Deleting Death and Dialysis: Conservative Care of Cardio-Vascular Risk and Kidney Function Loss in Chronic Kidney Disease (CKD)

Future of Uremic Toxin Management

During the progression of chronic kidney disease (CKD), the retention of uremic toxins plays a key role in the development of uremic syndrome. Knowledge about the nature and biological impact of uremic toxins has grown exponentially over the past decades. However, the science on reducing the concentration and effects of uremic toxins has not advanced in parallel. Additionally, the focus has remained for too long on dialysis strategies, which only benefit the small fraction of people with CKD who suffer from advanced kidney disease, whereas uremic toxicity effects are only partially prevented. This article reviews recent research on alternative methods to counteract uremic toxicity, emphasizing options that are also beneficial in the earlier stages of CKD, with a focus on both established methods and approaches which are still under investigation or at the experimental stage. We will consequently discuss the preservation of kidney function, the prevention of cardiovascular damage, gastro-intestinal interventions, including diet and biotics, and pharmacologic interventions. In the final part, we also review alternative options for extracorporeal uremic toxin removal. The future will reveal which of these options are valid for further development and evidence-based assessment, hopefully leading to a more sustainable treatment model for CKD than the current one.

Inflammation and all-cause mortality in patients undergoing peritoneal dialysis

OBJECTIVE

This study aimed to evaluate inflammatory biomarkers in patients undergoing peritoneal dialysis and investigate their association with all-cause mortality or transfer to hemodialysis.

METHODS

This prospective cohort study included 43 patients undergoing peritoneal dialysis. Plasma levels of cytokines were measured using flow cytometry and capture enzyme-linked immunosorbent assay. Biomarkers were categorized based on their respective median values. Survival analysis was conducted using the Kaplan-Meier estimator, considering two outcomes: all-cause mortality and transfer to hemodialysis.

RESULTS

After adjusting for confounding factors, plasma levels above the median of the levels of CCL2 and plasma, as well as below the median of TNF-α, and the median of dialysate IL-17 levels, were associated with an increased risk of experiencing the specified outcomes after approximately 16 months of follow-up.

CONCLUSION

These findings suggest that inflammatory biomarkers may be a valuable tool for predicting all-cause mortality and transfer to hemodialysis in patients undergoing peritoneal dialysis.

Indoxyl Sulfate-Induced Macrophage Toxicity and Therapeutic Strategies in Uremic Atherosclerosis

Cardiovascular disease (CVD) frequently occurs in patients with chronic kidney disease (CKD), particularly those undergoing dialysis. The mechanisms behind this may be related to traditional risk factors and CKD-specific factors that accelerate atherosclerosis and vascular calcification in CKD patients. The accumulation of uremic toxins is a significant factor in CKD-related systemic disorders. Basic research suggests that indoxyl sulfate (IS), a small protein-bound uremic toxin, is associated with macrophage dysfunctions, including increased oxidative stress, exacerbation of chronic inflammation, and abnormalities in lipid metabolism. Strategies to mitigate the toxicity of IS include optimizing gut microbiota, intervening against the abnormality of intracellular signal transduction, and using blood purification therapy with higher efficiency. Further research is needed to examine whether lowering protein-bound uremic toxins through intervention leads to a reduction in CVD in patients with CKD.

Effects of Dietary Intervention on Nutritional Status in Elderly Individuals with Chronic Kidney Disease

The prevalence of chronic kidney disease (CKD) is rising, especially in elderly individuals. The overlap between CKD and aging is associated with body composition modification, metabolic abnormalities, and malnutrition. Renal care guidelines suggest treating CKD patient with a low-protein diet according to the renal disease stage. On the other hand, geriatric care guidelines underline the need for a higher protein intake to prevent malnutrition. The challenge remains of how to reconcile a low dietary protein intake with insuring a favorable nutritional status in geriatric CKD populations. Therefore, this study aims to evaluate the effect of a low-protein adequate energy intake (LPAE) diet on nutritional risk and nutritional status among elderly CKD (stage 3-5) patients and then to assess its impact on CKD metabolic abnormalities. To this purpose, 42 subjects [age ≥ 65, CKD stage 3-5 in conservative therapy, and Geriatric Nutritional Risk Index (GNRI) ≥ 98] were recruited and the LPAE diet was prescribed. At baseline and after 6 months of the LPAE diet, the following data were collected: age, sex, biochemical parameters, anthropometric measurements, body composition, and the GNRI. According to their dietary compliance, the subjects were divided into groups: compliant and non-compliant. For the compliant group, the results obtained show no increased malnutrition risk incidence but, rather, an improvement in body composition and metabolic parameters, suggesting that the LPAE diet can provide a safe tool in geriatric CKD patients.

