Regulation of solute carriers oct2 and OAT1/3 in the kidney: a phylogenetic, ontogenetic, and cell dynamic perspective.

Over the course of more than 500 million years, the kidneys have undergone a remarkable evolution from primitive nephric tubes to intricate filtration-reabsorption systems that maintain homeostasis and remove metabolic end products from the body. The evolutionarily conserved solute carriers organic cation transporter 2 (OCT2) and organic anion transporters 1 and 3 (OAT1/3) coordinate the active secretion of a broad range of endogenous and exogenous substances, many of which accumulate in the blood of patients with kidney failure despite dialysis. Harnessing OCT2 and OAT1/3 through functional preservation or regeneration could alleviate the progression of kidney disease. Additionally, it would improve current in vitro test models that lose their expression in culture. With this review, we explore OCT2 and OAT1/3 regulation from different perspectives: phylogenetic, ontogenetic, and cell dynamic. Our aim is to identify possible molecular targets both to help prevent or compensate for the loss of transport activity in patients with kidney disease and to enable endogenous OCT2 and OAT1/3 induction in vitro in order to develop better models for drug development.

Integrated multi-omics with machine learning to uncover the intricacies of kidney disease.

The development of omics technologies has driven a profound expansion in the scale of biological data and the increased complexity in internal dimensions, prompting the utilization of machine learning (ML) as a powerful toolkit for extracting knowledge and understanding underlying biological patterns. Kidney disease represents one of the major growing global health threats with intricate pathogenic mechanisms and a lack of precise molecular pathology-based therapeutic modalities. Accordingly, there is a need for advanced high-throughput approaches to capture implicit molecular features and complement current experiments and statistics. This review aims to delineate strategies for integrating multi-omics data with appropriate ML methods, highlighting key clinical translational scenarios, including predicting disease progression risks to improve medical decision-making, comprehensively understanding disease molecular mechanisms, and practical applications of image recognition in renal digital pathology. Examining the benefits and challenges of current integration efforts is expected to shed light on the complexity of kidney disease and advance clinical practice.

K acetyltransferase 2B (KAT2B) variants can be responsible for early onset steroid-resistant nephrotic syndrome.

In children, 15% of nephrotic syndromes are steroid-resistant (SRNS); approximately 30% of early onset SRNS have a genetic origin, with more than 100 causal genes described so far. SRNS can be syndromic, if associated with signs and symptoms affecting other organs or systems, such as the central nervous system, the heart or the eyes. Patients with SRNS are at high risk of chronic kidney disease and progressive renal failure, and as such need multidisciplinary care, centred on renal protection. Recently, K acetyltransferase 2B (KAT2B) loss of function was identified as a risk factor for morphological and functional defects in Drosophila nephrocytes; in vitro knockdown of KAT2B also impaired the adhesion and migration ability of human podocytes.Here we provide the first clinical description of a family affected by a loss of function mutation of KAT2B Clinically, both siblings presented with early onset SRNS and bilateral cataract, without neurological or heart defects. Renal function was maintained in the teenage years; nephrotic-range proteinuria was insensitive to immunosuppressive therapies. Therefore, mutations of KAT2B should be sought in patients with unexplained syndromic SRNS affecting the eye.

Loss of the alpha subunit distal furin cleavage site blunts ENaC activation following Na+ restriction.

