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Sumedh Jayanti,1,2 Gopala K Rangan1,2 1Department of Renal Medicine, Westmead Hospital, Sydney, NSW, Australia; 2Michael Stern Laboratory for Polycystic Kidney Disease, Centre for Transplant and Renal Research, Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW, AustraliaCorrespondence: Gopala K Rangan, Centre for Transplant and Renal Research, Westmead Institute for Medical Research, 176 Hawkesbury Road, Westmead, Sydney, NSW, 2145, Australia, Email g.rangan@sydney.edu.auAbstract: Advances in the treatment of kidney failure with chronic dialysis have stagnated over the past three decades, with over 50% of patients still managed by conventional in-hospital haemodialysis. In parallel, the demands of chronic dialysis medical care have changed and evolved due to a growing population that has higher frailty and multimorbidity. Thus, the gap between the needs of kidney failure patients and the healthcare capability to provide effective overall management has widened. To address this problem, healthcare policy has increasingly aligned towards a human-centred approach. The paradigm shift of human-centred approach places patients at the forefront of decision-making processes, ensuring that specific needs are understood and prioritised. Integration of human-centred approaches with patient care has been shown to improve satisfaction and quality of life. The aim of this narrative is to evaluate the current clinical challenges for managing kidney failure for dialysis providers; summarise current experiences and unmet needs of chronic dialysis patients; and finally emphasise how human-centred care has advanced chronic dialysis care. Specific incremental advances include implementation of renal supportive care; home-assisted dialysis; hybrid dialysis; refinements to dialysis methods; whereas emerging advances include portable and wearable dialysis devices and the potential for the integration of artificial intelligence in clinical practice.Keywords: patient-centred care, chronic dialysis, kidney failure, patient preference, renal replacement therapy, innovation

Kristal O’Brien,1,2 Sayanthooran Saravanabavan,1,2 Jennifer QJ Zhang,1,2 Annette TY Wong,1,2 Alexandra Munt,1,2 Jane S Burgess,1,2 Gopala K Rangan1,2 1Centre for Transplant and Renal Research, Westmead Institute for Medical Research, The University of Sydney, Sydney, New South Wales, Australia; 2Department of Renal Medicine, Westmead Hospital, Western Sydney Local Health District, Sydney, New South Wales, AustraliaCorrespondence: Gopala K RanganCentre for Transplant and Renal Research, Westmead Institute for Medical Research, The University of Sydney, Level 5, 176 Hawkesbury Road (PO Box 412), Westmead, NSW 2145, AustraliaTel +61-2 8627 3502Fax +61-2 9475-1146Email g.rangan@sydney.edu.auBackground/Aim: The natural history of the renal microvasculature changes in PKD is not known. The aim of this study was to test the hypothesis that angiogenesis is coupled with kidney cyst expansion, and the loss of peritubular capillary networks precedes the onset of interstitial fibrosis.Methods: The renal microvasculature (RECA-1 and CD34) was evaluated in groups of Lewis polycystic kidney (LPK) rats and juvenile cystic kidney (jck) mice during the early, mid and late stage of disease. In addition, LPK rats and jck mice received sirolimus to determine if the reduction in renal cyst growth is in part mediated by the suppression of angiogenesis.Results: In LPK rats, the loss of peritubular capillaries occurred in early-stage disease and paralleled cyst formation whereas in jck mice it was delayed to the mid stage. In both models, vasa recta were displaced by growing cysts and regressed in LPK rats with disease progression but lengthened in jck mice. Cortical and medullary capillary neoangiogenesis occurred during the early stage in both models and persisted with progression. Treatment with sirolimus reduced cyst enlargement but did not alter the progression of renal microvasculature changes in either model.Conclusion: Regression of peritubular capillaries and disruption of vasa recta occur in parallel with angiogenesis and the progressive enlargement of kidney cysts. These data suggest that the regrowth of peritubular capillaries together with inhibition of angiogenesis are potential strategies to be considered in the treatment of PKD.Keywords: juvenile cystic kidney, jck, Lewis polycystic kidney, LPK, peritubular capillary loss, renal vasculature

Lena Succar,1 Ross A Boadle,2 David C Harris,1,3 Gopala K Rangan1,3 1Centre for Transplant and Renal Research, The Westmead Institute for Medical Research, The University of Sydney, 2Electron Microscopy Laboratory, Institute of Clinical Pathology and Medical Research, Westmead Hospital, 3Department of Renal Medicine, Westmead Hospital, Western Sydney Local Health District, Westmead, Sydney, NSW, Australia Purpose: In crescentic glomerulonephritis (CGN), the development of cellular bridges between podocytes and parietal epithelial cells (PECs) triggers glomerular crescent formation. However, the sequential changes in glomerular ultrastructure in CGN are not well defined. This study investigated the time course of glomerular ultrastructure in experimental CGN. Methods: Transmission electron microscopy (TEM) was performed using kidney samples from rats with nephrotoxic serum nephritis (NSN) from day 1 to day 14. Morphometric analysis was conducted on randomly selected glomeruli captured on TEM digital images. Results: On day 1 of NSN, there was widespread formation of focal contacts between the cell bodies of neighboring podocytes, and tight junctions were evident at the site of cell-to-cell contact. This was confirmed by the increased expression of the tight junction molecule, zonula occludens-1 (ZO-1), which localized to the points of podocyte cell–cell body contact. On day 2, the interpodocyte distance decreased and the glomerular basement membrane thickness increased. Foot process effacement (FPE) was segmental on day 3 and diffuse by day 5, accompanied by the formation of podocyte cellular bridges with Bowman’s capsule, as confirmed by a decrease in podocyte-to-PEC distance. Fibrinoid necrosis and cellular crescents were evident in all glomeruli by days 7 and 14. In vitro, the exposure of podocytes to macrophage-conditioned media altered cellular morphology and caused an intracellular redistribution of ZO-1. Conclusion: The formation of tight junctions between podocytes is an early ultrastructural abnormality in CGN, preceding FPE and podocyte bridge formation and occurring in response to inflammatory injury. Podocyte-to-podocyte tight junction formation may be a compensatory mechanism to maintain the integrity of the glomerular filtration barrier following severe endocapillary injury. Keywords: glomerular, crescent, inflammation, zonula occludens

Lena Succar,1 Julia Lai-Kwon,1 David J Nikolic-Paterson,2 Gopala K Rangan1 1Centre for Transplant and Renal Research, Westmead Millennium Institute, University of Sydney, Westmead Hospital, Sydney, NSW, Australia; 2Department of Nephrology and Monash University Department of Medicine, Monash Medical Centre, Clayton, VIC, Australia Background: The study aimed to test the hypothesis that therapeutic treatment with a mammalian target of rapamycin complex 1 inhibitor reduces renal cell proliferation and attenuates glomerular and tubulointerstitial injury in the early phase of nephrotoxic serum nephritis (NSN) in rats. Methods: Male Wistar-Kyoto rats received a single tail-vein injection of sheep anti-rat glomerular basement membrane serum (day 0) and were treated with vehicle or sirolimus (0.25 mg/kg/day by subcutaneous injection) from day 1 until day 14. Results: Treatment with sirolimus attenuated kidney enlargement by 41% (P