The European Kidney Health Alliance (EKHA) and the Decade of the KidneyTM

The European Kidney Health Alliance (EKHA) is an advocacy organization that defends the case of the kidney patients and the nephrological community at the level of the European Union (EU), and from there, top to bottom, also at the national level of the EU member states and the EU-associated countries. The Decade of the KidneyTM is a global initiative launched by the American Association of Kidney Patients (AAKP) to create greater awareness and organize patient demands for long overdue innovation in kidney care. This article describes the medical and patient burden of kidney disease, the history of EKHA, its major activities and tools for policy action and the need for innovation. We then describe the Decade of the KidneyTM initiative, the rationale why EKHA joined this activity to emanate parallel action at the European side, the novel professionalized structure of EKHA, and its immediate targets. The final aim is to align all major stakeholders for an action plan on kidney disease comparable to Europe's successful Beating Cancer Plan, with the additional intent that the EKHA model is applied also by the respective national kidney-related societies to create a broad mobilization at all levels. The ultimate aims are that the EU considers chronic kidney disease (CKD) as a major health and health-economic problem, to consequently have CKD included as a key health research target by the European Commission, and to improve quality of life and outcomes for all kidney patients.

Chronic kidney disease and renal replacement therapy: an overview for the advanced clinical practitioner

Chronic kidney disease (CKD), also known as chronic renal failure (CRF), is a common, globally significant condition, with associated significant mortality and morbidity. Due to the disease prevalence, advanced clinical practitioners (ACPs) in a variety of primary and secondary care settings will encounter patients with this diagnosis who will require care and treatment. This article examines definitions of CKD, describes a clinical approach to a patient with CKD, including key history and examination findings, and provides a brief overview of renal replacement strategies for the patient with end-stage renal failure. ACPs require a thorough understanding of this condition and the key elements of treatment and care in this population.

The Human Microbiome in Chronic Kidney Disease: A Double-Edged Sword

Chronic kidney disease (CKD) is an increasing global health burden. Current treatments for CKD include therapeutics to target factors that contribute to CKD progression, including renin–angiotensin–aldosterone system inhibitors, and drugs to control blood pressure and proteinuria control. Recently, associations between chronic disease processes and the human microbiota and its metabolites have been demonstrated. Dysbiosis—a change in the microbial diversity—has been observed in patients with CKD. The relationship between CKD and dysbiosis is bidirectional; gut-derived metabolites and toxins affect the progression of CKD, and the uremic milieu affects the microbiota. The accumulation of microbial metabolites and toxins is linked to the loss of kidney functions and increased mortality risk, yet renoprotective metabolites such as short-chain fatty acids and bile acids help restore kidney functions and increase the survival rate in CKD patients. Specific dietary interventions to alter the gut microbiome could improve clinical outcomes in patients with CKD. Low-protein and high-fiber diets increase the abundance of bacteria that produce short-chain fatty acids and anti-inflammatory bacteria. Fluctuations in the urinary microbiome are linked to increased susceptibility to infection and antibiotic resistance. In this review, we describe the potential role of the gut, urinary and blood microbiome in CKD pathophysiology and assess the feasibility of modulating the gut microbiota as a therapeutic tool for treating CKD.