Epithelial Na+ channels (ENaCs) are activated by proteolysis of the α and γ subunits at specific sites flanking embedded inhibitory tracts. To examine the role of α subunit proteolysis in channel activation in vivo, we generated mice lacking the distal furin cleavage site in the α subunit (αF2M mice). On a normal Na+ control diet, no differences in ENaC protein abundance in kidney or distal colon were noted between wild-type (WT) and αF2M mice. Patch-clamp analyses revealed similar levels of ENaC activity in kidney tubules, while no physiologically relevant differences in blood chemistry or aldosterone levels were detected. Male αF2M mice did exhibit diminished ENaC activity in the distal colon, as measured by amiloride-sensitive short-circuit current (ISC). Following dietary Na+ restriction, WT and αF2M mice had similar natriuretic and colonic ISC responses to amiloride. However, single-channel activity was significantly lower in kidney tubules from Na+-restricted αF2M mice compared with WT littermates. ENaC α and γ subunit expression in kidney and distal colon were also enhanced in Na+-restricted αF2M vs. WT mice, in association with higher aldosterone levels. These data provide evidence that disrupting α subunit proteolysis impairs ENaC activity in vivo, requiring compensation in response to Na+ restriction. KEY POINTS: The epithelial Na+ channel (ENaC) is activated by proteolytic cleavage in vitro, but key questions regarding the role of ENaC proteolysis in terms of whole-animal physiology remain to be addressed. We studied the in vivo importance of this mechanism by generating a mouse model with a genetic disruption to a key cleavage site in the ENaC's α subunit (αF2M mice). We found that αF2M mice did not exhibit a physiologically relevant phenotype under normal dietary conditions, but have impaired ENaC activation (channel open probability) in the kidney during salt restriction. ENaC function at the organ level was preserved in salt-restricted αF2M mice, but this was associated with higher aldosterone levels and increased expression of ENaC subunits, suggesting compensation was required to maintain homeostasis. These results provide the first evidence that ENaC α subunit proteolysis is a key regulator of channel activity in vivo.

Proteogenomics in Nephrology: A New Frontier in Nephrological Research.

Proteogenomics represents a transformative intersection in nephrology, uniting genomics, transcriptomics, and proteomics to unravel the molecular intricacies of kidney diseases. This review encapsulates the methodological essence of proteogenomics and its profound implications in chronic kidney disease (CKD) research. We explore the proteogenomic pipeline, highlighting the integrated analysis of genomic, transcriptomic, and proteomic data and its pivotal role in enhancing our understanding of kidney pathologies. Through case studies, we showcase the application of proteogenomics in clear cell renal cell carcinoma (ccRCC) and Autosomal Recessive Polycystic Kidney Disease (ARPKD), emphasizing its potential in personalized treatment strategies and biomarker discovery. The review also addresses the challenges in proteogenomic analysis, including data integration complexities and bioinformatics limitations, and proposes solutions for advancing the field. Ultimately, this review underscores the prospective future of proteogenomics in nephrology, particularly in advancing personalized medicine and providing novel therapeutic insights.

A pragmatic, open-label, randomized controlled trial of Plasma-Lyte-148 versus standard intravenous fluids in children receiving kidney transplants (PLUTO).

Acute electrolyte and acid-base imbalance is experienced by many children following kidney transplant. This is partly because doctors give very large volumes of artificial fluids to keep the new kidney working. When severe, fluid imbalance can lead to seizures, cerebral edema and death. In this pragmatic, open-label, randomized controlled trial, we randomly assigned (1:1) pediatric kidney transplant recipients to Plasma-Lyte-148 or standard of care perioperative intravenous fluids (predominantly 0.45% sodium chloride and 0.9% sodium chloride solutions). We then compared clinically significant electrolyte and acid-base abnormalities in the first 72 hours post-transplant. The primary outcome, acute hyponatremia, was experienced by 53% of 68 participants in the Plasma-Lyte-148 group and 58% of 69 participants in the standard fluids group (odds ratio 0·77 (0·34 - 1·75)). Five of 16 secondary outcomes differed with Plasma-Lyte-148: hypernatremia was significantly more frequent (odds ratio 3·5 (1·1 - 10·8)), significantly fewer changes to fluid prescriptions were made (rate ratio 0·52 (0·40-0·67)), and significantly fewer participants experienced hyperchloremia (odds ratio 0·17 (0·07 - 0·40)), acidosis (odds ratio 0·09 (0·04 - 0·22)) and hypomagnesemia (odds ratio 0·21 (0·08 - 0·50)). No other secondary outcomes differed between groups. Serious adverse events were reported in 9% of participants randomized to Plasma-Lyte-148 and 7% of participants randomized to standard fluids. Thus, perioperative Plasma-Lyte-148 did not change the proportion of children who experienced acute hyponatremia compared to standard fluids. However fewer fluid prescription changes were made with Plasma-Lyte-148, while hyperchloremia and acidosis were less common.

