and the combined effect of itching with sleep problems and with psychological symptoms on HRQOL.

Methods

Data were obtained from the RENINE/PROMs registry and included 2978 dialysis patients who completed patient-reported outcome measures between 2018 and 2020. Itching, sleep problems and psychological symptoms were assessed with the Dialysis Symptom Index (DSI) and HRQOL with the 12-item Short Form Health Survey. Effects of itching on HRQOL and interactions with sleep problems and psychological symptoms were investigated cross-sectionally and longitudinally using linear regression and linear mixed models.

Results

Half of the patients experienced itching and in 70% of them, itching was persistent. Itching was associated with a lower physical and mental HRQOL {−3.35 [95% confidence interval (CI) −4.12 to −2.59) and −3.79 [95% CI −4.56 to −3.03]}. HRQOL remained stable during 2 years and trajectories did not differ between patients with or without itching. Sleep problems (70% versus 52%) and psychological symptoms (36% versus 19%) were more common in patients with itching. These symptoms had an additional negative effect on HRQOL but did not interact with itching.

Conclusions

The persistence of itching, its impact on HRQOL over time and the additional effect on HRQOL of sleep problems and psychological symptoms emphasize the need for recognition and effective treatment of itching to reduce symptom burden and improve HRQOL.

Trends in home dialysis use differ among age categories in past two decades: A Dutch registry study

BACKGROUND

Although the number of patients with end-stage kidney disease is growing, the number of patients who perform dialysis at home has decreased during the past two decades. The aim of this study was to explore time trends in the use of home dialysis in the Netherlands.

METHODS

Dialysis episodes of patients who started dialysis treatment were studied using Dutch registry data (RENINE). The uptake of home dialysis between 1997 through 2016 was evaluated in time periods of 5 years. Home dialysis was defined as start with peritoneal dialysis or home haemodialysis, or transfer to either within 2 years of dialysis initiation. All analyses were stratified for age categories. Mixed model logistic regression analysis was used to adjust for clustering at patient level.

RESULTS

A total of 33 340 dialysis episodes in 31 569 patients were evaluated. Mean age at dialysis initiation increased from 62.5 ± 14.0 to 65.5 ± 14.5 years in in-centre haemodialysis patients, whereas it increased from 51.9 ± 15.1 to 62.5 ± 14.6 years in home dialysis patients. In patients <65 years, the uptake of home dialysis was significantly lower during each 5-year period compared with the previous period, whereas kidney transplantation occurred more often. In patients ≥65 years, the incidence of home dialysis remained constant, whereas mortality decreased.

CONCLUSIONS

In patients <65 years, the overall use of home dialysis declined consistently over the past 20 years. The age of home dialysis patients increased more rapidly than that of in-centre dialysis patients. These developments have a significant impact on the organization of home dialysis.

T-Cell Epitopes Shared Between Immunizing HLA and Donor HLA Associate With Graft Failure After Kidney Transplantation

CD4⁺ T-helper cells play an important role in alloimmune reactions following transplantation by stimulating humoral as well as cellular responses, which might lead to failure of the allograft. CD4⁺ memory T-helper cells from a previous immunizing event can potentially be reactivated by exposure to HLA mismatches that share T-cell epitopes with the initial immunizing HLA. Consequently, reactivity of CD4⁺ memory T-helper cells toward T-cell epitopes that are shared between immunizing HLA and donor HLA could increase the risk of alloimmunity following transplantation, thus affecting transplant outcome. In this study, the amount of T-cell epitopes shared between immunizing and donor HLA was used as a surrogate marker to evaluate the effect of donor-reactive CD4⁺ memory T-helper cells on the 10-year risk of death-censored kidney graft failure in 190 donor/recipient combinations using the PIRCHE-II algorithm. The T-cell epitopes of the initial theoretical immunizing HLA and the donor HLA were estimated and the number of shared PIRCHE-II epitopes was calculated. We show that the natural logarithm-transformed PIRCHE-II overlap score, or Shared T-cell EPitopes (STEP) score, significantly associates with the 10-year risk of death-censored kidney graft failure, suggesting that the presence of pre-transplant donor-reactive CD4⁺ memory T-helper cells might be a strong indicator for the risk of graft failure following kidney transplantation.

Key elements in selection of pre-dialysis patients for home dialysis

BACKGROUND

Most pre-dialysis patients are medically eligible for home dialysis, and home dialysis has several advantages over incentre dialysis. However, accurately selecting patients for home dialysis appears to be difficult, since uptake of home dialysis remains low. The aim of this study was to investigate which medical or psychosocial elements contribute most to the selection of patients eligible for home dialysis.

METHODS

All patients from a Dutch teaching hospital, who received treatment modality education and subsequently started dialysis treatment, were included. The pre-dialysis programme consisted of questionnaires for the patient, nephrologist and social worker, followed by an assessment of eligibility for home dialysis by a multidisciplinary team. Clinimetric assessment and logistic regression were used to identify domains and questions associated with home dialysis treatment.

RESULTS

A total of 135 patients were included, of whom 40 were treated with home dialysis and 95 with incentre haemodialysis. The key elements associated with long-term home dialysis treatment were part of the domains 'suitability of the housing', 'self-care', 'social support' and 'patient capacity', with adjusted odds ratios ranging from 0.13 for negative to 18.3 for positive associations.

CONCLUSION

The assessment of contraindications by a nephrologist followed by the assessment of possibilities by a social worker or dialysis nurse who investigates four key elements, ideally during a home visit, and subsequent detailed education offered by specialized nurses is an optimal way to select patients for home dialysis.

Clinical presentation and long-term follow-up of dopamine beta hydroxylase deficiency

Dopamine beta hydroxylase (DBH) deficiency is an extremely rare autosomal recessive disorder with severe orthostatic hypotension, that can be treated with L-threo-3,4-dihydroxyphenylserine (L-DOPS). We aimed to summarize clinical, biochemical, and genetic data of all world-wide reported patients with DBH-deficiency, and to present detailed new data on long-term follow-up of a relatively large Dutch cohort. We retrospectively describe 10 patients from a Dutch cohort and 15 additional patients from the literature. We identified 25 patients (15 females) from 20 families. Ten patients were diagnosed in the Netherlands. Duration of follow-up of Dutch patients ranged from 1 to 21 years (median 13 years). All patients had severe orthostatic hypotension. Severely decreased or absent (nor)epinephrine, and increased dopamine plasma concentrations were found in 24/25 patients. Impaired kidney function and anemia were present in all Dutch patients, hypomagnesaemia in 5 out of 10. Clinically, all patients responded very well to L-DOPS, with marked reduction of orthostatic complaints. However, orthostatic hypotension remained present, and kidney function, anemia, and hypomagnesaemia only partially improved. Plasma norepinephrine increased and became detectable, while epinephrine remained undetectable in most patients. We confirm the core clinical characteristics of DBH-deficiency and the pathognomonic profile of catecholamines in body fluids. Impaired renal function, anemia, and hypomagnesaemia can be part of the clinical presentation. The subjective response to L-DOPS treatment is excellent and sustained, although the neurotransmitter profile in plasma does not normalize completely. Furthermore, orthostatic hypotension as well as renal function, anemia, and hypomagnesaemia improve only partially.