Cardiovascular disease (CVD) is the major cause of mortality in autosomal dominant polycystic kidney disease (ADPKD) and contributes to significant burden of disease. The manifestations are varied, including left ventricular hypertrophy (LVH), intracranial aneurysms (ICAs), valvular heart disease, and cardiomyopathies; however, the most common presentation and a major modifiable risk factor is hypertension. The aim of this review is to detail the complex pathogenesis of hypertension and other extrarenal cardiac and vascular conditions in ADPKD drawing on preclinical, clinical, and epidemiological evidence. The main drivers of disease are the renin-angiotensin-aldosterone system (RAAS) and polycystin-related endothelial cell dysfunction, with the sympathetic nervous system (SNS), nitric oxide (NO), endothelin-1 (ET-1), and asymmetric dimethylarginine (ADMA) likely playing key roles in different disease stages. The reported rates of some manifestations, such as LVH, have decreased likely due to the use of antihypertensive therapies; and others, such as ischemic cardiomyopathy, have been reported with increased prevalence likely due to longer survival and higher rates of chronic disease. ADPKD-specific screening and management guidelines exist for hypertension, LVH, and ICAs; and these are described in this review., (Crown Copyright © 2023 Published by Elsevier Inc. on behalf of the International Society of Nephrology.)

Background: In autosomal dominant polycystic kidney disease (ADPKD) impaired nitric oxide (NO) synthesis, in part, contributes to early-onset hypertension. Beetroot juice (BRJ) reduces blood pressure (BP) by increasing NO-mediated vasodilation. The aim of this double-blind, randomised, placebo-controlled study is to test the hypothesis that BRJ reduces systolic and diastolic clinic BP in hypertensive adults with ADPKD., Methods: Participants with ADPKD and treated hypertension (n = 60) will be randomly allocated (1:1) to receive a daily dose of either nitrate-replete (400 mg nitrate/day) or nitrate-deplete BRJ for 4 weeks. The co-primary outcomes are change in mean systolic and diastolic clinic BP before and after 4 weeks of treatment with daily BRJ. Secondary outcomes are changes in daily home BP, urinary albumin to creatinine ratio, serum and salivary nitrate/nitrite levels and serum asymmetric dimethylarginine levels before and after 4 weeks of BRJ., Discussion: The effect of BRJ in ADPKD has not been previously tested. BRJ is an accessible, natural dietary supplement that, if effective, will provide a novel adjunctive approach for treating hypertension in ADPKD., Trial Registration: ClinicalTrials.gov NCT05401409. Retrospectively registered on 27th May 2022., (© 2023. Crown.)

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., (© 2023 The Authors.)

Introduction: This study aimed to determine the utility of different methods to predict rapid progressors (RPs) and their clinical characteristics in Asia-Pacific patients with autosomal dominant polycystic kidney disease (ADPKD)., Methods: This was a multinational retrospective observational cohort study of patients with ADPKD in the Asia-Pacific region. Five hospitals from Australia, China, South Korea, Taiwan, and Turkey participated in this study. RP was defined by European Renal Association-European Dialysis and Transplantation Association (ERA-EDTA) guidelines and compared to slow progressors (SPs)., Results: Among 768 patients, 426 patients were RPs. Three hundred six patients met only 1 criterion and 120 patients satisfied multiple criteria for RP. Historical estimated glomerular filtration rate (eGFR) decline fulfilled the criteria for RP in 210 patients. Five patients met the criteria for a historical increase in height-adjusted total kidney volume (TKV). The 210 patients satisfied the criteria for based on kidney volume. During the follow-up period, cyst infections, cyst hemorrhage, and proteinuria occurred more frequently in RP; and 13.9% and 2.1% of RPs and SPs, respectively, progressed to end-stage kidney disease (ESKD). RP criteria based on historical eGFR decline had the strongest correlation with eGFR change over a 2-year follow-up., Conclusion: Various assessment strategies should be used for identifying RPs among Asian-Pacific patients with ADPKD in real-world clinical practice during the follow-up period, cyst infections, cyst hemorrhage, and proteinuria occurred more frequently; and more patients progressed to ESKD in RPs compared with SPs., (Crown Copyright © 2023 Published by Elsevier Inc. on behalf of the International Society of Nephrology.)

The formation and growth of kidney cysts (fluid-filled structures lined by epithelial cells) is the primary pathological abnormality in polycystic kidney disease (PKD). Multiple molecular pathways are disrupted in kidney epithelial precursor cells, which lead to altered planar cell polarity, increased proliferation, and fluid secretion, which together with extracellular matrix remodelling culminates in the formation and growth of cysts. Three-dimensional (3D) in vitro cyst models serve as suitable preclinical models to screen candidate drugs for PKD. Madin-Darby Canine Kidney (MDCK) epithelial cells form polarized monolayers with a fluid-filled lumen when suspended in a collagen gel, and their growth is accelerated with the addition of forskolin, a cyclic adenosine monophosphate (cAMP) agonist. Candidate drugs for PKD can be screened for their ability to modulate growth of forskolin-treated MDCK cysts by measuring and quantifying cyst images acquired at progressive timepoints. In this chapter, we describe the detailed methods for the culture and growth of MDCK cysts in a collagen matrix and a protocol for their use in testing candidate drugs to prevent cyst formation and growth., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Increased DNA damage response (DDR) signaling in kidney cyst-lining epithelial cells (CECs) may provide an opportunity for cell-specific therapeutic targeting in autosomal dominant polycystic kidney disease (ADPKD). We hypothesized that inhibiting ataxia telangiectasia mutated (ATM; a proximal DDR kinase) together with low-dose cisplatin overwhelms the DDR response and leads to selective apoptosis of cyst-lining epithelial cells (CECs). Pkd1RC/RC/Atm+/− mice were treated with either vehicle or a single low-dose cisplatin, and the acute effects on CECs (DNA damage and apoptosis) after 72 h and chronic effects on progression (cyst size, inflammation, fibrosis) after 3 weeks were investigated. At 72 h, cisplatin caused a dose-dependent increase in γH2AX-positive nuclei in both CECs and non-cystic tubules but did not cause selective apoptosis in Pkd1RC/RC/Atm+/− mice. Moreover, the increase in γH2AX-positive nuclei was 1.7-fold lower in CECs compared to non-cystic epithelial cells (p < 0.05). Low-dose cisplatin also did not alter long-term disease progression in Pkd1RC/RC/Atm+/− mice. In vitro, human ADPKD cyst-derived cell lines were also resistant to cisplatin (WT9-12: 61.7 ± 4.6%; WT9-7: 64.8 ± 2.7% cell viability) compared to HK-2 (25.1 ± 4.2%), and 3D cyst growth in MDCK cells was not altered. Finally, combined low-dose cisplatin with AZD0156 (an ATM inhibitor) non-selectively reduced γH2AX in both cystic and non-cystic tubular cells and exacerbated cystic kidney disease. In conclusion, these data suggest that CECs are resistant to DNA damage, and that the combination of cisplatin with ATM inhibitors is not an effective strategy for selectively eliminating kidney cysts in ADPKD.

