Challenges in conducting clinical trials in nephrology: conclusions from a Kidney Disease-Improving Global Outcomes (KDIGO) Controversies Conference

Clinical Impacts of Urinary Neutrophil Gelatinase-Associated Lipocalin in Patients With Chronic Kidney Disease Undergoing Percutaneous Coronary Intervention

BACKGROUND

Chronic kidney disease (CKD) is associated with poor prognosis in patients undergoing percutaneous coronary intervention (PCI). Urinary neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker for renal injury. However, the association between urinary NGAL concentrations and renal and cardiovascular events in patients with CKD undergoing PCI has not been elucidated. This study investigated the clinical impact of urinary NGAL concentrations on renal and cardiovascular outcomes in patients with non-dialysis CKD undergoing PCI.Methods and Results: We enrolled 124 patients with non-dialysis CKD (estimated glomerular filtration rate <60 mL/min/1.73 m2) undergoing elective PCI. Patients were divided into low and high NGAL groups based on the median urinary NGAL concentration measured the day before PCI. Patients were monitored for renal and cardiovascular events during the 2-year follow-up period. Kaplan-Meier analyses showed that the incidence of renal and cardiovascular events was higher in the high than low NGAL group (log-rank P<0.001 and P=0.032, respectively). Multivariate Cox proportional hazards analyses revealed that urinary NGAL was an independent risk factor for renal (hazard ratio [HR] 4.790; 95% confidence interval [CI] 1.537-14.924; P=0.007) and cardiovascular (HR 2.938; 95% CI 1.034-8.347; P=0.043) events.

CONCLUSIONS

Urinary NGAL could be a novel and informative biomarker for predicting subsequent renal and cardiovascular events in patients with CKD undergoing elective PCI.

Effect of multidisciplinary care on diabetic kidney disease: a retrospective cohort study

BACKGROUND

Diabetic kidney disease (DKD) is the most common disease among patients requiring dialysis for the first time in Japan. Multidisciplinary care (MDC) may prevent the progression of kidney failure. However, the effectiveness and timing of MDC to preserve kidney function in patients with DKD is unclear. Therefore, the aim of this study was to investigate whether MDC for patients with DKD affects the preservation of kidney function as well as the timing of MDC in clinical practice.

METHODS

In this retrospective cohort study, we identified patients with type 2 diabetes mellitus and DKD from April 2012 to January 2020 using a nationwide Japanese healthcare record database. The fee code for medical guidance to prevent dialysis in patients with diabetes was used to distinguish between the MDC and non-MDC groups. The primary outcome was a 40% decline in the estimated glomerular filtration rate, and secondary outcomes were death, hospitalization, permanent dialysis, kidney failure with replacement therapy, and emergency temporary catheterization. Propensity score matching was performed, and Kaplan-Meier and multivariable Cox regression analyses were performed.

RESULTS

Overall, 9,804 eligible patients met the inclusion criteria, of whom 5,614 were matched for the main analysis: 1,039 in the MDC group, and 4,575 in the non-MDC group. The primary outcome did not differ between the groups (hazard ratio: 1.18, [95% confidence interval: 0.99-1.41], P = 0.07). The groups also did not differ in terms of the secondary outcomes. Most patients with DKD received their first MDC guidance within 1 month of diagnosis, but most received guidance only once per year.

CONCLUSIONS

Although we could not demonstrate the effectiveness of MDC on kidney function in patients with DKD, we clarified the characteristics of such patients assigned the fee code for medical guidance to prevent dialysis related to diabetes.

Current updates on metabolites and its interlinked pathways as biomarkers for diabetic kidney disease: A systematic review

Diabetic kidney disease (DKD) is a major microvascular complication of diabetes mellitus (DM) that poses a serious risk as it can lead to end-stage renal disease (ESRD). DKD is linked to changes in the diversity, composition, and functionality of the microbiota present in the gastrointestinal tract. The interplay between the gut microbiota and the host organism is primarily facilitated by metabolites generated by microbial metabolic processes from both dietary substrates and endogenous host compounds. The production of numerous metabolites by the gut microbiota is a crucial factor in the pathogenesis of DKD. However, a comprehensive understanding of the precise mechanisms by which gut microbiota and its metabolites contribute to the onset and progression of DKD remains incomplete. This review will provide a summary of the current scenario of metabolites in DKD and the impact of these metabolites on DKD progression. We will discuss in detail the primary and gut-derived metabolites in DKD, and the mechanisms of the metabolites involved in DKD progression. Further, we will address the importance of metabolomics in helping identify potential DKD markers. Furthermore, the possible therapeutic interventions and research gaps will be highlighted.

Left atrial appendage occlusion in patients suffering from advanced chronic kidney disease (stage 4 and 5). Long-term follow-up

INTRODUCTION AND OBJECTIVES

Advanced chronic kidney disease (A-CKD) combined with atrial fibrillation increases the risk of both thrombogenic and bleeding events. Left atrial appendage occlusion (LAAO) may be an alternative to oral anticoagulation to prevent thromboembolic events. We aimed to evaluate the outcomes of LAAO in patients with A-CKD.

METHODS

Comparison at long-term follow-up of patients diagnosed with and without A-CKD (eGFR<30 mL/min/1.73 m2 ) who underwent LAAO between 2009 and May 2022.

RESULTS

Five hundred seventy-three patients were included. Eighty-one (14%) were diagnosed with A-CKD. There were no differences in sex, age, and cardiovascular risk factors, except for diabetes which was more frequent in patients with A-CKD. The control group had higher rates of stroke, both ischemic and hemorrhagic. There were no differences in the CHA2 DS2 -VASc score, although A-CKD patients had a higher bleeding risk according to the HASBLED scale. Global procedural success was 99.1%. At follow-up, there were no differences in stroke rate: at 1-year (HR: 1.22, IC-95%: 0.14-10.42, p = 0.861); at 5-years (HR: 0.60, IC-95%: 0.08-4.58, p = 0.594). Although bleeding events were higher in the A-CKD group, no differences were found in major bleeding (defined BARC ≥ 3) at 1-year (HR: 1.34, IC-95%: 0.63-2.88, p = 0.464) or at 5-years follow-up (HR: 1.30, IC-95%: 0.69-2.48, p = 0.434). Mortality rate at 5 years was higher in the A-CKD patients (HR: 1.84, IC-95%: 1.18-2.87, p = 0.012).

CONCLUSIONS

LAAO is an effective and safe treatment in A-CKD patients to prevent ischemic events and bleeding. This strategy could be an alternative to oral anticoagulation in this high-risk group of patients.

A comprehensive review on 3D tissue models: Biofabrication technologies and preclinical applications

The limitations of traditional two-dimensional (2D) cultures and animal testing, when it comes to precisely foreseeing the toxicity and clinical effectiveness of potential drug candidates, have resulted in a notable increase in the rate of failure during the process of drug discovery and development. Three-dimensional (3D) in-vitro models have arisen as substitute platforms with the capacity to accurately depict in-vivo conditions and increasing the predictivity of clinical effects and toxicity of drug candidates. It has been found that 3D models can accurately represent complex tissue structure of human body and can be used for a wide range of disease modeling purposes. Recently, substantial progress in biomedicine, materials and engineering have been made to fabricate various 3D in-vitro models, which have been exhibited better disease progression predictivity and drug effects than convention models, suggesting a promising direction in pharmaceutics. This comprehensive review highlights the recent developments in 3D in-vitro tissue models for preclinical applications including drug screening and disease modeling targeting multiple organs and tissues, like liver, bone, gastrointestinal tract, kidney, heart, brain, and cartilage. We discuss current strategies for fabricating 3D models for specific organs with their strengths and pitfalls. We expand future considerations for establishing a physiologically-relevant microenvironment for growing 3D models and also provide readers with a perspective on intellectual property, industry, and regulatory landscape.

D-Serine as a sensor and effector of the kidney

D-Serine, a rare enantiomer of serine, is a biomarker of kidney disease and function. The level of D-serine in the human body is precisely regulated through the urinary clearance of the kidney, and its clearance serves as a new measure of glomerular filtration rate with a lower bias than creatinine clearance. D-Serine also has a direct effect on the kidneys and mediates the cellular proliferation of tubular cells via mTOR signaling and induces kidney remodeling as a compensatory reaction to the loss of kidney mass. In living kidney donors, the removal of the kidney results in an increase in blood D-serine level, which in turn accelerates kidney remodeling and augments kidney clearance, thus reducing blood levels of D-serine. This feedback system strictly controls D-serine levels in the body. The function of D-serine as a biomarker and modulator of kidney function will be the basis of precision medicine for kidney diseases.

eGFR slope as a surrogate endpoint for clinical study in early stage of chronic kidney disease: from The Japan Chronic Kidney Disease Database

BACKGROUND

In clinical trials targeting early chronic kidney disease (CKD), eGFR slope has been proposed as a surrogate endpoint for predicting end-stage kidney disease (ESKD). However, it is unclear whether the eGFR slope serves as a surrogate endpoint for predicting long-term prognosis in Japanese early CKD populations.