Anti-slit diaphragm antibodies on kidney biopsy identify pediatric patients with steroid-resistant nephrotic syndrome responsive to second-line immunosuppressants.

Podocytopathies represent a group of glomerular disorders associated with minimal changes (MC) or focal segmental glomerulosclerosis (FSGS) lesion patterns at biopsy and heterogeneous responses to steroids. Anti-nephrin antibodies were previously found in such patients, suggesting an autoimmune form of podocytopathy. High resolution confocal microscopy on kidney biopsies of a cohort of 128 pediatric patients revealed localization of IgG along the slit diaphragm in 30% of patients with MC and 25% of those with FSGS, but not in other lesion patterns. Anti-nephrin IgG ELISA assay in the serum and stimulated emission depletion microscopy of kidney biopsies showed IgG-nephrin co-localization only in 77.8% of cases. Similar observations were obtained in a cohort of 48 adult patients with MC or FSGS at kidney biopsy, where IgG-nephrin colocalization was only 44.4%, suggesting the existence of autoantibodies binding to other slit proteins. Patients with anti-slit antibodies showed nephrotic syndrome at onset in 94.4% of cases. Patients with primary steroid-resistance had anti-slit antibodies in 27%, while those with secondary steroid-resistance in 87.5% of cases, irrespective of the histopathological lesion pattern. Steroid-resistant patients with anti-slit antibodies responded to second-line immunosuppressants in 92.3% vs. only 20% of patients that were anti-slit negative. No patient with anti-slit antibodies developed kidney failure vs. 51.7% of those negative for antibodies (66.7% with a genetic cause and 41.2% with a non-genetic cause). Thus, the detection of anti-slit antibodies can identify patients with an autoimmune podocytopathy responsive to treatment with second-line immunosuppressants, irrespective of the histopathological lesion pattern at biopsy.

Providing environmentally sustainable nephrology care: focus in low- and middle-income countries.

Health care on a global scale significantly contributes to carbon emissions, with high-income countries being the primary culprits. Within health care, dialysis plays a significant role as a major source of emissions. Low- and middle-income countries have a high burden of kidney disease and are facing an increasing demand for dialysis. This reality presents multiple opportunities to plan for environmentally sustainable and quality kidney care. By placing a stronger emphasis on primary and secondary prevention of kidney disease and its progression, within the framework of universal health coverage, as well as empowering patients to enhance self-care, we can significantly reduce the need for costly and environmentally detrimental kidney replacement therapy. Mandating the adoption of lean and innovative low-carbon dialysis practices while also promoting the growth of kidney transplantation would enable low- and middle-income countries to take the lead in implementing environmentally friendly nephrology practices and reducing costs, thus optimizing sustainability and the well-being of individuals living with kidney disease.

The randomized controlled trial (NAVKIDS2) of a patient navigator program created for children with chronic kidney disease.

Patient navigators enable adult patients to circumnavigate complex health systems, improving access to health care and outcomes. Here, we aimed to evaluate the effects of a patient navigation program in children with chronic kidney disease (CKD). In this multi-center, randomized controlled trial, we randomly assigned children (aged 0-16 years) with CKD stages 1-5 (including children on dialysis or with kidney transplants), from low socioeconomic status backgrounds, and/or residing in remote areas, to receive patient navigation at randomization (immediate) or at six months (waitlist). The primary outcome was self-rated health (SRH) of participating children at six months, using intention to treat analysis. Secondary outcomes included caregivers' SRH and satisfaction with health care, children's quality of life, hospitalizations, and missed school days. Repeated measures of the primary outcome from baseline to six months were analyzed using cumulative logit mixed effects models. Semi-structured interviews were thematically evaluated. Of 398 screened children, 162 were randomized (80 immediate and 82 waitlist); mean age (standard deviation) of 8.8 (4.8) years with 64.8% male. SRH was not significantly different between the immediate and wait-listed groups at six months. There were also no differences across all secondary outcomes between the two groups. Caregivers' perspectives were reflected in seven themes: easing mental strain, facilitating care coordination, strengthening capacity to provide care, reinforcing care collaborations, alleviating family tensions, inability to build rapport and unnecessary support. Thus, in children with CKD, self-rated health may not improve in response to a navigator program, but caregivers gained skills related to providing and accessing care.

