Participant Perceptions in a Long-term Clinical Trial of Autosomal Dominant Polycystic Kidney Disease.

Rationale & Objective: The development of new therapies for autosomal dominant polycystic kidney disease requires clinical trials to be conducted efficiently. In this study, the factors affecting the recruitment and retention of participants enrolled in a 3-year randomized controlled trial in autosomal dominant polycystic kidney disease were investigated. Study Design: Qualitative study. Setting & Participants: All participants (N=187) were invited to complete a 16-item questionnaire at the final study visit of the primary trial. Participants were recruited to complete a semistructured interview using purposeful sampling according to age, self-reported gender, and randomization group. Analytical Approach: Descriptive statistics were used for demographic data and questionnaires. The interview transcripts underwent inductive thematic coding. Results: One hundred and forty-six of the 187 randomized participants (79%) completed the post-trial questionnaire, and 31 of the 187 participants (21%) completed the interview. Most participants (94%) rated their global satisfaction with the trial as high (a score of 8 or more out of 10). Altruism, knowledge gain, and access to new treatments were the main motivators for recruitment. The main reasons for considering leaving the study were concerns about the risk of intervention and family or work issues. Strategies that favored retention included flexibility in attending different study sites, schedule flexibility, staff interactions, and practical support with parking and reminders. The main burden was time away from work with lost wages, and burden associated with magnetic resonance imaging scans and 24-hour urine output collections. Limitations: The study population was restricted to participants in a single nondrug clinical trial, and the results could be influenced by selection and possible social desirability bias. Conclusions: Participants reported high levels of satisfaction that occurred as a function of the trial meeting participants' expectations. Furthermore, retention was a balance between the perceived benefits and burden of participation. Consideration of these perspectives in the design of future clinical trials will improve their efficiency and conduct. Plain-Language Summary: Advances in the clinical practice of autosomal dominant polycystic kidney disease (ADPKD) require affected individuals to voluntarily participate in long-term multicenter randomized controlled trials (RCTs). In this qualitative post hoc study of a 3-year RCT of increased water intake in ADPKD, altruism, knowledge gain, and access to a nondrug treatment positively influenced the decision to volunteer. Ongoing participation was enabled by building flexibility into the study protocol and staff prioritizing a participant's needs during study visits. Although participants completed the required tests, most were considered burdensome. This study highlights the importance of incorporating protocol flexibility into trial design; the preference for interventions with a low risk of adverse effects; and the urgent requirement for robust surrogate noninvasive biomarkers to enable shorter RCTs in ADPKD.

Prescribed Water Intake in Autosomal Dominant Polycystic Kidney Disease.

Prescribed Water Intake in Autosomal Dominant Polycystic Kidney Disease The effect of increased water intake on kidney cyst growth in patients with polycystic kidney disease was compared for two groups randomly assigned to either prescribed or ad libitum water intake. Over 3 years, there was no difference in height-corrected total kidney volume between the groups.

Effect of Hemodiafiltration on the Progression of Neuropathy with Kidney Failure: A Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: Neuropathy is a common complication of kidney disease that lacks proven disease-modifying treatments. Hemodiafiltration improves clearance of uremic toxins and is associated with better nerve function than hemodialysis. We aimed to determine whether hemodiafiltration reduces the progression of neuropathy in people receiving hemodialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The Filtration in the Neuropathy of End-Stage Kidney Disease Symptom Evolution (FINESSE) study was an open-label, blinded end point assessment, controlled trial that randomized maintenance hemodialysis recipients to hemodiafiltration or high-flux hemodialysis for 48 months or until death or cessation of dialysis at four study centers. The primary outcome was the mean change in the yearly modified total neuropathy score from baseline, with time points weighted equally. RESULTS: A total of 124 participants were randomized and followed for a mean of 41 months. At baseline, neuropathy was present in 91 (73%) participants (modified total neuropathy score greater than or equal to two), and 38 (31%) had moderate to severe neuropathy (modified total neuropathy score 9-28). Convection volume in the hemodiafiltration arm was a median of 24.7 (interquartile range, 22.4-26.5) L. The mean modified total neuropathy score (SEM) worsened by 1.7 (0.4)/28 and 1.2 (0.4)/28 in the hemodiafiltration and hemodialysis groups, respectively, with a mean difference of 0.5 (95% confidence interval, -0.7 to 1.7; P=0.37). There was no difference in survival (hazard ratio, 1.24; 95% confidence interval, 0.61 to 2.51; log rank P=0.55) or any of the prespecified adverse events. There was no difference between groups in the number of participants who suffered an adverse event adjusted by follow-up time (relative risk, 1.05; 95% confidence interval, 0.83 to 1.32; P=0.68). CONCLUSIONS: Neuropathy is still a common complication of kidney disease without disease-altering therapy. Hemodiafiltration did not affect neuropathy progression compared with hemodialysis. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Filtration in the Neuropathy of End-Stage Kidney Disease Symptom Evolution (FINESSE), ACTRN12609000615280.

