A new era in the science and care of kidney diseases.

Notable progress in basic, translational and clinical nephrology research has been made over the past five decades. Nonetheless, many challenges remain, including obstacles to the early detection of kidney disease, disparities in access to care and variability in responses to existing and emerging therapies. Innovations in drug development, research technologies, tissue engineering and regenerative medicine have the potential to improve patient outcomes. Exciting prospects include the availability of new drugs to slow or halt the progression of chronic kidney disease, the development of bioartificial kidneys that mimic healthy kidney functions, and tissue engineering techniques that could enable transplantable kidneys to be created from the cells of the recipient, removing the risk of rejection. Cell and gene therapies have the potential to be applied for kidney tissue regeneration and repair. In addition, about 30% of kidney disease cases are monogenic and could potentially be treated using these genetic medicine approaches. Systemic diseases that involve the kidney, such as diabetes mellitus and hypertension, might also be amenable to these treatments. Continued investment, communication, collaboration and translation of innovations are crucial to realize their full potential. In addition, increasing sophistication in exploring large datasets, implementation science, and qualitative methodologies will improve the ability to deliver transformational kidney health strategies.

Post-translational modifications in kidney diseases and associated cardiovascular risk.

Patients with chronic kidney disease (CKD) are at an increased cardiovascular risk compared with the general population, which is driven, at least in part, by mechanisms that are uniquely associated with kidney disease. In CKD, increased levels of oxidative stress and uraemic retention solutes, including urea and advanced glycation end products, enhance non-enzymatic post-translational modification events, such as protein oxidation, glycation, carbamylation and guanidinylation. Alterations in enzymatic post-translational modifications such as glycosylation, ubiquitination, acetylation and methylation are also detected in CKD. Post-translational modifications can alter the structure and function of proteins and lipoprotein particles, thereby affecting cellular processes. In CKD, evidence suggests that post-translationally modified proteins can contribute to inflammation, oxidative stress and fibrosis, and induce vascular damage or prothrombotic effects, which might contribute to CKD progression and/or increase cardiovascular risk in patients with CKD. Consequently, post-translational protein modifications prevalent in CKD might be useful as diagnostic biomarkers and indicators of disease activity that could be used to guide and evaluate therapeutic interventions, in addition to providing potential novel therapeutic targets.

Cardiovascular Consequences of Uremic Metabolites: an Overview of the Involved Signaling Pathways.

The crosstalk of the heart with distant organs such as the lung, liver, gut, and kidney has been intensively approached lately. The kidney is involved in (1) the production of systemic relevant products, such as renin, as part of the most essential vasoregulatory system of the human body, and (2) in the clearance of metabolites with systemic and organ effects. Metabolic residue accumulation during kidney dysfunction is known to determine cardiovascular pathologies such as endothelial activation/dysfunction, atherosclerosis, cardiomyocyte apoptosis, cardiac fibrosis, and vascular and valvular calcification, leading to hypertension, arrhythmias, myocardial infarction, and cardiomyopathies. However, this review offers an overview of the uremic metabolites and details their signaling pathways involved in cardiorenal syndrome and the development of heart failure. A holistic view of the metabolites, but more importantly, an exhaustive crosstalk of their known signaling pathways, is important for depicting new therapeutic strategies in the cardiovascular field.

Extracorporeal Techniques in Kidney Failure.

During the last decades, various strategies have been optimized to enhance clearance of a variable spectrum of retained molecules to ensure hemodynamic tolerance to fluid removal and improve long-term survival in patients affected by kidney failure. Treatment effects are the result of the interaction of individual patient characteristics with device characteristics and treatment prescription. Historically, the nephrology community aimed to provide adequate treatment, along with the best possible quality of life and outcomes. In this article, we analyzed blood purification techniques that have been developed with their different characteristics.

Diagnosis of cardiovascular disease in patients with chronic kidney disease.

Patients with chronic kidney disease (CKD) are at high risk of cardiovascular disease (CVD) and cardiovascular death. Identifying and monitoring cardiovascular complications and hypertension is important for managing patients with CKD or kidney failure and transplant recipients. Biomarkers of myocardial ischaemia, such as troponins and electrocardiography (ECG), have limited utility for diagnosing cardiac ischaemia in patients with advanced CKD. Dobutamine stress echocardiography, myocardial perfusion scintigraphy and dipyridamole stress testing can be used to detect coronary disease in these patients. Left ventricular hypertrophy and left ventricular dysfunction can be detected and monitored using various techniques with differing complexity and cost, including ECG, echocardiography, nuclear magnetic resonance, CT and myocardial scintigraphy. Atrial fibrillation and other major arrhythmias are common in all stages of CKD, and ambulatory heart rhythm monitoring enables precise time profiling of these disorders. Screening for cerebrovascular disease is only indicated in asymptomatic patients with autosomal dominant polycystic kidney disease. Standardized blood pressure is recommended for hypertension diagnosis and treatment monitoring and can be complemented by ambulatory blood pressure monitoring. Judicious use of these diagnostic techniques may assist clinicians in detecting the whole range of cardiovascular alterations in patients with CKD and enable timely treatment of CVD in this high-risk population.

