Chronic inflammation and mortality in haemodialysis: effect of different renal replacement therapies. Results from the RISCAVID study

Is hemodiafiltration superior to high-flow hemodialysis in reducing all-cause and cardiovascular mortality in kidney failure patients? A meta-analysis of randomized controlled trials

INTRODUCTION

Hemodiafiltration (HDF) and high-flux hemodialysis (hf-HD) are different methods of kidney replacement therapy (KRT) used for the treatment of kidney failure patients. A debate has raged over the last decade about the survival benefit of patients with the use of HDF compared with hf-HD, but with divergent results from randomized controlled trials. Therefore, this study aimed to perform a meta-analysis to compare HDF and hf-HD regarding all-cause and cardiovascular mortality.

METHODS

PubMed and Cochrane databases were searched until July 19, 2023, for randomized clinical trials comparing HDF and hf-HD in patients on maintenance dialysis. A meta-analysis was performed using Stata 16.1, applying fixed or random effect models according to the heterogeneity between studies.

FINDINGS

Of the 496 studies found, five met the inclusion criteria. Compared with the hf-HD group, the risk ratio (RR) for all-cause mortality with HDF use was 0.76 (95% CI: 0.67-0.88, I2 = 0%). HDF was associated with lower cardiovascular mortality, although the sensitivity analysis showed that the result differed between scenarios. Subgroup analysis showed lower all-cause mortality among patients without diabetes in the HDF group compared with hf-HD (RR 0.66, 95% CI: 0.51-0.81, I2 = 0%), but not in diabetic patients (RR = 0.89, 95% CI: 0.65-1.12, I2 = 0.0%). A subgroup analysis considering convection volumes was not performed, but the studies with the highest weight in the meta-analysis described convection volume as more than 20 L/session.

DISCUSSION

More clinical studies considering critical risk factors, such as advanced age and preexisting cardiovascular disease, are needed to confirm the supremacy of HDF over hf-HD on the survival of patients treated by these two forms of kidney replacement therapy.

ABCs of hemodiafiltration prescription: The Pisa style

In end-stage kidney disease patients, hemodiafiltration, a mixed diffusive-convective technique, has shown beneficial effects in terms of improvement of anemia, inflammation, mineral bone disorders, malnutrition and cardiovascular stability. Greater convective volume exchange was also associated with improved overall and cardiovascular survival. However, absolute target threshold volume would be difficult to define and achieve in daily clinical practice, mainly because of differences in patient size. Convective volumes standardized for body surface area would appear to be the simplest approach in clinical practice. Several factors can affect achievement of optimal convective volume, with vascular access being the main limiting factor. Based on our own clinical experience, hemodiafiltration is a more effective and preferable dialysis technique but only when a target convective volume greater than 20 L can be achieved. Conversely, standard high flux hemodialysis or expanded hemodialysis may be helpful and valuable alternative dialysis techniques.

Comparison of the pre-dilution and post-dilution methods for online hemodiafiltration

Online hemodiafiltration (OL-HDF) is a treatment modality using diffusion and ultrafiltration. There are two types of dilution methods in OL-HDF: pre-dilution, which is commonly provided in Japan, and post-dilution, which is commonly provided in Europe. The optimal OL-HDF method for individual patients is not well studied. In this study, we compared the clinical symptoms, laboratory data, spent dialysate, and adverse events of pre- and post-dilution OL-HDF. We conducted a prospective study of 20 patients who underwent OL-HDF between January 1, 2019 and October 30, 2019. Their clinical symptoms and dialysis efficacy were evaluated. All patients underwent OL-HDF every 3 months in the following sequence: first pre-dilution, post-dilution, and second pre-dilution. We evaluated 18 patients for the clinical study and 6 for the spent dialysate study. No significant differences in spent dialysates regarding small and large solutes, blood pressure, recovery time, and clinical symptoms were observed between the pre- and post-dilution methods. However, the serum α1-microglobulin level in post-dilution OL-HDF was lower than that in pre-dilution OL-HDF (first pre-dilution: 124.8 ± 14.3 mg/L; post-dilution: 116.6 ± 13.9 mg/L; second pre-dilution: 125.8 ± 13.0 mg/L; first pre-dilution vs. post-dilution, post-dilution vs. second pre-dilution, and first pre-dilution vs. second pre-dilution: p = 0.001, p < 0.001, and p = 1.000, respectively). The most common adverse event was an increase in transmembrane pressure in the post-dilution period. Compared to pre-dilution, the post-dilution method decreased the α1-microglobulin level; however, there were no significant differences in clinical symptoms or laboratory data.

Latest Trends in Hemodiafiltration

This review provides a detailed analysis of hemodiafiltration (HDF), its progress from an emerging technique to a potential conventional treatment for chronic hemodialysis patients, and its current status. The article covers the advances, methods, and clinical benefits of HDF, specifically focusing on its impact on cardiovascular health, survival rates, and overall well-being. The review also addresses questions about the safety of HDF and provides evidence to dispel concerns related to the elimination of beneficial substances and infection risks. Additionally, the article explores the potential implications of expanded hemodialysis (HDx) as an alternative to HDF, its classification, safety profile, and an ongoing trial assessing its non-inferiority to HDF. Supported by evidence from randomized controlled trials and observational studies, the review emphasizes the superiority of HDF as a hemodialysis modality and advocates for its positioning as the gold standard in treatment. However, it acknowledges the need for extensive research to define the role of HDx in comprehensive treatment approaches in individuals undergoing dialysis. The synthesis of current knowledge underscores the importance of ongoing exploration and research to refine hemodialysis practices for optimal patient outcomes.

Impact of C-Reactive Protein on Long-Term Cardiac Events in Stable Coronary Artery Disease Patients with Chronic Kidney Disease

AIM

Chronic inflammation is associated with atherosclerosis development. Chronic kidney disease (CKD) is an independent risk factor for cardiovascular events and is associated with chronic inflammation. We aimed to investigate the influence of C-reactive protein (CRP), an important marker of inflammation, on the clinical outcomes of patients with CKD and stable coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI).

METHODS

Among patients with stable CAD and CKD who underwent PCI, 516 patients whose CRP levels were available before the PCI procedure were identified. The patients were divided into two groups according to the CRP levels: those with CRP ≥ 2.0 mg/L (high-CRP group) and those with CRP ＜2.0 mg/L (low-CRP group). The primary endpoint of this study was the occurrence of major adverse cardiac events (MACE), defined as a composite of cardiac death, myocardial infarction, and unplanned revascularization.

RESULTS

Overall, the mean age of the patients was 72.5±9.7 years, and 20.7% were female. The median CRP level was 1.43 mg/L (0.6-4.9 mg/L). The median follow-up period was 3.6 years. The occurrence of MACE was significantly higher in the high-CRP group than in the low-CRP group (log-rank p＜0.001). Notably, the incidence rate of cardiac death was significantly higher in the high-CRP group (log-rank p＜0.001). According to the multivariable analysis, CRP level ≥ 2.0 mg/L was found to be a significant predictor of MACE (hazard ratio [HR]: 1.54, 95% confidence interval [CI]: 1.04-2.28, p=0.003), as well as estimated glomerular filtration rate (HR: 0.98, 95% CI: 0.97-0.99, p＜0.01).

CONCLUSION

High-CRP levels adversely affect long-term cardiac events in patients with stable CAD and CKD.