BACKGROUND: Arginine vasopressin promotes kidney cyst growth in autosomal dominant polycystic kidney disease (ADPKD). Increased water intake reduces arginine vasopressin and urine osmolality and may slow kidney cyst growth. METHODS: In this randomized controlled 3-year clinical trial, we randomly assigned adults with ADPKD who had a height-corrected total kidney volume in Mayo imaging subclass categories 1B to 1E and an estimated glomerular filtration rate of 30 ml/min/1.73 m2 or greater to (1) water intake prescribed to reduce 24-hour urine osmolality to 270 mOsmol/kg or less or (2) ad libitum water intake irrespective of 24-hour urine osmolality. The primary end point was the percentage annualized rate of change in height-corrected total kidney volume. RESULTS: A total of 184 patients participated in either the ad libitum water intake group (n=92) or the prescribed water intake group (n=92). Over 3 years, there was no difference in the annualized rate of change in height-corrected total kidney volume between the ad libitum (7.8% per year; 95% confidence interval [CI], 6.6 to 9.0) and prescribed (6.8% per year; 95% CI, 5.8 to 7.7) water intake groups (mean difference, −0.97% per year; 95% CI, −2.37 to 0.44; P=0.18). The difference in mean 24-hour urine osmolality between the ad libitum and prescribed water intake groups was −91 mOsmol/kg (95% CI, −127 to −54 mOsmol/kg), with 52.3% of patients achieving adherence to the target 24-hour urine osmolality and no reduction in serum copeptin over 3 years. The frequency of adverse events was similar between groups. CONCLUSIONS: For patients with ADPKD, prescribed water intake was not associated with excess adverse events and achieved the target 24-hour urine osmolality for half of the patients but did not reduce copeptin or slow the growth of total kidney volume over 3 years compared with ad libitum water intake. (Funded by the National Health and Medical Research Council of Australia [grant GNT1138533], Danone Research, PKD Australia, the University of Sydney, and the Westmead Medical Research Foundation; Australian New Zealand Clinical Trials Registry number, ACTRN12614001216606).

Introduction: Excessive water intake is rarely associated with life-threatening hyponatraemia. The aim of this study was to determine the clinical characteristics and outcomes of hyponatraemia associated with excess water intake., Methods: This review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All studies (case reports, observational or interventional studies) reporting excess water intake and hyponatraemia in adults (1946-2019) were included., Results: A total of 2970 articles were identified and 177 were included (88.7% case reports), consisting of 590 patients. The mean age was 46±16 years (95% CI 44 to 48 years), 47% female, 52% had a chronic psychiatric disorder and 31% had no underlying condition. The median volume of water consumed and serum sodium at presentation was 8 L/day (95% CI 8.9 to 12.2 L/day) and 118 mmol/L (95% CI 116 to 118 mmol/L), respectively. The motivator for increased water consumption was psychogenic polydipsia (55%); iatrogenic (13%); exercise (12%); habitual/dipsogenic polydipsia (7%) and other reasons (13%). The clinical features on presentation were severe in 53% (seizures, coma); moderate in 35% (confusion, vomiting, agitation) and mild in 5% (dizziness, lethargy, cognitive deficit) and not reported in 5% of studies. Treatment was supportive in 41% of studies (fluid restriction, treatment of the underlying cause, emergency care), and isotonic and hypertonic saline was used in 18% and 28% of cases, respectively. Treatment-related complications included osmotic demyelination (3%) and rhabdomyolysis (7%), and death occurred in 13% of cases., Conclusion: Water intoxication is associated with significant morbidity and mortality and requires daily intake to substantially exceed population-based recommendations. The limitations of this analysis are the low quality and high risk of bias of the included studies., Prospero Registration Number: A pre-existing protocol in the international prospective register of systematic reviews was updated to incorporate any new amendments and reregistered at http://www.crd.york.ac.uk/PROSPERO (registration no. CRD42019129809)., Competing Interests: Competing interests: GKR is chief investigator of an investigator-initiated grant from Danone Nutricia, but this project was conducted independently of this work. All other authors have no other relevant affiliations or financial involvement with any organisation or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic renal disease in adults and is due to heterozygous germ line variants in either PKD1, PKD2 or rarely other genes. It is characterized by marked intra-familial disease variability suggesting that other genetic and/or environmental factors are involved in determining the lifetime course ADPKD. Recently, research indicates that polycystin-mediated mitochondrial dysfunction and metabolic re-programming contributes to the progression of ADPKD. Although biochemical abnormalities have gained the most interest, variants in the mitochondrial genome could be one of the mechanisms underlying the phenotypic variability in ADPKD. This narrative review aims to evaluate the role of the mitochondrial genome in the pathogenesis of APDKD., (© 2021 Asian Pacific Society of Nephrology.)

Vitamin D secosteroids are intranuclear regulators of cellular growth and suppress the renin-angiotensin system. The aim of this study was to test the hypothesis that the vitamin D receptor agonist, paricalcitol (PC), either alone or with enalapril (E) (an angiotensin-converting enzyme inhibitor), reduces the progression of polycystic kidney disease. Preventative treatment of Lewis polycystic kidney (LPK) and Lewis control rats with PC (0.2 μg/kg i.p. 5 days/week) or vehicle from postnatal weeks 3 to 10 did not alter kidney enlargement. To evaluate the efficacy in established disease, LPK rats received either PC (0.8 μg/kg i.p; 3 days/week), vehicle, E (50 mg/L in water) or the combination of PC + E from weeks 10 to 20. In established disease, PC also did not alter the progression of kidney enlargement, kidney cyst growth or decline in renal function in LPK rats. Moreover, the higher dose of PC was associated with increased serum calcium and weight loss. However, in established disease, the combination of PC + E reduced systolic blood pressure and heart-body weight ratio compared to vehicle and E alone ( p < 0.05). In conclusion, the combination of PC + E attenuated cardiovascular disease but caused hypercalcaemia and did not alter kidney cyst growth in LPK rats.