METHODS

The data source was the J-CKD-Database, which contains real-world data on patients with CKD in Japan. eGFR slope was calculated from the eGFR of each period, 1-year (1-year slope), 2-year (2-year slope), and 3-year (3-year slope), for participants with a baseline eGFR ≥ 30 ml/min/1.73 m2. The outcome was ESKD (defined as dialysis initiation or incidence of CKD stage G5). The relationship between eGFR slope and the sub-distribution hazard ratio (SHR) of ESKD with death as a competing event was investigated using a Fine-Gray proportional hazard regression model.

RESULTS

The number of participants and mean observation periods were 7768/877 ± 491 days for 1-year slope, 6778/706 ± 346 days for 2-year slope, and 5219/495 ± 215 days for 3-year slope. As the eGFR slope decreased, a tendency toward a lower risk of ESKD was observed. Compared with the 1-year slope, there was a smaller variation in the slope values for the 2-year or 3-year slope and a greater decrease in the SHR; therefore, a calculation period of 2 or 3 years for the eGFR slope was considered appropriate.

CONCLUSION

Even in Japanese patients with early stage CKD, a slower eGFR slope calculated from eGFR values over 2-3 years was associated with a decreased risk of ESKD.

Impact of outcome adjudication in kidney disease trials: observations from the Study of Heart and Renal Protection (SHARP)

Introduction

We aimed to assess opportunities for trial streamlining and the scientific impact of adjudication on kidney and cardiovascular outcomes in CKD.

Methods

We analysed the effects of adjudication of ~2100 maintenance kidney replacement therapy (KRT) and ~1300 major atherosclerotic events (MAEs) recorded in SHARP. We first compared outcome classification before versus after adjudication, and then re-ran randomised comparisons using pre-adjudicated follow-up data.

Results

For maintenance KRT, adjudication had little impact with only 1% of events being refuted (28/2115). Consequently, randomised comparisons using pre-adjudication reports found almost identical results (pre-adjudication: simvastatin/ezetimibe 1038 vs placebo 1077; risk ratio [RR] 0.95, 95%CI 0.88-1.04; post-adjudicated: 1057 vs 1084; RR=0.97, 95%CI 0.89-1.05). For MAEs, about one-quarter of patient reports were refuted (324/1275 [25%]), and reviewing 3538 other potential vascular events and death reports identified only 194 additional MAEs. Nevertheless, randomised analyses using SHARP's pre-adjudicated data alone found similar results to analyses based on adjudicated outcomes (pre-adjudication: 573 vs 702; RR=0.80, 95%CI 0.72-0.89; adjudicated: 526 vs 619; RR=0.83, 95%CI 0.74- 0.94), and also suggested refuted MAEs were likely to represent atherosclerotic disease (RR for refuted MAEs=0.80, 95%CI 0.65-1.00).

Conclusions

These analyses provide three key insights. First, they provide a rationale for nephrology trials not to adjudicate maintenance KRT. Secondly, when an event that mimics an atherosclerotic outcome is not expected to be influenced by the treatment under study (e.g. heart failure), the aim of adjudicating atherosclerotic outcomes should be to remove such events. Lastly, restrictive definitions for the remaining suspected atherosclerotic outcomes may reduce statistical power.

Associations of health literacy with self-management behaviours and health outcomes in chronic kidney disease: a systematic review

INTRODUCTION

Low health literacy is widely reported in people with chronic kidney disease (CKD) and has been associated with reduced disease self-management, poor health outcomes, increased mortality and poorer quality of life. However, these associations are still not well understood.

METHODS

Electronic-based systematic searches were performed to identify studies examining associations between health literacy and self-management behaviours and/or health outcomes in patients with CKD. A tabular and narrative synthesis of the data was performed. Meta-analysis was not appropriate due to the heterogeneity of study designs and methods.

RESULTS

Searches identified 48 studies that met the inclusion criteria. A total of 41 published articles, six conference abstracts, and one thesis were included. Of the 48 studies, 11 were cohort and 37 were cross-sectional. In total there were 25,671 patients; 16,952 from cohort studies. Median study sample size was 159 (IQR 92-275). Study quality was high (5), moderate (24) and poor (19). Thirteen measures of health literacy were used. Despite the limitations of the available evidence, there appear to be consistent relationships between higher health literacy and favourable self-management behaviours for patients with CKD. Definitive relationships between health literacy and patient outcomes are far less clear and remain incompletely understood.

DISCUSSION

Conclusive evidence describing a causal link between health literacy and patient outcomes remains limited, but for many outcomes, a consistent association is described. In addition to associations with mortality, hospitalisation and clinical events, there were consistent associations between health literacy and favourable self-management behaviours which could support the development of patient education aimed at improving health literacy.

Targeting the Alternative Complement Pathway With Iptacopan to Treat IgA Nephropathy: Design and Rationale of the APPLAUSE-IgAN Study

Introduction

Targeting the alternative complement pathway (AP) is an attractive therapeutic strategy because of its role in immunoglobulin A nephropathy (IgAN) pathophysiology. Iptacopan (LNP023), a proximal complement inhibitor that specifically binds to factor B and inhibits the AP, reduced proteinuria and attenuated AP activation in a Phase 2 study of patients with IgAN, thereby supporting the rationale for its evaluation in a Phase 3 study.

Methods

APPLAUSE-IgAN (NCT04578834) is a multicenter, randomized, double-blind, placebo-controlled, parallel-group, Phase 3 study enrolling approximately 450 adult patients (aged ≥18 years) with biopsy-confirmed primary IgAN at high risk of progression to kidney failure despite optimal supportive treatment. Eligible patients receiving stable and maximally tolerated doses of angiotensin-converting enzyme inhibitors (ACEis) or angiotensin receptor blockers (ARBs) will be randomized 1:1 to either iptacopan 200 mg or placebo twice daily for a 24-month treatment period. A prespecified interim analysis (IA) will be performed when approximately 250 patients from the main study population complete the 9-month visit. The primary objective is to demonstrate superiority of iptacopan over placebo in reducing 24-hour urine protein-to-creatinine ratio (UPCR) at the IA and demonstrate the superiority of iptacopan over placebo in slowing the rate of estimated glomerular filtration rate (eGFR) decline (total eGFR slope) estimated over 24 months at study completion. The effect of iptacopan on patient-reported outcomes, safety, and tolerability will be evaluated as secondary outcomes.

Conclusions

APPLAUSE-IgAN will evaluate the benefits and safety of iptacopan, a novel targeted therapy for IgAN, in reducing complement-mediated kidney damage and thus slowing or preventing disease progression.

The dynamic nature of patient engagement within a Canadian patient-oriented kidney health research network: Perspectives of researchers and patient partners

INTRODUCTION

Canadians Seeking Solutions and Innovations to Overcome Chronic Kidney Disease (Can-SOLVE CKD) is a pan-Canadian health research network that engages patients as partners across 18 unique projects and core infrastructure. In this qualitative study, we explored how research teams integrated patient partners into network research activities to inform our patient engagement approach.

METHODS

To capture a breadth of perspectives, this qualitative descriptive study purposively sampled researchers and patient partners across 18 network research teams. We conducted 4 focus groups (2 patients and 2 researchers; n = 26) and 28 individual telephone interviews (n = 12 patient partners; n = 16 researchers). Transcripts were coded in duplicate, and themes were developed through an inductive, thematic analysis approach.

RESULTS

We included 24 patient partners and 24 researchers from 17 of the 18 projects and all core committees within the network. Overarching concepts relate participants' initial impressions and uncertainty about patient engagement to an evolving appreciation of its value, impact and sustainability. We identified four themes with subthemes that characterized the dynamic nature of patient engagement and how participants integrated patients across network initiatives: (1) Reinforcing a shared purpose (learning together, collective commitment, evolving attitudes); (2) Fostering a culture of responsive and innovative research (accessible supports, strengthened process and product); (3) Aligning priorities, goals and needs (amenability to patient involvement, mutually productive relationships, harmonizing expectations); (4) Building a path to sustainability (value creation, capacity building, sustaining knowledge use).

CONCLUSIONS

Our findings demonstrate the dynamic and adaptive processes related to patient engagement within a national, patient-oriented kidney health research network. Optimization of support structures and capacity are key factors to promote sustainability of engagement processes within and beyond the network.

PATIENT OR PUBLIC CONTRIBUTION

This project was conceived in collaboration with a Can-SOLVE CKD patient partner (N. F.), with lived experience of kidney failure. He also co-designed the study's protocol, led focus groups and researcher interviews, and contributed to data analysis. L. G. has lived experience as a caregiver for a person with CKD and facilitated patient partner focus groups. The patient partners, both of whom are listed authors, provided important insights that shaped our interpretation and presentation of study findings.