Dialysis Patients Respond Adequately to Influenza Vaccination Irrespective of Dialysis Modality and Chronic Inflammation

(1) Background: Chronic inflammation and suboptimal immune responses to vaccinations are considered to be aspects of immune dysregulation in patients that are undergoing dialysis. The present study aimed to evaluate immune responses in hemodialysis (HD) and online hemodiafiltration (OL-HDF) patients to a seasonal inactivated quadrivalent influenza vaccine (IQIV). (2) Methods: We enrolled 172 chronic dialysis patients (87 on HD and 85 on OL-HDF) and 18 control subjects without chronic kidney disease in a prospective, cross-sectional cohort study. Participants were vaccinated with a seasonal IQIV, and antibody titers using the hemagglutination inhibition (HI) assay were determined before vaccination (month 0) and 1, 3, and 6 months thereafter. Demographics and inflammatory markers (CRP, IL-6, IL-1β) were recorded at month 0. The primary endpoints were the rates of seroresponse (SR), defined as a four-fold increase in the HI titer, and seroprotection (SP), defined as HI titer ≥ 1/40 throughout the study period. Statistical analyses were conducted in R (version 3.6.3) statistical software. The differences between groups were analyzed using chi-square and t-test analyses for dichotomous and continuous variables, respectively. To identify independent determinants of SR and SP, generalized linear models were built with response or protection per virus strain as the dependent variable and group, age, sex, time (month 0, 1, 3, 6), diabetes, IL-6, dialysis vintage, HD access, and HDF volume as independent explanatory variables. (3) Results: SR and SP rates were similar between control subjects, and dialysis patients were not affected by dialysis modality. SP rates were high (> 70%) at the beginning of the study and practically reached 100% after vaccination in all study groups. These results applied to all four virus strains that were included in the IQIV. IL-6 levels significantly differed between study groups, with HD patients displaying the highest values, but this did not affect SP rates. (4) Conclusions: Dialysis patients respond to influenza immunization adequately and similarly to the general population. Thus, annual vaccination policies should be encouraged in dialysis units. OL-HDF reduces chronic inflammation; however, this has no impact on SR rates.

Unveiling the Clinical Benefits of High-Volume Hemodiafiltration: Optimizing the Removal of Medium-Weight Uremic Toxins and Beyond

Dialysis treatment has improved the survival of patients with kidney failure. However, the hospitalization and mortality rates remain alarmingly high, primarily due to incomplete uremic toxin elimination. High-volume hemodiafiltration (HDF) has emerged as a promising approach that significantly improves patient outcomes by effectively eliminating medium and large uremic toxins, which explains its increasing adoption, particularly in Europe and Japan. Interest in this therapy has grown following the findings of the recently published CONVINCE study, as well as the need to understand the mechanisms behind the benefits. This comprehensive review aims to enhance the scientific understanding by explaining the underlying physiological mechanisms that contribute to the positive effects of HDF in terms of short-term benefits, like hemodynamic tolerance and cardiovascular disease. Additionally, it explores the rationale behind the medium-term clinical benefits, including phosphorus removal, the modulation of inflammation and oxidative stress, anemia management, immune response modulation, nutritional effects, the mitigation of bone disorders, neuropathy relief, and amyloidosis reduction. This review also analyzes the impact of HDF on patient-reported outcomes and mortality. Considering the importance of applying personalized uremic toxin removal strategies tailored to the unique needs of each patient, high-volume HDF appears to be the most effective treatment to date for patients with renal failure. This justifies the need to prioritize its application in clinical practice, initially focusing on the groups with the greatest potential benefits and subsequently extending its use to a larger number of patients.

Combined use of CRP with neutrophil-to-lymphocyte ratio in differentiating between infectious and noninfectious inflammation in hemodialysis patients

We tested whether CRP combined with the neutrophil-to-lymphocyte ratio (NLR) optimizes the prediction of infectious inflammation in hemodialysis patients. We conducted a retrospective study of 774 (mean age 71.1 ± 12.8 years, 35% women) hemodialysis patients from our institution, hospitalized between 2007 and 2021 for various reasons, with CRP levels available at admission. Infection was defined according to the International Sepsis Definition Conference criteria. An algorithm for the optimal CRP and NLR cutoff points for predicting infection was developed based on a decision tree analysis in the training cohort (n = 620) and then tested in the validation cohort (n = 154). A CRP level above 40 mg/L (obtained as the cutoff point in predicting infections in the training group, using ROC curve analysis) predicted an infection diagnosis with a sensitivity of 75% and a specificity of 76% with an odds ratio (OR) of 9.37 (95% CI: 5.36-16.39), according to a multivariate logistic regression analysis. Whereas, CRP levels above 23 mg/L together with an NLR above 9.7 predicted an infection diagnosis with a sensitivity of 69% and a specificity of 84% with an OR of 25.59 (95% CI: 9.73-67.31). All these results were reproduced in the validation set. Combined use of CRP with NLR may lower the CRP cutoff point in distinguishing between infectious and noninfectious inflammation in hemodialysis patients.

Post-dialysis fatigue: Comparison of bicarbonate hemodialysis and online hemodiafiltration

INTRODUCTION

The present cross-sectional study aimed to compare the prevalence, the characteristics of post-dialysis fatigue and the length of recovery time after hemodialysis in prevalent end-stage renal disease patients (ESRD) receiving bicarbonate hemodialysis (HD) or hemodiafiltration (HDF).

METHODS

Patients were suffering from post-dialysis fatigue if they spontaneously offered this complaint when asked the open-ended question: "Do you feel fatigued after dialysis?". Moreover, each patient was invited to rate the intensity, duration, and frequency of post-dialysis fatigue from 1 to 5. In order to assess RECOVERY TIME AFTER DIALYSIS, patients were invited to answer to the following single open-ended question: "How long does it take you to recover from a dialysis session?"

FINDINGS

We included 335 patients: 252 received HD and 83 received HDF. Post-dialysis fatigue was present in 204 patients (60.9%). Prevalence of post-dialysis fatigue did not differ significantly between patients on HD (62.3%) and on HDF (56.6%; p = 0.430). Median recovery time after dialysis was 180 min [180-240] and did not differ significantly between the two subgroups (180 min [130-240] and 240 min [120-332] p = 0.671, respectively). Median post-dialysis fatigue intensity, duration, and frequency were 3 [1-5], 3 [1-5], and 4 [1-5] and did not differ significantly between patients on HD and on HDF. At the multivariate analysis, age, ADL and hemoglobin levels were the independent predictors of the HDF treatment.

DISCUSSION

Prevalence and characteristics of post-dialysis fatigue do not differ significantly between patients receiving bicarbonate HD or HDF.

Echocardiogram screening in pediatric dialysis and transplantation

Transthoracic echocardiography is commonly used to identify structural and functional cardiac abnormalities that can be prevalent in childhood chronic kidney failure (KF). Left ventricular mass (LVM) increase is most frequently reported and may persist post-kidney transplant especially with hypertension and obesity. While systolic dysfunction is infrequently seen in childhood chronic KF, systolic strain identified by speckle tracking echocardiography has been frequently identified in dialysis and it can also persist post-transplant. Echocardiogram association with long-term outcomes has not been studied in childhood KF but there are many adult studies demonstrating associations between increased LVM, systolic dysfunction, strain, diastolic dysfunction, and cardiovascular events and mortality. There has been limited study of interventions to improve echocardiogram status. In childhood, improved blood pressure has been associated with better LVM, and conversion from hemodialysis to hemodiafiltration has been associated with better diastolic and systolic function. Whether long-term cardiac outcomes are also improved with these interventions is unclear. Echocardiography is a well-established technique, and regular use in childhood chronic KF seems justified. A case can be made to extend screening to include speckle tracking echocardiography and intradialytic studies in high-risk populations. Further longitudinal studies including these newer echocardiogram modalities, interventions, and long-term outcomes would help clarify recommendations for optimal use as a screening tool.

Clinical performance, intermediate and long-term outcomes of high-volume hemodiafiltration in patients with kidney failure

Hemodiafiltration (HDF), in which both convective and diffusion methods are combined, yields an increased overall solute clearance compared with hemodialysis (HD), specifically for medium and larger molecular weight uremic toxins. Due to uncertainty in the treatment effects, the nephrology community still perceives the implementation of HDF and the achievement of high convective volume as complex. In this article, we review practical aspects of the implementation of HDF that can effectively deliver a high-volume HDF therapy and assure clinical performance to most patients. We also present an overview of the impact of high-volume HDF (compared to HD) on a series of relevant biochemical, patient-reported, and clinical outcomes, including uremic toxin removal, phosphate, Inflammation and oxidative stress, hemodynamic stability, cardiac outcomes, nutritional effects, health-related quality of life, morbidity, and mortality.

Diet-Related Inflammation is Associated with Malnutrition-Inflammation Markers in Maintenance Hemodialysis Patients: Results of a Cross-Sectional Study in China Using Dietary Inflammatory Index

Purpose

This cross-sectional study aimed to explore the association between the inflammation potential of the diet and malnutrition-inflammation status in Chinese maintenance hemodialysis (MHD) patients.