DNA-dependent protein kinase (DNA-PK) is a serine/threonine protein involved in DNA damage response (DDR) signaling that may mediate kidney cyst growth in autosomal dominant polycystic kidney disease (ADPKD) due to its pleiotropic effects on proliferation and survival. To test this hypothesis, the expression of DNA-PK in human ADPKD and the in vitro effects of DNA-PK inhibition in a three-dimensional model of Madin-Darby Canine Kidney (MDCK) cyst growth and human ADPKD cells were assessed. In human ADPKD, the mRNA expression for all three subunits of the DNA-PK complex was increased, and using immunohistochemistry, the catalytic subunit (DNA-PKcs) was detected in the cyst lining epithelia of human ADPKD, in a focal manner. In vitro, NU7441 (a DNA-PK kinase inhibitor) reduced MDCK cyst growth by up to 52% after long-term treatment over 6-12 days. Although human ADPKD cell lines (WT9-7/WT9-12) did not exhibit synthetic lethality in response to DNA-PK kinase inhibition compared to normal human kidney cells (HK-2), the combination of low-dose NU7441 enhanced the anti-proliferative effects of sirolimus in WT9-7 and WT9-12 cells by 17 ± 10% and 11 ± 7%, respectively. In conclusion, these preliminary data suggest that DNA-PK mediates kidney cyst growth in vivo without a synthetically lethal interaction, conferring cell-specificity in human ADPKD cells. NU7441 enhanced the anti-proliferative effects of rapamycin complex 1 inhibitors, but the effect was modest.

Background: Pain is the highest prioritized patient-reported outcome in people with autosomal dominant polycystic kidney disease (ADPKD) but remains infrequently and inconsistently measured in clinical trials and poorly managed in clinical settings. A recently completed systematic review of pain in ADPKD identified 26 different outcome measures. None of these measures were considered appropriate as a core outcome measure due to the lack of patient-important dimensions, inadequate content, relatively long duration of completion time and limited evidence to support psychometric robustness., Methods: We convened an international Standardized Outcomes in Nephrology-Polycystic Kidney Disease consensus workshop involving 21 patients/caregivers and 40 health professionals (clinicians, nurses, researchers, policy makers and industry representatives) from 18 countries to discuss the identification or development of a core outcome measure for pain., Results: Four themes were identified highlighting fundamental issues for the measurement of pain in ADPKD: distressing and disrupting life participation; variability and ambiguity in defining pain; stigma, frustration and adaptation to pain; and ensuring validity and feasibility of pain measures., Conclusions: Existing measures were found to be insufficient in capturing pain as a core outcome and there was consensus on the need for a new validated measure that is simple, succinct and addresses the impact of pain on life participation. This measure will facilitate the appropriate prioritization of pain in all trials and guide clinical decision making in people with ADPKD., (© The Author(s) 2021. Published by Oxford University Press on behalf of the ERA.)

Pain is a common symptom in people with autosomal dominant polycystic kidney disease (ADPKD), but it is assessed and reported inconsistently in research, and the validity of the measures remain uncertain. The aim of this study was to identify the characteristics, content, and psychometric properties of measures for pain used in ADPKD. We conducted a systematic review including all trials and observational studies that reported pain in people with ADPKD. Items from all measures were categorized into content and measurement dimensions of pain. We assessed the general characteristics and psychometric properties of all measures. 118 studies, we identified 26 measures: 12 (46%) measures were developed for a non-ADPKD population, 1 (4%) for chronic kidney disease, 2 (8%) for polycystic liver disease and 11 (42%) specifically for ADPKD. Ten anatomical sites were included, with the lower back the most common (10 measures [39%]), four measurement dimensions (intensity (23 [88%]), frequency (3 [12%]), temporality (2 [8%]), and sensory (21 [81%]), two pain types, nociceptive including visceral (15 [58%]) and somatic (5 [20%]), and neuropathic (2 [8%]), and twelve impact dimensions, where the most frequent was work (5 [31%]). The validation data for the measures were variable and only the ADPKD Impact Scale reported all psychometric domains. The measures for pain in ADPKD varied in terms of content and length, and most had not been validated in ADPKD. A standardized psychometrically robust measure that captures patient-important dimensions of pain is needed to evaluate and manage this debilitating complication of ADPKD., Competing Interests: The authors have declared that no competing interests exist.

DNA damage and alterations in DNA damage response (DDR) signaling could be one of the molecular mechanisms mediating focal kidney cyst formation in autosomal dominant polycystic kidney disease (ADPKD). The aim of this study was to test the hypothesis that markers of DNA damage and DDR signaling are increased in human and experimental ADPKD. In the human ADPKD transcriptome, the number of up-regulated DDR-related genes was increased by 16.6-fold compared with that in normal kidney, and by 2.5-fold in cystic compared with that in minimally cystic tissue (P < 0.0001). In end-stage human ADPKD tissue, γ-H2A histone family member X (H2AX), phosphorylated ataxia telangiectasia and radiation-sensitive mutant 3 (Rad3)-related (pATR), and phosphorylated ataxia telangiectasia mutated (pATM) localized to cystic kidney epithelial cells. In vitro, pATR and pATM were also constitutively increased in human ADPKD tubular cells (WT 9-7 and 9-12) compared with control (HK-2). In addition, extrinsic oxidative DNA damage by hydrogen peroxide augmented γ-H2AX and cell survival in human ADPKD cells, and exacerbated cyst growth in the three-dimensional Madin-Darby canine kidney cyst model. In contrast, DDR-related gene expression was only transiently increased on postnatal day 0 in Pkd1 RC/RC mice, and not altered at later time points up to 12 months of age. In conclusion, DDR signaling is dysregulated in human ADPKD and during the early phases of murine ADPKD. The constitutive expression of the DDR pathway in ADPKD may promote survival of PKD1-mutated cells and contribute to kidney cyst growth., (Copyright © 2021 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Augmentation of endogenous nitric oxide (NO) synthesis, either by the classical L-arginine-NO synthase pathway, or the recently discovered entero-salivary nitrate-nitrite-NO system, may slow the progression of autosomal dominant polycystic kidney disease (ADPKD). To test this hypothesis, the expression of NO in human ADPKD cell lines (WT 9-7, WT 9-12), and the effect of L-arginine on an in vitro model of three-dimensional cyst growth using MDCK cells, was examined. In addition, groups of homozygous Pkd1RC/RC mice (a hypomorphic genetic ortholog of ADPKD) received either low, moderate or high dose sodium nitrate (0.1, 1 or 10 mmol/kg/day), or sodium chloride (vehicle; 10 mmol/kg/day), supplemented drinking water from postnatal month 1 to 9 (n = 12 per group). In vitro, intracellular NO, as assessed by DAF-2/DA fluorescence, was reduced by >70% in human ADPKD cell lines, and L-arginine and the NO donor, sodium nitroprusside, both attenuated in vitro cyst growth by up to 18%. In contrast, in Pkd1RC/RC mice, sodium nitrate supplementation increased serum nitrate/nitrite levels by ~25-fold in the high dose group (P<0.001), but kidney enlargement and percentage cyst area was not altered, regardless of dose. In conclusion, L-arginine has mild direct efficacy on reducing renal cyst growth in vitro, whereas long-term sodium nitrate supplementation was ineffective in vivo. These data suggest that the bioconversion of dietary nitrate to NO by the entero-salivary pathway may not be sufficient to influence the progression of renal cyst growth in ADPKD., Competing Interests: The authors have declared that no competing interests exist.