The Impact of COVID-19 on the mental health of dialysis patients

Background

Studies have shown increased anxiety, depression, and stress levels among different populations during the coronavirus disease 2019 (COVID-19) pandemic. However, the impact of the pandemic on the mental health of dialysis patients remains unknown. The aim of this study was to investigate the mental health of dialysis patients during the COVID-19 pandemic compared to the period preceding the pandemic.

Methods

Data originate from the ongoing multicentre observational Dutch nOcturnal and hoME dialysis Study To Improve Clinical Outcomes (DOMESTICO). Patients who filled in a health-related quality of life (HRQoL) questionnaire during the pandemic and six to three months prior were included. The mean difference in Mental Component Summary (MCS) score of the Short Form 12 (SF-12) was analysed with multilevel linear regression. A McNemar test was used to compare presence of mental health-related symptoms during and prior to the COVID-19 pandemic.

Results

A total of 177 patients were included. The mean MCS score prior to COVID-19 was 48.08 ± 10.15, and 49.00 ± 10.04 during the COVID-19 pandemic. The adjusted mean MCS score was 0.93 point (95% CI − 0.57 to 2.42) higher during the COVID-19 pandemic than during the period prior to the pandemic. Furthermore, no difference in the presence of the following mental health-related symptoms was found during the COVID-19 pandemic: feeling anxious, feeling sad, worrying, feeling nervous, trouble falling asleep, and trouble staying asleep.

Conclusions

The mental health of dialysis patients appears to be unaffected by the COVID-19 pandemic. Dialysis patients may be better able to cope with the pandemic, since they have high resilience and are less impacted by social distancing measures.

Trial registration number

Netherlands Trial Register NL6519, date of registration: 22 August 2017.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s40620-021-01005-1.

Funnel plots of patient-reported outcomes to evaluate health-care quality: Basic principles, pitfalls and considerations

A funnel plot is a graphical method to evaluate health-care quality by comparing hospital performances on certain outcomes. So far, in nephrology, this method has been applied to clinical outcomes like mortality and complications. However, patient-reported outcomes (PROs; eg, health-related quality of life [HRQOL]) are becoming increasingly important and should be incorporated into this quality assessment. Using funnel plots has several advantages, including clearly visualized precision, detection of volume-effects, discouragement of ranking hospitals and easy interpretation of results. However, without sufficient knowledge of underlying methods, it is easy to stumble into pitfalls, such as overinterpretation of standardized scores, incorrect direct comparisons of hospitals and assuming a hospital to be in-control (ie, to perform as expected) based on underpowered comparisons. Furthermore, application of funnel plots to PROs is accompanied by additional challenges related to the multidimensional nature of PROs and difficulties with measuring PROs. Before using funnel plots for PROs, high and consistent response rates, adequate case mix correction and high-quality PRO measures are required. In this article, we aim to provide insight into the use and interpretation of funnel plots by presenting an overview of the basic principles, pitfalls and considerations when applied to PROs, using examples from Dutch routine dialysis care.

Health-Related Quality of Life in Home Dialysis Patients Compared to In-Center Hemodialysis Patients: A Systematic Review and Meta-analysis

RATIONALE & OBJECTIVE

Dialysis patients judge health-related quality of life (HRQoL) as an essential outcome. Remarkably, little is known about HRQoL differences between home dialysis and in-center hemodialysis (HD) patients worldwide.

STUDY DESIGN

Systematic review and meta-analysis.

SETTING & STUDY POPULATIONS

Search strategies were performed on the Cochrane Library, Pubmed, and EMBASE databases between 2007 and 2019. Home dialysis was defined as both peritoneal dialysis and home HD.

SELECTION CRITERIA FOR STUDIES

Randomized controlled trials and observational studies that compared HRQoL in home dialysis patients versus in-center HD patients.

DATA EXTRACTION

The data extracted by 2 authors included HRQoL scores of different questionnaires, dialysis modality, and subcontinent.

ANALYTICAL APPROACH

Data were pooled using a random-effects model and results were expressed as standardized mean difference (SMD) with 95% CIs. Heterogeneity was explored using subgroup analyses.

RESULTS

Forty-six articles reporting on 41 study populations were identified. Most studies were cross-sectional in design (90%), conducted on peritoneal dialysis patients (95%), and used the 12-item or 36-item Short-Form Health Survey questionnaires (83%). More than half the studies showed moderate or high risk of bias. Pooled analysis of 4,158 home dialysis patients and 7,854 in-center HD patients showed marginally better physical HRQoL scores in home dialysis patients compared with in-center HD patients (SMD, 0.14; 95% CI, 0.04 to 0.24), although heterogeneity was high (I 2>80%). In a subgroup analysis, Western European home dialysis patients had higher physical HRQoL scores (SMD, 0.39; 95% CI, 0.17 to 0.61), while home dialysis patients from Latin America had lower physical scores (SMD, -0.20; 95% CI, -0.28 to -0.12). Mental HRQoL showed no difference in all analyses.

LIMITATIONS

No randomized controlled trials were found and high heterogeneity among studies existed.

CONCLUSIONS

Although pooled data showed marginally better physical HRQoL for home dialysis patients, the quality of design of the included studies was poor. Large prospective studies with adequate adjustments for confounders are necessary to establish whether home dialysis results in better HRQoL.

TRIAL REGISTRATION

PROSPERO 95985.

Routinely measuring symptom burden and health-related quality of life in dialysis patients: first results from the Dutch registry of patient-reported outcome measures

Background

The use of patient-reported outcome measures (PROMs) is becoming increasingly important in healthcare. However, incorporation of PROMs into routine nephrological care is challenging. This study describes the first experience with PROMs in Dutch routine dialysis care.

Methods

A pilot study was conducted in dialysis patients in 16 centres. Patients were invited to complete PROMs at baseline and 3 and 6 months. PROMs consisted of the 12-item short-form and Dialysis Symptom Index to assess health-related quality of life (HRQoL) and symptom burden. Response rates, HRQoL and symptom burden scores were analysed. Qualitative research methods were used to gain insight into patients’ views on using PROMs in clinical practice.

Results

In total, 512 patients (36%) completed 908 PROMs (24%) across three time points. Response rates varied from 6 to 70% among centres. Mean scores for physical and mental HRQoL were 35.6 [standard deviation (SD) 10.2] and 47.7 (SD 10.6), respectively. Patients experienced on average 10.8 (SD 6.1) symptoms with a symptom burden score of 30.7 (SD 22.0). Only 1–3% of the variation in PROM scores can be explained by differences between centres. Patients perceived discussing their HRQoL and symptom scores as insightful and valuable. Individual feedback on results was considered crucial.