Continuous glucose monitoring for the prediction of posttransplant diabetes mellitus and impaired glucose tolerance on day 90 after kidney transplantation-A prospective proof-of-concept study.

Posttransplant diabetes mellitus (PTDM) and prediabetes represent serious complications after kidney transplantation and are associated with increased cardiovascular morbidity and mortality. We assessed the predictive performance of continuous glucose monitoring (CGM) compared with plasma glucose and hemoglobin A1c in 46 kidney transplant recipients (KTRs) without known preexisting diabetes mellitus. CGM (14-day recording duration) was performed on days 8, 30, 45, 60, 90, and 180 posttransplant. Eight patients (17%) developed PTDM and nine (20%) impaired glucose tolerance (IGT), as diagnosed by oral glucose tolerance test (oGTT)-derived 2-hour plasma glucose (2hPG) or glucose-lowering therapy on day 90. CGM-readouts percent of time >140 mg/dL (%TAR (140 mg/dL)) and percent of time >180 mg/dL (%TAR (180 mg/dL)) showed excellent in-sample test characteristics regarding PTDM from day 8 onward (days 8-90 receiver operating characteristic area under the curve: 0.88-0.99) and regarding PTDM/IGT with the commencement of maintenance immunosuppression from day 30 onward (days 30-90 receiver operating characteristic area under the curve: 0.88-0.91). Exploratory CGM-%TAR (140 mg/dL)-screening thresholds of 31.8% on day 8 and 13.2% on day 30 yielded sensitivities/specificities of 88%/83% for PTDM and 94%/78% for PTDM/IGT on day 90, respectively. Although our findings need to be replicated in studies with larger sample sizes, CGM bears promising potential to facilitate clinical practice and research regarding PTDM.

Probable antibody-mediated rejection in kidney transplantation is a rare and challenging phenotype to define: Findings from a single-center study.

The Banff 2022 consensus introduced probable antibody-mediated rejection (AMR), characterized by mild AMR histologic features and human leukocyte antigen (HLA) donor-specific antibody (DSA) positivity. In a single-center observational cohort study of 1891 kidney transplant recipients transplanted between 2004 and 2021, 566 kidney biopsies were performed in 178 individual HLA-DSA-positive transplants. Evaluated at time of the first HLA-DSA-positive biopsy of each transplant (N = 178), 84 of the 178 (47.2%) of first biopsies were scored as no AMR, 22 of the 178 (12.4%) as probable AMR, and 72 of the 178 (40.4%) as AMR. The majority (77.3%) of probable AMR cases were first diagnosed in indication biopsies. Probable AMR was associated with lower estimated glomerular filtration rate (mL/min/1.73m2) than no AMR (20.2 [8.3-32.3] vs 40.1 [25.4-53.3]; P = .001). The one-year risk of (repeat) AMR was similar for probable AMR and AMR (subdistribution hazard ratio (sHR), 0.99; 0.42-2.31; P = .97) and higher than after no AMR (sHR, 3.05; 1.07-8.73; P = .04). Probable AMR had a higher five-year risk of transplant glomerulopathy vs no AMR (sHR, 4.29; 0.92-19.98; P = 06), similar to AMR (sHR, 1.74; 0.43-7.04; P = .44). No significant differences in five-year risk of graft failure emerged between probable AMR and AMR (sHR, 1.14; 0.36-3.58; P = .82) or no AMR (sHR, 2.46; 0.78-7.74; P = .12). Probable AMR is a rare phenotype, however, sharing significant similarities with AMR in this single-center study. Future studies are needed to validate reproducible diagnostic criteria and associated clinical outcomes to allow for defining best management of this potentially relevant phenotype.