OUP accepted manuscript

The world faces a dramatic man-made ecologic disaster and healthcare is a crucial part of this problem. Compared with other therapeutic areas, nephrology care, and especially dialysis, creates an excessive burden via water consumption, greenhouse gas emission and waste production. In this advocacy article from the European Kidney Health Alliance we describe the mutual impact of climate change on kidney health and kidney care on ecology. We propose an array of measures as potential solutions related to the prevention of kidney disease, kidney transplantation and green dialysis. For dialysis, several proactive suggestions are made, especially by lowering water consumption, implementing energy-neutral policies, waste triage and recycling of materials. These include original proposals such as dialysate regeneration, dialysate flow reduction, water distillation systems for dialysate production, heat pumps for unit climatization, heat exchangers for dialysate warming, biodegradable and bio-based polymers, alternative power sources, repurposing of plastic waste (e.g. incorporation in concrete), registration systems of ecologic burden and platforms to exchange ecologic best practices. We also discuss how the European Green Deal offers real potential for supporting and galvanizing these urgent environmental changes. Finally, we formulate recommendations to professionals, manufacturers, providers and policymakers on how this correction can be achieved.

Uremic Toxins and Cardiovascular System

When chronic kidney disease develops, the capacity of the kidneys to clear metabolic waste products from the body is gradually lost. This process results in the retention of a large array of compounds affecting biochemical and biological functions (uremic toxins), of which several can cause cardiovascular damage. This article reviews the main cardiotoxic mechanisms related to uremic toxin retention (endothelial dysfunction, vascular smooth muscle cell alterations, inflammation, mineral bone disorder, insulin resistance, and thrombogenicity) and the main responsible retention compounds. Therapeutic options are reviewed, such as influencing solute generation by intestinal microbiota.

Fighting the unbearable lightness of neglecting kidney health: the decade of the kidney

A brief comprehensive overview is provided of the elements constituting the burden of kidney disease [chronic kidney disease (CKD) and acute kidney injury]. This publication can be used for advocacy, emphasizing the importance and urgency of reducing this heavy and rapidly growing burden. Kidney diseases contribute to significant physical limitations, loss of quality of life, emotional and cognitive disorders, social isolation and premature death. CKD affects close to 100 million Europeans, with 300 million being at risk, and is projected to become the fifth cause of worldwide death by 2040. Kidney disease also imposes financial burdens, given the costs of accessing healthcare and inability to work. The extrapolated annual cost of all CKD is at least as high as that for cancer or diabetes. In addition, dialysis treatment of kidney diseases imposes environmental burdens by necessitating high energy and water consumption and producing plastic waste. Acute kidney injury is associated with further increases in global morbidity, mortality and economic burden. Yet investment in research for treatment of kidney disease lags behind that of other diseases. This publication is a call for European investment in research for kidney health. The innovations generated should mirror the successful European Union actions against cancer over the last 30 years. It is also a plea to nephrology professionals, patients and their families, caregivers and kidney health advocacy organizations to draw, during the Decade of the Kidney (2020–30), the attention of authorities to realize changes in understanding, research and treatment of kidney disease.

Phosphate, Microbiota and CKD

Phosphate is a key uremic toxin associated with adverse outcomes. As chronic kidney disease (CKD) progresses, the kidney capacity to excrete excess dietary phosphate decreases, triggering compensatory endocrine responses that drive CKD-mineral and bone disorder (CKD-MBD). Eventually, hyperphosphatemia develops, and low phosphate diet and phosphate binders are prescribed. Recent data have identified a potential role of the gut microbiota in mineral bone disorders. Thus, parathyroid hormone (PTH) only caused bone loss in mice whose microbiota was enriched in the Th17 cell-inducing taxa segmented filamentous bacteria. Furthermore, the microbiota was required for PTH to stimulate bone formation and increase bone mass, and this was dependent on bacterial production of the short-chain fatty acid butyrate. We review current knowledge on the relationship between phosphate, microbiota and CKD-MBD. Topics include microbial bioactive compounds of special interest in CKD, the impact of dietary phosphate and phosphate binders on the gut microbiota, the modulation of CKD-MBD by the microbiota and the potential therapeutic use of microbiota to treat CKD-MBD through the clinical translation of concepts from other fields of science such as the optimization of phosphorus utilization and the use of phosphate-accumulating organisms.