Conclusions

The first results show low average response rates with high variability among centres. Dialysis patients experienced a high symptom burden and poor HRQoL. Using PROMs at the individual patient level is suitable and may improve patient–professional communication and shared decision making. Further research is needed to investigate how the collection and the use of PROMs can be successfully integrated into routine care to improve healthcare quality and outcomes.

Long-Term Peridialytic Blood Pressure Patterns in Patients Treated by Hemodialysis and Hemodiafiltration

Introduction

Online postdilution hemodiafiltration (HDF) is associated with a lower all-cause and cardiovascular mortality than hemodialysis (HD). This may depend on a superior peridialytic (pre- and postdialysis, and the difference between these 2 parameters) hemodynamic profile.

Methods

In this retrospective cohort analysis of individual participant data (IPD) from 3 randomized controlled trials (RCTs) (n = 2011), the effect of HDF and HD on 2-year peridialytic blood pressure (BP) patterns was assessed. Long-term peridialytic systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP), as well as the deltas (post- minus predialytic) were assessed in the total group of patients. Thereafter, these variables were compared between patients on HD and HDF, and in the latter group between quartiles of convection volume.

Results

Mean pre- and postdialysis SBP, DBP, and MAP declined significantly during follow-up (predialytic: SBP −2.16 mm Hg, DBP −2.88 mm Hg, MAP −2.64 mm Hg), PP increased (predialytic 0.96 mm Hg). Peridialytic deltas remained unaltered. Differences between the 2 modalities, or between quartiles of convection volume were not observed. BP changes were independent of various baseline characteristics, including the decline in body weight over time.

Conclusion

We speculate that the combination of a decreasing SBP and an increasing PP may be the clinical sequelae of a worsening cardiovascular system. Because especially HDF with a high convection volume has been associated with a beneficial effect on survival, our study does not support the view that superior peridialytic BP control contributes to this effect.

Antibodies against ARHGDIB are associated with long-term kidney graft loss

The clinical significance of non-HLA antibodies on renal allograft survival is a matter of debate, due to differences in reported results and lack of large-scale studies incorporating analysis of multiple non-HLA antibodies simultaneously. We developed a multiplex non-HLA antibody assay against 14 proteins highly expressed in the kidney. In this study, the presence of pretransplant non-HLA antibodies was correlated to renal allograft survival in a nationwide cohort of 4770 recipients transplanted between 1995 and 2006. Autoantibodies against Rho GDP-dissociation inhibitor 2 (ARHGDIB) were significantly associated with graft loss in recipients transplanted with a deceased-donor kidney (N = 3276) but not in recipients of a living-donor kidney (N = 1496). At 10 years after deceased-donor transplantation, recipients with anti-ARHGDIB antibodies (94/3276 = 2.9%) had a 13% lower death-censored covariate-adjusted graft survival compared to the anti-ARHGDIB-negative (3182/3276 = 97.1%) population (hazard ratio 1.82; 95% confidence interval, 1.32-2.53; P = .0003). These antibodies occur independently from donor-specific anti-HLA antibodies (DSA) or other non-HLA antibodies investigated. No significant relations with graft loss were found for the other 13 non-HLA antibodies. We suggest that pretransplant risk assessment can be improved by measuring anti-ARHGDIB antibodies in all patients awaiting deceased-donor transplantation.

Allocation to highly sensitized patients based on acceptable mismatches results in low rejection rates comparable to nonsensitized patients

Whereas regular allocation avoids unacceptable mismatches on the donor organ, allocation to highly sensitized patients within the Eurotransplant Acceptable Mismatch (AM) program is based on the patient's HLA phenotype plus acceptable antigens. These are HLA antigens to which the patient never made antibodies, as determined by extensive laboratory testing. AM patients have superior long-term graft survival compared with highly sensitized patients in regular allocation. Here, we questioned whether the AM program also results in lower rejection rates. From the PROCARE cohort, consisting of all Dutch kidney transplants in 1995-2005, we selected deceased donor single transplants with a minimum of 1 HLA mismatch and determined the cumulative 6-month rejection incidence for patients in AM or regular allocation. Additionally, we determined the effect of minimal matching criteria of 1 HLA-B plus 1 HLA-DR, or 2 HLA-DR antigens on rejection incidence. AM patients showed significantly lower rejection rates than highly immunized patients in regular allocation, comparable to nonsensitized patients, independent of other risk factors for rejection. In contrast to highly sensitized patients in regular allocation, minimal matching criteria did not affect rejection rates in AM patients. Allocation based on acceptable antigens leads to relatively low-risk transplants for highly sensitized patients with rejection rates similar to those of nonimmunized individuals.

Patient-reported outcome measures: selection of a valid questionnaire for routine symptom assessment in patients with advanced chronic kidney disease - a four-phase mixed methods study

Background

Patient-reported outcome measures (PROMs) are becoming increasingly important in healthcare. In nephrology, there is no agreement on which chronic kidney disease (CKD) symptom questionnaire to use. Therefore, the aim of this study is to select a valid symptom questionnaire for routine assessment in patients with advanced CKD.

Methods

A four-phase mixed methods approach, using qualitative and quantitative research methods, was applied. First, a systematic literature search was conducted to retrieve existing symptom questionnaires. Second, a symptom list was created including all symptoms in existing questionnaires and symptoms mentioned in interviews with patients with CKD, from which symptom clusters were identified. Next, questionnaires were selected based on predefined criteria regarding content validity. Last, two online feedback panels of patients with CKD (n = 151) and experts (n = 6) reviewed the most promising questionnaires.

Results

The literature search identified 121 questionnaires, of which 28 were potentially suitable for symptom assessment in patients with advanced CKD. 101 unique symptoms and 10 symptom clusters were distinguished. Based on predefined criteria, the Dialysis Symptom Index (DSI) and Palliative Care Outcome Scale-Renal Version (IPOS-Renal) were selected and reviewed by feedback panels. Patients needed 5.4 and 7.5 min to complete the DSI and IPOS-Renal, respectively (p < 0.001). Patients experienced the DSI as more specific, complete and straightforward compared to the IPOS-Renal.

Conclusions

The DSI was found to be valid and reliable, the most relevant, complete, and comprehensible symptom questionnaire available for routine assessment in patients with advanced CKD. Routine PROMs collection could be of great value to healthcare, both at individual patient and national level. Feedback on scores and involvement of healthcare providers may promote adaptation and implementation in healthcare.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1521-9) contains supplementary material, which is available to authorized users.

Physical performance in patients treated with nocturnal hemodialysis - a systematic review of the evidence

Background

Patients treated with conventional hemodialysis have poor physical performance, explained by insufficient metabolic clearance and shortage of time by time-consuming dialysis. Nocturnal hemodialysis improves metabolic control and results in increased spare time. Our aim is to investigate whether physical performance in nocturnal hemodialysis is superior to conventional hemodialysis.

Methods

A systematic search was conducted in MEDLINE, Embase, CINAHL, PhycInfo and Web of Science until January 2018. Primary outcomes were physical performance, activity, strength and muscle mass in home or in-center nocturnal hemodialysis. Methodological quality was assessed with the Newcastle-Ottawa scale.