Red blood cells as oxygen carrier during normothermic machine perfusion of kidney grafts: Friend or foe?

Renal ex vivo normothermic machine perfusion (NMP) is under development as an assessment tool for high-risk kidney grafts and as a means of achieving more physiologically accurate organ preservation. On-going hemolysis has been reported during NMP, as this technique relies on red blood cells for oxygen delivery. In this study, we confirm the occurrence of progressive hemolysis during 6-hour kidney NMP. NMP-associated erythrostasis in the glomeruli and in peri-glomerular vascular networks points to an interaction between the red blood cells and the graft. Continuous hemolysis resulted in prooxidative changes in the perfusate, which could be quenched by addition of fresh frozen plasma. In a cell-based system, this hemolysis induced redox stress and exhibited toxic effects at high concentrations. These findings highlight the need for a more refined oxygen carrier in the context of renal NMP.

American Board of Internal Medicine Nephrology Procedure Requirements for Initial Certification: Time for a Change and Pursuing Consensus in the Nephrology Community.

In 1988, the American Board of Internal Medicine (ABIM) defined essential procedural skills in nephrology, and candidates for ABIM certification were required to present evidence of possessing the skills necessary for placement of temporary dialysis vascular access, hemodialysis, peritoneal dialysis, and percutaneous renal biopsy. In 1996, continuous renal replacement therapy was added to the list of nephrology requirements. These procedure requirements have not been modified since 1996 while the practice of nephrology has changed dramatically. In March 2021, the ABIM Nephrology Board embarked on a policy journey to revise the procedure requirements for nephrology certification. With the guidance of nephrology diplomates, training program directors, professional and patient organizations, and other stakeholders, the ABIM Nephrology Board revised the procedure requirements to reflect current practice and national priorities. The approved changes include the Opportunity to Train standard for placement of temporary dialysis catheters, percutaneous kidney biopsies, and home hemodialysis, which better reflects the current state of training in most training programs, and the new requirements for home dialysis therapies training will align with the national priority to address the underuse of home dialysis therapies. This perspective details the ABIM process for considering changes to the certification procedure requirements and how ABIM collaborated with the larger nephrology community in considering revisions and additions to these requirements.

Performance and Interpretation of Sonography in the Practice of Nephrology: Core Curriculum 2024.

Ultrasonography is increasingly being performed by clinicians at the point of care, and nephrologists are no exception. This Core Curriculum illustrates how ultrasonography can be incorporated into clinical decision making across the spectrum of kidney disease to optimize the care nephrologists provide to patients. Sonography is valuable in outpatient and inpatient settings for the diagnosis and management of acute and chronic kidney disease, evaluation of cystic disease, urinary obstruction, pain, hematuria, proteinuria, assessment of volume status, and in providing guidance for kidney biopsy. As kidney disease advances, ultrasound is useful in the placement and maintenance of temporary and permanent access for dialysis. After kidney transplantation, ultrasonography is critical for evaluation of allograft dysfunction and for biopsies. Sonography skills expedite patient care and enhance the practice of nephrology and are relatively easily acquired with training. It is our hope that this curriculum will encourage nephrologists to learn and apply this valuable skill.

KDOQI Commentary on the KDIGO 2022 Update to the Clinical Practice Guideline for Diabetes Management in CKD.

The Kidney Disease: Improving Global Outcomes (KDIGO) guideline for diabetes management in chronic kidney disease (CKD) was updated in 2022, just 2 years after the previous update. The need for this rapid update is reflective of the recent and unprecedented positive results of numerous clinical trials aimed at reducing kidney and cardiovascular morbidity and mortality in people with diabetes. The Kidney Disease Outcomes Quality Initiative (KDOQI) work group for diabetes in CKD, convened by the National Kidney Foundation, provides herein a commentary on these changes, particularly the implications for health care in the United States. Changes to the KDIGO guideline mirror the evolution of sodium/glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide 1 receptor agonists from purely antihyperglycemic agents to cardiorenal-metabolic therapeutics, and the lower estimated glomerular filtration rate of≥20mL/min/1.73m2 for SGLT2 inhibitor initiation. New data have also brought the addition of the first-in-class, Federal Drug Administration-approved nonsteroidal mineralocorticoid receptor antagonist finerenone as an agent to reduce cardiorenal end points. While there has been significant progress in innovation, there remain serious challenges to implementation, particularly in the United States where inequities in insurance coverage and high costs limit their use, particularly in vulnerable populations, ultimately widening health care disparities.