Assessment of Dietary Sodium Intake Using the Scored Salt Questionnaire in Autosomal Dominant Polycystic Kidney Disease.

The excess intake of dietary sodium is a key modifiable factor for reducing disease progression in autosomal dominant polycystic kidney disease (ADPKD). The aim of this study was to test the hypothesis that the scored salt questionnaire (SSQ; a frequency questionnaire of nine sodium-rich food types) is a valid instrument to identify high dietary salt intake in ADPKD. The performance of the SSQ was evaluated in adults with ADPKD with an estimated glomerular filtration rate (eGFR) ≥ 30 mL/min/1.73 m2 during the screening visit of the PREVENT-ADPKD trial. High dietary sodium intake (HSI) was defined by a mean 24-h urinary sodium excretion ≥ 100 mmol/day from two collections. The median 24-h urine sodium excretion was 132 mmol/day (IQR: 112-172 mmol/d) (n = 75; mean age: 44.6 ± 11.5 years old; 53% female), and HSI (86.7% of total) was associated with male gender and higher BMI and systolic blood pressure (p < 0.05). The SSQ score (73 ± 23; mean ± SD) was weakly correlated with log10 24-h urine sodium excretion (r = 0.29, p = 0.01). Receiving operating characteristic analysis showed that the optimal cut-off point in predicting HSI was an SSQ score of 74 (area under the curve 0.79; sensitivity 61.5%; specificity 90.0%; p < 0.01). The evaluation of the SSQ in participants with a BMI ≥ 25 (n = 46) improved the sensitivity (100%) and the specificity (100%). Consumers with an SSQ score ≥ 74 (n = 41) had higher relative percentage intake of processed meats/seafood and flavourings added to cooking (p < 0.05). In conclusion, the SSQ is a valid tool for identifying high dietary salt intake in ADPKD but its value proposition (over 24-h urinary sodium measurement) is that it may provide consumers and their healthcare providers with insight into the potential origin of sodium-rich food sources.

Randomised controlled trial of the impact of haemodiafiltration on uraemic neuropathy: FINESSE study protocol.

INTRODUCTION: The majority of patients undergoing haemodialysis (HD) show evidence of uraemic neuropathy, a condition with no known disease-modifying treatments. The pathogenesis of uraemic neuropathy is poorly understood, but may be related to cumulative exposure to middle molecules or other solutes such as potassium. It is not known whether haemodiafiltration (HDF) reduces the progression of uraemic neuropathy. METHODS AND ANALYSIS: Filtration In the Neuropathy of End-Stage kidney disease Symptom Evolution (FINESSE) is a multicentre, randomised, open-label, blinded endpoint assessment, controlled trial designed to assess the impact of HDF versus HD on uraemic neuropathy. Maintenance HD patients will be randomised in a 1:1 ratio to receive HDF or HD with high-flux membranes for 4 years. The primary endpoint is the difference in the mean change in Total Neuropathy Score (TNS)-a measure of peripheral neuropathy combining symptoms, signs and nerve conduction velocity-over the study period. Secondary outcomes include change at annual timepoints in the TNS and the Neuropathy Symptom Score; and in morbidity, mortality and safety events. ETHICS AND DISSEMINATION: The FINESSE trial has been approved by the Ethics Review Committee of the Sydney South West Area Health Service (HREC/09/RPAH/268) and of Adventist HealthCare Limited (2012-027). When published in a peer-reviewed journal, it will be the largest and longest reported randomised trial aimed at reducing the incidence and severity of uraemic neuropathy. It will advance the understanding of the natural history of uraemic neuropathy and the influence of convective therapies on both neurophysiological and clinical outcomes. It will also allow refinement of current hypotheses surrounding the pathogenesis of uraemic neuropathy and, most importantly, may lead to improvements in the lives of the many patients affected by this debilitating condition. TRIAL REGISTRATION NUMBER: ACTRN12609000615280.