Methods

Dietary Inflammatory Index (DII) was computed based on a semi-quantitative food frequency questionnaire. Malnutrition-inflammation status was assessed by six indexes, including C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), hemoglobin (HB), albumin (ALB) and malnutrition-inflammation score (MIS). Multivariable linear regression and logistic regression were employed adjusting for covariables including age, gender, body mass index and dialysis vintage.

Results

A total of 161 Chinese MHD patients with an average age of 60.0 ± 13.6 years were enrolled. The median (IQR) DII score among participants was 0.60 (−0.80, 2.32), revealing a generally pro-inflammatory diet. DII was positively associated with MIS score (β= 0.61, 95% CI: 0.51, 0.69, p < 0.0001) and CRP (β = 0.54, 95% CI: 0.46, 0.63, p < 0.0001). A negative relationship between DII and NLR (β = −0.37, 95% CI: −0.61, −0.13, p = 0.008) was found in the most anti-inflammatory diet. Multivariable logistic regression showed that each unit increase in DII was linked with 3.06 (95% CI: 1.39, 6.69, p = 0.005) times increased odds of MIS.

Conclusion

Diet with a higher DII score may act as a potential trigger contributing to the development of malnutrition-inflammation status. Further studies for verification and for developing strategies to decrease the dietary inflammation burden are warranted.

Novel Biomarkers Detected by Proteomics Predict Death and Cardiovascular Events in Hemodialysis Patients

End-stage kidney disease increases mortality and the risk of cardiovascular (CV) disease. It is crucial to explore novel biomarkers to predict CV disease in the complex setting of patients receiving hemodialysis (HD). This study investigated the association between 92 targeted proteins with all-cause death, CV death, and composite vascular events (CVEs) in HD patients. From December 2010 to March 2011, 331 HD patients were included and followed prospectively for 5 years. Serum was analyzed for 92 CV-related proteins using Proseek Multiplex Cardiovascular I panel, a high-sensitivity assay based on proximity extension assay (PEA) technology. The association between biomarkers and all-cause death, CV death, and CVEs was evaluated using Cox-regression analyses. Of the PEA-based proteins, we identified 20 proteins associated with risk of all-cause death, 7 proteins associated with risk of CV death, and 17 proteins associated with risk of CVEs, independent of established risk factors. Interleukin-8 (IL-8), T-cell immunoglobulin and mucin domain 1 (TIM-1), and C-C motif chemokine 20 (CCL20) were associated with increased risk of all-cause death, CV death, and CVE in multivariable-adjusted models. Stem cell factor (SCF) and Galanin peptides (GAL) were associated with both decreased risk of all-cause death and CV death. In conclusion, IL-8, TIM-1, and CCL20 predicted death and CV outcomes in HD patients. Novel findings were that SCF and GAL were associated with a lower risk of all-cause death and CV death. The SCF warrants further study with regard to its possible biological effect in HD patients.

Diabetes acts on mortality in hemodialysis patients predicted by asymmetric dimethylarginine and inflammation

BACKGROUND

The mortality rate of diabetic patients on dialysis is higher than that of non-diabetic patients. Asymmetric dimethylarginine and inflammation are strong predictors of death in hemodialysis. This study aimed to evaluate asymmetric dimethylarginine and C-reactive protein interaction in predicting mortality in hemodialysis according to the presence or absence of diabetes.

METHODS

Asymmetric dimethylarginine and C-reactive protein were measured in 202 patients in maintenance hemodialysis assembled from 2011 to 2012 and followed for four years. Effect modification of C-reactive protein on the relationship between asymmetric dimethylarginine and all-cause mortality was investigated dividing the population into four categories according to the median of asymmetric dimethylarginine and C-reactive protein.

RESULTS

Asymmetric dimethylarginine and C-reactive protein levels were similar between diabetics and non-diabetics. Asymmetric dimethylarginine - median IQR μM - (1.95 1.75-2.54 versus 1.03 0.81-1.55 P=0.000) differed in non-diabetics with or without evolution to death (HR 2379 CI 1.36-3.68 P=0.000) and was similar in diabetics without or with evolution to death. Among non-diabetics, the category with higher asymmetric dimethylarginine and C-reactive protein levels exhibited the highest mortality (69.0% P=0.000). No differences in mortality were seen in diabetics. A joint effect was found between asymmetric dimethylarginine and C-reactive protein, explaining all-cause mortality (HR 15.21 CI 3.50-66.12 P=0.000).

CONCLUSIONS

Asymmetric dimethylarginine is an independent predictor of all-cause mortality in non-diabetic patients in hemodialysis. Other risk factors may overlap asymmetric dimethylarginine in people with diabetes. Inflammation dramatically increases the risk of death associated with high plasma asymmetric dimethylarginine in hemodialysis.

Global real-world data on hemodiafiltration: An opportunity to complement clinical trial evidence

Hemodiafiltration (HDF) is a renal replacement therapy that utilizes both diffusive clearance and convective transport to achieve greater clearance of middle-molecular-weight solutes. Among other factors, important prerequisites for the implementation of HDF include access to high-flux dialyzers, achievement of high blood flow rates, and availability of high volumes of sterile substitution/replacement fluids. Online hemodiafiltration (OL-HDF) is an established kidney replacement therapy, frequently used in many countries. Although in the United States, some prerequisites (e.g., access to high-flux dialyzers and achievement of high blood flow rates) for OL-HDF treatment are readily available; however, a machine capable of generating the online solution for OL-HDF is currently not available. As the clinical experience with HDF accumulates globally, it is worth examining the evidence for this kidney replacement therapy as used in routine clinical care. Such real-world evidence is increasingly recognized as valuable by clinicians and may inform regulatory decisions. In this review, we will focus on emerging global real-world data derived from routine clinical practices and examine how these data may complement those derived from clinical trials.

Why and how high volume hemodiafiltration may reduce cardiovascular mortality in stage 5 chronic kidney disease dialysis patients? A comprehensive literature review on mechanisms involved

Online hemodiafiltration (HDF) is an established renal replacement modality for patients with end stage chronic kidney disease that is now gaining rapid clinical acceptance worldwide. Currently, there is a growing body of evidence indicating that treatment with HDF is associated with better outcomes and reduced cardiovascular mortality for dialysis patients. In this comprehensive review, we provide an update on the potential mechanisms which may improve survival in HDF treated patients. The strongest evidence is for better hemodynamic stability and reduced endothelial dysfunction associated with HDF treatments. Clinically, this is marked by a reduced incidence of intradialytic hypotensive episodes, with a better hemodynamic response to ultrafiltration, mediated by an increase in total peripheral vascular resistance and extra-vascular fluid recruitment, most likely driven by the negative thermal balance associated with online HDF therapy. In addition, endothelial function appears to be improved due to a combination of a reduction of the inflammatory and oxidative stress complex syndrome and exposure to circulating cardiovascular uremic toxins. Reports of reversed cardiovascular remodeling effects with HDF may be confounded by volume and blood pressure management, which are strongly linked to center clinical practices. Currently, treatment with HDF appears to improve the survival of dialysis patients predominantly due to a reduction in their cardiovascular burden, and this reduction is linked to the sessional convection volume exchanged.

Supportive Effects of Online Hemodiafiltration Therapy on the Nutritional State and Lipid Profile in Very Elderly Dialysis Patients

INTRODUCTION

Online hemodiafiltration (HDF) therapy has been recognized as one of the potential dialysis modalities. However, the long-term effects of online HDF therapy on very elderly dialysis patients older than 75 years have yet to be fully elucidated.

METHODS

Seventy-four very elderly patients older than 75 years undergoing maintenance dialysis therapy were studied retrospectively. Twenty-four (mean ± SE, 81.5 ± 1.0 years) were treated by predilution online HDF, and fifty (81.2 ± 0.6 years) were treated by conventional hemodialysis (HD) for 3 years. Laboratory data related to the nutritional state and lipid profile were collected. Body composition was measured by a bioelectrical impedance method.