Measuring quality of life in trials including patients on haemodialysis: methodological issues surrounding the use of the Kidney Disease Quality of Life Questionnaire

BACKGROUND

Haemodialysis (HD) treatment causes a significant decrease in quality of life (QoL). When enrolled in a clinical trial, some patients are lost prior to follow-up because they die or they receive a kidney transplant. It is unclear how these patients are dealt with in the analysis of QoL data. There are questions surrounding the consistency of how QoL measures are used, reported and analysed.

METHODS

A systematic search of electronic databases for trials measuring QoL in HD patients using any variation of the Kidney Disease Quality of Life (KDQoL) Questionnaire was conducted. The review was conducted in Covidence version 2. Quantitative analysis was conducted in Stata version 16.

RESULTS

We included 61 trials in the review, of which 82% reported dropouts. The methods to account for missing data due to dropouts include imputation (7%) and complete case analysis (72%). Few trials (7%) conducted a sensitivity analysis to assess the impact of missing data on the study results. Single imputation techniques were used, but are only valid under strong assumptions regarding the type and pattern of missingness. There was inconsistency in the reporting of the KDQoL, with many articles (70%) amending the validated questionnaires or reporting only statistically significant results.

CONCLUSIONS

Missing data are not dealt with according to the missing data mechanism, which may lead to biased results. Inconsistency in the use of patient-reported outcome measures raises questions about the validity of these trials. Methodological issues in nephrology trials could be a contributing factor to why there are limited effective interventions to improve QoL in this patient group.

PROSPERO REGISTRATION

CRD42020223869.

Randomized, double-blind, placebo-controlled phase 3 study of bardoxolone methyl in patients with diabetic kidney disease: Design and baseline characteristics of AYAME study

BACKGROUND

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease (ESKD), but currently available treatments do not improve kidney function or prevent the initiation of dialysis/kidney replacement therapy. A previous study demonstrated that bardoxolone methyl improves the estimated glomerular filtration rate (eGFR), but the study was prematurely terminated because of an imbalance in heart failure between treatment groups. The subsequent phase 2 TSUBAKI study demonstrated no incidence of heart failure and an improved eGFR and GFR as determined by inulin clearance in DKD patients.

METHODS

This randomized, double-blind, placebo-controlled multicenter phase 3 study was designed to assess the efficacy and safety of bardoxolone methyl in DKD patients with an eGFR of ≥ 15.0 to < 60.0 mL/min/1.73 m2 and urinary albumin/creatinine ratio of ≤3500 mg/g but without risk factors for heart failure. The primary endpoint is the time to onset of a ≥ 30% decrease in the eGFR or ESKD. Randomized patients (1:1) have been under treatment with once-daily oral bardoxolone methyl (5, 10, or 15 mg by intra-patient dose adjustment) or placebo for at least 3 years. Results The 1013 patients' mean age is 65.9 years, 21.5% are female, the mean eGFR is 37.84 mL/min/1.73 m2, and the median urinary albumin/creatinine ratio is 351.80 mg/g.

CONCLUSIONS

Appropriate patients are enrolled in this study. This study will investigate the long-term efficacy and safety of bardoxolone methyl in DKD patients covering a wider range of the eGFR (≥15.0 to < 60.0 mL/min/1.73 m2) and albuminuria (≤3500 mg/g) compared with previous studies.

Comparing Kidney Health Outcomes in Children, Adolescents, and Adults With Focal Segmental Glomerulosclerosis

IMPORTANCE

Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage kidney disease (ESKD) across the lifespan. While 10% to 15% of children and 3% of adults who develop ESKD have FSGS, it remains uncertain whether the natural history differs in pediatric vs adult patients, and this uncertainty contributes to the exclusion of children and adolescents in clinical trials.

OBJECTIVE

To examine whether there are differences in the kidney health outcomes among children, adolescents, and adults with FSGS.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used pooled and parallel analyses, completed July 5, 2022, from 3 complimentary data sources: (1) Nephrotic Syndrome Rare Disease Clinical Research Network (NEPTUNE); (2) FSGS clinical trial (FSGS-CT); and (3) Kidney Research Network (KRN). NEPTUNE is a multicenter US/Canada cohort study; FSGS-CT is a multicenter US/Canada clinical trial; and KRN is a multicenter US electronic health record-based registry from academic and community nephrology practices. NEPTUNE included 166 patients with incident FSGS enrolled at first kidney biopsy; FSGS-CT included 132 patients with steroid-resistant FSGS randomized to cyclosporine vs dexamethasone with mycophenolate; and KRN included 184 patients with prevalent FSGS. Data were collected from November 2004 to October 2019 and analyzed from October 2020 to July 2022.

EXPOSURES

Age: children (age <13 years) vs adolescents (13-17 years) vs adults (≥18 years). Covariates of interest included sex, disease duration, APOL1 genotype, urine protein-to-creatinine ratio, estimated glomerular filtration rate (eGFR), edema, serum albumin, and immunosuppressive therapy.

MAIN OUTCOMES AND MEASURES

ESKD, composite outcome of ESKD or 40% decline in eGFR, and complete and/or partial remission of proteinuria.

RESULTS

The study included 127 (26%) children, 102 (21%) adolescents, and 253 (52%) adults, including 215 (45%) female participants and 138 (29%) who identified as Black, 98 (20%) who identified as Hispanic, and 275 (57%) who identified as White. Overall, the median time to ESKD was 11.9 years (IQR, 5.2-19.1 years). There was no difference in ESKD risk among children vs adults (hazard ratio [HR], 0.67; 95% CI, 0.43-1.03) or adolescents vs adults (HR, 0.85; 95% CI, 0.52-1.36). The median time to the composite end point was 5.7 years (IQR 1.6-15.2 years), with hazard ratio estimates for children vs adults of 1.12 (95% CI, 0.83-1.52) and adolescents vs adults of 1.06 (95% CI, 0.75-1.50).

CONCLUSIONS AND RELEVANCE

In this study, the association of FSGS with kidney survival and functional outcomes was comparable at all ages.

Twice-Weekly Hemodialysis With Adjuvant Pharmacotherapy and Transition to Thrice-Weekly Hemodialysis: A Pilot Study

RATIONALE & OBJECTIVE

Thrice-weekly hemodialysis (HD) is the most common treatment modality for kidney failure in the United States. We conducted a pilot study to assess the feasibility and safety of incremental-start HD in patients beginning maintenance HD.

STUDY DESIGN

Pilot study.

SETTING & PARTICIPANTS

Adults with estimated glomerular filtration rate (eGFR) ≥5 mL/min/1.73 m² and urine volume ≥500 mL/d beginning maintenance HD at 14 outpatient dialysis units.

EXPOSURE

Randomized allocation (1:1 ratio) to twice-weekly HD and adjuvant pharmacologic therapy for 6 weeks followed by thrice-weekly HD (incremental HD group) or thrice-weekly HD (conventional HD group).

OUTCOME

The primary outcome was feasibility. Secondary outcomes included changes in urine volume and solute clearance.

RESULTS

Of 77 patients invited to participate, 51 consented to do so, representing 66% of eligible patients. We randomized 23 patients to the incremental HD group and 25 patients to the conventional HD group. Protocol-based loop diuretics, sodium bicarbonate, and patiromer were prescribed to 100%, 39%, and 17% of patients on twice-weekly HD, respectively. At a mean follow-up of 281.9 days, participant adherence was 96% to the HD schedule (22 of 23 and 24 of 25 in the incremental and conventional groups, respectively) and 100% in both groups to serial timed urine collection. The incidence rate ratio for all-cause hospitalization was 0.31 (95% CI, 0.08-1.17); and 7 deaths were recorded (1 in the incremental and 6 in the conventional group). At week 24, the incremental HD group had lower declines in urine volume (a difference of 51.0 [95% CI, -0.7 to 102.8] percentage points) and in the averaged urea and creatinine clearances (a difference of 57.9 [95% CI, -22.6 to 138.4] percentage points).

LIMITATIONS

Small sample size, time-limited twice-weekly HD.

CONCLUSIONS

It is feasible to enroll patients beginning maintenance HD into a randomized study of incremental-start HD with adjuvant pharmacotherapy who adhere to the study protocol during follow-up. Larger multicenter clinical trials are indicated to determine the efficacy and safety of incremental HD with longer twice-weekly HD periods.

FUNDING

Funding was provided by Vifor Inc.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov, identifier NCT03740048.

Machine Learning for Renal Pathologies: An Updated Survey

Within the literature concerning modern machine learning techniques applied to the medical field, there is a growing interest in the application of these technologies to the nephrological area, especially regarding the study of renal pathologies, because they are very common and widespread in our society, afflicting a high percentage of the population and leading to various complications, up to death in some cases. For these reasons, the authors have considered it appropriate to collect, using one of the major bibliographic databases available, and analyze the studies carried out until February 2022 on the use of machine learning techniques in the nephrological field, grouping them according to the addressed pathologies: renal masses, acute kidney injury, chronic kidney disease, kidney stone, glomerular disease, kidney transplant, and others less widespread. Of a total of 224 studies, 59 were analyzed according to inclusion and exclusion criteria in this review, considering the method used and the type of data available. Based on the study conducted, it is possible to see a growing trend and interest in the use of machine learning applications in nephrology, becoming an additional tool for physicians, which can enable them to make more accurate and faster diagnoses, although there remains a major limitation given the difficulty in creating public databases that can be used by the scientific community to corroborate and eventually make a positive contribution in this area.

