The Roles of Indoxyl Sulphate and p-Cresyl Sulphate in Patients with Chronic Kidney Disease: A Review of Therapeutic Options

Indoxyl sulphate (IS) and p-cresyl sulphate (PCS) are products of proteolytic bacterial fermentation by gut microbiota. They accumulate in the sera of patients with chronic kidney disease (CKD) and have been associated with CKD progression and cardiovascular and all-cause mortality. Therapeutic strategies for lowering IS and PCS include increased clearance (enhanced dialysis), gastrointestinal sequestration (oral adsorbents), reduced synthesis (dietary protein restriction, dietary fibre augmentation and pre-, pro- or synbiotics), antioxidants and organic anion transporter modulators. This review will discuss the roles of IS and PCS as therapeutic targets and examine the clinical evidence for different treatment options and their effects on CKD and cardiovascular disease risk. We will include our group’s research with pre-, pro- and synbiotic interventions to mitigate serum uraemic toxin accumulation and modify cardiovascular and renal risk

Establishing a core outcome set for peritoneal dialysis : report of the SONG-PD (standardized outcomes in nephrology-peritoneal dialysis) consensus workshop

Outcomes reported in randomized controlled trials in peritoneal dialysis (PD) are diverse, are measured inconsistently, and may not be important to patients, families, and clinicians. The Standardized Outcomes in Nephrology-Peritoneal Dialysis (SONG-PD) initiative aims to establish a core outcome set for trials in PD based on the shared priorities of all stakeholders. We convened an international SONG-PD stakeholder consensus workshop in May 2018 in Vancouver, Canada. Nineteen patients/caregivers and 51 health professionals attended. Participants discussed core outcome domains and implementation in trials in PD. Four themes relating to the formation of core outcome domains were identified: life participation as a main goal of PD, impact of fatigue, empowerment for preparation and planning, and separation of contributing factors from core factors. Considerations for implementation were identified: standardizing patient-reported outcomes, requiring a validated and feasible measure, simplicity of binary outcomes, responsiveness to interventions, and using positive terminology. All stakeholders supported inclusion of PD-related infection, cardiovascular disease, mortality, technique survival, and life participation as the core outcome domains for PD

Recurrent severe hypophosphatemia following intravenous iron administration

Key Clinical Message Hypophosphatemia postintravenous iron is frequent but under-recognized. If prolonged or recurrent, it can cause osteomalacia. The likely mechanisms are direct toxicity to proximal tubular cells causing phosphate wasting, elevated Fibroblast growth factor-23 (FGF-23), and reduced 1,25-dihydroxyvitamin D (1,25(OH)(2)D). Hypophosphatemia may be severe and persist for months, necessitating phosphate replacement until normalization of serum levels occurs

Recent clinical trials of pharmacologic cardiovascular interventions in patients with chronic kidney disease: An update

As a consequence of both traditional and non-traditional risk factors, cardiovascular disease is over-represented, and the leading cause of mortality, among patients with Chronic Kidney Disease (CKD). Whilst recommendations for reducing cardiovascular risk in the general population exist, their applicability to the CKD population is questionable due to the exclusion of CKD patients from the majority of contemporary cardiovascular interventional studies. The aim of this review is to critically evaluate the literature regarding pharmacologic cardiovascular interventions in patients with CKD, with an emphasis on studies published since our 2008 review. Interventions discussed include erythropoiesis-stimulating agents (TREAT, U.S. Normal Hematocrit, CHOIR, CREATE, Palmer meta-analysis); statins (SHARP, AURORA, PPP, 4D, ALERT); Fibrates (VA-HIT); Folic Acid (ASFAST, US FOLIC acid trial, HOST); Antihypertensive Agents, Including Angiotensin-Converting Enzyme Inhibitors, angiotensin-receptor blockers, Beta-blockers and Combination therapy (Cice et al, FOSDIAL, Agarwal et al, ONTARGET); sevelamer (DCOR); Cinacalcet (ADVANCE, EVOLVE, Cunningham meta-analysis); Anti-oxidants (SPACE, HOPE, ATIC); Aspirin (HOT study re-analysis); vitamin D analogues (PRIMO); and multidisciplinary intervention (LANDMARK). Unfortunately, there remains a paucity of evidence in this area and a large number of methodologically poor quality studies with negative results. It is possible that these interventions do not have the same positive effect in CKD patients due to differences in the pathogenesis driving cardiovascular disease burden, such as altered bone metabolism and calcific vascular disease. Further well-designed studies with appropriately selected study populations and patient level outcomes are required. Until such time, physicians must consider on an individual patient basis the appropriateness of these interventions

Association between peritoneal glucose exposure and peritonitis in peritoneal dialysis patients: the balANZ trial

Background: Glucose is the primary osmotic medium used in most peritoneal dialysis (PD) solutions, and exposure to glucose has been shown to exert detrimental effects both locally, at the peritoneal membrane, and systemically. Moreover, high dialysate glucose exposure may predispose patients to an increased risk of peritonitis, perhaps as a result of impaired host defences, vascular disease, and damage to the peritoneal membrane