Results

Ten studies met the inclusion criteria, including 2 RCTs, evaluating 526 nocturnal hemodialysis patients with a mean follow-up of 15, 3 months. The methodological quality of 4 studies was limited. Physical capacity tests were done in 3 studies with different methodology: short-physical performance battery, exercise spirometry and 6-min walk test. The latter 2 showed significant improvements in physical performance. Four studies assessed lean mass using dual-energy X-ray absorptiometry (2×) and bioelectrical impedance analysis (2×), of which 1 demonstrated increased lean body and skeletal muscle mass. In 5 studies a Quality of Life questionnaire was used, of which 2 showed improved physical component score.

Conclusions

The evidence on the effect of nocturnal hemodialysis on physical performance is either of insufficient methodological quality or only measures isolated aspects of physical performance. As literature emphasizes the importance of physical activity on clinical outcomes, it is necessary to conduct larger studies of high methodological quality using capacity tests for answering the question whether nocturnal hemodialysis can improve physical performance of patients with end-stage renal disease.

Trial registration

NTR4715, Netherlands Trial Register. Registered 30 July 2014.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1518-4) contains supplementary material, which is available to authorized users.

Effect of initial immunosuppression on long-term kidney transplant outcome in immunological low-risk patients

BACKGROUND

Few studies have evaluated the effect of different immunosuppressive strategies on long-term kidney transplant outcomes. Moreover, as they were usually based on historical data, it was not possible to account for the presence of pretransplant donor-specific human-leukocyte antigen antibodies (DSA), a currently recognized risk marker for impaired graft survival. The aim of this study was to evaluate to what extent frequently used initial immunosuppressive therapies increase graft survival in immunological low-risk patients.

METHODS

We performed an analysis on the PROCARE cohort, a Dutch multicentre study including all transplantations performed in the Netherlands between 1995 and 2005 with available pretransplant serum (n = 4724). All sera were assessed for the presence of DSA by a luminex single-antigen bead assay. Patients with a previous kidney transplantation, pretransplant DSA or receiving induction therapy were excluded from the analysis.

RESULTS

Three regimes were used in over 200 patients: cyclosporine (CsA)/prednisolone (Pred) (n = 542), CsA/mycophenolate mofetil (MMF)/Pred (n = 857) and tacrolimus (TAC)/MMF/Pred (n = 811). Covariate-adjusted analysis revealed no significant differences in 10-year death-censored graft survival between patients on TAC/MMF/Pred therapy (79%) compared with patients on CsA/MMF/Pred (82%, P = 0.88) or CsA/Pred (79%, P = 0.21). However, 1-year rejection-free survival censored for death and failure unrelated to rejection was significantly higher for TAC/MMF/Pred (81%) when compared with CsA/MMF/Pred (67%, P < 0.0001) and CsA/Pred (64%, P < 0.0001).

CONCLUSION

These results suggest that in immunological low-risk patients excellent long-term kidney graft survival can be achieved irrespective of the type of initial immunosuppressive therapy (CsA or TAC; with or without MMF), despite differences in 1-year rejection-free survival.

Prescribing quality in secondary care patients with different stages of chronic kidney disease: a retrospective study in the Netherlands

OBJECTIVES

Insight in the prescribing quality for patients with chronic kidney disease (CKD) in secondary care is limited. The aim of this study is to assess the prescribing quality in secondary care patients with CKD stages 3-5 and possible differences in quality between CKD stages.

DESIGN

This was a retrospective cohort study.

SETTING

Data were collected at two university (n=569 and n=845) and one non-university nephrology outpatient clinic (n=1718) in the Netherlands.

PARTICIPANTS

Between March 2015 and August 2016, data were collected from patients with stages 3a-5 CKD seen at the clinics. Blood pressure measurements, laboratory measurements and prescription data were extracted from medical records. For each prescribing quality indicator, patients with incomplete data required for calculation were excluded.

OUTCOME MEASURES

Potentially appropriate prescribing of antihypertensives, renin-angiotensin-aldosterone system (RAAS) inhibitors, statins, phosphate binders and potentially inappropriate prescribing according to prevailing guidelines was assessed using prescribing quality indicators. Χ² or Fisher's exact tests were used to test for differences in prescribing quality.

RESULTS

RAAS inhibitors alone or in combination with diuretics (57% or 52%, respectively) and statins (42%) were prescribed less often than phosphate binders (72%) or antihypertensives (94%) when indicated. Active vitamin D was relatively often prescribed when potentially not indicated (19%). Patients with high CKD stages were less likely to receive RAAS inhibitors but more likely to receive statins when indicated than stage 3 CKD patients. They also received more active vitamin D and erythropoietin-stimulating agents when potentially not indicated.

CONCLUSIONS

Priority areas for improvement of prescribing in CKD outpatients include potential underprescribing of RAAS inhibitors and statins, and potential overprescribing of active vitamin D. CKD stage should be taken into account when assessing prescribing quality.

Ethnic Differences in the Association of Depressive Symptoms with Clinical Outcome in Dialysis Patients

BACKGROUND

Studies show mixed results on the association between depressive symptoms and adverse clinical outcomes in patients on dialysis therapy. Ethnicity may play a role in these heterogeneous results. No studies have investigated the interplay between ethnicity and depressive symptoms on clinical outcome in this patient population. This study aims to examine interaction between ethnicity and depressive symptoms on hospitalization and mortality in dialysis patients.

METHODS

A multi-ethnic cohort in 10 dialysis centers included 687 dialysis patients between 2012 and 2017, with an average follow-up of 3.2 years. Depressive symptoms were measured using the Beck Depression Inventory. Interaction was assessed by investigating excess risk on an additive scale using both absolute rates and relative risks. Multivariable regression models included demographic, social, and clinical variables.

RESULTS

Adverse outcomes are more pronounced in native patients, compared to immigrant patients. The risk for mortality and hospitalization is considerably higher in native patients compared to immigrants. An excess risk on an additive scale indicates the presence of possible causal interaction.

CONCLUSIONS

Depressive symptoms are a risk factor for hospitalization and mortality, especially in native dialysis patients. Adverse clinical events associated with depressive symptoms differ among ethnic groups. This differential association could play a role in the conflicting findings in literature. Ethnicity is an important factor when investigating depressive symptoms and clinical outcome in dialysis patients. Future research should focus on the possible mechanisms and pathways involved in these differential associations.

Anxiety Symptoms, Mortality, and Hospitalization in Patients Receiving Maintenance Dialysis: A Cohort Study

RATIONALE & OBJECTIVE

Anxiety symptoms are common in dialysis patients and have a large impact on quality of life. The association of anxiety symptoms with adverse clinical outcomes in dialysis patients is largely unknown. This study examined the association of anxiety symptoms with hospitalization and mortality in patients receiving maintenance dialysis.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Maintenance dialysis patients treated at 10 dialysis centers in the Netherlands between 2012 and 2016.

EXPOSURES

Time-varying symptoms of anxiety and depression using the Beck Anxiety Inventory and Beck Depression Inventory.