RESULTS

Dry weight and body mass index decreased in HD patients (2.9%, p = 0.003 and 3.1%, p = 0.001, respectively), while no significant changes were found in online HDF patients. Serum albumin levels reduced in both HD and online HDF groups (3.5%, p = 0.003 and 2.9%, p = 0.026, respectively). The geriatric nutritional risk index decreased in HD patients (3.0%, p < 0.001), while no significant change was shown in online HDF patients. Body composition analysis demonstrated a significant decrease in intracellular water and increases in extracellular water and edema ratio in both groups. Fat mass and %fat showed significant decreases in HD patients (8.1%, p = 0.003 and 7.3%, p = 0.003, respectively), but no significant changes in online HDF patients. Among laboratory data, serum high-density lipoprotein cholesterol levels did not change in HD patients. However, the levels elevated significantly (10.6%, p = 0.03) in online HDF patients.

DISCUSSION/CONCLUSION

These results indicated that the time-dependent deterioration of the nutritional state in very elderly dialysis patients was inevitable; however, such deterioration was not prominent in online HDF patients. Moreover, the lipid profile showed unique changes in online HDF patients. In order to treat very elderly dialysis patients, online HDF should preferentially be taken into consideration because the maintenance of general condition seems to be a practical goal against the natural time-dependent deterioration.

Development of online hemodiafiltration in Japan

Evidence concerning online hemodiafiltration (ol-HDF) includes increased uremic toxin removal, prevention of dialysis-related hypotension, improved survival, and recovery of dialysis-related uncertain symptoms. In particular, evidence has been shown regarding prevention of dialysis hypotension and improvement of survival, but the mechanism of its manifestation is still unclear and its effects themselves are questionable. In Japan, pre dilution ol-HDF is mainly performed, and improvement in survival rate has been shown on the condition of convection volume is 40 L/session or more. In particular, the removal of α1-microglubulin (αMG), which is a medium-middle solute, is targeted. The antioxidant action (Heme Scavenger) of αMG, is presumed, but in dialysis patients, the majority in serum are deteriorated (oxidized) αMG. It has been pointed out that removing the deteriorated αMG by ol-HDF may produce new αMG from the liver and lead to recovery of the original antioxidant effect. However, clinical evidence of this mechanism is desired. Obtaining evidence for the indicated αMG removal activity of ol-HDF will lead to advancement in HDF.

C-X-C Motif Chemokine Ligand 16 Is a Potent Predictor of Outcomes in Dialysis Patients

INTRODUCTION

C-X-C motif chemokine ligand 16 (CXCL16) is an inflammatory marker that has been found to be predictive of outcomes in patients with cardiovascular disease. Our previous work has also demonstrated its relation to cardiac injury in dialysis patients. However, it is yet unclear whether there is an association between CXCL16 and adverse outcomes in dialysis patients. We aimed to evaluate its prognostic value along with several traditional inflammatory markers in the current study.

METHODS

This is a multicenter longitudinal study of prevalent dialysis patients. Circulating inflammatory markers including CXCL16, C-reactive protein (CRP), tumor necrosis factor-α, and interleukin-6 (IL-6) were measured using a multiplex assay. The primary outcomes were all-cause mortality and a composite of major adverse cardiovascular events (MACEs). The associations between biomarkers and outcomes were analyzed using Cox proportional hazards regression models.

RESULTS

Of the 366 participants with available plasma samples, the average age was 52.5 (±12.1) years, and there were 160 (43.7%) female participants. For all-cause mortality, logarithmically transformed CXCL16, IL-6, and CRP were independent predictors after adjustment for covariates. When the 3 markers were included in the same model, CXCL16 was the only one remaining its significance. For MACEs, logarithmically transformed CXCL16 and IL-6 were significant predictors when analyzed separately and CXCL16 was an independent predictor even after adjustment for IL-6. When the biomarkers were analyzed as categorical variables, only CXCL16 was associated with both outcomes. Adding CXCL16 to established risk factors improved risk prediction as revealed by Net Reclassification Index (NRI).

CONCLUSION

Using a multimarker approach, we determined that CXCL16 is a potent predictor of all-cause mortality and cardiovascular events in dialysis patients. Our data suggest CXCL16 may improve risk stratification and could be a potential interventional target.

Diabetes acts on mortality in hemodialysis patients predicted by asymmetric dimethylarginine and inflammation

BACKGROUND

The mortality rate of diabetic patients on dialysis is higher than that of non-diabetic patients. Asymmetric dimethylarginine and inflammation are strong predictors of death in hemodialysis. This study aimed to evaluate asymmetric dimethylarginine and C-reactive protein interaction in predicting mortality in hemodialysis according to the presence or absence of diabetes.

METHODS

Asymmetric dimethylarginine and C-reactive protein were measured in 202 patients in maintenance hemodialysis assembled from 2011 to 2012 and followed for four years. Effect modification of C-reactive protein on the relationship between asymmetric dimethylarginine and all-cause mortality was investigated dividing the population into four categories according to the median of asymmetric dimethylarginine and C-reactive protein.

RESULTS

Asymmetric dimethylarginine and C-reactive protein levels were similar between diabetics and non-diabetics. Asymmetric dimethylarginine - median IQR μM - (1.95 1.75-2.54 versus 1.03 0.81-1.55 P=0.000) differed in non-diabetics with or without evolution to death (HR 2379 CI 1.36-3.68 P=0.000) and was similar in diabetics without or with evolution to death. Among non-diabetics, the category with higher asymmetric dimethylarginine and C-reactive protein levels exhibited the highest mortality (69.0% P=0.000). No differences in mortality were seen in diabetics. A joint effect was found between asymmetric dimethylarginine and C-reactive protein, explaining all-cause mortality (HR 15.21 CI 3.50-66.12 P=0.000).

CONCLUSIONS

Asymmetric dimethylarginine is an independent predictor of all-cause mortality in non-diabetic patients in hemodialysis. Other risk factors may overlap asymmetric dimethylarginine in people with diabetes. Inflammation dramatically increases the risk of death associated with high plasma asymmetric dimethylarginine in hemodialysis.

The Innate Immune System and Cardiovascular Disease in ESKD: Monocytes and Natural Killer Cells

Adverse innate immune responses have been implicated in several disease processes, including cardiovascular disease (CVD) and chronic kidney disease (CKD). The monocyte subsets natural killer (NK) cells and natural killer T (NKT) cells are involved in innate immunity. Monocytes subsets are key in atherogenesis and the inflammatory cascade occurring in heart failure. Upregulated activity and counts of proinflammatory CD16+ monocyte subsets are associated with clinical indices of atherosclerosis, heart failure syndromes and CKD. Advanced CKD is a complex state of persistent systemic inflammation characterized by elevated expression of proinflammatory and pro-atherogenic CD14++CD16+ monocytes, which are associated with cardiovascular events and death both in the general population and among patients with CKD. Diminished NK cells and NKT cells counts and aberrant activity are observed in both coronary artery disease and end-stage kidney disease. However, evidence of the roles of NK cells and NKT cells in atherogenesis in advanced CKD is circumstantial and remains to be clarified. This review describes the available evidence regarding the roles of specific immune cell subsets in the pathogenesis of CVD in patients with CKD. Future research is expected to further uncover the links between CKD associated innate immune system dysregulation and accelerated CVD and will ideally be translated into therapeutic targets.

Phosphate Balance and CKD-Mineral Bone Disease

Chronic kidney disease–mineral bone disorder (CKD-MBD) is a common comorbidity in patients with CKD. Characterized by laboratory abnormalities, bone abnormality, and vascular calcification, CKD-MBD encompasses a group of mineral and hormone disturbances that are strongly associated with increased cardiovascular (CV) morbidity and mortality. Abnormal serum phosphate concentrations are an independent risk factor for CV morbidity and mortality, and overall mortality. Phosphate retention plays a central role in initiating and driving many other disturbances in CKD-MBD (e.g., increased parathyroid hormone and fibroblast growth factor 23 concentrations, hypocalcemia, low vitamin D) that are also linked to increased CV risk. Thus, effective phosphate control is a logical therapeutic target for CKD-MBD treatment. Current phosphate management strategies (dietary restrictions, dialysis, phosphate binders) are insufficient to consistently achieve and maintain target phosphate concentrations in patients on dialysis. Phosphate binders reduce available phosphate for intestinal absorption but do not impair the dominant phosphate absorption pathway. Novel therapies that consider new mechanistic understandings of intestinal phosphate absorption are needed. One such therapy is tenapanor, a targeted sodium-hydrogen exchanger isoform 3 inhibitor that has been shown to reduce serum phosphate concentrations in multiple clinical trials. Tenapanor has a novel mechanism of action that reduces intestinal phosphate absorption in the primary paracellular phosphate absorption pathway.