Randomised controlled trial to determine the efficacy and safety of prescribed water intake to prevent kidney failure due to autosomal dominant polycystic kidney disease (PREVENT-ADPKD).

INTRODUCTION: Maintaining fluid intake sufficient to reduce arginine vasopressin (AVP) secretion has been hypothesised to slow kidney cyst growth in autosomal dominant polycystic kidney disease (ADPKD). However, evidence to support this as a clinical practice recommendation is of poor quality. The aim of the present study is to determine the long-term efficacy and safety of prescribed water intake to prevent the progression of height-adjusted total kidney volume (ht-TKV) in patients with chronic kidney disease (stages 1-3) due to ADPKD. METHODS AND ANALYSIS: A multicentre, prospective, parallel-group, open-label, randomised controlled trial will be conducted. Patients with ADPKD (n=180; age ≤65 years, estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m2) will be randomised (1:1) to either the control (standard treatment+usual fluid intake) or intervention (standard treatment+prescribed fluid intake) group. Participants in the intervention arm will be prescribed an individualised daily fluid intake to reduce urine osmolality to ≤270 mOsmol/kg, and supported with structured clinic and telephonic dietetic review, self-monitoring of urine-specific gravity, short message service text reminders and internet-based tools. All participants will have 6-monthly follow-up visits, and ht-TKV will be measured by MRI at 0, 18 and 36 months. The primary end point is the annual rate of change in ht-TKV as determined by serial renal MRI in control vs intervention groups, from baseline to 3 years. The secondary end points are differences between the two groups in systemic AVP activity, renal disease (eGFR, blood pressure, renal pain), patient adherence, acceptability and safety. ETHICS AND DISSEMINATION: The trial was approved by the Human Research Ethics Committee, Western Sydney Local Health District. The results will inform clinicians, patients and policy-makers regarding the long-term safety, efficacy and feasibility of prescribed fluid intake as an approach to reduce kidney cyst growth in patients with ADPKD. TRIAL REGISTRATION NUMBER: ANZCTR12614001216606.

Incidence and survival of end-stage kidney disease due to polycystic kidney disease in Australia and New Zealand (1963-2014).

BACKGROUND: The aim of this study was to determine whether the incidence and survival of patients with end-stage kidney disease (ESKD) due to polycystic kidney disease (PKD) has changed in Australia and New Zealand. METHODS: Data for all PKD patients who developed ESKD and commenced renal replacement therapy (RRT) was assessed using the Australia and New Zealand Dialysis and Transplant Registry from 1963 to 2014. RESULTS: A total 4678 patients with ESKD due to PKD received RRT during the study period. The incidence rate of ESKD (per million population per year) due to PKD rose by 3.2-fold (1970-2010), but the percentage increase between each decade decreased (54.4, 43.8, 25.6 and 6.57%). The median age of onset of new patients developing ESKD has been stable since 1990. Haemodialysis was the most common initial mode of RRT (between 62 and 76% of patients) whereas 24-29% received peritoneal dialysis. The 5-year survival rate of PKD patients on RRT (censored for transplantation and adjusted for age) improved from 26 to 84%, with the percentage increase between each successive time period being 123, 7, 21, 19 and 7.4%. The percentage of deaths on RRT due to cerebrovascular disease declined from 15 to 6%. CONCLUSIONS: The incidence and age of onset of ESKD due to PKD has remained unchanged in the modern era though patient survival on RRT has continued to improve. These data suggest that the development and implementation of disease-specific treatments prior to RRT is needed to effectively diminish the incidence of ESKD due to PKD.