Design, recruitment, and baseline characteristics of the EMPA-KIDNEY trial

BACKGROUND

The effects of the sodium-glucose co-transporter 2 inhibitor empagliflozin on renal and cardiovascular disease have not been tested in a dedicated population of people with chronic kidney disease (CKD).

METHODS

The EMPA-KIDNEY trial is an international randomized, double-blind, placebo-controlled trial assessing whether empagliflozin 10 mg daily decreases the risk of kidney disease progression or cardiovascular death in people with CKD. People with or without diabetes mellitus (DM) were eligible provided they had an estimated glomerular filtration rate (eGFR) ≥20 but <45 mL/min/1.73 m2 or an eGFR ≥45 but <90 mL/min/1.73 m2 with a urinary albumin:creatinine ratio (uACR) ≥200 mg/g. The trial design is streamlined, as extra work for collaborating sites is kept to a minimum and only essential information is collected.

RESULTS

Between 15 May 2019 and 16 April 2021, 6609 people from eight countries in Europe, North America and East Asia were randomized. The mean age at randomization was 63.8 years [standard deviation (SD) 13.9)], 2192 (33%) were female and 3570 (54%) had no prior history of DM. The mean eGFR was 37.5 mL/min/1.73 m2 (SD 14.8), including 5185 (78%) with an eGFR <45 mL/min/1.73 m2. The median uACR was 412 mg/g) (quartile 1-quartile 3 94-1190), with a uACR <300 mg/g in 3194 (48%). The causes of kidney disease included diabetic kidney disease [n = 2057 (31%)], glomerular disease [n = 1669 (25%)], hypertensive/renovascular disease [n = 1445 (22%)], other [n = 808 (12%)] and unknown causes [n = 630 (10%)].

CONCLUSIONS

EMPA-KIDNEY will evaluate the efficacy and safety of empagliflozin in a widely generalizable population of people with CKD at risk of kidney disease progression. Results are anticipated in 2022.

Patient-centred clinical trial design

Patient involvement in clinical trial design can facilitate the recruitment and retention of participants as well as potentially increase the uptake of the tested intervention and the impact of the findings on patient outcomes. Despite these benefits, patients still have very limited involvement in designing and conducting trials in nephrology. Many trials do not address research questions and outcomes that are important to patients, including patient-reported outcomes that reflect how patients feel and function. This limitation can undermine the relevance, reliability and value of trial-based evidence for decision-making in clinical practice and health policy. However, efforts to involve patients with kidney disease are increasing across all stages of the trial process from priority setting, to study design (including selection of outcomes and approaches to improve participant recruitment and retention) and dissemination and implementation of the findings. Harnessing the patient voice in designing trials can ensure that efforts and resources are directed towards patient-centred trials that address the needs, concerns and priorities of patients living with kidney disease with the aim of achieving transformative improvements in care and outcomes.

Improving Cancer Care for Patients With CKD: The Need for Changes in Clinical Trials

Chemotherapeutic agents used to treat cancer generally have narrow therapeutic indices along with potentially serious adverse toxicities. Many cancer drugs are at least partially excreted through the kidney and, thus, the availability of accurate data on safe and effective dosing of these drugs in patients with chronic kidney disease (CKD) is essential to guide treatment decisions. Typically, during drug development, initial clinical studies only include patients with normal or only mildly impaired kidney function. In subsequent preregistration studies, a limited number of patients with more severe kidney dysfunction are included. Data obtained from patients with either severe kidney dysfunction (here defined as an estimated glomerular filtration rate [eGFR] < 30 ml/min or stage 4G CKD) or end-stage kidney disease (ESKD) requiring kidney replacement treatment are particularly limited before drug registration and only a minority of new drug applications to the US Food and Drug Administration (FDA) include data from this population. Unfortunately, limited data and/or other safety concerns may result in a manufacturer statement that the drug is contraindicated in patients with advanced kidney disease, which hinders access to potentially beneficial drugs for these patients. This systemic exclusion of patients with CKD from cancer drug trials remains an unsolved problem, which prevents provision of optimal clinical care for these patients, raises questions of inclusion, diversity, and equity. In addition, with the aging of the population, there are increasing numbers of patients with CKD and cancer who face these issues. In this review, we evaluate the scientific basis to exclude patients with CKD from cancer trials and propose a comprehensive strategy to address this problem.

Allograft Function as Endpoint for Clinical Trials in Kidney Transplantation

Clinical study endpoints that assess the efficacy of interventions in patients with chronic renal insufficiency can be adopted for use in kidney transplantation trials, given the pathophysiological similarities between both conditions. Kidney dysfunction is reflected in the glomerular filtration rate (GFR), and although a predefined (e.g., 50%) reduction in GFR was recommended as an endpoint by the European Medicines Agency (EMA) in 2016, many other endpoints are also included in clinical trials. End-stage renal disease is strongly associated with a change in estimated (e)GFR, and eGFR trajectories or slopes are increasingly used as endpoints in clinical intervention trials in chronic kidney disease (CKD). Similar approaches could be considered for clinical trials in kidney transplantation, although several factors should be taken into account. The present Consensus Report was developed from documentation produced by the European Society for Organ Transplantation (ESOT) as part of a Broad Scientific Advice request that ESOT submitted to the EMA in 2020. This paper provides a contemporary discussion of primary endpoints used in clinical trials involving CKD, including proteinuria and albuminuria, and evaluates the validity of these concepts as endpoints for clinical trials in kidney transplantation.

Evaluation of the design, conduct and reporting of randomised controlled trials in the haemodialysis population: a scoping review and interview study

BACKGROUND

Fewer trials are conducted in nephrology than any other specialty, often failing to recruit to target, resulting in unclear evidence affecting translation to clinical practice. This mixed-methods study aims to provide guidance for designing and reporting future randomised controlled trials (RCTs) in the haemodialysis population.

METHOD

A scoping review was conducted. Five databases (MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Embase, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov) were searched for RCTs published between 2013 and 2019 involving prevalent adult haemodialysis patients. Reporting of sample size, recruitment, retention and statistical significance of primary outcome were assessed. Face-to-face semistructured interviews were conducted with individuals from a single centre during dialysis sessions. Interviews were analysed thematically.

RESULTS

Of 786 RCTs identified, 636 (80.9%) were parallel-group, 139 (17.7%) were crossover and 11 (1.4%) were cluster (including one stepped-wedge) design. Sample size justification was reported in 73.1%, 53.8% and 45.5% of parallel-group, crossover and cluster trials, respectively.Target recruitment was achieved by 45.5% of cluster, 53.8% of crossover and 57.7% of parallel-group trials with patient retention at 75.6%, 83.1% and 87.8%, respectively. Primary outcome reached statistical significance in 81.8% of cluster trials, 69.2% of parallel-group and 38.5% of crossover trials.Themes identified from individual interviews: perceptions of the convenience of trial participation; group allocation; perceptions of the benefits and adverse effects of taking part in clinical trials.

CONCLUSION

The recruitment and reporting of RCTs involving people on haemodialysis could be improved. Involvement of all stakeholders and especially participants in the trial design process may address issues around participant burden and ultimately improve the evidence base for clinical practice.

A pilot randomised controlled trial of an energy management programme for adults on maintenance haemodialysis: the fatigue-HD study

BACKGROUND

Identifying interventions to reduce fatigue and improve life participation are top research priorities of people on maintenance haemodialysis.

OBJECTIVE

Our primary objective was to explore the feasibility of conducting a randomised controlled trial of an energy management programme for people on maintenance haemodialysis.

DESIGN

Parallel-arm, 1:1, blinded, pilot randomised controlled trial.

PARTICIPANTS

Participants were recruited from 6 dialysis units in Calgary, Canada. Eligible patients were on maintenance haemodialysis, clinically stable and reported disabling fatigue on the Fatigue Severity Scale items 5, 7, 8 and 9.

RANDOMISATION

Participants were randomised using a computer-generated random number sequence according to permuted blocked randomisation, stratified by dialysis unit.

BLINDING

Participants were blinded to treatment allocation.

INTERVENTIONS

Participants received an attention control (general disease self-management education) or the Personal Energy Planning (PEP) programme, a tailored, web-supported 7-9 weeks energy management programme.

OUTCOMES

Eligibility, recruitment and attrition rates were recorded, and standardised intervention effects (Hedge's G) were calculated for fatigue and life participation questionnaires at one1-week postintervention and 12-week postintervention.