Changes in the Risk of Stroke in Dialysis Patients: A Retrospective Analysis over the Last 40 Years

The stroke incidence in hemodialysis (HD) patients is high, but the associated factors remain largely unknown. This study aimed to analyze stroke incidence in HD patients and changes in risk factors. Data of 291 patients were retrospectively analyzed. The cumulative stroke incidences were 21.6% at 10 years and 31.5% at 20. Diabetic nephropathy (DN) significantly increased overall stroke (hazard ratio (HR), 2.24; 95% confidence interval (CI), 1.21-4.12; p = 0.001) and ischemic stroke (HR, 2.16; 95% CI, 1.00-4.64; p = 0.049). Patients treated with online HDF were less likely to have overall stroke (HR, 0.13; 95% CI, 0.03-0.56; p = 0.006) and ischemic stroke (HR, 0.08; 95% CI, 0.01-0.60; p = 0.014). DN (HR, 1.56; 95% CI, 1.08-2.27; p = 0.019) and age >80 years at HD initiation (20-49 years old; HR 0.13, 95% CI, 0.05-0.35, p < 0.001 and age 50-79 years; HR 0.42, 95% CI, 0.26-0.66, p < 0.001 (reference: age >80 years)) were significantly associated with stroke and/or death events. Over time, stroke risk increased in HD patients, due to the increasing number of DN. Although dialysis technology has advanced over time, these advances could not overcome other risk factors for stroke. Further increase in stroke and mortality due to aging remains a concern.

Citrate high volume on-line hemodiafiltration modulates serum Interleukin-6 and Klotho levels: the multicenter randomized controlled study "Hephaestus"

BACKGROUND

Studies addressing the anti-inflammatory properties of citrate dialysate enrolled patients in both hemodialysis (HD) and hemodiafiltration (HDF), the latter not adjusted for adequate convective exchange. This is a potential source of confounding in that HDF itself has anti-inflammatory effects regardless of the buffer, and optimal clinical outcomes are related to the amount of convection.

METHODS

To distinguish the merits of the buffer from those of convection, we performed a 6-month, prospective, randomized, crossover AB-BA study. Comparisons were made during the 3-month study period of on-line HDF with standard dialysate containing three mmol of acetic acid (OL-HDFst) and the 3-month of OL-HDF with dialysate containing one mmol of citric acid (OL-HDFcit). Primary outcome measure of the study was interleukin-6 (IL-6). Klotho, high sensitivity C-reactive protein (hsCRP), fetuin and routine biochemical parameters were also analyzed.

RESULTS

We analyzed 47 patients (mean age 64 years, range 27-84 years) enrolled in 10 participating Nephrology Units. Convective volumes were around 25 L/session with 90 percent of sessions > 20 L and ß2-microglobulin reduction rate 76% in both HDFs. Baseline median IL-6 values in OL-HDFst were 5.6 pg/ml (25:75 interquartile range IQR 2.9:10.6) and in OL-HDFcit 6.6 pg/ml (IQR 3.4:11.4 pg/ml). The difference was not statistically significant (p 0.88). IL-6 values were lower during OL-HDFcit than during OL-HDFst, both when analyzed as the median difference of overall IL-6 values (p 0.02) and as the median of pairwise differences between the baseline and the 3-month time points (p 0.03). The overall hsCRP values too, were lower during OL-HDFcit than during OL-HDFst (p 0.01). Klotho levels showed a time effect (p 0.02) and the increase was significant only during OL-HDFcit (p 0.01).

CONCLUSIONS

Citrate buffer modulated IL-6, hsCRP and Klotho levels during high volume OL-HDF. These results are not attributable to differences in the dialysis technology that was applied and may suggest a potential biological effect of citrate on CKD-associated inflammatory state. ClinicalTrials.gov identifier NCT02863016.

Circulating fatty acid profiles are associated with protein energy wasting in maintenance hemodialysis patients: a cross-sectional study

The metabolic impact of circulating fatty acids (FAs) in patients requiring hemodialysis (HD) is unknown. We investigated the associations between plasma triglyceride (TG) FAs and markers of inflammation, insulin resistance, nutritional status and body composition. Plasma TG-FAs were measured using gas chromatography in 341 patients on HD (age = 55.2 ± 14.0 years and 54.3% males). Cross-sectional associations of TG-FAs with 13 markers were examined using multivariate linear regression adjusted for potential confounders. Higher levels of TG saturated fatty acids were associated with greater body mass index (BMI, r = 0.230), waist circumference (r = 0.203), triceps skinfold (r = 0.197), fat tissue index (r = 0.150), serum insulin (r = 0.280), and homeostatic model assessment of insulin resistance (r = 0.276), but lower malnutrition inflammation score (MIS, r =  − 0.160). Greater TG monounsaturated fatty acid levels were associated with lower lean tissue index (r =  − 0.197) and serum albumin (r =  − 0.188), but higher MIS (r = 0.176). Higher levels of TG n-3 polyunsaturated fatty acids (PUFAs) were associated with lower MIS (r =  − 0.168) and interleukin-6 concentrations (r =  − 0.115). Higher levels of TG n-6 PUFAs were associated with lower BMI (r =  − 0.149) but greater serum albumin (r = 0.112). In conclusion, TG monounsaturated fatty acids were associated with poor nutritional status, while TG n-3 PUFAs were associated with good nutritional status. On the other hand, TG saturated fatty acids and TG n-6 PUFAs had both favorable and unfavorable associations with nutritional parameters.

Benefits of resistant starch type 2 for patients with end-stage renal disease under maintenance hemodialysis: a systematic review and meta-analysis

Background: Resistant starch type 2 (RS2) has been documented to regulate gut microbiota and to improve the clinical outcomes of several diseases. However, whether RS2 may benefit patients with end-stage renal disease under maintenance hemodialysis (MHD) remains unknown. Methods: We conducted a systemic review and meta-analysis of randomized controlled trials (RCTs). Adult patients receiving MHD were treated with RS2 (CRD42020160332). The primary outcomes were changes of uremic toxins, and the secondary outcomes were changes of inflammatory indicators, albumin and phosphorus. Results: After screening 65 records, five RCTs (n = 179) were included. A significant decrease of blood urea nitrogen (weighted mean difference (WMD) = -6.91, 95% CI: -11.87 to -1.95, I² = 0%, P = 0.006), serum creatinine (WMD = -1.11, 95% CI: -2.18 to -0.05, I² = 44%, P = 0.04) and interleukin (IL)-6 in blood (standard mean difference (SMD) = -1.08, 95% CI: -1.64 to -0.53, I² = 35%, P = 0.0001) was revealed in the RS2 group. Analyses of blood levels of uric acid, p-cresyl sulfate, indoxyl sulfate, high sensitive C-reaction protein, albumin and phosphorus yielded no significant difference. Conclusions: Our results suggest that RS2 may improve the residual renal function of patients under MHD and mitigate a proinflammatory response.

Survival with low- and high-flux dialysis

Background

Besides advances in haemodialysis (HD), mortality rates are still high. The effect of the different types of HD membranes on survival is still a controversial issue. The aim of this COSMOS (Current management Of Secondary hyperparathyroidism: a Multicentre Observational Study) analysis was to survey, in HD patients, the relationship between the use of conventional low- or high-flux membranes and all-cause and cardiovascular mortality.

Methods

COSMOS is a multicentre, open-cohort, 3-year prospective study, designed to evaluate mineral and bone disorders in the European HD population. The present analysis included 5138 HD patients from 20 European countries, 3502 randomly selected at baseline (68.2%), plus 1636 new patients with <1 year on HD (31.8%) recruited to replace patients who died, were transplanted, switched to peritoneal dialysis or lost to follow-up by other reasons. Cox-regression analysis with time-dependent variables, propensity score matching and the use of an instrumental variable (facility-level analysis) were used.