Inequities in kidney health and kidney care.

Health inequity refers to the existence of unnecessary and unfair differences in the ability of an individual or community to achieve optimal health and access appropriate care. Kidney diseases, including acute kidney injury and chronic kidney disease, are the epitome of health inequity. Kidney disease risk and outcomes are strongly associated with inequities that occur across the entire clinical course of disease. Insufficient investment across the spectrum of kidney health and kidney care is a fundamental source of inequity. In addition, social and structural inequities, including inequities in access to primary health care, education and preventative strategies, are major risk factors for, and contribute to, poorer outcomes for individuals living with kidney diseases. Access to affordable kidney care is also highly inequitable, resulting in financial hardship and catastrophic health expenditure for the most vulnerable. Solutions to these injustices require leadership and political will. The nephrology community has an important role in advocacy and in identifying and implementing solutions to dismantle inequities that affect kidney health.

Disasters and kidney care: pitfalls and solutions.

Patients with kidney disease, especially those with kidney failure, are particularly susceptible to the adverse effects of disasters because their survival depends on functional infrastructure, advanced technology, the availability of specific drugs and well-trained medical personnel. The risk of poor outcomes across the entire spectrum of patients with kidney diseases (acute kidney injury, chronic kidney disease and kidney failure on dialysis or with a functioning transplant) increases as a result of disaster-related logistical challenges. Patients who are displaced face even more complex problems owing to additional threats that arise during travel and after reaching their new location. Overall, risks may be mitigated by pre-disaster preparedness and training. Emergency kidney disaster responses depend on the type and severity of the disaster and include medical and/or surgical treatment of injuries, treatment of mental health conditions, appropriate diet and logistical interventions. After a disaster, patients should be evaluated for problems that were not detected during the event, including those that may have developed as a result of the disaster. A retrospective review of the disaster response is vital to prevent future mistakes. Important ethical concerns include fair distribution of limited resources and limiting harm. Patients with kidney disease, their care-givers, health-care providers and authorities should be trained to respond to the medical and logistical problems that occur during disasters to improve outcomes.

A Policy Call to Address Rare Kidney Disease in Health Care Plans.

Despite a large number of people globally being affected by rare kidney diseases, research support and health care policy programs usually focus on the management of the broad spectrum of CKD without particular attention to rare causes that would require a targeted approach for proper cure. Hence, specific curative approaches for rare kidney diseases are scarce, and these diseases are not treated optimally, with implications on the patients' health and quality of life, on the cost for the health care system, and society. There is therefore a need for rare kidney diseases and their mechanisms to receive the appropriate scientific, political, and policy attention to develop specific corrective approaches. A wide range of policies are required to address the various challenges that target care for rare kidney diseases, including the need to increase awareness, improve and accelerate diagnosis, support and implement therapeutic advances, and inform the management of the diseases. In this article, we provide specific policy recommendations to address the challenges hindering the provision of targeted care for rare kidney diseases, focusing on awareness and prioritization, diagnosis, management, and therapeutic innovation. In combination, the recommendations provide a holistic approach aiming for all aspects of rare kidney disease care to improve health outcomes, reduce the economic effect, and deliver benefits to society. Greater commitment from all the key stakeholders is now needed, and a central role should be assigned to patients with rare kidney disease to partner in the design and implementation of potential solutions.

Distribution, preparedness and management of Ukrainian adult refugees on dialysis-an international survey by the Renal Disaster Relief Task Force of the European Renal Association.