Dose-dependent association between estimated glomerular filtration rate and the subsequent risk of depression: An analysis of a nationwide epidemiological dataset.

BACKGROUND: Although the risk of depression is well-known in the patients with kidney dysfunction, especially at the late stages, little is known about the exact point at which the decline in estimated glomerular filtration rate (eGFR) begins to significantly increase the risk of depression. In the present study, we analysed a nationwide epidemiological dataset to investigate the dose-dependent association between baseline eGFR and a future risk of developing depression in a general population. METHODS: We retrospectively analysed 1,518,885 individuals (male: 46.3%) without a history of depression identified between April 2014 and November 2022 within a nationwide epidemiological database, provided by DeSC Healthcare (Tokyo, Japan). We investigated the association of eGFR with the incidence of depression using Cox regression analyses and also conducted cubic spline analysis to investigate the dose-dependent association between eGFR and depression. RESULTS: In the mean follow-up of 1218 ± 693 days, 45,878 cases (3.0% for total participants, 2.6% for men and 3.3% for women) of depression were recorded. The risk of depression increased with the eGFR decline as well as the presence of proteinuria. Multivariable Cox regression analysis showed the hazard ratio (95% CI) of depression in each kidney function category (eGFR ≥90, 60-89, 45-59, 30-44, 15-29, and < 15 mL/min/1.73 m2) was 1.14 (1.11-1.17), 1 (reference), 1.11 (1.08-1.14), 1.51 (1.43-1.59), 1.77 (1.57-1.99) and 1.77 (1.26-2.50), respectively. In the cubic spline analysis, the risk of depression continued to increase monotonically as the eGFR declined when the eGFR fell below approximately 65 mL/min/1.73 m2. CONCLUSIONS: Our analysis using a large-scale epidemiological dataset presented the dose-dependent association between eGFR decline and the risk of depression, which highlights the importance of incorporating mental health assessments into the routine care of patients with kidney dysfunction, regardless of the stage of their disease.

When impact trials are not feasible: alternatives to study the impact of prediction models on clinical practice.

Patients with kidney disease have an uncertain future with prognosis varying greatly per patient. To get a better idea of what the future holds and tailor interventions to the individual patient, prediction models can be of great value. Before a prediction model can be applied in practice, its performance should be measured in target populations of interest (i.e., external validation) and whether it helps improve clinical practice (i.e., whether it impacts clinical practice) should be determined. The impact would ideally be determined using an impact trial, but such a trial is often not feasible, and the impact of prediction models is therefore rarely assessed. As a result, prediction models that may not be so impactful may end up in clinical practice and impactful models may not be implemented due to a lack of impact studies. Ultimately, many prediction models end up never being implemented, resulting in much research waste. To allow researchers to get an indication of a prediction model's impact on clinical practice, alternative methods to assess a prediction model's impact are important. In this paper, we discuss several alternatives, including interviews, case-based surveys, decision comparisons, outcome modelling, before-after analyses, and decision curve analyses. We discuss the general idea behind these approaches, including what information can be gathered from such studies and important pitfalls. Lastly, we provide examples of the different alternatives.

Adult outcomes of childhood kidney replacement therapy in Europe from 2008 to 2019: an ERA Registry study.