Results

After adjustments using three different multivariate models, patients treated with high-flux membranes showed a lower all-cause and cardiovascular mortality risks {hazard ratio (HR) = 0.76 [95% confidence interval (CI) 0.61-0.96] and HR = 0.61 (95% CI 0.42-0.87), respectively}, that remained significant after matching by propensity score for all-cause mortality (HR = 0.69, 95% CI 0.52-0.93). However, a facility-level analysis showed no association between the case-mix-adjusted facility percentage of patients dialysed with high-flux membranes and all-cause and cardiovascular mortality.

Conclusions

High-flux dialysis was associated with a lower relative risk of all-cause and cardiovascular mortality. However, dialysis facilities using these dialysis membranes to a greater extent did not show better survival.

Online hemodiafilteration use in children: a single center experience with a twist

Background

Haemodiafilteration (HDF) is a promising new modality of renal replacement therapy (RRT). It is an improvement in the quality of hemodialysis (HD) and thus in the quality of patients’lives. The main obstacle to using HDF is the cost, especially in developing countries. The purpose of this study was to evaluate the benefits of incorporating HDF with different regimens in the treatment of children with end stage renal disease (ESRD).

Methods

Thirty-four children with ESRD on regular HD in Pediatric Dialysis Unit, Children’s Hospital, Ain Shams University were followed up in 2 phases: initial phase (all patients: HD thrice weekly for 3 months) and second phase, patients were randomized into 2 groups, HDF group and HD group, the former was subdivided into once and twice weekly HDF subgroups. Evaluation using history, clinical and laboratory parameters at 0, 3, 9 and 18 months was carried out.

Results

On short term, we found that the HDF group was significantly superior to HD group regarding all clinical and laboratory parameters. Also, twice HDF subgroup was significantly superior to once HDF subgroup. This was confirmed on long term follow up, but the once HDF proved comparable to twice subgroup.

Conclusions

Incorporating online hemodiafilteration (OL-HDF) in the RRT of children was beneficial in most of the clinical and laboratory parameters measured. It’s not all or non; OL-HDF, even once a week, can improve outcomes of HD without significantly affecting the cost.

Dietary intake, clinical-nutritional status, and homocysteine in hemodialysis subjects: the mediating role of inflammation (NUGE-HD study)

The aim of the present study was to test the hypothesis that inflammation mediates the associations among food intake, clinical-nutritional status, and plasma homocysteine (Hcys) in hemodialysis (HD) subjects. This was a cross-sectional analysis of data on 129 subjects undergoing HD (58.9% male, 61.8 ± 15.5 years of age) from the cohort Nutrition and Genetics on HD outcomes (NUGE-HD study). Sociodemographic, anthropometric, and metabolic data were collected, and food intake was assessed using a quantitative food frequency questionnaire. Plasma C-reactive protein (CRP) was used as an inflammatory marker. Data were analyzed by structural equation modeling. Regarding the direct effects, complex B vitamin intake was negatively associated with body mass index, and diabetes mellitus was positively associated with CRP. Plasma CRP also showed a negative association with Hcys, and the ratio of saturated and polyunsaturated fatty acids intake showed a positive association with Hcys. Regarding indirect effects, the results showed that the relationship between the presence of diabetes mellitus and Hcys is mediated by plasma CRP. In conclusion, the ratio of saturated and polyunsaturated fatty acids had a direct effect on plasma Hcys, whereas inflammation had a direct and mediating effect on the relationship between Hcys and diabetes mellitus in HD subjects. Novelty In end-stage renal disease, CRP influences plasma Hcys directly and also indirectly through its mediating effect. The quantity and quality of dietary fatty acids influence plasma Hcys concentrations in HD subjects.

The Influence of Inflammation on Anemia in CKD Patients

Anemia is frequently observed in the course of chronic kidney disease (CKD) and it is associated with diminishing the quality of a patient’s life. It also enhances morbidity and mortality and hastens the CKD progression rate. Patients with CKD frequently suffer from a chronic inflammatory state which is related to a vast range of underlying factors. The results of studies have demonstrated that persistent inflammation may contribute to the variability in Hb levels and hyporesponsiveness to erythropoietin stimulating agents (ESA), which are frequently observed in CKD patients. The understanding of the impact of inflammatory cytokines on erythropoietin production and hepcidin synthesis will enable one to unravel the net of interactions of multiple factors involved in the pathogenesis of the anemia of chronic disease. It seems that anti-cytokine and anti-oxidative treatment strategies may be the future of pharmacological interventions aiming at the treatment of inflammation-associated hyporesponsiveness to ESA. The discovery of new therapeutic approaches towards the treatment of anemia in CKD patients has become highly awaited. The treatment of anemia with erythropoietin (EPO) was associated with great benefits for some patients but not all.

Macronutrients, micronutrients intake and inflammation in hemodialysis patients

Inflammation in hemodialysis patients occurs since before undergoing hemodialysis. Inflammation is associated with an increase in oxidative stress. Hemodialysis patients are at risk for macronutrients and micronutrients deficiencies which can influence the increase in oxidative stress and inflammation. The purpose of this study was to evaluate the intake of micronutrients and inflammatory status in hemodialysis patients. This study was a cross-sectional study with 76 hemodialysis patients (40 male and 36 female) who attended in two hemodialysis centers of Kendal, Indonesia. After obtaining the written consent, then patients were interviewed food intake consisting of macronutrient and micronutrient intake. Macronutrient and micronutrient intake are obtained by the semi quantitative food frequency method and classified as a deficit (<100% adequacy level) and normal/ more (≥100% adequacy level), according to specific recommendations for individuals undergoing dialysis. Serum albumin was examined using the Brom Cresol Purple (BCP) method with a low category (<3.5 mg.dL-1) and normal (3.5 – 4.5 mg.dL-1). The hs-CRP serum was examined using the ELISA method and categorized as low (<1 mg.L-1), moderate (1 – 3 mg.L-1) and high (> 3 mg.L-1). A descriptive analysis was performed. The results of this study showed that 88.2% deficit energy intake, 84.2% deficit protein intake, 85.5% deficit of vitamin A intake, 85.5% deficit of vitamin C intake, 100% deficit of vitamin E intake, 98, 7% deficit zinc intake , 92.1% deficit copper intake. 63.2% subjects are low level of serum albumin and 61.8% subjects is high level of hs-CRP serum. Macronutrient and micronutrient intake in most hemodialysis patients shows deficit. The serum albumin of most hemodialysis patients shows low level. Serum hs-CRP most hemodialysis patients show high level.

Evolution of high-sensitivity troponin-T and echocardiography parameters in patients undergoing high efficiency on-line hemodiafiltration versus conventional low-flux hemodialysis

BACKGROUND AND OBJECTIVES

On-line hemodiafiltration (HDF) has been associated with better inflammatory markers profile and survival than low-flux hemodialysis (HD). This study aimed at determining the effect of HDF vs HD on hs-TnT and echocardiography parameters evolution at one year follow-up.

METHOD

Patients were randomized from 2007 to 2013 to HD or HDF in accordance with the CONvective TRAnsport STudy protocol initially as part of the Montreal cohort and subsequently as part of a local cohort. Pre-dialysis hs-TnT were analyzed at baseline and 1-year follow-up.

RESULTS

A total of 54 HDF patients and 59 HD patients were included. At baseline, median hs-TnT value was 49 ng/L (IQR 31-89) in the HDF group vs. 60 ng/L (36-96) in the HD group (p = 0.370). At one year follow-up, median hs-TnT remained stable in the HDF group (p = 0.707 vs. baseline), but significantly increased to 62 ng/L (40-104) in the HD group (p = 0.021 vs. baseline). The median variation (delta) in hs-TnT values was -3 ng/L (IQR -7-+8) in the HDF group vs. +8 ng/L (-5 -+25) in the HD group (p = 0.042). In the HDF group, LVEF increased from 60.0% (IQR 55.0-65.0) at baseline to 65.0% (60.0-65.5) at 1-year follow-up (p = 0.040) whereas it remained stable in the HD group (LVEF of 60.0% [IQR 55.0-65.0] at baseline and 65.0% [55.0-65.0] at 1-year follow-up [p = 0.312]).