RESULTS

159 of 253 screened patients were eligible to be approached. 42 (26%) had fatigue, were interested and consented to participate, of whom 30 met eligibility criteria and were randomised (mean age 62.4 years (±14.7), 60% male). 22 enrolled participants (73%) completed all study procedures. Medium-sized intervention effects were observed on the Canadian Occupational Performance Measure (COPM)-Performance Scale, Global Life Participation Scale and Global Life Participation Satisfaction Scale at 1-week postintervention follow-up, compared with control. At 12-week follow-up, large and very large intervention effects were observed on the COPM-Performance Scale and COPM-Satisfaction Scale, respectively.

CONCLUSION

It is feasible to enrol and follow patients on haemodialysis in a randomised controlled trial of an energy management intervention. As the intervention was associated with improved life participation on some measures, a larger trial is justified.

Research Priorities for Kidney-Related Research-An Agenda to Advance Kidney Care: A Position Statement From the National Kidney Foundation

Despite the high prevalence and economic burden of chronic kidney disease (CKD) in the United States, federal funding for kidney-related research, prevention, and education activities under the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) remains substantially lower compared to other chronic diseases. More federal support is needed to promote critical research that will expand knowledge of kidney health and disease, develop new and effective therapies, and reduce health disparities. In 2021, the National Kidney Foundation (NKF) convened 2 Research Roundtables (preclinical and clinical research), comprising nephrology leaders from prominent US academic institutions and the pharmaceutical industry, key bodies with expertise in research, and including individuals with CKD and their caregivers and kidney donors. The goal of these roundtables was to identify priorities for preclinical and clinical kidney-related research. The research priorities identified by the Research Roundtables and presented in this position statement outline attainable opportunities for groundbreaking and critically needed innovations that will benefit patients with kidney disease in the next 5-10 years. Research priorities fall within 4 preclinical science themes (expand data science capability, define kidney disease mechanisms and utilize genetic tools to identify new therapeutic targets, develop better models of human disease, and test cell-specific drug delivery systems and utilize gene editing) and 3 clinical science themes (expand number and inclusivity of clinical trials, develop and test interventions to reduce health disparities, and support implementation science). These priorities in kidney-related research, if supported by additional funding by federal agencies, will increase our understanding of the development and progression of kidney disease among diverse populations, attract additional industry investment, and lead to new and more personalized treatments.

Past, Present, and Future of Phosphate Management

Cardiovascular (CV) disease (CVD) accounts for >50% of deaths with known causes in patients on dialysis. Elevated serum phosphorus levels are an important nontraditional risk factor for bone mineral disease and CVD in patients with chronic kidney disease (CKD). Given that phosphorus concentrations drive other disorders associated with increased CV risk (e.g., endothelial dysfunction, vascular calcification, fibroblast growth factor-23, parathyroid hormone), phosphate is a logical target to improve CV health. Phosphate binders are the only pharmacologic treatment approved for hyperphosphatemia. Although their safety has improved since inception, the mechanism of action leads to characteristics that make ingestion difficult and unpleasant; large pill size, objectionable taste, and multiple pills required for each meal and snack make phosphate binders a burden. Side effects, especially those affecting the gastrointestinal (GI) system, are common with binders, often leading to treatment discontinuation. The presence of “hidden” phosphates in processed foods and certain medications makes phosphate management even more challenging. Owing to these significant issues, most patients on dialysis are not consistently achieving and maintaining target phosphorus concentrations of <5.5 mg/dl, let alone more normal levels of <4.5 mg/dl, indicating novel approaches to improve phosphate management and CV health are needed. Several new nonbinder therapies that target intestinal phosphate absorption pathways have been developed. These include EOS789, which acts on the transcellular pathway, and tenapanor, which targets the dominant paracellular pathway. As observational evidence has established a strong association between phosphorus concentration and clinical outcomes, such as mortality, phosphate is an important target for improving the health of patients with CKD and end-stage kidney disease (ESKD).

Polypharmacy influences the renal composite outcome in patients treated with sodium-glucose cotransporter 2 inhibitors

Polypharmacy is a serious concern in general practice, especially among elder patients; however, the evidence showing significantly poor renal outcomes is not sufficient. This survey was performed to evaluate the effect of polypharmacy on the incidence of the renal composite outcome among a sample of patients with sodium-glucose cotransporter 2 inhibitor (SGLT2i) treatment. We assessed 624 Japanese patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease who received SGLT2i treatment for greater than 1 year. The patients were classified as those with concomitant treatment, that was limited to the medications for hypertension, T2DM, and dyslipidemia, with greater than or equal to seven medications (n = 110) and those with less than seven medications (n = 514). Evaluation of the renal composite outcome was performed by propensity score matching and stratification into quintiles. A subgroup analysis of patients of greater than or equal to 62 years of age and less than 62 years of age was also performed. The incidence of the renal composite outcome was larger in patients with greater than or equal to seven medications than in those with less than seven medications in the propensity score-matched cohort model (6% vs. 17%, respectively, p = 0.007) and also in the quintile-stratified analysis (odds ratio [OR], 2.23, 95% confidence interval [CI, 1.21-4.12, p = 0.01). The quintile-stratified analysis of patients of less than 62 years of age-but not those of greater than or equal to 62 years of age-also showed a significant difference (OR, 3.29, 95% CI, 1.41-7.69, p = 0.006). Polypharmacy appears to be associated to the incidence of the renal composite outcome, especially in young patients.

A Core Outcome Set for Trials in Glomerular Disease: A Report of the Standardized Outcomes in Nephrology-Glomerular Disease (SONG-GD) Stakeholder Workshops

BACKGROUND AND OBJECTIVES

Outcomes reported in trials in adults with glomerular disease are often selected with minimal patient input, are heterogeneous, and may not be relevant for clinical decision making. The Standardized Outcomes in Nephrology-Glomerular Disease (SONG-GD) initiative aimed to establish a core outcome set to help ensure that outcomes of critical importance to patients, care partners, and clinicians are consistently reported.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

We convened two 1.5-hour workshops in Melbourne, Australia, and Washington, DC, United States. Attendees were identified purposively with 50 patients/care partners and 88 health professionals from 19 countries; 51% were female. Patients and care partners were from the United States, Australia, and Canada, and had experience of a glomerular disease with systemic features (n=9), kidney-limited nephrotic disease (n=9), or other kidney-limited glomerular disease (n=8). Attendees reviewed the results of the SONG-GD Delphi survey and aims of the workshop and then discussed potential core outcomes and their implementation in trials among moderated breakout groups of eight to 12 people from diverse backgrounds. Transcripts of discussions were analyzed thematically.

RESULTS

Three themes were identified that supported the proposed core outcomes: limiting disease progression, stability and control, and ensuring universal relevance (i.e., applicable across diverse populations and settings). The fourth theme, preparedness for implementation, included engaging with funders and regulators, establishing reliable and validated measures, and leveraging existing endorsements for patient-reported outcomes.

CONCLUSIONS

Workshop themes demonstrated support for kidney function, disease activity, death, life participation, and cardiovascular disease, and these were established as the core outcomes for trials in adults with glomerular disease. Future work is needed to establish the core measures for each domain, with funders and regulators central to the uptake of the core outcome set in trials.

Trends in Adaptive Design Methods in Dialysis Clinical Trials: A Systematic Review

Rationale & Objective

Adaptive design methods are intended to improve the efficiency of clinical trials and are relevant to evaluating interventions in dialysis populations. We sought to determine the use of adaptive designs in dialysis clinical trials and quantify trends in their use over time.

Study Design

We completed a novel full-text systematic review that used a machine learning classifier (RobotSearch) for filtering randomized controlled trials and adhered to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines.

Setting & Study Populations

We searched MEDLINE (PubMed) and ClinicalTrials.gov using sensitive dialysis search terms.

Selection Criteria for Studies

We included all randomized clinical trials with patients receiving dialysis or clinical trials with dialysis as a primary or secondary outcome. There was no restriction of disease type or intervention type.

Data Extraction & Analytical Approach

We performed a detailed data extraction of trial characteristics and a completed a narrative synthesis of the data.

Results

57 studies, available as 68 articles and 7 ClinicalTrials.gov summaries, were included after full-text review (initial search, 209,033 PubMed abstracts and 6,002 ClinicalTrials.gov summaries). 31 studies were conducted in a dialysis population and 26 studies included dialysis as a primary or secondary outcome. Although the absolute number of adaptive design methods is increasing over time, the relative use of adaptive design methods in dialysis trials is decreasing over time (6.12% in 2009 to 0.43% in 2019, with a mean of 1.82%). Group sequential designs were the most common type of adaptive design method used. Adaptive design methods affected the conduct of 50.9% of trials, most commonly resulting in stopping early for futility (41.2%) and early stopping for safety (23.5%). Acute kidney injury was studied in 32 trials (56.1%), kidney failure requiring dialysis was studied in 24 trials (42.1%), and chronic kidney disease was studied in 1 trial (1.75%). 27 studies (47.4%) were supported by public funding. 44 studies (77.2%) did not report their adaptive design method in the title or abstract and would not be detected by a standard systematic review.