The DNA damage response (DDR) pathway is upregulated in autosomal dominant polycystic kidney disease (ADPKD) but its functional role is not known. The ataxia-telangiectasia mutated (ATM) and AT and Rad3-related (ATR) protein kinases are key proximal transducers of the DDR. This study hypothesized that reducing either ATM or ATR attenuates kidney cyst formation and growth in experimental ADPKD. In vitro, pharmacological ATM inhibition by AZD0156 reduced three-dimensional cyst growth in MDCK and human ADPKD cells by up to 4.4- and 4.1-fold, respectively. In contrast, the ATR inhibitor, VE-821, reduced in vitro MDCK cyst growth but caused dysplastic changes. In vivo, treatment with AZD0156 by oral gavage for 10 days reduced renal cell proliferation and increased p53 expression in Pkd1 RC/RC mice (a murine genetic ortholog of ADPKD). However, the progression of cystic kidney disease in Pkd1 RC/RC mice was not altered by genetic ablation of ATM from birth, in either heterozygous ( Pkd1 RC/RC /Atm +/- ) or homozygous ( Pkd1 RC/RC /Atm -/- ) mutant mice at 3 months. In conclusion, despite short-term effects on reducing renal cell proliferation, chronic progression was not altered by reducing ATM in vivo, suggesting that this DDR kinase is dispensable for kidney cyst formation in ADPKD.

Background and Objective: Patients with early chronic kidney disease (CKD) face challenges in accessing healthcare, including delays in diagnosis, fragmented speciality care and lack of tailored education and psychosocial support. Patient navigator programmes have the potential to improve the process of care and outcomes. The objective of this study is to describe the experiences of patients on communication, access of care and self-management and their perspectives on patient navigator programmes in early CKD., Design, Setting and Participants: We convened a workshop in Australia with 19 patients with CKD (all stages including CKD Stage 1 to 5 not on dialysis, 5D (dialysis), and 5T (transplant)) and five caregivers. All of them were over 18 years and English-speaking. Transcripts from the workshop were analysed thematically., Results: Four themes that captured discussions were: lost in the ambiguity of symptoms and management, battling roadblocks while accessing care, emotionally isolated after diagnosis and re-establishing lifestyle and forward planning. Five themes that focussed on patient navigator programmes were: trust and credibility, respecting patient choices and readiness to accept the programme, using accessible language to promote the programme, offering multiple ways to engage and communicate and maintaining confidentiality and privacy. Of the 17 features identified as important for a patient navigator programme, the top five were delivery of education, psychosocial support, lifestyle modification, communication and decision-making support and facilitating care., Conclusion: Patient navigator services can address gaps in services around health literacy, communication, psychosocial support and coordination across multiple healthcare settings. In comparison to the existing navigator programmes, and other services that are aimed at addressing these gaps, credible, accessible and flexible patient navigator programmes for patients with early CKD, that support education, decision-making, access to care and self-management designed in partnership with patients, may be more acceptable to patients., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

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 m 2 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 log 10 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.

Background and Objectives: Presymptomatic testing is available for early diagnosis of hereditary autosomal dominant polycystic kidney disease (ADPKD). However, the complex ethical and psychosocial implications can make decision-making challenging and require an understanding of patients' values, goals and priorities. This study aims to describe patient and caregiver beliefs and expectations regarding presymptomatic testing for ADPKD., Design, Setting and Participants: 154 participants (120 patients and 34 caregivers) aged 18 years and over from eight centres in Australia, France and Korea participated in 17 focus groups. Transcripts were analysed thematically., Results: We identified five themes: avoiding financial disadvantage (insecurity in the inability to obtain life insurance, limited work opportunities, financial burden); futility in uncertainty (erratic and diverse manifestations of disease limiting utility, taking preventive actions in vain, daunted by perplexity of results, unaware of risk of inheriting ADPKD); lacking autonomy and support in decisions (overwhelmed by ambiguous information, medicalising family planning, family pressures); seizing control of well-being (gaining confidence in early detection, allowing preparation for the future, reassurance in family resilience); and anticipating impact on quality of life (reassured by lack of symptoms, judging value of life with ADPKD)., Conclusions: For patients with ADPKD, presymptomatic testing provides an opportunity to take ownership of their health through family planning and preventive measures. However, these decisions can be wrought with tensions and uncertainty about prognostic implications, and the psychosocial and financial burden of testing. Healthcare professionals should focus on genetic counselling, mental health and providing education to patients' families to support informed decision-making. Policymakers should consider the cost burden and risk of discrimination when informing government policies. Finally, patients are recommended to focus on self-care from an early age., Competing Interests: Competing interests: GKR declares he is site investigator of clinical trials sponsored by Sanofi, Otsuka and Reata, principal investigator of the PREVENT-ADPKD clinical trial (funded in part by the NHMRC, Danone Nutricia—manufacturer of bottled water—PKD Australia, Westmead Medical Research Foundation) and Chair, Scientific Advisory Board, PKD Australia. RP declares he is site investigator of clinical trials sponsored by Sanofi, Kadmon, Reata, Otsuka and the US Department of Defense (TAME PKD), and section editor for Cystic Kidney Disease, UpToDate., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Elevated serum urate levels are associated with progression of chronic kidney disease. Whether urate-lowering treatment with allopurinol can attenuate the decline of the estimated glomerular filtration rate (eGFR) in patients with chronic kidney disease who are at risk for progression is not known., Methods: In this randomized, controlled trial, we randomly assigned adults with stage 3 or 4 chronic kidney disease and no history of gout who had a urinary albumin:creatinine ratio of 265 or higher (with albumin measured in milligrams and creatinine in grams) or an eGFR decrease of at least 3.0 ml per minute per 1.73 m 2 of body-surface area in the preceding year to receive allopurinol (100 to 300 mg daily) or placebo. The primary outcome was the change in eGFR from randomization to week 104, calculated with the Chronic Kidney Disease Epidemiology Collaboration creatinine equation., Results: Enrollment was stopped because of slow recruitment after 369 of 620 intended patients were randomly assigned to receive allopurinol (185 patients) or placebo (184 patients). Three patients per group withdrew immediately after randomization. The remaining 363 patients (mean eGFR, 31.7 ml per minute per 1.73 m 2 ; median urine albumin:creatinine ratio, 716.9; mean serum urate level, 8.2 mg per deciliter) were included in the assessment of the primary outcome. The change in eGFR did not differ significantly between the allopurinol group and the placebo group (-3.33 ml per minute per 1.73 m 2 per year [95% confidence interval {CI}, -4.11 to -2.55] and -3.23 ml per minute per 1.73 m 2 per year [95% CI, -3.98 to -2.47], respectively; mean difference, -0.10 ml per minute per 1.73 m 2 per year [95% CI, -1.18 to 0.97]; P = 0.85). Serious adverse events were reported in 84 of 182 patients (46%) in the allopurinol group and in 79 of 181 patients (44%) in the placebo group., Conclusions: In patients with chronic kidney disease and a high risk of progression, urate-lowering treatment with allopurinol did not slow the decline in eGFR as compared with placebo. (Funded by the National Health and Medical Research Council of Australia and the Health Research Council of New Zealand; CKD-FIX Australian New Zealand Clinical Trials Registry number, ACTRN12611000791932.)., (Copyright © 2020 Massachusetts Medical Society.)