BACKGROUND AND HYPOTHESIS: Young adults starting kidney replacement therapy (KRT) during childhood and reaching their 18th birthday (i.e. adult survivors of childhood KRT) form a challenging population of interest to nephrologists treating adults, as during this period there will be a transition to adult renal centres. Nonetheless, few studies have focused on the epidemiology of KRT in this group. We aimed to provide an update on these patients' characteristics, treatment history, graft and patient survival, to report their 5-year prognosis, and expected remaining lifetime. METHODS: Data on KRT patients reaching their 18th birthday in 2008-2019 were collected from 21 European countries/regions providing individual patient data to the European Renal Association (ERA) Registry. Patient characteristics and treatment trajectories were examined before and after turning 18 years. Kaplan-Meier and Cox proportional hazards regression were used for patient and graft survival analyses. RESULTS: In total, 2944 patients were included. The proportion of adult survivors initiating KRT at a very young age (0-4 years), and undergoing pre-emptive kidney transplantation increased. Unadjusted 5-year patient survival was 96.9% (95% CI: 96.2-97.5). Dialysis patients had a higher risk of death than kidney transplant recipients (adjusted hazard ratio 5.44 (95% CI: 3.34-8.86)). Between ages 18 and 23 years, about 21% of the adult survivors lost their kidney transplant and 34% of the dialysis patients continued this treatment. Compared with the general population, life expectancy for eighteen-year-old kidney transplant and dialysis patients was 17 and 40 years shorter, respectively. CONCLUSION: Life expectancy of 18-year-old kidney transplant recipients was lower compared with the general population. Yet, having a functioning kidney graft at age 18 years resulted in better outcomes than being on dialysis. Nevertheless, between ages 18 and 23 years, about one-fifth of the kidney grafts failed and one-third of the patients remained on dialysis.

Placement of tunneled hemodialysis catheters - interventional standard.

While the native arterio-venous fistula (AVF) remains the first choice in vascular access for most hemodialysis patients, tunneled hemodialysis catheters (tHDC) continue to be an option in selected patients. Since timely access to vascular surgery-due to delayed referral or resource limitations-is not always possible, nephrologists have to become more actively involved in planning, creation and monitoring of vascular access. Moreover, this approach could also strengthen patient-centered care in nephrology. This manuscript reviews the current standard in tHDC creation, patient selection and strategies to mitigate the risk of infectious complications and catheter thrombosis. Presentation of novel developments in catheter placement with ultrasound-guided or ECG-guided positioning, their benefits and possible disadvantages emphasizes the complexity of vascular access planning. We offer an approach for choice of insertion method, depending on selected side and existing resources and set focus on the necessity and required resources of 'interventional nephrology' training programs.

Immune checkpoint inhibitor-associated nephritis - treatment standard.

Over the last 13 years, the use of immune checkpoint inhibitor (ICI) therapy has grown remarkably, owing to their unprecedented anti-tumor efficacy in certain tumor groups. With increased use of ICIs, we are seeing immune-related adverse events (irAE's) more frequently. Renal irAE's, such as ICI-associated acute kidney injury (ICI-AKI), are reported in 2-5% of patients treated with ICIs, with acute tubulointerstitial nephritis (ATIN) as the most common histopathologic lesion, though various forms of glomerulonephritis have also been reported. Modifiable risk factors for ICI-AKI include concurrent use of ATIN-associated drugs, like proton pump inhibitors, non-steroidal anti-inflammatory drugs and antibiotics, and dual ICI therapy with both CTLA-4 and PD1/PDL-1 blockade. Kidney biopsies remain the diagnostic modality of choice, though several promising non-invasive biomarkers, which have not yet been broadly clinically validated have emerged. The treatment of ICI-AKI involves holding ICIs, discontinuation of ATIN-associated drugs, and initiation of immunosuppression with corticosteroids as first-line therapy. With prompt treatment initiation, most patients achieve full or partial renal recovery, allowing for re-challenge with ICI. However, a subset of patients will require additional steroid-sparing therapies for corticosteroid-dependent or refractory ICI-AKI. Here we review developments in our understanding of the pathophysiology of ICI-AKI, the approach to diagnosis (with a focus on the emergence of novel diagnostic tools), prognostic factors and the current evidence for establishing treatment standards for ICI-AKI. As the evidence base remains largely retrospective, we identify questions that would benefit from future prospective studies in the diagnosis, management, and prognostication of ICI-AKI.