OUTCOMES

All-cause mortality, 1-year hospitalization rate, and hospital length of stay.

ANALYTICAL APPROACH

Cox proportional hazards and Poisson regression models adjusted for sociodemographic and clinical variables. Sensitivity analyses included multiple imputation of missing data and restriction to incident patients only.

RESULTS

687 patients were included, composed of 433 prevalent and 242 incident dialysis patients. Median follow-up time was 3.1 (IQR, 3.0-3.5) years, during which 172 deaths occurred. 22% of patients had anxiety symptoms and 42% had depressive symptoms. Anxiety symptoms were associated with all-cause mortality and 1-year hospitalization rate and length of stay in all multivariable models. Anxiety symptoms showed a clear dose-response relationship with mortality.

LIMITATIONS

Depression and anxiety often coexist and share symptoms. The observational design of this study limits inferences about causal mechanisms between anxiety and clinical outcomes.

CONCLUSIONS

Anxiety symptoms are independently associated with increased risk for mortality and 1-year hospitalization. Anxiety symptoms are a clinically relevant risk factor for morbidity and mortality in dialysis patients and warrant further research on effective treatment.

Short-term effects of sevelamer-carbonate on fibroblast growth factor 23 and pulse wave velocity in patients with normophosphataemic chronic kidney disease Stage 3

Background

High concentrations of both phosphate and fibroblast growth factor 23 (FGF23) observed in chronic kidney disease (CKD) are associated with an increased risk of cardiovascular morbidity and mortality. Pulse wave velocity (PWV) is a surrogate marker for cardiovascular events and all-cause mortality. It is not known whether a reduction of FGF23 or phosphate alters cardiovascular risk. Sevelamer has shown to have the ability to reduce both phosphate and FGF23 concentrations. Furthermore, reduction of PWV is reported with sevelamer use as well, but it is unclear if this is mediated by decline of phosphate or FGF23. We investigated if sevelamer induced a decline in PWV and if this was associated with a reduction in FGF23.

Methods

In all, 24 normophosphataemic CKD Stage 3 patients started treatment with a fixed dose of sevelamer-carbonate (Renvela^®) 2.4 g twice daily, with their usual diet for 8 weeks in a single-arm study. PWV was measured and blood samples were obtained before, during and after washout of treatment with sevelamer. Vascular calcification was quantified using the Kauppila Index (KI). The primary outcome was the change of PWV from baseline to 8 weeks of treatment and the secondary endpoint was the difference of FGF23 following treatment with sevelamer. One of the linear mixed models was used to analyse the association between treatment and outcome. Mediation analysis was performed as a sensitivity analysis. The study was registered in the Dutch trial register (http://www.trialregister.nl: NTR2383).

Results

A total of 18 patients completed 8 weeks of treatment with sevelamer and were analysed. Overall, treatment with sevelamer did not induce a significant reduction of PWV (β = −0.36, P = 0.12). However, in patients with less vascular calcification (lower KI score), there was a statistically significant reduction of PWV, adjusted for mean arterial pressure, after treatment (β = 0.63, P = 0.02). Addition of FGF23 to the model did not alter this association. Mediation analysis yielded similar results. FGF23 did not decrease during treatment with sevelamer.

Conclusion

In this short-term pilot study in normophosphataemic CKD patients, treatment with sevelamer did not improve PWV. In subgroup analysis, however, PWV improved in patients with no or limited abdominal aorta calcifications. This was not associated with a decline of FGF23.

Development and Validation of a Multiplex Non-HLA Antibody Assay for the Screening of Kidney Transplant Recipients

The best treatment for patients with end-stage renal disease is kidney transplantation. Although graft survival rates have improved in the last decades, patients still may lose their grafts partly due to the detrimental effects of donor-specific antibodies (DSA) against human leukocyte antigens (HLA) and to a lesser extent also by antibodies directed against non-HLA antigens expressed on the donor endothelium. Assays to detect anti-HLA antibodies are already in use for many years and have been proven useful for transplant risk stratification. Currently, there is a need for assays to additionally detect multiple non-HLA antibodies simultaneously in order to study their clinical relevance in solid organ transplantation. This study describes the development, technical details and validation of a high-throughput multiplex assay for the detection of antibodies against 14 non-HLA antigens coupled directly to MagPlex microspheres or indirectly via a HaloTag. The non-HLA antigens have been selected based on a literature search in patients with kidney disease or following transplantation. Due to the flexibility of the assay, this approach can be used to include alternative antigens and can also be used for screening of other organ transplant recipients, such as heart and lung.

Impaired nocturnal blood pressure dipping in patients with type 2 diabetes mellitus

Hypertension is a common comorbidity of type 2 diabetes mellitus (T2DM). Both conditions are associated with an increased cardiovascular risk, which is reduced by tight blood pressure (BP) and glycemic control. However, nondipping BP status continues to be an enduring cardiovascular risk factor in T2DM. Cardiovascular autonomic neuropathy and endothelial dysfunction have been proposed as potential mechanisms. This study tested the hypothesis that microvascular disease rather than cardiovascular autonomic neuropathy interferes with the physiological nocturnal BP reduction. Cardiovascular autonomic function and baroreflex sensitivity were determined in 22 type 2 diabetic patients with (DM+) and 23 diabetic patients without (DM-) manifest microvascular disease. BP dipping status was assessed from 24-hour ambulatory BP measurements. Sixteen nondiabetic subjects served as controls (CTRL). Cardiovascular autonomic function was normal in all subjects. Baroreflex sensitivity was lower in DM- compared with CTRL (7.7 ± 3.3 vs. 12.3 ± 8.3 ms·mm Hg^-1; P < 0.05) and was further reduced in DM + (4.6 ± 2.0 ms·mm Hg^-1; P < 0.01 vs. DM- and CTRL). The nocturnal decline in systolic and diastolic BP was blunted in DM- (12% and 14% vs. 17% and 19% in CTRL; P < 0.05) and even more so in DM+ (8% and 11%; P < 0.05 vs. DM- and P < 0.001 vs. CTRL). A nocturnal reduction in pulse pressure was observed in CTRL and DM- but not in DM+ (P < 0.05 vs. DM- and P < 0.01 vs. CTRL). In T2DM, progression of microvascular disease interferes with the normal nocturnal BP decline and coincides with a persistently increased pulse pressure and reduced baroreflex sensitivity, contributing to their increased cardiovascular risk.