High cut-off dialysis mitigates pro-calcific effects of plasma on vascular progenitor cells

Mortality of patients with end-stage renal disease tremendously exceeds that of the general population due to excess cardiovascular morbidity. Large middle-sized molecules (LMM) including pro-inflammatory cytokines are major drivers of uremic cardiovascular toxicity and cannot be removed sufficiently by conventional high-flux (HFL) hemodialysis. We tested the ability of plasma from 19 hemodialysis patients participating in a trial comparing HFL with high cut-off (HCO) membranes facilitating removal of LMM to induce calcification in mesenchymal stromal cells (MSC) functioning as vascular progenitors. HCO dialysis favorably changed plasma composition resulting in reduced pro-calcific activity. LMM were removed more effectively by HCO dialysis including FGF23, a typical LMM we found to promote osteoblastic differentiation of MSC. Protein-bound uremic retention solutes with known cardiovascular toxicity but not LMM inhibited proliferation of MSC without direct toxicity in screening experiments. We could not attribute the effect of HCO dialysis on MSC calcification to distinct mediators. However, we found evidence of sustained reduced inflammation that might parallel other anti-calcifying mechanisms such as altered generation of extracellular vesicles. Our findings imply protection of MSC from dysfunctional differentiation by novel dialysis techniques targeted at removal of LMM. HCO dialysis might preserve their physiologic role in vascular regeneration and improve outcomes in dialysis patients.

Respiratory muscle strength and quality of life in chronic kidney disease patients undergoing hemodialysis

Abstract Introduction: Hemodialysis (HD) sessions associated with the chronic kidney disease (CKD) repercussions may cause respiratory muscle impairment and limitations of daily living activities, which may compromise the quality of life. Objective: To evaluate respiratory muscle strength and quality of life in HD patients. Methods: A cross-sectional study involving CKD patients of both sexes undergoing HD. All were evaluated during HD, using an evaluation form containing personal and clinical data, presence of comorbidities, lifestyle (including self-reported physical activity) and vital signs. Respiratory muscle strength was analyzed by maximum inspiratory (MIP) and maximum expiratory (MEP) pressures by manovacuometer and quality of life using the SF-36 questionnaire. Results: Sixty-eight patients were evaluated (69.1% men), with a mean age of 54.9 ± 13.6 years. The MEP% was below of predicted (79.5 ± 25.7) and the MIP% was reduced only in women (77.8 ± 38.7). The MIP% was related to CKD time (p = 0.04) in men. The SF-36 domain that showed the most impairment was physical limitation [25.0 (13.0-67.0)], while mental health was the least impaired domain [72.0 (62.0-84.0)]. Those who reported the practice of physical activity obtained better results in vitality domain (p = 0.01). In the analysis stratified by sex, the functional capacity domain was less compromised in men who practiced self-reported physical activity (p = 0.02). Conclusion: CKD patients undergoing HD had a reduction in MEP relative to predicted, in addition to a greater impairment of MIP in men with longer CKD time and in women alone, although the clinical relevance of this finding is uncertain. Quality of life was more compromised in the physical limitation domain, where those who self-reported physical activity achieved better results in the domains of vitality (total sample) and functional capacity (men).

Pelacarsen for lowering lipoprotein(a): implications for patients with chronic kidney disease

Chronic kidney disease (CKD) patients are at an increased risk of cardiovascular disease (CVD) and statins may not be protective in advanced CKD. The reasons for the limited efficacy of statins in advanced CKD are unclear, but statins may increase plasma levels of the highly atherogenic molecule lipoprotein(a), also termed Lp(a), as well as PCSK9 (protein convertase subtilisin/kexin type 9) levels. Lp(a) has also been linked to calcific aortic stenosis, which is common in CKD. Moreover, circulating Lp(a) levels increase in nephrotic syndrome with declining renal function and are highest in patients on peritoneal dialysis. Thus, the recent publication of the Phase 2 randomized controlled trial of pelacarsen [also termed AKCEA-APO(a)-LRx and TQJ230], a hepatocyte-directed antisense oligonucleotide targeting the LPA gene messenger RNA, in persons with CVD should be good news for nephrologists. Pelacarsen safely and dose-dependently decreased Lp(a) levels by 35-80% and a Phase 3 trial [Lp(a)HORIZON, NCT04023552] is planned to run from 2020 to 2024. Unfortunately, patients with estimated glomerular filtration rate <60 mL/min or urinary albumin:creatinine ratio >100 mg/g were excluded from Phase 2 trials and those with 'significant kidney disease' will be excluded from the Phase 3 trial. Optimized exclusion criteria for Lp(a)HORIZON would provide insights into the role of Lp(a) in CVD in CKD patients.