A hallmark of polycystic kidney diseases (PKDs) is aberrant proliferation, which leads to the formation and growth of renal cysts. Proliferation is mediated by cyclin-dependent kinases (Cdks), and the administration of roscovitine (a pan-Cdk inhibitor) attenuates renal cystic disease in juvenile cystic kidney (jck) mice. Cdk2 is a key regulator of cell proliferation, but its specific role in PKD remains unknown. The aim of this study was to test the hypothesis that Cdk2 deficiency reduces renal cyst growth in PKD. Three studies were undertaken: (i) a time course (days 28, 56, and 84) of cyclin and Cdk activity was examined in jck mice and compared with wild-type mice; (ii) the progression was compared in jck mice with or without Cdk2 ablation from birth; and (iii) the effect of sirolimus (an antiproliferative agent) on Cdk2 activity in jck mice was investigated. Renal disease in jck mice was characterized by diffuse tubular cyst growth, interstitial inflammation and fibrosis, and renal impairment, peaking on day 84. Renal cell proliferation peaked during earlier stages of disease (days 28-56), whereas the expression of Cdk2-cyclin partners (A and E) and Cdk1 and 2 activity, was maximal in the later stages of disease (days 56-84). Cdk2 ablation did not attenuate renal disease progression and was associated with persistent Cdk1 activity. In contrast, the postnatal treatment of jck mice with sirolimus reduced both Cdk2 and Cdk1 activity and reduced renal cyst growth. In conclusion, (i) the kinetics of Cdk2 and Cdk2-cyclin partners did not correlate with proliferation in jck mice; and (ii) the absence of Cdk2 did not alter renal cyst growth, most likely due to compensation by Cdk1. Taken together, these data suggest that Cdk2 is dispensable for the proliferation of cystic epithelial cells and progression of PKD.

Introduction: Patients with autosomal dominant polycystic kidney disease (ADPKD) reach end-stage renal disease in their fifth decade on average. For effective treatment and early intervention, identifying subgroups with rapid disease progression is important in ADPKD. However, there are no epidemiological data on the clinical manifestations and disease progression of patients with ADPKD from the Asia-Pacific region., Methods and Analysis: The RAPID-ADPKD ( R etrospective epidemiological study of A sia- P acific patients with rap I d D isease progression of A utosomal D ominant P olycystic K idney D isease) study is a multinational, retrospective, observational cohort study of patients with ADPKD in the Asia-Pacific region (Australia, China, Hong Kong, South Korea, Taipei and Turkey). This study was designed to identify the clinical characteristics of patients with ADPKD with rapid disease progression. Adult patients with ADPKD diagnosed according to the unified ultrasound criteria and with an estimated glomerular filtration rate (eGFR) ≥45 mL/min/1.73 m 2 at baseline will be included. The cohort will include patients with ≥2 records of eGFR and at least 24 months of follow-up data. Demographic information, clinical characteristics, comorbidities, medications, eGFR, radiological findings that allow calculation of height-adjusted total kidney volume, ADPKD-related complications and the Predicting Renal Outcomes in autosomal dominant Polycystic Kidney Disease (PRO-PKD) score will be collected. Rapid progression will be defined based on the European Renal Association - European Dialysis and Transplant Association (ERA-EDTA) guideline. All other patients without any of these criteria will be classified to be of slow progression. Clinical characteristics will be compared between patients with rapid progression and those with slow progression. The incidence of complications and the effects of race and water intake on renal progression will also be analysed. The planned sample size of the cohort is 1000 patients, and data from 600 patients have been collected as of 30 May 2019., Ethics and Dissemination: This study was approved or is in the process of approval by the institutional review boards at each participating centre. The results will be presented in conferences and published in a journal, presenting data on the clinical characteristics, risk factors for disease progression and patterns of complications of ADPKD in Asian populations., Competing Interests: Competing interests: GKR received grant support from Danone Nutricia Research for clinical research on ADPKD., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic kidney disease and is caused by heterozygous germ-line mutations in either PKD1 (85%) or PKD2 (15%). It is characterised by the formation of numerous fluid-filled renal cysts and leads to adult-onset kidney failure in ~50% of patients by 60 years. Kidney cysts in ADPKD are focal and sporadic, arising from the clonal proliferation of collecting-duct principal cells, but in only 1-2% of nephrons for reasons that are not clear. Previous studies have demonstrated that further postnatal reductions in PKD1 (or PKD2) dose are required for kidney cyst formation, but the exact triggering factors are not clear. A growing body of evidence suggests that DNA damage, and activation of the DNA damage response pathway, are altered in ciliopathies. The aims of this review are to: (i) analyse the evidence linking DNA damage and renal cyst formation in ADPKD; (ii) evaluate the advantages and disadvantages of biomarkers to assess DNA damage in ADPKD and finally, (iii) evaluate the potential effects of current clinical treatments on modifying DNA damage in ADPKD. These studies will address the significance of DNA damage and may lead to a new therapeutic approach in ADPKD.

Polycystic kidney disease (PKD) is the most common inherited cause of kidney failure and currently has limited treatment options. Increasing water intake reduces renal cyst growth in the pck rat (a genetic ortholog of autosomal recessive PKD) but it is not clear if this beneficial effect is present in other models of PKD. In this study, we tested the hypothesis that high water intake (HWI) reduces the progression of cystic renal disease in Lewis polycystic kidney (LPK) rats (a genetic ortholog of human nephronophthisis-9). Groups of female and male LPK (n = 8-10 per group) and Lewis (n = 4 per group) rats received water ad libitum supplemented with or without 5% glucose [to simulate HWI or normal water intake (NWI) respectively] from postnatal weeks 3 to 16. Water intake increased ~1.3-fold in the LPK+HWI group compared to LPK+NWI rats between weeks 3 to 10 but the differences were not significant at later timepoints. In LPK rats, HWI reduced the increases in the kidney to body weight ratio by 54% at week 10 and by 42% at week 16 compared to NWI (both p<0.01). The reduction in kidney enlargement was accompanied by decreases in the percentage renal cyst area, percentage renal interstitial collagen and proteinuria (all p<0.05). At week 16, HWI reduced systolic blood pressure and the heart to body to weight ratio by 16% and 21% respectively in males LPK rats (both p<0.01). In conclusion, a modest increase in water intake during the early phase of disease was sufficient to attenuate renal cystic disease in LPK rats, with secondary benefits on hypertension and cardiovascular disease. These data provide further preclinical evidence that increased water intake is a potential intervention in cystic renal diseases., Competing Interests: G.R. has declared travel support from Otsuka Pharmaceuticals in October 2018. The other authors have declared that no competing interests exist. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

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 m 2 ) 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., Competing Interests: Competing interests: The study protocol was developed independently by the authors listed of this manuscript. GR is the sole principal investigator listed on the grant received from Danone Nutricia Research to conduct this trial. The grant was awarded in December 2015 and is being administered by the study sponsor (Western Sydney Local Health District). GR has received travel support from Danone Nutricia Research to attend an international meeting on hydration (2016 and 2017). No other authors have competing interests to declare., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

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.