Associations Between Peritoneal Glucose Exposure, Glucose Degradation Product Exposure, and Peritoneal Membrane Transport Characteristics in Peritoneal Dialysis Patients: Secondary Analysis of the balANZ Trial

Background: Glucose is the most commonly used osmotic medium in peritoneal dialysis (PD) solutions, and its use has been associated with both local and systemic adverse effects. Previous, single-center, observational cohort studies have reported conflicting findings regarding whether a relationship exists between peritoneal glucose exposure and peritoneal small solute transport rate.Methods: In this secondary analysis of the baIANZ multicenter, multinational, randomized controlled trial of a neutral pH, ultra-low glucose degradation product (biocompatible) versus conventional PD solutions over a 2-year period, the relationship between time varying peritoneal glucose exposure and change in peritoneal solute transport rate, (measured as dialysate to plasma creatinine ratio at 4 hours [D:PCr4h]), was evaluated using multivariable, multilevel linear regression. Baseline peritoneal glucose exposure was also assessed as either a continuous or categorical variable.Results: The studyincluded 165 patients (age 58.1 +/- 14.2 years, 55% male, 33% diabetic). Peritoneal glucose exposure increased over time (coefficient 1.49, 95% confidence interval [C1] 1.07 - 1.92 and was not significantly associated with change in D:PCr4h (coefficient 0.00004, 95% CI -0.0001 - 0.0002, p= 0.68). Similar results were found when peritoneal glucose exposure was examined as a baseline continuous or categorical variable. A significant 2-way interaction was observed with PD solution type, whereby a progressive increase in D:PCr4h was seen in the patients receiving conventional PD solution, but not in those receiving biocompatible solution.Conclusions: Increases in peritoneal solute transport rate in PD patients over time were not associated with peritoneal glucose exposure, although a strong and positive association with PD solution glucose degradation product content was identified. Peritoneal glucose exposure may be a less important consideration than peritoneal glucose degradation product exposure with respect to peritoneal membrane function over time

Patient-reported outcome measures for life participation in peritoneal dialysis: a systematic review.

BackgroundPatients receiving peritoneal dialysis (PD) endure an ongoing regimen of daily fluid exchanges and are at risk of potentially life-threatening complications and debilitating symptoms that can limit their ability to participate in life activities. The aim of the study was to identify the characteristics, content and psychometric properties of measures for life participation used in research in PD.MethodsWe searched MEDLINE, Embase, PsychInfo, the Cumulative Index to Nursing and Allied Health Literature (CINAHL) and the Cochrane Central Register of Controlled Trials from inception to May 2020 for all studies that reported life participation in patients on PD. The characteristics, dimensions of life participation and psychometric properties of these measures were extracted and analyzed.ResultsOf the 301 studies included, 17 (6%) were randomized studies and 284 (94%) were nonrandomized studies. Forty-two different measures were used to assess life participation. Of these, 23 (55%) were used in only one study. Fifteen (36%) measures were specifically designed to assess life participation, while 27 (64%) measures assessed broader constructs, such as quality of life, but included questions on life participation. The 36-Item Short Form Health Survey and Kidney Disease Quality of Life Short Form were the most frequently used measures [122 (41%) and 86 (29%) studies, respectively]. Eight (19%) measures had validation data to support their use in patients on PD.ConclusionsThe many measures currently used to assess life participation in patients receiving PD vary in their characteristics, content and validation. Further work to pilot and validate potential measures is required to establish a core patient-reported outcome measure to assess life participation in patients receiving PD

A Core Outcome Set for Trials in Glomerular Disease

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.</div

Establishing a Core Outcome Measure for Peritoneal Dialysis-related Peritonitis: A Standardized Outcomes in Nephrology—Peritoneal Dialysis Consensus Workshop Report

IntroductionPeritoneal dialysis (PD)-related peritonitis is one of the leading causes of discontinuation of PD and is considered a critically important outcome for patients on PD. However, there is no universally accepted method of measuring this outcome in clinical trials.MethodsWe convened an online consensus workshop to establish a core outcome measure for PD-related peritonitis in clinical trials.ResultsA total of 53 participants, including 18 patients and caregivers, from 12 countries engaged in breakout discussions in this workshop. Transcripts were analyzed thematically. We identified the following 3 themes: (i) feasibility and applicability across diverse settings, which reflected the difficulty with implementing laboratory-based measures in resource-limited environments; (ii) ensuring validity, which included minimizing false positives and considering the specificity of symptoms; and (iii) being meaningful and tangible to patients, which meant that the measure should be easy to interpret, reflect the impact that symptoms have on patients, and promote transparency by standardizing the reporting of peritonitis among dialysis units.ConclusionA core outcome measure for PD-related peritonitis should include both symptom-based and laboratory-based criteria. Thus, the International Society for Peritoneal Dialysis (ISPD) definition of peritonitis is acceptable. However, there should be consideration of reporting suspected peritonitis in cases where laboratory confirmation is not possible. The measure should include all infections from the time of catheter insertion and capture both the rate of infection and the number of patients who remain peritonitis free. A&nbsp;core outcome measure with these features would increase the impact of clinical trials on the care and decision-making of patients receiving PD