Nephrology and Public Policy Committee propositions to stimulate research collaboration in adults and children in Europe

The strengths and the limitations of research activities currently present in Europe are explored in order to outline how to proceed in the near future. Epidemiological and clinical research and public policy in Europe are generally considered to be comprehensive and successful, and the European Renal Association – European Dialysis and Transplant Association (ERA-EDTA) is playing a key role in the field of nephrology research. The Nephrology and Public Policy Committee (NPPC) aims to improve the current situation and translation into public policy by planning eight research topics to be supported in the coming 5 years by ERA-EDTA.

The Impact of Inflammatory Profile on Selenium Levels in Hemodialysis Patients

INTRODUCTION

Hemodialysis stands out as an eligible treatment for patients with chronic kidney disease. The subsequent inflammatory process resulting from this disease and hemodialysis per se is exacerbated in this therapy. Selenium (Se) is an essential trace element that can participate in the inhibition of pro-oxidant and pro-inflammatory processes and could be considered a measurement that indicates the progression of chronic kidney disease and inflammation.

OBJECTIVES

The present study investigated selenemia in hemodialysis patients of the ABC region of São Paulo and aimed to establish the correlation between an inflammatory marker and selenemia in this conditions disease.

METHODS

This is an observational cross-sectional study of the Faculdade de Medicina do ABC in patients submitted to hemodialysis three times a week for at least six months. The eligible group composed of 21 patients, who filled out forms and underwent biochemical tests (colorimetric enzyme methods, flow cytometer, turbidimetric method and mass spectrometry).

RESULTS

The study population showed, women (70%), men (30%) with a mean age of 47 ± 17 years, Caucasians (36%) and non-Caucasian (64%), hypertensive (68%), smokers (53%) and non-smokers (64%). There was a hegemonic prevalence of systolic arterial hypertension (SAH) 68.1% in relation to diabetes mellitus (DM) (50%). Pre and post hemodialysis (HD) selenemia showed statistical significance, which did not occur with Creactive protein. There was a predominance of females in our sample; the pre- and post- HD selenemia were within the normal range of the reference values; there was a statistically significant correlation between pre and post-HD selenemia; there was no correlation with statistical significance between values of pre and post-HD C-reactive protein.

CONCLUSION

Our data showed that there was no direct relationship between pre- and post- HD inflammation and pre- and post-HD selenemia.

Antimicrobial peptide HPA3NT3-A2 effectively inhibits biofilm formation in mice infected with drug-resistant bacteria

Bacterial biofilms formed through secretion of extracellular polymeric substances (EPS) have been implicated in many serious infections and can increase antibiotic resistance by a factor of more than 1000. Here, we examined the abilities of the antimicrobial peptide HPA3NT3-A2 to inhibit and reduce biofilm formation, eliminate EPS, and suppress inflammation in mice infected with clinical isolates of drug-resistant Pseudomonas aeruginosa strains. HPA3NT3-A2 was developed from a desirable analogue peptide, HPA3NT3, derived from residues 2-20 of the Helicobacter pylori ribosomal protein L1. HPA3NT3-A2 showed stronger activity against planktonic cells (MIC: 8 μM) compared to ciprofloxacin or tobramycin (>512 μM), and a favorable minimum biofilm inhibition and elimination concentration. This peptide also neutralized LPS; decreased levels of EPS; inhibited the production of pro-inflammatory cytokines in the lung, kidney, and spleen; decreased white blood cell counts; and increased survival among infected mice.

Treating potassium disturbances: kill the killers but avoid overkill

OBJECTIVES

In this publication, we review the definitions, symptoms, causes, differential diagnoses and therapies of hypokalemia and hyperkalemia.