The disease-modifying effects of target of rapamycin complex 1 (TORC1) inhibitors during different stages of polycystic kidney disease (PKD) are not well defined. In this study, male Lewis Polycystic Kidney Disease (LPK) rats (a genetic ortholog of human NPHP9, phenotypically characterised by diffuse distal nephron cystic growth) and Lewis controls received either vehicle (V) or sirolimus (S, 0.2 mg/kg by intraperitoneal injection 5 days per week) during the early (postnatal weeks 3 to 10) or late stages of disease (weeks 10 to 20). In early-stage disease, sirolimus reduced kidney enlargement (by 63%), slowed the rate of increase in total kidney volume (TKV) in serial MRI by 78.2% (LPK+V: 132.3±59.7 vs. LPK+S: 28.8±12.0% per week) but only partly reduced the percentage renal cyst area (by 19%) and did not affect the decline in endogenous creatinine clearance (CrCl) in LPK rats. In late-stage disease, sirolimus reduced kidney enlargement (by 22%) and the rate of increase in TKV by 71.8% (LPK+V: 13.1±6.6 vs. LPK+S: 3.7±3.7% per week) but the percentage renal cyst area was unaltered, and the CrCl only marginally better. Sirolimus reduced renal TORC1 activation but not TORC2, NF-κB DNA binding activity, CCL2 or TNFα expression, and abnormalities in cilia ultrastructure, hypertension and cardiac disease were also not improved. Thus, the relative treatment efficacy of TORC1 inhibition on kidney enlargement was consistent at all disease stages, but the absolute effect was determined by the timing of drug initiation. Furthermore, cystic microarchitecture, renal function and cardiac disease remain abnormal with TORC1 inhibition, indicating that additional approaches to normalise cellular dedifferentiation, inflammation and hypertension are required to completely arrest the progression of PKDs., Competing Interests: The authors have declared that no competing interests exist.

Background: Maintaining adequate fluid intake has been hypothesized to be beneficial for the progression of chronic kidney disease (CKD). The aim of this study was to undertake a systematic review to determine the most effective interventions to increase water intake., Methods: Six electronic databases were searched from 1910 until March 2015 in the English language. Additional sources through hand-searches, expert recommendations and reviews were checked. Intervention studies increasing water intake in adults through non-pharmacological methods were eligible for inclusion. The quality of included studies was assessed., Results: A total of 950 studies were found of which 16 met the inclusion criteria. Eight studies were randomized controlled trials, and seven studies spanned 6 months or longer. The study populations varied and included patients with recurrent nephrolithiasis (n = 6), autosomal dominant polycystic kidney disease (n = 3), CKD (n = 1), urinary tract infection (n = 1) and other miscellaneous conditions (n = 5). The quality of the studies was mostly neutral (63%) with no studies of high quality. Interventions ranged from instruction alone to self-monitoring tools, providing water bottles and counselling and education. Most interventions successfully increased water intake with 13 studies reporting an increase of at least 500 mL. The most effective strategies were instruction and self-monitoring using urine dipstick or 24 h urine volume., Conclusion: All interventions carried out in the studies succeeded in increasing water intake, with none leading to decreases in intake, and these could be implemented in potential clinical trials in CKD. However, more high quality long-term intervention studies are required to further validate findings., (© 2015 Asian Pacific Society of Nephrology.)

Autosomal-dominant polycystic kidney disease (ADPKD) is the most common genetic renal disease in adults, affecting one in every 1000 Australians. It is caused by loss-of-function heterozygous mutations in either PKD1 or PKD2 , which encode the proteins, polycystin-1 and polycystin-2 respectively. The disease hallmark is the development of hundreds of microscopic fluid-filled cysts in the kidney during early childhood, which grow exponentially and continuously through life at varying rates (between 2% and 10% per year), causing loss of normal renal tissue and up to a 50% lifetime risk of dialysis-dependent kidney failure. Other systemic complications include hypertensive cardiac disease, hepatic cysts, intracranial aneurysms, diverticular disease and hernias. Over the last two decades, advances in the genetics and pathogenesis of this disease have led to novel treatments that reduce the rate of renal cyst growth and may potentially delay the onset of kidney failure. New evidence indicates that conventional therapies (such as angiotensin inhibitors and statins) have mild attenuating effects on renal cyst growth and that systemic levels of vasopressin are critical for promoting renal cyst growth in the postnatal period. Identifying and integrating patient-centred perspectives in clinical trials is also being advocated. This review will provide an update on recent advances in the clinical management of ADPKD., (© 2016 Royal Australasian College of Physicians.)

Aim: To determine the temporal expression and pattern of Rel/nuclear factor (NF)-κB proteins in renal tissue in polycystic kidney disease (PKD)., Methods: The renal expression of Rel/NF-κB proteins was determined by immunohistochemistry, immunofluorescence and immunoblot analysis in Lewis polycystic kidney rats (LPK, a genetic ortholog of human nephronopthsis-9) from postnatal weeks 3 to 20. At each timepoint, renal disease progression and the mRNA expression of NF-κB-dependent genes (TNFα and CCL2) were determined. NF-κB was also histologically assessed in human PKD tissue., Results: Progressive kidney enlargement in LPK rats was accompanied by increased renal cell proliferation and interstitial monocyte accumulation (peaking at weeks 3 and 10 respectively), and progressive interstitial fibrosis (with α smooth muscle actin and Sirius Red deposition significantly increased compared to Lewis kidneys from weeks 3 to 6 onwards). Rel/NF-κB proteins (phosphorylated-p105, p65, p50, c-Rel and RelB) were expressed in cystic epithelial cells (CECs) of LPK kidneys as early as postnatal week 3 and sustained until late-stage disease at week 20. From weeks 10 to 20, nuclear p65, p50, RelB and cytoplasmic IκBα protein levels, and TNFα and CCL2 expression, were upregulated in LPK compared to Lewis kidneys. NF-κB proteins were consistently expressed in CECs of human PKD. The DNA damage marker γ-H2AX was also identified in the CECs of LPK and human polycystic kidneys., Conclusion: Several NF-κB proteins are consistently expressed in CECs in human and experimental PKD. These data suggest that the upregulation of both the canonical and non-canonical pathways of NF-κB signaling may be a constitutive and early pathological feature of cystic renal diseases.