Pretransplant C3d-Fixing Donor-Specific Anti-HLA Antibodies Are Not Associated with Increased Risk for Kidney Graft Failure

Background Complement-fixing antibodies against donor HLA are considered a contraindication for kidney transplant. A modification of the IgG single-antigen bead (SAB) assay allows detection of anti-HLA antibodies that bind C3d. Because early humoral graft rejection is considered to be complement mediated, this SAB-based technique may provide a valuable tool in the pretransplant risk stratification of kidney transplant recipients.Methods Previously, we established that pretransplant donor-specific anti-HLA antibodies (DSAs) are associated with increased risk for long-term graft failure in complement-dependent cytotoxicity crossmatch-negative transplants. In this study, we further characterized the DSA-positive serum samples using the C3d SAB assay.Results Among 567 pretransplant DSA-positive serum samples, 97 (17%) contained at least one C3d-fixing DSA, whereas 470 (83%) had non-C3d-fixing DSA. At 10 years after transplant, patients with C3d-fixing antibodies had a death-censored, covariate-adjusted graft survival of 60%, whereas patients with non-C3d-fixing DSA had a graft survival of 64% (hazard ratio, 1.02; 95% confidence interval, 0.70 to 1.48 for C3d-fixing DSA compared with non-C3d-fixing DSA; P=0.93). Patients without DSA had a 10-year graft survival of 78%.Conclusions The C3d-fixing ability of pretransplant DSA is not associated with increased risk for graft failure.

Routine hemodialysis induces a decline in plasma magnesium concentration in most patients: a prospective observational cohort study

In hemodialysis patients, lower plasma magnesium (Mg) concentrations are associated with a higher overall and cardiovascular mortality. The optimal concentration appears to be above the reference range for the healthy population. Plasma Mg is not routinely measured after hemodialysis. Aim of this study was to determine the effect of routine hemodialysis on plasma Mg. Plasma Mg was measured in duplicate before (Mgpre) and after (Mgpost) dialysis in 6 consecutive hemodialysis sessions of 34 patients using a fixed 0.50 mmol/L dialysate Mg concentration. Mean Mgpre was 0.88 mmol/L (±0.14) and mean Mgpost was statistically significantly lower: mean intra-dialytic decline 0.10 mmol/L (95%-CI 0.06-0.13). A 0.10 mmol/L higher Mgpre was associated with a 0.03 mmol/L higher Mgpost (95%-CI 0.024-0.037). At a Mgpre of 0.74 mmol/L, Mgpost equalled Mgpre. There was an intra-dialytic decline of plasma Mg at higher Mgpre values and an increase at lower Mgpre values. In conclusion, in the majority of the hemodialysis patients, Mgpre concentrations are in the reference range of the healthy population, which may be too low for hemodialysis patients. Routine hemodialysis with the widely used 0.50 mmol/L dialysate Mg concentration, further declines magnesium in the majority of patients. Current dialysate Mg concentrations may be too low.

PIRCHE-II Is Related to Graft Failure after Kidney Transplantation

Individual HLA mismatches may differentially impact graft survival after kidney transplantation. Therefore, there is a need for a reliable tool to define permissible HLA mismatches in kidney transplantation. We previously demonstrated that donor-derived Predicted Indirectly ReCognizable HLA Epitopes presented by recipient HLA class II (PIRCHE-II) play a role in de novo donor-specific HLA antibodies formation after kidney transplantation. In the present Dutch multi-center study, we evaluated the possible association between PIRCHE-II and kidney graft failure in 2,918 donor–recipient couples that were transplanted between 1995 and 2005. For these donors–recipients couples, PIRCHE-II numbers were related to graft survival in univariate and multivariable analyses. Adjusted for confounders, the natural logarithm of PIRCHE-II was associated with a higher risk for graft failure [hazard ratio (HR): 1.13, 95% CI: 1.04–1.23, p = 0.003]. When analyzing a subgroup of patients who had their first transplantation, the HR of graft failure for ln(PIRCHE-II) was higher compared with the overall cohort (HR: 1.22, 95% CI: 1.10–1.34, p < 0.001). PIRCHE-II demonstrated both early and late effects on graft failure in this subgroup. These data suggest that the PIRCHE-II may impact graft survival after kidney transplantation. Inclusion of PIRCHE-II in donor-selection criteria may eventually lead to an improved kidney graft survival.

Effects of Oral Paricalcitol and Calcitriol Treatment on Peritoneal Membrane Characteristics of Peritoneal Dialysis Patients - A Pilot Study

BACKGROUND

Long-term peritoneal dialysis (PD) is frequently complicated by technique failure preceded by peritoneal remodeling. Vitamin D has potent immunomodulatory characteristics: anti-inflammatory, anti-angiogenic, anti-fibrotic properties, and influences on the macrophage phenotype. Little is known about the relation between pleiotropic effects attributed to vitamin D₃ and the peritoneal membrane and what is the most appropriate vitamin D sterol in prevention of peritoneal remodeling in PD patients. Animal studies have suggested that paricalcitol has advantageous effects: decrease in plasma markers of inflammation, less peritoneal fibrosis, less pronounced PD-induced omental angiogenesis, and prevention of loss of ultrafiltration. We investigated whether paricalcitol is advantageous over calcitriol in PD patients.

METHOD

A multicenter open-label 1:1 randomized non-blinded clinical pilot study enrolled prevalent continous ambulatory PD (CAPD) patients for a period of 6 months comparing paricalcitol with calcitriol. All patients were treated with biocompatible PD fluids. The primary endpoint was peritoneal transport parameters, exploratory endpoints were biomarkers of peritoneal damage and cell analysis (including M1/M2 macrophages), and safety endpoints were metabolic parameters.

RESULTS

Twenty-seven patients were included. Fourteen were randomized to treatment with paricalcitol. There was no difference in peritoneal transport parameters between the groups. We found similar Kt/V, D/P creatinine, D/D0 glucose, ultrafiltration, residual renal function and 24-h urine volume during the study. There was no difference in biomarker concentrations in peritoneal effluents, and no difference in leucocyte differentiation or mesothelial cells between the groups at any time point. Parathyroid hormone (PTH) levels decreased after administration of calcitriol after 12 and 24 weeks compared with baseline (p = 0.001; p = 0.025). Parathyroid hormone levels in the paricalcitol group did not change significantly.

CONCLUSION

In this pilot study we investigated the effect of active vitamin D in PD patients. We found no specific benefit of active vitamin D₃ in vitamin D₃-sufficient PD patients. Additional studies in preferably incident patients, with an adequate PTH suppression in the intervention groups and during a longer period, are required to test the beneficial effects of active vitamin D₃ over no treatment and to investigate whether in 25(OH)D₃-deficient PD patients the type of active vitamin D₃ matters.

Prediction models for the mortality risk in chronic dialysis patients: a systematic review and independent external validation study

OBJECTIVE

In medicine, many more prediction models have been developed than are implemented or used in clinical practice. These models cannot be recommended for clinical use before external validity is established. Though various models to predict mortality in dialysis patients have been published, very few have been validated and none are used in routine clinical practice. The aim of the current study was to identify existing models for predicting mortality in dialysis patients through a review and subsequently to externally validate these models in the same large independent patient cohort, in order to assess and compare their predictive capacities.

METHODS

A systematic review was performed following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. To account for missing data, multiple imputation was performed. The original prediction formulae were extracted from selected studies. The probability of death per model was calculated for each individual within the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD). The predictive performance of the models was assessed based on their discrimination and calibration.