Rituximab to treat gemcitabine-induced hemolytic-uremic syndrome (HUS) in pancreatic adenocarcinoma: a case series and literature review.

PURPOSE: Hemolytic-uremic syndrome (HUS) is a rare side effect of gemcitabine, which is reported as having a high morbidity and mortality despite interventions with standard HUS therapies including plasmapheresis. The purpose of this report was to describe the successful treatment of gemcitabine-induced HUS (G-HUS) with rituximab. It also aims to summarize the literature regarding the morbidity and mortality of G-HUS in pancreatic adenocarcinoma depending on the treatment given, ultimately providing some guidance for beneficial therapies. METHODS: This is a retrospective report of three patients with pancreatic adenocarcinoma who developed G-HUS and were treated with a combination of therapies including rituximab. RESULTS: All three patients received a combination of therapies to treat their HUS. One patient appeared to have some benefit with plasmapheresis. Resolution occurred following one course of rituximab for all three patients. This resolution has been long lasting with a minimum of eighteen month's follow-up. Similarly, in our literature review a variety of therapies were utilized, but immune therapies appear to reverse HUS if other therapies are failing. CONCLUSION: Rituximab can be an effective therapy for reversal of hemolysis and stabilization of renal function in G-HUS when other therapies fail.

Unlocking the code: mining the urinary proteome after renal transplantation.

Diagnosis of transplant dysfunction usually requires kidney biopsy. Sidgel et al. compared urinary proteomics with matched kidney biopsies to develop a biomarker panel to differentiate acute rejection, BK viral nephropathy, and chronic allograft nephropathy. The results suggest that monitoring a panel of urinary peptides may ultimately facilitate noninvasive diagnosis and management of common transplant complications.

Fab fragments of ovine antibody to colchicine enhance its clearance in the rat.

CONTEXT: Colchicine is an anti-inflammatory alkaloid used for the treatment of acute gout, but has a narrow therapeutic index. Colchicine overdoses are relatively rare, but have high mortality requiring rapid treatment. OBJECTIVE: To evaluate the ability of a newly available ovine fragment antigen-binding (Fab) antibody to colchicine (ColchiFab(™)) to protect rats against renal and other injury 24 h after colchicine ingestion. MATERIALS AND METHODS: Rats were gavaged with colchicine (5 mg/kg), then 2 h later injected intraperitoneally with 5 ml of sterile saline, or Fab anti-colchicine, a newly available ovine antibody to colchicine. Samples of blood were taken at 1, 2, 5 and 24 h after gavage, and urine was collected from 5 to 24 h after gavage. Concentrations of colchicine in tissue, blood and urine were measured by liquid chromatography/mass spectrometry, concentrations of Fab anti-colchicine, urinary neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 or KIM-1 by enzyme-linked immunosorbent assay or ELISA, while concentrations of creatine kinase and creatinine (Cr) were measured enzymatically. RESULTS: Colchicine equilibrated rapidly throughout the body and increased serum creatine kinase. Fab anti-colchicine also rapidly redistributed to the blood and remained at high concentrations over 24 h. Fab anti-colchicine caused a rapid 7.1-fold increase in serum colchicine level, followed by excretion of both colchicine and Fab anti-colchicine through the urine. This was associated with the accumulation of colchicine in the kidney, a reversal of colchicine-induced diarrhoea, and increasing urinary NGAL level; from 168 ± 48 to 477 ± 255 ng/mmol Cr [mean ± standard deviation or SD]. DISCUSSION: Fab anti-colchicine greatly increased the clearance of colchicine, although increasing NGAL level suggested the presence of mild kidney damage. CONCLUSION: These data suggest clinical utility for Fab anti-colchicine in the treatment of colchicine overdose.

Biomarkers of calcineurin inhibitor nephrotoxicity in transplantation.