Limitations

We limited our search to 2 databases (PubMed and ClinicalTrials.gov) due to the scale of studies sourced (209,033 and 6,002 results, respectively).

Conclusions

Adaptive design methods are used in dialysis trials but there has been a decline in their relative use over time.

Assessing and counteracting fibrosis is a cornerstone of the treatment of CKD secondary to systemic and renal limited autoimmune disorders

Chronic kidney disease (CKD) is an increasing cause of morbidity and mortality worldwide. Besides the higher prevalence of diabetes, hypertension and aging worldwide, immune mediated disorders remain an important cause of kidney disease and are especially prevalent in young adults. Regardless of the initial insult, final pathway to CKD and kidney failure is always the loss of normal tissue and fibrosis development, in which the dynamic equilibrium between extracellular matrix synthesis and degradation is disturbed, leading to excessive production and accumulation. During fibrosis, a multitude of cell types intervene at different levels, but myofibroblasts and inflammatory cells are considered critical in the process. They exert their effects through different molecular pathways, of which transforming growth factor β (TGF-β) has demonstrated to be of particular importance. Additionally, CKD itself promotes fibrosis due to the accumulation of toxins and hormonal changes, and proteinuria is simultaneously a manifestation of CKD and a specific driver of renal fibrosis. Pathways involved in renal fibrosis and CKD are closely interrelated, and although important advances have been made in our knowledge of them, it is still necessary to translate them into clinical practice. Given the complexity of this process, it is highly likely that its treatment will require a multi-target strategy to control the origin of the damage but also the mechanisms that perpetuate it. Fortunately, rapid technology development over the last years and new available drugs in the nephrologist's armamentarium give reasons for optimism that more personalized assistance for CKD and renal fibrosis will appear in the future.

The evaluation of noninferiority for renal composite outcomes between sodium-glucose cotransporter inhibitors in Japan

BACKGROUND

In Japan, six types of sodium-glucose cotransporter inhibitors (SGLT2Is) are currently in use. Here, we evaluated differences in renal composite outcomes between SGLT2Is with or without evidence of cardio vascular outcome trials (CVOTs).

METHODS

We retrospectively surveyed 536 Japanese patients with type 2 diabetes mellitus with chronic kidney disease who received SGLT2Is for more than 1 year. Patients were classified as having received empagliflozin, canagliflozin, or dapagliflozin (n = 270, Evidence (+) group) or as having received ipragliflozin, tofogliflozin, or luseogliflozin (n = 266, Evidence (-) group). The propensity score matching method was performed.

RESULT

On matched cohort model including 205 cases in each group, there were no significant differences in the incidence of renal composite outcomes (n = 28 [14%] in the Evidence (+) group, n = 21 [10%] in the Evidence (-) group for the matched model; p = 0.29) between groups. Cox hazard analyses in the matched cohort model showed that the risk ratio for renal composite outcomes in the Evidence (-) group was 0.73 (95% confidence interval: 0.40-1.32), which was greater than the noninferiority margin of 1.22.

CONCLUSION

Three SGLT2Is with no CVOT's evidence did not show noninferiority compared with other SGLT2Is with evidences.

Big Data in Nephrology

A huge array of data in nephrology is collected through patient registries, large epidemiological studies, electronic health records, administrative claims, clinical trial repositories, mobile health devices and molecular databases. Application of these big data, particularly using machine-learning algorithms, provides a unique opportunity to obtain novel insights into kidney diseases, facilitate personalized medicine and improve patient care. Efforts to make large volumes of data freely accessible to the scientific community, increased awareness of the importance of data sharing and the availability of advanced computing algorithms will facilitate the use of big data in nephrology. However, challenges exist in accessing, harmonizing and integrating datasets in different formats from disparate sources, improving data quality and ensuring that data are secure and the rights and privacy of patients and research participants are protected. In addition, the optimism for data-driven breakthroughs in medicine is tempered by scepticism about the accuracy of calibration and prediction from in silico techniques. Machine-learning algorithms designed to study kidney health and diseases must be able to handle the nuances of this specialty, must adapt as medical practice continually evolves, and must have global and prospective applicability for external and future datasets.

Standardised Outcomes in Nephrology - Chronic Kidney Disease (SONG-CKD): a protocol for establishing a core outcome set for adults with chronic kidney disease who do not require kidney replacement therapy

BACKGROUND

Globally, over 1.2 million people die from chronic kidney disease (CKD) every year. Patients with CKD are up to 10 times more likely to die prematurely than progress to kidney failure requiring kidney replacement therapy. The burden of symptoms and impaired quality of life in CKD may be compounded by comorbidities and treatment side effects. However, patient-important outcomes remain inconsistently and infrequently reported in trials in patients with CKD, which can limit evidence-informed decision-making. The Standardised Outcomes in Nephrology - Chronic Kidney Disease (SONG-CKD) aims to establish a consensus-based core outcome set for trials in patients with CKD not yet requiring kidney replacement therapy to ensure outcomes of relevance to patients, caregivers and health professionals are consistently reported in trials.

METHODS

SONG-CKD involves four phases: a systematic review to identify outcomes (domains and measures) that have been reported in randomised controlled trials involving adults with CKD who do not require kidney replacement therapy; stakeholder key informant interviews with health professionals involved in the care of adults with CKD to ascertain their views on establishing core outcomes in CKD; an international two-round online Delphi survey with patients, caregivers, clinicians, researchers, policy makers and industry representatives to obtain consensus on critically important outcome domains; and stakeholder consensus workshops to review and finalise the set of core outcome domains for trials in CKD.

DISCUSSION

Establishing a core outcome set to be reported in trials in patients with CKD will enhance the relevance, transparency and impact of research to improve the lives of people with CKD.

TRIAL REGISTRATION

Not applicable. This study is registered with the Core Outcome Measures in Effectiveness Trials (COMET) database: http://www.comet-initiative.org/Studies/Details/1653 .

Changes in GFR and Albuminuria in Routine Clinical Practice and the Risk of Kidney Disease Progression

RATIONALE & OBJECTIVE

Changes in urinary albumin-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) have been used separately as alternative kidney disease outcomes in randomized trials. We tested the hypothesis that combined changes in UACR and eGFR predict advanced kidney disease better than either alone.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

91,319 primary care patients assembled from the Clinical Practice Research Datalink in the United Kingdom between 2000 and 2015.

EXPOSURES

Changes in UACR and eGFR (categorized as ≥30% increase, stable, or ≥30% decrease), alone and in combination, over a 3-year period.

OUTCOMES

The primary outcome was advanced CKD (sustained eGFR <30 mL/min/1.73 m2); secondary outcomes included kidney failure, cardiovascular disease, and all-cause mortality.

ANALYTICAL APPROACH

Multivariable Cox regression with bias from missing values assessed using multiple imputation; discrimination statistics compared across exposure groups.

RESULTS

91,319 individuals were studied, with a mean eGFR of 72.6 mL/min/1.73 m2 and median UACR of 9.7 mg/g; 70,957 (77.7%) had diabetes. During a median follow-up of 2.9 years, 2,541 people progressed to advanced CKD. Compared with stable values, hazard ratios for a ≥30% increase in UACR and ≥30% decrease in eGFR were 1.78 (95% CI, 1.59-1.98) and 7.53 (95% CI, 6.70-8.45), respectively, for the outcome of advanced CKD. Compared with stable values of both, the hazard ratio for the combination of an increase in UACR and a decrease in eGFR was 15.15 (95% CI, 12.43-18.46) for the outcome of advanced CKD. The combination of changes in UACR and eGFR predicted kidney outcomes better than either alone.

LIMITATIONS

Selection bias, relatively small proportion of individuals without diabetes, and very few kidney failure events.

CONCLUSIONS

In a large-scale general population, the combination of an increase in UACR and a decrease in eGFR was strongly associated with the risk of advanced CKD. Further assessment of combined changes in UACR and eGFR as an alternative outcome for kidney failure in trials of CKD progression is warranted.

Measuring quality of life in trials including patients on dialysis: how are transplants and mortality incorporated into the analysis? A systematic review protocol

INTRODUCTION

It is estimated that 25 000 people in the UK receive dialysis. Dialysis is an intrusive and time-consuming intervention that causes significant reductions in quality of life. When enrolled in a clinical trial, often some patients drop out of the study either because they die, receive a kidney transplant or are lost to follow-up for other reasons. It is unclear how these events are dealt with when analysing quality of life measures within clinical trials. This review will assess current practice for dealing with loss to follow-up in trials including patients on haemodialysis. The methods currently used will be analysed in terms of their adequacy and will form the basis of future work assessing the most appropriate methods to employ under these circumstances. The results of this review will feed into recommendations for future nephrology trials.