RESULTS

In total, 16 articles were included in the systematic review. External validation was performed in 1,943 dialysis patients from NECOSAD for a total of seven models. The models performed moderately to well in terms of discrimination, with C-statistics ranging from 0.710 (interquartile range 0.708-0.711) to 0.752 (interquartile range 0.750-0.753) for a time frame of 1 year. According to the calibration, most models overestimated the probability of death.

CONCLUSION

Overall, the performance of the models was poorer in the external validation than in the original population, affirming the importance of external validation. Floege et al's models showed the highest predictive performance. The present study is a step forward in the use of a prediction model as a useful tool for nephrologists, using evidence-based medicine that combines individual clinical expertise, patients' choices, and the best available external evidence.

Increased risk of graft failure and mortality in Dutch recipients receiving an expanded criteria donor kidney transplant

Survival of expanded criteria donor (ECD) kidneys and their recipients has not been thoroughly evaluated in Europe. Therefore, we compared the outcome of ECD and non-ECD kidney transplantations in a Dutch cohort, stratifying by age and diabetes. In all first Dutch kidney transplants in recipients ≥18 years between 1995 and 2005, both relative risks (hazard ratios, HR) and adjusted absolute risk differences (RD) for ECD kidney transplantation were analysed. In 3062 transplantations [recipient age 49.0 (12.8) years; 20% ECD], ECD kidney transplantation was associated with graft failure including death [HR 1.62 (1.44-1.82)]. The adjusted HR was lower in recipients ≥60 years of age [1.32 (1.07-1.63)] than in recipients 40-59 years [1.71 (1.44-2.02) P = 0.12 for comparison with ≥60 years] and recipients 18-39 years [1.92 (1.42-2.62) P = 0.03 for comparison with ≥60 years]. RDs showed a similar pattern. In diabetics, the risks for graft failure and death were higher than in the nondiabetics. ECD kidney grafts have a poorer prognosis than non-ECD grafts, especially in younger recipients (<60 years), and diabetic recipients. Further studies and ethical discussions should reveal whether ECD kidneys should preferentially be allocated to specific subgroups, such as elderly and nondiabetic individuals.

Improved Outcome of Enteric Peritonitis in Peritoneal Dialysis Patients Aged 50 Years and Older with Temporary Discontinuation of Peritoneal Dialysis and Intravenous Meropenem

Background

Peritonitis is a major cause of morbidity, mortality, and technique failure in peritoneal dialysis (PD) patients, especially when caused by enteric microorganisms (EM). We have implemented a treatment protocol specifically aimed at improving the outcome in EM peritonitis. The adapted protocol was applied in all PD patients 50 years and older presenting with peritonitis who were considered to be at risk of EM peritonitis and involves 3 interventions: 1) temporary discontinuation of PD without removing the catheter (peritoneal rest), 2) intravenous meropenem, and 3) meropenem intracatheter as lock (Mero-PerRest protocol).

Methods

In this observational study, we compared the outcome of 203 peritonitis episodes in 71 patients treated with the Mero-PerRest protocol, with 217 episodes in 104 patients treated with a more traditional intraperitoneal gentamicin-rifampicin-based regimen.

Results

In EM peritonitis episodes, the Mero-PerRest protocol resulted in a higher primary cure rate (90.0% vs 65.3%, adjusted odds ratio [OR] 4.54 [95% confidence interval (CI) 1.46 – 14.15]) and better technique survival (90.0% vs 69.4%, adjusted OR 3.41 [95% CI 1.07 – 10.87]). This effect was most distinct in patients with polymicrobial EM peritonitis (cure rate 87.5% vs 34.8%, p = 0.0003). Interestingly, primary cure rate (95.6% vs 84.7%, adjusted OR 3.92 [95% CI 1.37 – 11.19]) and technique survival (95.6% vs 85.6%, adjusted OR 3.60 [95% CI 1.25 – 10.32]) were also excellent in non-EM peritonitis episodes. Patient survival did not differ significantly.

Conclusion

The poor outcome of peritonitis caused by EM in PD patients aged 50 years and older could be improved by applying a treatment protocol involving temporary discontinuation of PD without catheter removal and intravenous and intracatheter meropenem.

Effects of Conversion to a Bicarbonate/Lactate-Buffered, Neutral-pH, Low-GDP PD Regimen in Prevalent PD: A 2-Year Randomized Clinical Trial

♦ BACKGROUND: The use of pH-neutral peritoneal dialysis (PD) fluids low in glucose degradation products (GDP) may better preserve the peritoneal membrane and have fewer systemic effects. The effects of conversion from conventional to neutral-pH, low-GDP PD fluids in prevalent patients are unclear. Few studies on the role of neutral-pH, low-GDP PD have studied residual renal function, ultrafiltration, peritonitis incidence and technique failure, transport characteristics, and local and systemic markers of inflammation in prevalent PD patients. ♦ METHODS: In a multi-center open-label randomized clinical trial (RCT), we randomly assigned 40 of 78 stable continuous ambulatory PD (CAPD) and automated PD (APD) patients to treatment with bicarbonate/lactate, neutral-pH, low-GDP PD fluid (Physioneal; Baxter Healthcare Corporation, Deerfield, IL, USA) and compared them with 38 patients continuing their current standard lactate-buffered PD fluid (PDF) (Dianeal; Baxter Healthcare Corporation, Deerfield, IL, USA) during 2 years. Primary outcome was residual renal function (RRF) and ultrafiltration (UF) during peritoneal equilibration test (PET); peritonitis incidence was a secondary outcome. Furthermore, clinical parameters as well as several biomarkers in effluents and serum were measured. ♦ RESULTS: During follow-up, RRF did not differ between the groups. In the Physioneal group ultrafiltration (UF) during PET remained more or less stable (-20 mL [confidence interval (CI): -163.5 - 123.5 mL]; p = 0.7 over 24 months), whereas it declined in the Dianeal group (-243 mL [CI: -376.6 to -109.4 mL]; p < 0.0001 over 24 months), resulting in a difference of 233.7 mL [95% CI 41.0 - 425.5 mL]; p = 0.017 between the groups at 24 months. The peritonitis rate was lower in the Physioneal group: adjusted odds ratio (OR) 0.38 (0.15 - 0.97) p = 0.043. No differences were observed between the 2 groups in peritoneal adequacy or transport characteristics nor effluent markers of local inflammation (cancer antigen [CA]125, hyaluronan [HA], vascular endothelial growth factor [VEGF], macrophage chemo-attractant protein [MCP]-1, HA and transforming growth factor [TGF]β-1). ♦ CONCLUSION: In prevalent PD patients, our study did not find a difference in RRF after conversion from conventional to neutral-pH, low-GDP PD fluids, although there is a possibility that the study was underpowered to detect a difference. Decline in UF during standardized PET was lower after 2 years in the Physioneal group.