BACKGROUND: Due to the Russian-Ukrainian war, some of the about 10 000 adults requiring dialysis in Ukraine fled their country to continue dialysis abroad. To better understand the needs of conflict-affected dialysis patients, the Renal Disaster Relief Task Force of the European Renal Association conducted a survey on distribution, preparedness and management of adults requiring dialysis who were displaced due to the war. METHODS: A cross-sectional online survey was sent via National Nephrology Societies across Europe and disseminated to their dialysis centers. Fresenius Medical Care shared a set of aggregated data. RESULTS: Data were received on 602 patients dialyzed in 24 countries. Most patients were dialyzed in Poland (45.0%), followed by Slovakia (18.1%), Czech Republic (7.8%) and Romania (6.3%). The interval between last dialysis and the first in the reporting center was 3.1 ± 1.6 days, but was ≥4 days in 28.1% of patients. Mean age was 48.1 ± 13.4 years, 43.5% were females. Medical records were carried by 63.9% of patients, 63.3% carried a list of medications, 60.4% carried the medications themselves and 44.0% carried their dialysis prescription, with 26.1% carrying all of these items and 16.1% carrying none. Upon presentation outside Ukraine, 33.9% of patients needed hospitalization. Dialysis therapy was not continued in the reporting center by 28.2% of patients until the end of the observation period. CONCLUSIONS: We received information about approximately 6% of Ukrainian dialysis patients, who had fled their country by the end of August 2022. A substantial proportion were temporarily underdialyzed, carried incomplete medical information and needed hospitalization. The results of our survey may help to inform policies and targeted interventions to respond to the special needs of this vulnerable population during wars and other disasters in the future.

Cardiovascular complications in chronic kidney disease: a review from the European Renal and Cardiovascular Medicine Working Group of the European Renal Association.

Chronic kidney disease (CKD) is classified into five stages with kidney failure being the most severe stage (stage G5). CKD conveys a high risk for coronary artery disease, heart failure, arrhythmias, and sudden cardiac death. Cardiovascular complications are the most common causes of death in patients with kidney failure (stage G5) who are maintained on regular dialysis treatment. Because of the high death rate attributable to cardiovascular (CV) disease, most patients with progressive CKD die before reaching kidney failure. Classical risk factors implicated in CV disease are involved in the early stages of CKD. In intermediate and late stages, non-traditional risk factors, including iso-osmotic and non-osmotic sodium retention, volume expansion, anaemia, inflammation, malnutrition, sympathetic overactivity, mineral bone disorders, accumulation of a class of endogenous compounds called 'uremic toxins', and a variety of hormonal disorders are the main factors that accelerate the progression of CV disease in these patients. Arterial disease in CKD patients is characterized by an almost unique propensity to calcification and vascular stiffness. Left ventricular hypertrophy, a major risk factor for heart failure, occurs early in CKD and reaches a prevalence of 70-80% in patients with kidney failure. Recent clinical trials have shown the potential benefits of hypoxia-inducible factor prolyl hydroxylase inhibitors, especially as an oral agent in CKD patients. Likewise, the value of proactively administered intravenous iron for safely treating anaemia in dialysis patients has been shown. Sodium/glucose cotransporter-2 inhibitors are now fully emerged as a class of drugs that substantially reduces the risk for CV complications in patients who are already being treated with adequate doses of inhibitors of the renin-angiotensin system. Concerted efforts are being made by major scientific societies to advance basic and clinical research on CV disease in patients with CKD, a research area that remains insufficiently explored.

Role of the Microbiome in Gut-Heart-Kidney Cross Talk.

Homeostasis is a prerequisite for health. When homeostasis becomes disrupted, dysfunction occurs. This is especially the case for the gut microbiota, which under normal conditions lives in symbiosis with the host. As there are as many microbial cells in and on our body as human cells, it is unlikely they would not contribute to health or disease. The gut bacterial metabolism generates numerous beneficial metabolites but also uremic toxins and their precursors, which are transported into the circulation. Barrier function in the intestine, the heart, and the kidneys regulates metabolite transport and concentration and plays a role in inter-organ and inter-organism communication via small molecules. This communication is analyzed from the perspective of the remote sensing and signaling theory, which emphasizes the role of a large network of multispecific, oligospecific, and monospecific transporters and enzymes in regulating small-molecule homeostasis. The theory provides a systems biology framework for understanding organ cross talk and microbe-host communication involving metabolites, signaling molecules, nutrients, antioxidants, and uremic toxins. This remote small-molecule communication is critical for maintenance of homeostasis along the gut-heart-kidney axis and for responding to homeostatic perturbations. Chronic kidney disease is characterized by gut dysbiosis and accumulation of toxic metabolites. This slowly impacts the body, affecting the cardiovascular system and contributing to the progression of kidney dysfunction, which in its turn influences the gut microbiota. Preserving gut homeostasis and barrier functions or restoring gut dysbiosis and dysfunction could be a minimally invasive way to improve patient outcomes and quality of life in many diseases, including cardiovascular and kidney disease.

Lessons learned during the war in Ukraine: a report from the Renal Disaster Relief Task Force of the ERA.