METHODS AND ANALYSIS

A systematic search of electronic databases including MEDLINE and the Cochrane Library will be conducted to find clinical trials enrolling patients on haemodialysis that measure quality of life using either the kidney disease quality of life (KDQoL) or the short form 36 health survey (SF-36) (or any variation of these two measures). Ongoing trials will be identified through a search of trial registers. Articles will be screened against inclusion/exclusion criteria and data will be extracted using a predetermined data extraction form. General information such as the title, location, trial design will be extracted along with more specific information on how the study dealt with patients that died or received a transplant before the end of the follow-up period. Two independent reviewers will perform screening and extraction. Disagreements will be resolved by discussion or by a third independent reviewer. Data synthesis will be performed as a narrative summary.

ETHICS AND DISSEMINATION

Ethics approval is not required. Dissemination will be by publication in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42020223869.

Re-Envisioning the Canadian Nephrology Trials Network: A Can-SOLVE-CKD Stakeholder Meeting of Patient Partners and Researchers

Purpose

The Canadian Nephrology Trials Network (CNTN) was formed in 2014 to support Canadian researchers in developing, designing, and conducting prospective studies in nephrology. In response to the changing landscape and needs within the Canadian nephrology research community, an interest in further growth and development of the network was identified. In the following report, we describe the process undertaken to re-envision the network through the creation of 3 new committees and how the committees are facilitating change and growth within the CNTN for future sustainability.

Sources of information

To understand areas for improvement and capacity building, the organization charged with overseeing the CNTN, Canadians Seeking Solutions and Innovations to Overcome Chronic Kidney Disease (Can-SOLVE CKD), began by conducting an environmental scan. As well, 2 informal surveys were sent to nephrology professionals (who were members of the CNTN and the Canadian Society of Nephrology) and patient partners (from Can-SOLVE CKD).

Methods

In September 2018, 44 CNTN members and other stakeholders from across Canada (including patient partners and representatives from research funding agencies) convened for a 2-day visioning workshop in Mississauga, Ontario. The agenda for this workshop was largely based on the results from the informal surveys. CNTN leadership participated and chose other workshop participants through informal stakeholder mapping and purposeful recruitment. Patient partners were recruited to participate in the workshop through advertisement within the Can-SOLVE-CKD patient council. The survey results and discussion questions were presented to participants at the workshop who, in turn, discussed in large- and small-group session ways in which the CNTN might be expanded.

Results

Surveys of patient partners indicated that they would like to see greater involvement of patients in the research process. Surveys of researchers indicated that they wanted more support and resources for coordinating prospective trials. The themes which emerged from the workshop discussions were peer review, engagement, and training. These themes were broadened and formally re-named to Scientific Operations, Communications and Engagement, and Capacity Building. A working committee, each co-led by a nephrologist with research experience and a patient partner, was created to advance each of these identified themes. An executive committee was created to provide overall strategic leadership and governance to the network. The Scientific Operations Committee conducts peer reviews; provides letters of endorsement after peer review; and holds semi-annual in-person meetings where researchers can present their proposals and obtain feedback from multiple stakeholders, including patients. The Communications and Engagement Committee publishes a quarterly newsletter, engages the community on Twitter, and reaches out to community sites and new nephrologists to engage them in research. The Capacity Building Committee conducts webinars to encourage patient partners to develop their own research questions and is developing a hub-and-spoke model to improve research collaboration.

Limitations

We did not conduct formal stakeholder mapping. Only attendees of the visioning workshop provided input, and not everyone's comment or opinion was included in the workshop report. Perspectives were limited to the sample of people who attended the workshop or were surveyed and may not reflect perspectives of all stakeholders in nephrology research in Canada. We did not use formal qualitative methodology to summarize the workshops.

Implications

Renewed areas of focus and related committees within the CNTN could lead to an increased capacity for nephrology research, increased engagement and collaboration with researchers, a higher likelihood of funding with rigorous peer review, and more clinical trials and multicenter collaborative prospective research being conducted in Canada.

Developing the subspecialty of cardio-nephrology: The time has come. A position paper from the coordinating committee from the Working Group for Cardiorenal Medicine of the Spanish Society of Nephrology

Patients with the dual burden of chronic kidney disease (CKD) and cardiovascular disease (CVD) experience unacceptably high rates of morbidity and mortality, which also entail unfavorable effects on healthcare systems. Currently, concerted efforts to identify, prevent and treat CVD in CKD patients are lacking at the institutional level, with emphasis still being placed on individual specialty views on this topic. The authors of this position paper endorse the need for a dedicated interdisciplinary team of subspecialists in cardio-nephrology that manages appropriate clinical interventions across the inpatient and outpatient settings. There is a critical need for training programs, guidelines and best clinical practice models, and research funding from nephrology, cardiology and other professional societies, to support the development of the subspecialty of cardio-nephrology. This position paper from the coordinating committee from the Working Group for Cardiorenal Medicine of the Spanish Society of Nephrology (S.E.N.) is intended to be the starting point to develop the subspecialty of cardio-nephrology within the S.E.N.. The implementation of the subspecialty in day-to-day nephrological practice will help to diagnose, treat, and prevent CVD in CKD patients in a precise, clinically effective, and health cost-favorable manner.

Effect of estimating equations for glomerular filtration rate on novel surrogate markers for renal outcome

Backgrounds

Recently, alternative surrogate endpoints such as a 30% or 40% decline in estimated glomerular filtration rate (eGFR) or eGFR slope over 2 to 3 years have been proposed for predicting renal outcomes. However, the impact of GFR estimation methods on the accuracy and effectiveness of surrogate markers is unknown.

Methods

We retrospectively enrolled participants in health screening programs at three hospitals from 1995 to 2009. We defined two different participant groups as YR1 and YR3, which had available 1-year or 3-year eGFR values along with their baseline eGFR levels. We compared the effectiveness of eGFR percentage change or slope to estimate end-stage renal disease (ESRD) risk according to two estimating equations (modified Modification of Diet in Renal Disease equation [eGFRm] and Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation [eGFRc]) for GFR.

Results

In the YR1 and YR3 groups, 9,971 and 10,171 candidates were enrolled and ESRD incidence during follow-up was 0.26% and 0.19%, respectively. The eGFR percentage change was more effective than eGFR slope in estimating ESRD risk, regardless of the method of estimation. A 40% of decline in eGFR was better than 30%, and a 3-year baseline period was better than a 1-year period for prediction accuracy. Although some diagnostic indices from the CKD-EPI equation were better, we found no significant differences in the discriminative ability and hazard ratios for incident ESRD between eGFRc and eGFRm in either eGFR percentage change or eGFR slope.

Conclusion

There were no significant differences in the prediction accuracy of GFR percentage change or eGFR slope between eGFRc and eGFRm in the general population.

The WISHED Randomized Controlled Trial: Impact of an Interactive Health Communication Application on Home Dialysis Use in People With Chronic Kidney Disease

Background:

While home dialysis therapies are more cost effective and may offer improved health-related quality of life, uptake compared to in-center hemodialysis remains low.

Objective:

To test whether a web-based interactive health communication application (IHCA) compared to usual care would increase home dialysis use.

Design:

Randomized control trial

Setting:

Patients were recruited from 3 multidisciplinary kidney clinics across Ontario, Canada (Hamilton, Kingston, London).

Patients:

We included adults with advanced chronic kidney disease (CKD) followed in multidisciplinary kidney clinics. Patients who had not completed dialysis modality education, who did not have access to a home computer or the internet, who had significant hearing or vision impairment, who could not read/write/speak English, who had a medical contraindication for home dialysis, or who had selected conservative kidney care were excluded.

Measurements:

The primary outcome was any use of home dialysis (peritoneal dialysis or home hemodialysis) within 90 days of dialysis initiation. Secondary outcomes were social support, decision conflict and dialysis knowledge measured at baseline, 6 months and 1 year.

Methods:

Eligible patients were randomized to either usual care or the IHCA in addition to usual care in a 1:1 ratio. As part of usual care, all patients received education about dialysis modalities and kidney transplantation delivered by clinic nurses according to local practices. Randomization was performed using a computer-generated sequence in randomly permuted block sizes, stratified by site, and allocation occurred using sequentially numbered sealed, opaque envelopes. Participants, care providers, and outcome assessors were not blinded to the intervention. All analyses were performed blinded using an intention to treat approach. We estimated the effect of the ICHA on the odds of the primary outcome using unadjusted logistic regression models. Linear mixed models for repeated measures over time were used to analyze the impact of the IHCA on the secondary outcomes of interest.

Results:

We randomized 140 (usual care, n = 71; IHCA, n = 69) out of a planned 264 patients (mean [SD] age 61 [14.5] years, 65% men). Among patients randomized to the IHCA group that completed 6-month and 1-year follow-up visits, 56.8% and 71.4%, respectively, had not accessed the IHCA website within the past month. There were 23 (32.4%) and 26 (37.7%) patients in the usual care and IHCA groups who received a home dialysis therapy within 90 days of dialysis initiation (odds ratio, OR = 1.3, 95% CI = [0.6-2.5], P = .5). Among the 78 patients who initiated dialysis (n = 38 usual care, n = 40 IHCA), 60.5% and 65% in the usual care and IHCA groups received a home therapy within 90 days of dialysis initiation (OR = 1.2, 95% CI = [0.5-3.0], P = .7). Secondary outcomes did not differ by intervention group over time.