Over 35 years of use has demonstrated the revolutionary therapeutic benefits of calcineurin inhibitors (CNI) in not only preventing transplant rejection, but also the renal and nonrenal toxicity of CNI. Acute reversible and insidious irreversible forms of CNI nephrotoxicity have been identified, with ischemia from an imbalance between vasoconstrictors and vasodilators playing an important role. The ongoing search to define toxicity pathways has been enriched by 'Omics' studies. Changes in proteins including those involved in activation of pro-inflammatory responses, oxidative stress, ER stress and the unfolded protein response have been identified, and these may serve as biomarkers of toxicity. However, the current standard of CNI toxicity, histology, lacks specificity, which creates challenges for biomarker validation. This review focuses on progress in nephrotoxic pathway identification of CNI and biomarker validation.

A comparison of the ability of levels of urinary biomarker proteins and exosomal mRNA to predict outcomes after renal transplantation.

BACKGROUND: mRNA for biomarkers of kidney injury extracted from urinary exosomes may reflect or predict levels of the corresponding protein after transplantation and clinical outcomes. METHODS: Urinary exosomes were isolated from patients following renal transplantation, from healthy controls, and patients with CKD. Expression of exosomal mRNA for the injury biomarkers neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), kidney injury molecule-1 (KIM-1), and cystatin C was compared with the concentrations of corresponding urinary proteins, 18S RNA and serum creatinine. RESULTS: All biomarker protein concentrations increased after transplantation, and urinary NGAL and IL-18 at 24 and 168 h correlated with the day 7 creatinine reduction ratio (CRR). Exosomal18S RNA increased after transplantation, but exosomal mRNA for NGAL, IL-18 and cystatin C did not correlate with the day 7 CRR, or urinary biomarker concentrations at any time after transplantation. Exosomal NGAL mRNA was lower 4 h after transplantation than in control exosomes. In contrast, exosomal mRNA for cystatin C was unchanged after transplantation and in CKD, although urinary cystatin C temporarily increased following transplantation. Urinary KIM-1 increased after transplantation, but exosomal mRNA for KIM-1 remained undetectable. In CKD 18S RNA was raised, and exosomal mRNA for NGAL, IL-18 and cystatin C was detected in all patients. While urinary NGAL was greater in CKD than control subjects, exosomal NGAL mRNA was unchanged. Exosomal IL-18 mRNA was increased in CKD, but not IL-18 protein. CONCLUSIONS: After renal transplantation, urinary NGAL and IL-18 levels reflect the day 7 CRR. However, while mRNA for these biomarkers is present in exosomes, their levels do not reflect or predict urinary biomarker levels or the CRR. This likely reflects the fact that packaging of mRNA in exosomes is selective, and is not necessarily representative of mRNA in the parent cells responsible for biomarker production.

Outcomes of cardiac surgery in chronic kidney disease.

OBJECTIVE: To identify predictors of early and late outcomes of cardiac surgery in patients with chronic kidney disease. METHODS: Patients (n=545) with serum creatinine≥200 µmol/L or renal dialysis were identified from databases maintained by the largest Sydney cardiothoracic surgical units with data consistent with the Australian and New Zealand Society of Cardiothoracic Surgeons data definitions. The patient data were matched against the National Dialysis Database and the New South Wales Register of Births, Deaths, and Marriages. Statistical analysis was used to identify predictors of early and late outcomes. RESULTS: The Kaplan-Meier estimate of 1-, 5-, and 10-year survival for all patients was 78%, 56%, and 36%, respectively. The outcomes were similar after coronary bypass surgery and valve replacement and were also similar for dialysis and nondialysis patients. The odds ratios for the significant independent predictors of outcomes were, for perioperative death, age (1.4 per decade), emergency surgery (7.0), redo surgery (3.8), left ventricular impairment (moderate, 2.7; severe, 4.4); for new early postoperative dialysis, estimated glomerular filtration rate<20 mL/min (3.8), emergency surgery (2.7), tricuspid valve surgery (4.4); for new permanent dialysis within 6 months of surgery, serum estimated glomerular filtration rate<20 mL/min (odds ratio, 4.6). The hazard ratio for the independent predictors of late death in those alive 6 months after surgery was 1.4 per decade for age and 1.4 for moderate or severe left ventricular impairment. CONCLUSIONS: Left ventricular impairment is a risk factor for perioperative and late death in patients with kidney disease. After cardiac surgery, preoperative dialysis-dependent and dialysis-free patients had similar long-term outcomes.