CONCLUSIONS

High-efficiency HDF is associated with stability in hs-TnT values, whereas low-flux HD is associated with significant increase in hs-TnT levels.

Two Distinct Immune Pathways Linking Social Relationships With Health: Inflammatory and Antiviral Processes

OBJECTIVE

Social relationships can both influence and be influenced by immune processes. Past work implicates two distinct pathways along which this interaction may occur: inflammatory processes and antiviral processes. This article reviews how social behavior is modulated by these two immune processes and how such processes may in turn regulate social behavior.

METHODS

This narrative review outlines existing work on social behavior and both inflammatory and antiviral processes. We propose an evolutionary framework that aims to integrate these findings. Specifically, social isolation has evolutionarily increased the likelihood of wounding and therefore increased the need for inflammation, which works to promote healing. Conversely, broader social networks provide protection from physical threats but also lead to increased pathogen exposure, necessitating a more robust antiviral response.

RESULTS

This review highlights that social adversity, such as social exclusion or loneliness, is associated with increased inflammation, whereas social contact is associated with increased antiviral immunity. Furthermore, increased inflammation leads to sensitivity to social stimuli, presumably to avoid hostile conspecifics and approach allies who may provide care while vulnerable. Individuals with inadequate antiviral immunity engage in behaviors that minimize pathogen exposure, such as reduced affiliative behavior.

CONCLUSIONS

This review suggests that adverse social experiences (social isolation, perceived social threat) may induce inflammatory responses while suppressing antiviral immunity, whereas positive experiences of social connection may reduce inflammation and bolster antiviral responses. Although acutely elevated inflammation would be adaptive under conditions where wounding is likely, chronic inflammation related to continued social adversity may have detrimental health consequences.

Tumour necrosis factor-alpha in uraemic serum promotes osteoblastic transition and calcification of vascular smooth muscle cells via extracellular signal-regulated kinases and activator protein 1/c-FOS-mediated induction of interleukin 6 expression

Background

Vascular calcification is enhanced in uraemic chronic haemodialysis patients, likely due to the accumulation of midsize uraemic toxins, such as interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α). Here we have assessed the impact of uraemia on vascular smooth muscle cell (VSMC) calcification and examined the role of IL-6 and TNF-α as possible mediators and, most importantly, its underlying signalling pathway in VSMCs.

Methods

VSMCs were incubated with samples of uraemic serum obtained from patients treated with haemodialysis for renal failure in the Permeability Enhancement to Reduce Chronic Inflammation-I clinical trial. The VSMCs were assessed for IL-6 gene regulation and promoter activation in response to uraemic serum and TNF-α with reporter assays and electrophoretic mobility shift assay and for osteoblastic transition, cellular calcification and cell viability upon osteogenic differentiation.

Results

Uraemic serum contained higher levels of TNF-α and IL-6 compared with serum from healthy individuals. Exposure of VSMCs to uraemic serum or recombinant TNF-α lead to a strong upregulation of IL-6 mRNA expression and protein secretion, which was mediated by activator protein 1 (AP-1)/c-FOS-pathway signalling. Uraemic serum induced osteoblastic transition and calcification of VSMCs could be strongly attenuated by blocking TNF-α, IL-6 or AP-1/c-FOS signalling, which was accompanied by improved cell viability.

Conclusion

These results demonstrate that uraemic serum contains higher levels of uraemic toxins TNF-α and IL-6 and that uraemia promotes vascular calcification through a signalling pathway involving TNF-α, IL-6 and the AP-1/c-FOS cytokine-signalling axis. Thus treatment modalities aiming to reduce systemic TNF-α and IL-6 levels in chronic haemodialysis patients should be evaluated in future clinical trials.

Overexposure to Bisphenol A and Its Chlorinated Derivatives of Patients with End-Stage Renal Disease during Online Hemodiafiltration

The health safety conditions governing the practice of online hemodiafiltration (OL-HDF) do not yet incorporate the risks related to the presence of endocrine disruptors such as bisphenol A (BPA). The aim of this study was to assess, for the first time, the exposure to BPA but also to its chlorinated derivatives (ClxBPA) (100 times more estrogenic than BPA) during OL-HDF. We demonstrated that BPA is transmitted by the different medical devices used in OL-HDF: ultrafilters, dialysis concentrate cartridges (and not only dialyzers, as previously described). Moreover, BPA has been found in dialysis water as well as in ultrapure dialysate and replacement fluid due to contamination of water coming from municipal network. Indeed, due to contaminations provided by both ultrafilters and water, high levels of BPA were determined in the infused replacement fluid (1033 ng.L⁻¹) from the beginning of the session. Thus, our results demonstrate that dialysis water must be considered as an important exposure source to endocrine disruptors, especially since other micropollutants such as ClxBPA have also been detected in dialysis fluids. While assessment of the impact of this exposure remains to be done, these new findings should be taken into account to assess exposure risks in end-stage renal disease patients.

Comparison of Solute Clearance, Hospitalization Rate, and Aortic Arch Calcification between Online Hemodiafiltration and High-Flux Hemodialysis: A 6-Year Observational Study

BACKGROUND/AIMS

Studies on the long-term clinical benefits of hemodiafiltration (HDF) and high-flux hemodialysis (HFHD) are very limited. This study aimed to investigate the hospitalization rate and aortic arch calcification (AAC) of these two dialysis modalities over 6 years.

METHODS

Participants who received regular HDF and HFHD in one hospital-facilitated hemodialysis center were prospectively enrolled after matching for age, sex, and diabetes between January 2009 and December 2014. Medical records were reviewed retrospectively on demographics, laboratory variables, calcified scores in aortic arch measured by chest radiography, and rates of hospital admission. Cox proportional hazard regression and linear regression were used to obtain the outcome results.

RESULTS

The HDF and HFHD groups consisted of 108 and 102 participants, respectively. Levels of laboratory variables including small soluble solutes and Kt/V were not statistically different over the 6-year period between the HDF and HFHD groups. Calcified scores of the aortic arch increased over 6 years in both groups. The changes in the mean calcified scores were significant when compared between the two groups (0.44-1.82 in HFHD, 0.79-1.8 in HDF, respectively, p = 0.008). Hospitalization rates were 735 per 1,000 patients in the HDF group and 852 per 1,000 patients in the HFHD group, respectively. No significant difference was observed in frequency and days of hospitalization between HDF and HFHD.

CONCLUSION

Hospitalization rates and AAC were observed to be equal for HDF and HFHD.

Online Hemodiafiltration Inhibits Inflammation-Related Endothelial Dysfunction and Vascular Calcification of Uremic Patients Modulating miR-223 Expression in Plasma Extracellular Vesicles

Decreased inflammation and cardiovascular mortality are evident in patients with end-stage chronic kidney disease treated by online hemodiafiltration. Extracellular vesicles (EV) are mediators of cell-to-cell communication and contain different RNA types. This study investigated whether mixed online hemodiafiltration (mOL-HDF) beneficial effects associate with changes in the RNA content of plasma EV in chronic kidney disease patients. Thirty bicarbonate hemodialysis (BHD) patients were randomized 1:1 to continue BHD or switch to mOL-HDF. Concentration, size, and microRNA content of plasma EV were evaluated for 9 mo; we then studied EV effects on inflammation, angiogenesis, and apoptosis of endothelial cells (HUVEC) and on osteoblast mineralization of vascular smooth muscle cells (VSMC). mOL-HDF treatment reduced different inflammatory markers, including circulating CRP, IL-6, and NGAL. All hemodialysis patients showed higher plasma levels of endothelial-derived EV than healthy subjects, with no significant differences between BHD and mOL-HDF. However, BHD-derived EV had an increased expression of the proatherogenic miR-223 with respect to healthy subjects or mOL-HDF. Compared with EV from healthy subjects, those from hemodialysis patients reduced angiogenesis and increased HUVEC apoptosis and VSMC calcification; however, all these detrimental effects were reduced with mOL-HDF with respect to BHD. Cell transfection with miR-223 mimic or antagomiR proved the role of this microRNA in EV-induced HUVEC and VSMC dysfunction. The switch from BHD to mOL-HDF significantly reduced systemic inflammation and miR-223 expression in plasma EV, thus improving HUVEC angiogenesis and reducing VSMC calcification.