METHODS

Comprehensive tables and diagnostic algorithms are provided when appropriate.

RESULTS AND CONCLUSIONS

Although both hypokalemia and hyperkalemia may be life-threatening, this is essentially the case with severe changes (serum potassium < 2.5 or > 6.5 mmol/L), the presence of symptoms or electrocardiographic deviations, the association with aggravating factors (e.g. digitalis intake) and/or rapid acute changes. Only these truly need an emergency therapeutic approach. In all other cases, a careful consideration of the causes and their correction should prevail over additional approaches to modify serum potassium concentration. Although most therapeutic approaches to both hypokalemia and hyperkalemia have been well established since many years, recently two new intestinal potassium binders have been introduced on the market. It remains to be elucidated whether these drugs truly have an additional role on top of the existing treatments.

Contribution of the uremic milieu to an increased pro-inflammatory monocytic phenotype in chronic kidney disease

Intermediate (CD14⁺⁺CD16⁺) monocytes have important pro-inflammatory and atherogenic features and are increased in patients with chronic kidney disease (CKD). The present study aims to elucidate the role of the uremic milieu and of platelet activation in monocyte differentiation. Monocyte subtypes were analyzed in CKD patients (n = 193) and healthy controls (n = 27). Blood from healthy controls (Ctrl; n = 8) and hemodialysis patients (HD; n = 8) was centrifuged, and plasma (pl) was exchanged between Ctrl and HD (Ctrlcells/HDpl and HDcells/Ctrlpl) or reconstituted as original (Ctrlsham and HDsham) and incubated for 24 h (T24). Monocyte differentiation and platelet aggregation to monocytes (MPA) was assessed by flow cytometry. Especially, a higher proportion of CD14⁺⁺CD16⁺ monocytes was found in hemodialysis (HD) patients (p < 0.01). In plasma exchange experiments, Ctrl cells/HD pl T24 showed an increased percentage of CD14⁺⁺CD16⁺ monocytes versus Ctrl sham (33.7% ± 15 vs. 15.7% ± 9.6; P < 0.005), comparable to the level of CD14⁺⁺CD16⁺ monocytes in the HD sham condition. The percentage of CD14⁺⁺CD16⁺ monocytes was lowered by suspending HD cells in Ctrl pl (18.4% ± 7.8 vs. 36.7% ± 15 in HD sham; P < 0.005) reaching the level of the Ctrl sham condition (15.7% ± 9.6). A mixture of uremic sulfates increased CD14⁺⁺CD16⁺ monocytes compared to control (19.8 ± 9.6% vs. 15.8 ± 10.9%; P < 0.05), paralleled by a rise MPA. Blocking MPA by abciximab, a potential therapeutic strategy, or anti-CD62P did not inhibit differentiation towards the CD14⁺⁺CD16⁺ monocytes. In conclusion, in the present cohort, CD14⁺⁺CD16⁺ monocytes are especially increased in HD patients and this can at least in part be attributed to the presence of the uremic milieu, with uremic sulfates inducing a reversible shift towards pro-inflammatory CD14⁺⁺CD16⁺ monocytes.

Very Low Protein Diet for Patients with Chronic Kidney Disease: Recent Insights

Use of nutritional therapy (NT) in chronic kidney disease (CKD) patients is still debated among nephrologists, but it represents a fundamental point in the conservative treatment of CKD. It has been used for years and it has new goals today, such as (1) the reduction of edema, diuretics, and blood pressure values with a low sodium-content diet; (2) the dose reduction of phosphate levels and phosphate binders; (3) the administration of bicarbonate with vegetables in order to correct metabolic acidosis and delay CKD progression; (4) the reduction of the number and the doses of drugs and chemical substances; and (5) the lowering of urea levels, the cure of intestinal microbioma, and the reduction of cyanates levels (such as indoxyl-sulphate and p-cresol sulphate), which are the most recent known advantages achievable with NT. In conclusion, NT and especially very low protein diet (VLPD) have several beneficial effects in CKD patients and slows the progression of CKD.