People living with kidney disease are among the most vulnerable at times of natural or man-made disasters. In addition to their unpredictable course, armed conflicts impose a major threat given the disruption of infrastructure, sanitation and access to food, water and medical care. The ongoing war in Ukraine has once more demonstrated the importance of preparedness, organization, coordination and solidarity during disasters. People living with kidney disease face serious challenges given their dependence on life-sustaining treatment, irrespective of whether they remain in the war zone or are displaced internally or externally. This especially affects those requiring kidney replacement therapy, dialysis or transplantation, but also patients with other kidney diseases and the medical staff who care for them. Soon after the war started, the European Renal Association assigned a Renal Disaster Relief Task Force dedicated to support the people living with kidney disease and the nephrology community in Ukraine. This report summarizes the major challenges faced, actions taken and lessons learned by this task force. We anticipate that the experience will help to increase preparedness and mitigate the devastating effects of armed conflicts on the kidney community in the future and propose to establish an international collaboration to extend this effort to other parts of the world facing similar challenges.

Our shared responsibility: the urgent necessity of global environmentally sustainable kidney care.

In response to Earth's accelerating climate crisis, we, an international group of nephrologists, call on our global community to unite and align kidney care in accordance with United Nation's 26th Conference of the Parties health sector principles. We announce a global and inclusive initiative, "GREEN-K": Global Environmental Evolution in Nephrology and Kidney Care, with a vision of "sustainable kidney care for a healthy planet and healthy kidneys" and mission to "promote and support environmentally sustainable and resilient kidney care globally through advocacy, education, and collaboration." A patient-centric approach that permits climate change mitigation and adaptation is proposed. Multi-stakeholder GREEN-K action and focus areas will include education, sustainable clinical care, and advances toward environmentally sustainable innovations, procurement, and infrastructure. Mindful of the disproportionately high climate impact of kidney therapies, we welcome the opportunity to work together in shared accountability to patients and Earth's natural systems.

Factors influencing kidney transplantation rates: a study from the ERA Registry.

BACKGROUND: Large international differences exist in kidney transplantation (KT) rates. We aimed to investigate which factors may explain the total, deceased donor and living donor KT rates over the last decade. METHODS: KT experts from 39 European countries completed the Kidney Transplantation Rate Survey on measures and barriers and their potential effect on the KT rate in their country. In the analyses, countries were divided into low, middle and high KT rate countries based on the KT rate at the start of study period in 2010. RESULTS: Experts from low KT rate countries reported more frequently that they had taken measures regarding staff, equipment and facilities to increase the total KT rate compared with middle and high KT rate countries. For donor type-specific KT, the largest international differences in measures taken were reported for deceased donor KT, with middle and high KT rate countries taking more measures, such as the use of expanded criteria donor kidneys, the presence of transplantation coordinators and (inter)national exchange of donor kidneys. Once a measure was taken, experts' opinion on its success was similar across the low, middle and high KT rate countries. Experts from low KT rate countries more often reported potential barriers, such as patients' lack of knowledge and distrust in the healthcare system. CONCLUSIONS: Particularly in low KT rate countries, the KT rate might be stimulated by optimizing staff, equipment and facilities. In addition, all countries may benefit from measures specific to deceased and living donors.

Critical Appraisal of Limitations in the Current Definition/Classification of Uremic Toxins.

Progress in the identification and characterization of uremic retention solutes has refined our understanding of the pathophysiology of the uremic syndrome. Furthermore, the evolution of dialysis and other techniques designed to remove uremic retention solutes offers opportunities to provide a more personalized and targeted treatment for patients with chronic kidney disease (CKD) with an aim to improve outcomes. Considering these developments, a consensus report was recently published that readdressed the 2003 definition and classification of uremic toxins and formulated recommendations for future research to enhance the understanding of uremic retention solutes. In the present work, the authors of a work group that contributed to the consensus report provide a more detailed rationale for the recommendations related to their theme "Critical appraisal of limitations in the current definition/classification of uremic toxins." In summary, the authors propose that the current definition of uremic toxins should remain organized on hemodialysis strategies, membranes, and removal patterns since hemodialysis is the most frequently applied therapeutic strategy to reduce their concentration in advanced CKD. Nevertheless, the work group also acknowledges that any classification based on cutoff values and/or molecular spatial configurations is arbitrary and will likely need to be changed with therapeutic advancements. Furthermore, the current physicochemical classification might be extended to reflect the degree of toxicity of a specific toxin that is likely to support more personalized and targeted dialysis prescriptions and improve the outcomes for patients with CKD.

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 of kidney care. We then describe the Decade of the KidneyTM initiative, the rationale behind 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.