Effects of high-volume online mixed-hemodiafiltration on anemia management in dialysis patients

Background

Anemia is a major comorbidity of patients with end-stage renal disease and poses an enormous economic burden to health-care systems. High dose erythropoiesis-stimulating agents (ESAs) have been associated with unfavorable clinical outcomes. We explored whether mixed-dilution hemodiafiltration (Mixed-HDF), based on its innovative substitution modality, may improve anemia outcomes compared to the traditional post-dilution hemodiafiltration (Post-HDF).

Methods

We included 174 adult prevalent dialysis patients (87 on Mixed-HDF, 87 on Post-HDF) treated in 24 NephroCare dialysis centers between January 2010 and August 2016 into this retrospective cohort study. All patients were dialyzed three times per week and had fistula/graft as vascular access. Patients were matched at baseline and followed over a one-year period. The courses of hemoglobin levels (Hb) and monthly ESA consumption were compared between the two groups with linear mixed models.

Results

Mean baseline Hb was 11.9±1.3 and 11.8±1.1g/dl in patients on Mixed- and Post-HDF, respectively. While Hb remained stable in patients on Mixed-HDF, it decreased slightly in patients on Post-HDF (at month 12: 11.8±1.2 vs 11.1±1.2g/dl). This tendency was confirmed by our linear mixed model (p = 0.0514 for treatment x time interaction). Baseline median ESA consumption was 6000 [Q1:0;Q3:16000] IU/4 weeks in both groups. Throughout the observation period ESA doses tended to be lower in the Mixed-HDF group (4000 [Q1:0;Q3:16000] vs 8000 [Q1:0;Q3:20000] IU/4 weeks at month 12; p = 0.0791 for treatment x time interaction). Sensitivity analyses, adjusting for differences not covered by matching at baseline, strengthened our results (Hb: p = 0.0124; ESA: p = 0.0687).

Conclusions

Results of our explorative study suggest that patients on Mixed-HDF may have clinical benefits in terms of anemia management. This may also have a beneficial economic impact. Future studies are needed to confirm our hypothesis-generating results and to provide additional evidence on the potential beneficial effects of Mixed-HDF.

Perspectives in renal replacement therapy: Haemodialysis

Haemodialysis (HD) was the first procedure that had demonstrated the ability to partially replace renal function, and became the most widely utilized treatment for patients with end-stage renal disease (ESRD). In a great majority of countries around the world, conventional in-centre HD had become the predominant renal replacement therapy, being touted as able to achieve better solute clearance and more successful in attaining euvolemia than patients on peritoneal dialysis. This is despite the antecedent hemodynamic risks, more rapid loss of residual renal function, greater infectious perils, excessive erythropoietin requirements and higher infrastructure costs. In addition, quality of life had been suggested to be worse among patients on HD, though this had been challenged repeatedly. Consequently, the concept of integrated ESRD care over the last few decades had placed HD, as a complementary rather than a competitive treatment modality to the entire armamentarium of renal replacement therapies. Incorporating HD as part of integrated care into health-care policies and national resource planning will become an essential strategy in improving access and outcome to care among the ESRD population. The improvement in technologies and innovation in prescription had brought forth enhanced dialyzer membrane and machine upgrades, and expanded modalities including more frequent HD and haemodiafiltration. While boasting of controversial improvement in outcomes, many of these therapies remain expensive and insurmountable for widespread utility in many countries. In addition, the results of these new technologies had been conflicting across studies, with some even suggesting that they could be detrimental. Therefore, judicial consideration has to be undertaken to appropriate their use in clinical practice.

Evaluation of the efficacy of a medium cut-off dialyser and comparison with other high-flux dialysers in conventional haemodialysis and online haemodiafiltration

BACKGROUND

Online haemodiafiltration (OL-HDF) has been shown to reduce all-cause mortality versus conventional haemodialysis (HD); however, it is not always available. In these situations, a novel class of membranes with a higher pore size, medium cut-off (MCO) dialysers, could be promising. The aim of this study is to evaluate the efficacy of an MCO dialyser in the removal of small and medium-size molecules and compare it with standard high-flux (HF) dialysers in HD and OL-HDF.

METHODS

In this crossover study, 18 prevalent HD patients were studied in three single mid-week dialysis treatments during three consecutive weeks as follows: first week with OL-HDF with a standard HF dialyser, second week with conventional HD with a standard HF dialyser and third week with conventional HD with an MCO dialyser. Reduction ratios (RRs) of different-sized molecules and albumin losses were collected for the different dialysers.

RESULTS

MCO HD provided a greater reduction of middle and larger middle molecules compared with standard HF HD [rate reduction (RR) β2-microglobulin 74.7% versus 69.7%, P=0.01; RR myoglobin 62.5% versus 34.3%, P=0.001; RR prolactin 60% versus 32.8%, P=0.001; RR α1-glycoprotein 2.8% versus -0.1%, P=0.01]. We found no difference in the clearance of small and larger middle molecules comparing MCO HD with OL-HDF. Albumin losses were 0.03  g/session with MCO HD and 3.1  g/session with OL-HDF (P=0.001).

CONCLUSION

MCO HD is superior to standard HF HD in the removal of middle and larger middle molecules and it is not inferior to OL-HDF in the clearance of small and larger middle molecules. Thus it could be an alternative in patients in which it is not possible to perform OL-HDF.

Hemodiafiltration to Address Unmet Medical Needs ESKD Patients

Hemodiafiltration combines diffusive and convective solute removal in a single therapy by ultrafiltering 20% or more of the blood volume processed using a high-flux hemodialyzer and maintaining fluid balance by infusing sterile nonpyrogenic replacement fluid directly into the patient's blood. In online hemodiafiltration, the large volumes of replacement fluid required are obtained by online filtration of standard dialysate through a series of bacteria- and endotoxin-retaining filters. Currently available systems for online hemodiafiltration are on the basis of conventional dialysis machines with added features to safely prepare and infuse replacement fluid and closely control fluid balance. Hemodiafiltration provides greater removal of higher molecular weight uremic retention solutes than conventional high-flux hemodialysis, and recently completed randomized, controlled clinical trials suggest better patient survival with online hemodiafiltration compared with standard high-flux hemodialysis when a high convection volume is delivered. Hemodiafiltration is also associated with improvements in other clinical outcomes, such as a reduction in intradialytic hypotension, and it is now used routinely to treat >100,000 patients, mainly in Europe and Japan.

Mortality risk in patients on hemodiafiltration versus hemodialysis: a 'real-world' comparison from the DOPPS

Background

With its convective component, hemodiafiltration (HDF) provides better middle molecule clearance compared with hemodialysis (HD) and is postulated to improve survival. A previous analysis of Dialysis Outcomes and Practice Patterns Study (DOPPS) data in 1998-2001 found lower mortality rates for high replacement fluid volume HDF versus HD. Randomized controlled trials have not shown uniform survival advantage for HDF; in secondary (non-randomized) analyses, better outcomes were observed in patients receiving the highest convection volumes.

Methods

In a 'real-world' setting, we analyzed patients on dialysis >90 days from seven European countries in DOPPS Phases 4 and 5 (2009-15). Adjusted Cox regression was used to study HDF (versus HD) and mortality, overall and by replacement fluid volume.

Results

Among 8567 eligible patients, 2012 (23%) were on HDF, ranging from 42% in Sweden to 12% in Germany. Median follow-up was 1.5 years during which 1988 patients died. The adjusted mortality hazard ratio (95% confidence interval) was 1.14 (1.00-1.29) for any HDF versus HD and 1.08 (0.92-1.28) for HDF >20 L replacement fluid volume versus HD. Similar results were found for cardiovascular and infection-related mortality. In an additional analysis aiming to avoid treatment-by-indication bias, we did not observe lower mortality rates in facilities using more HDF (versus HD).

Conclusions

Our results do not support the notion that HDF provides superior patient survival. Further trials designed to test the effect of high-volume HDF (versus lower volume HDF versus HD) on clinical outcomes are needed to adequately inform clinical practices.