Limitations:

The trial was underpowered due to poor recruitment and use of the IHCA was low.

Conclusions:

We did not find evidence of a difference in home dialysis uptake with IHCA use, but our analyses were notably underpowered. The incorporation of greater patient engagement, qualitative research and design research, and pilot implementation may help future evaluations of strategies to improve home dialysis uptake.

Trial Registration:

ClinicalTrials.gov #NCT01403454, registration date: Jul 21, 2011

Spontaneous remission in adult patients with IgA nephropathy treated with conservative therapy

Background

There are few studies describing the clinical course and spontaneous remission of IgA nephropathy (IgAN) in adult patients receiving conservative treatment.

Method

Data from 62 adult patients with biopsy-diagnosed IgAN, who received conservative treatment at least 5 years prior, were retrospectively investigated. No patients received corticosteroids, other immunosuppressants, or tonsillectomy. Remission of proteinuria and hematuria were defined as proteinuria <0.3 g/gCr and urine red blood cells (RBC) <5 / high power field (HPF) on three consecutive urinalyses obtained during an observation period of ≥6 months.

Result

Thirty-eight (61.3%) patients had remission of hematuria, 24 (38.7%) had remission of proteinuria, and 19 (30.6%) had remission of both. Remission rates increased in patients with proteinuria <0.5 g/g Cr at diagnosis. The median time to remission of hematuria was 2.8 years and that of proteinuria was 2.6 years. Patients who showed renal function decline (defined as 30% decline of estimated glomerular filtration rate [eGFR] from baseline) were older, had significantly lower eGFR, and higher proteinuria at diagnosis. Two patients with preserved renal function and normal proteinuria at diagnosis experienced renal function decline. Renal function did not decline within 3 years of diagnosis in patients with proteinuria <1 g/gCr at diagnosis.

Conclusions

Relatively high rates of spontaneous remission were observed. Remission of both hematuria and proteinuria were frequent within 3 years after diagnosis, and renal function was well preserved during this period. These data indicate that it is rational to use conservative treatment for 3 years after the diagnosis instead of aggressive treatments.

Major adverse renal events (MARE): a proposal to unify renal endpoints

BACKGROUND

In renal studies, various outcome endpoints are used with variable definitions, making it nearly impossible to perform meta-analyses and deduce meaningful conclusions. Increasing attention is directed towards standardization of renal outcome reporting.

METHODS

A working group was formed to produce a unifying definition of renal outcomes that can be used by all investigators. We propose major adverse renal events (MARE) as the term for a standardized composite of hard renal outcomes. We discuss the components for inclusion in MARE from existing evidence.

RESULTS

MARE could include three to five items, considered relevant to patients and regulators. New onset of kidney injury, that is persistent albuminuria/proteinuria and/or decreasing glomerular filtration rate (GFR) <60 ml/min/1.73 m2, persistent signs of worsening kidney disease, development of end-stage kidney disease with estimated GFR <15 ml/min/1.73 m2 without or with initiation of kidney replacement therapy, and death from renal cause are core items of MARE. Additionally, patient reported outcomes should be reported in parallel to MARE as a standard set of primary (or secondary) endpoints in studies on kidney disease of diabetic, hypertensive-vascular, or other origin.

CONCLUSIONS

MARE as a reporting standard will enhance the ability to compare studies and thus, facilitate meaningful meta-analyses. This will result in standardized endpoints that should result in guideline improvement to better individualize care of patients with kidney disease.

Understanding and Overcoming the Challenges Related to Cardiovascular Trials Involving Patients with Kidney Disease

Cardiovascular disease is a prevalent and prognostically important comorbidity among patients with kidney disease, and individuals with kidney disease make up a sizeable proportion (30%-60%) of patients with cardiovascular disease. However, several systematic reviews of cardiovascular trials have observed that patients with kidney disease, particularly those with advanced kidney disease, are often excluded from trial participation. Thus, currently available trial data for cardiovascular interventions in patients with kidney disease may be insufficient to make recommendations on the optimal approach for many therapies. The Kidney Health Initiative, a public-private partnership between the American Society of Nephrology and the US Food and Drug Administration, convened a multidisciplinary, international work group and hosted a stakeholder workshop intended to understand and develop strategies for overcoming the challenges with involving patients with kidney disease in cardiovascular clinical trials, with a particular focus on those with advanced disease. These efforts considered perspectives from stakeholders, including academia, industry, contract research organizations, regulatory agencies, patients, and care partners. This article outlines the key challenges and potential solutions discussed during the workshop centered on the following areas for improvement: building the business case, re-examining study design and implementation, and changing the clinical trial culture in nephrology. Regulatory and financial incentives could serve to mitigate financial concerns with involving patients with kidney disease in cardiovascular trials. Concerns that their inclusion could affect efficacy or safety results could be addressed through thoughtful approaches to study design and risk mitigation strategies. Finally, there is a need for closer collaboration between nephrologists and cardiologists and systemic change within the nephrology community such that participation of patients with kidney disease in clinical trials is prioritized. Ultimately, greater participation of patients with kidney disease in cardiovascular trials will help build the evidence base to guide optimal management of cardiovascular disease for this population.

Developing the subspecialty of cardio-nephrology: The time has come. A position paper from the coordinating committee from the Working Group for Cardiorenal Medicine of the Spanish Society of Nephrology

Patients with the dual burden of chronic kidney disease (CKD) and cardiovascular disease (CVD) experience unacceptably high rates of morbidity and mortality, which also entail unfavorable effects on healthcare systems. Currently, concerted efforts to identify, prevent and treat CVD in CKD patients are lacking at the institutional level, with emphasis still being placed on individual specialty views on this topic. The authors of this position paper endorse the need for a dedicated interdisciplinary team of subspecialists in cardio-nephrology that manages appropriate clinical interventions across the inpatient and outpatient settings. There is a critical need for training programs, guidelines and best clinical practice models, and research funding from nephrology, cardiology and other professional societies, to support the development of the subspecialty of cardio-nephrology. This position paper from the coordinating committee from the Working Group for Cardiorenal Medicine of the Spanish Society of Nephrology (S.E.N.) is intended to be the starting point to develop the subspecialty of cardio-nephrology within the S.E.N.. The implementation of the subspecialty in day-to-day nephrological practice will help to diagnose, treat, and prevent CVD in CKD patients in a precise, clinically effective, and health cost-favorable manner.

The need for a cardionephrology subspecialty

Chronic kidney disease (CKD) has structural and functional repercussions for the cardiovascular system that facilitate the development of cardiovascular disease (CVD). In fact, cardiovascular complications are frequent in the CKD population and thus cause a great clinical, public health and economic burden. Despite this challenge, the prevention and management of cardiovascular complications is one among several aspects of CKD that meets the criteria of an unmet medical need. This probably has to do with the misperception by the nephrologist of the global relevance of CVD in the CKD patient which, in turn, may be due to insufficient cardiovascular training during nephrology specialization. Therefore a change in approach is necessary to understand CKD as a disease in which the manifestations and complications related to CVD become so frequent and important that they require dedicated multidisciplinary clinical management. From this perspective, it makes sense to consider training in the subspecialty of cardionephrology to provide adequate cardiovascular care for CKD patients by the nephrologist. In addition, the cardionephrology subspecialist would be better able to interact with other specialists in multidisciplinary care settings created to achieve a deeper understanding and more effective clinical handling of the interactions between CKD and CVD.

Comparison of chronic kidney disease trial designs and analysis strategies

Background

Despite the large burden of chronic kidney disease (CKD), it is challenging to conduct adequately powered clinical trials in this setting. Sound and efficient trials are needed to advance treatment. Various analysis strategies can be used to compare the efficacy of a parallel trial design with that of three two period trial designs.

Methods

The type 1 error rates and powers of various trial designs were calculated using simulated data from models fit to two recent CKD trials. In addition, we assessed the influences of a variety of analysis strategies and of the presence of a carryover effect.

Results

The parallel and crossover designs (with analysis of change from baseline to the off treatment value) maintained the target type 1 error rate in all scenarios. In some scenarios, an open label design yielded inflated type 1 error rates. In many scenarios, the open label and delayed start designs had unacceptably low power and high type 1 error rates. Overall, the crossover design had the highest power by far, and always controlled the type 1 error rate.

Conclusion

The recommended approach to a CKD trial is a two period design with an endpoint that is the rate of change in estimated glomerular filtration rate from pretreatment to off treatment. As compared to a parallel trial, a crossover study involves a considerably smaller sample size and shorter total follow-up duration. A crossover design may also be preferable for patients, and facilitates recruitment of a sufficient number of subjects.