Reduction of Oxidative Stress in Chronic Kidney Disease Does Not Increase Circulating α-Klotho Concentrations

The CKD-associated decline in soluble α-Klotho levels is considered detrimental. Some in vitro and in vivo animal studies have shown that anti-oxidant therapy can upregulate the expression of α-Klotho in the kidney. We examined the effect of anti-oxidant therapy on α-Klotho concentrations in a clinical cohort with mild tot moderate chronic kidney disease (CKD). We performed a post-hoc analysis of a prospective randomized trial involving 62 patients with mild to moderate CKD (the ATIC study), all using an angiotensin-converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB) for 12 months. On top of that, the intervention group received anti-oxidative therapy consisting of the combination of pravastatin (40 mg/d) and vitamin E (α-tocopherol acetate, 300 mg/d) while the placebo was not treated with anti-oxidants. α-Klotho concentrations were measured at baseline and after 12 months of anti-oxidant therapy. Data were analysed using T-tests and Generalized Estimating Equations, adjusting for potential confounders such as vitamin D, parathyroid hormone, fibroblast-growth-factor 23 (FGF23) and eGFR. The cohort existed of 62 patients with an eGFR (MDRD) of 35 ± 14 ml/min/1.72m², 34 were male and mean age was 53.0 ± 12.5 years old. Anti-oxidative therapy did successfully reduce oxLDL and LDL concentrations (P <0.001). α-Klotho concentrations did not change in patients receiving either anti-oxidative therapy (476.9 ± 124.3 to 492.7 ± 126.3 pg/mL, P = 0.23) nor in those receiving placebo 483.2 ± 142.5 to 489.6 ± 120.3 pg/mL, P = 0.62). Changes in α-Klotho concentrations were not different between both groups (p = 0.62). No evidence was found that anti-oxidative therapy affected α-Klotho concentrations in patients with mild-moderate CKD.

Development and initial validation of prescribing quality indicators for patients with chronic kidney disease

BACKGROUND

Quality assessment is a key element for improving the quality of care. Currently, a comprehensive indicator set for measuring the quality of medication treatment in patients with chronic kidney disease (CKD) is lacking. Our aim was to develop and validate a set of prescribing quality indicators (PQIs) for CKD care, and to test the feasibility of applying this set in practice.

METHODS

Potential indicators were based on clinical practice guidelines and evaluated using the RAND/UCLA Appropriateness Method. This is a structured process in which an expert panel assesses the validity of the indicators. Feasibility was tested in a Dutch primary care database including >4500 diabetes patients with CKD.

RESULTS

An initial list of 22 PQIs was assessed by 12 experts. After changing 10 PQIs, adding 2 and rejecting 8, a final list of 16 indicators was accepted by the expert panel as valid. These PQIs focused on the treatment of hypertension, albuminuria, mineral and bone disorder, statin prescribing and possible unsafe medication. The indicators were successfully applied to measure treatment quality in the primary care database, but for some indicators the number of eligible patients was too small for reliable calculation. Results showed that there was room for improvement in the treatment quality of this population.

CONCLUSIONS

We developed a set of 16 PQIs for measuring the quality of treatment in CKD patients, which had sufficient content and face validity as well as operational feasibility. These PQIs can be used to point out priority areas for improvement.

Relation between Red Cell Distribution Width and Fibroblast Growth Factor 23 Cleaving in Patients with Chronic Kidney Disease and Heart Failure

OBJECTIVE

In chronic kidney disease (CKD), both anemia and deregulated phosphate metabolism are common and predictive of adverse outcome. Previous studies suggest that iron status influences phosphate metabolism by modulating proteolytic cleavage of FGF23 into C-terminal fragments. Red cell distribution width (RDW) was recently identified as a strong prognostic determinant for cardiovascular morbidity and mortality, independently of iron status. We assessed whether RDW is associated with FGF23 cleaving in CKD patients with heart failure.

MATERIALS AND METHODS

The associations between RDW and either intact FGF23 (iFGF23), C-terminal FGF23 (cFGF23, reflecting iFGF23 and C-terminal fragments together) and the iFGF23/cFGF23 ratio were analyzed in 52 patients with CKD (eGFR 34,9 ± 13.9 ml/min/1.73m2) and chronic heart failure (CHF). Associations between RDW and FGF23 forms were studied by linear regression analysis adjusted for parameters of renal function, iron metabolism, phosphate metabolism and inflammation.

RESULTS

Median cFGF23 levels were 197.5 [110-408.5] RU/ml, median iFGF23 levels were 107.3 [65.1-162.2] pg/ml and median FGF23 ratio was 0.80 [0.37-0.86]. Mean RDW was 14.1 ± 1.2%. cFGF23 and RDW were associated (β = 1.63 x 10(-3), P < 0.001), whereas iFGF23 and RDW were not (β = -1.38 x 10(-3), P = 0.336). The iFGF23/cFGF23 ratio was inversely associated with RDW. The difference between cFGF23 and iFGF23 (cFGF23- iFGF23) was positively associated with RDW (β = 1.74 x 10(-3), P < 0.001). The association between cFGF23 and RDW persisted upon multivariable linear regression analysis, adjusted for parameters of renal function, phosphate metabolism, iron metabolism and inflammation (β = 0.97 x 10(-3), P = 0.047).

CONCLUSION

RDW is associated with cFGF23 but not with iFGF23 levels in patients with CKD and CHF. This suggests a connection between RDW and FGF23 catabolism, independent of iron status and inflammation. Future studies are needed to unravel underlying mechanisms and whether these pertain to the link between RDW and outcome.

Long-term effects of melatonin on quality of life and sleep in haemodialysis patients (Melody study): a randomized controlled trial

AIM

The disturbed circadian rhythm in haemodialysis patients results in perturbed sleep. Short term melatonin supplementation has alleviated these sleep problems. Our aim was to investigate the effects of long-term melatonin supplementation on quality of life and sleep.

METHODS

In this randomized double-blind placebo-controlled trial haemodialysis patients suffering from subjective sleep problems received melatonin 3 mg day(-1) vs. placebo during 12 months. The primary endpoint quality of life parameter 'vitality' was measured with Medical Outcomes Study Short Form-36. Secondary outcomes were improvement of three sleep parameters measured by actigraphy and nighttime salivary melatonin concentrations.

RESULTS

Sixty-seven patients were randomized. Forty-two patients completed the trial. With melatonin, no beneficial effect on vitality was seen. Other quality of life parameters showed both advantageous and disadvantageous effects of melatonin. Considering sleep, at 3 months sleep efficiency and actual sleep time had improved with melatonin compared with placebo on haemodialysis days (difference 7.6%, 95% CI 0.77, 14.4 and 49 min, 95% CI 2.1, 95.9, respectively). At 12 months none of the sleep parameters differed significantly from placebo. Melatonin salivary concentrations at 6 months had significantly increased in the melatonin group compared with the placebo group.

CONCLUSIONS

The high drop-out rate limits the strength of our conclusions. However, although a previous study reported beneficial short term effects of melatonin on sleep in haemodialysis patients, in this long-term study the positive effects disappeared during follow up (6-12 months). Also the quality of life parameter, vitality, did not improve. Efforts should be made to elucidate the mechanism responsible for the loss of effect with chronic use.