Aim: To determine whether complement membrane attack complex (C5b-9) has a pathogenic role in tubulointerstitial injury in a renal disease model characterized by acute highly selective proteinuria., Methods: Protein-overload nephropathy (PON) was induced in adult female Piebald-Viral-Glaxo rats with or without complement C6 deficiency (C6(-) and C6(+)) by daily intraperitoneal injections of bovine serum albumin (BSA, 2 g/d), and examined on days 2, 4 and 8., Results: Groups with PON developed equivalent levels of heavy proteinuria within 24 h of BSA injection. In C6(+) rats with PON, the tubulointerstitial expression of C5b-9 was increased and localized predominantly to the basolateral surface of tubular epithelial cells (TECs), whereas it was undetectable in C6(-) animals. TEC proliferation (as assessed by the number of BrdU+ cells) increased by more than 50-fold in PON, peaking on day 2 and declining on days 4 to 8. There was a trend for a reduction in the number of BrdU+ TECs on day 4 in the C6(-) PON group (P = 0.10 compared to C6(+)) but not at any other time-point. Kidney enlargement, TEC apoptosis (TUNEL(+) cells) and markers of tubular injury (tubule dilatation, loss of TEC height, protein cast formation) were not altered by C6 deficiency in PON. Interstitial monocyte (ED-1+ cell) accumulation was partially reduced in C6(-) animals with PON on day 4 (P = 0.01) but there was no change in myofibroblast accumulation., Conclusion: These data suggest that C5b-9 does not mediate tubulointerstitial injury in acute glomerular diseases characterized by selective proteinuria.

Aim: This study aimed to identify consumer perspectives on topics and outcomes to integrate in the Kidney Health Australia Caring for Australasians with Renal Impairment (KHA-CARI) clinical practice guidelines on autosomal-dominant polycystic kidney disease (ADPKD)., Methods: A workshop involving three concurrent focus groups with 18 consumers (patients with ADPKD (n = 15), caregivers (n = 3)) was convened. Guideline topics, interventions and outcomes were identified, and integrated into guideline development. Thematic analysis was used to analyse the reasons for their choices., Results: Twenty-two priority topics were identified, with most focussed on non-pharmacological management (diet, fluid intake, physical activity, complementary medicine), pain management and psychosocial care (mental health, counselling, cognitive and behavioural training, education, support groups). They also identified 26 outcomes including quality of life (QoL), progression of kidney disease, kidney function, cyst growth and nephrotoxity. Almost all topics and outcomes suggested were identified by health professionals with the exception of five topics/outcomes. Six themes reflected reasons for their choices: clarifying ambiguities, resolving debilitating pain, concern for family, preparedness for the future, taking control and significance of impact., Conclusion: Although there was considerable concordance between the priority topics and outcomes of health professionals and consumers for guidelines of ADPKD, there was also important discordance with consumers focused on fewer issues, but particularly on lifestyle, psychosocial support, pain, and QoL and renal outcomes. Active consumer engagement in guidelines development can help to ensure the inclusion of patient-centred recommendations, which may lead to better management of disease progression, symptoms, complications, and psychosocial impact., (© 2015 Asian Pacific Society of Nephrology.)

Background: Cyst infection is one of the complications of autosomal dominant polycystic kidney disease and polycystic liver disease. The diagnosis is typically made on a mix of clinical, laboratory and imaging abnormalities but the importance of individual items is uncertain. We aimed to perform a Delphi survey amongst physicians to achieve consensus on diagnostic criteria., Methods: We retrieved diagnostic items from the literature and conducted physician and patient interviews. All items were combined to create the online questionnaire. Participants rated each item during 3 consecutive rounds. Items were rated for diagnostic helpfulness for hepatic and renal cyst infection on a 9-point scale with anchors, from extremely unimportant (n = 1) to extremely important (n = 9). We determined consensus with the disagreement index. The median rating of each item was calculated and categorized into inappropriate (≤3.4), uncertain (3.5-6.4) or appropriate (≥6.5). By combining all items that reached an appropriate consensus rating, we developed a diagnostic algorithm based on expert consensus., Results: We invited 58 physicians to participate in the survey. In total, 35 (60%) responded to round 1 of which 91% (n = 32) and 86% (n = 30) responded to round 2 and 3, respectively. The final panel included 23 nephrologists, 5 hepatologists, a nuclear medicine specialist and an infectious disease physician from 11 countries (male 67%, mean age 47 ± 11 years, median clinical experience 21 years). The panel rated the diagnostic helpfulness of 59 potential items. Ultimately, 22 hepatic and 26 renal items were rated appropriate, including positive blood cultures and fluorodeoxyglucose positron-emission CT imaging. Ultrasonography and absence of intracystic bleeding were amongst those deemed uncertain or inappropriate. Subsequently, by combining items rated appropriate, we developed a clinical tool to diagnose hepatic and renal cyst infection., Conclusions: We identified diagnostic items for hepatic and renal cyst infection and developed an expert-based diagnostic algorithm, which may aid physicians in the diagnostic work-up. A prospective study is necessary to validate this algorithm., (© 2016 S. Karger AG, Basel.)

Background: Pyrrolidine dithiocarbamate (PDTC) reduces renal cyst growth in a rodent model of polycystic kidney disease (PKD) but the mechanism of action is not clear. Here, we investigated the hypothesis that PDTC reduces the proliferation of cystic epithelial cells in vitro in a nuclear factor (NF)-κB-dependent manner., Methods: Immortalized autosomal dominant PKD (ADPKD) cells that are heterozygous (WT9-7) and homozygous (WT-9-12) for a truncating Pkd1 mutation, and immortalized normal human tubular cells (HK-2), were exposed to NF-κB-inducing agents with or without PDTC. Cell proliferation and apoptosis were assessed by bromodeoxyuridine assay and Annexin V flow cytometry, respectively. NF-κB activity was assessed by luciferase reporter assay and western blotting for nuclear p65, p50, and RelB subunits and cytoplasmic phosphorylated-IκBα., Results: Serum-induced proliferation was similar in all cell lines over 72 h. PDTC demonstrated anti-proliferative effects that were delayed in ADPKD cells compared to HK-2. Basal NF-κB-dependent luciferase reporter activity was lower in ADPKD cells compared to normal cells. Classical NF-κB stimulants, lipopolysaccharide (LPS) and tumor necrosis factor (TNF)-α, increased NF-κB luciferase activity in HK-2, whereas in PKD cell lines, NF-κB activity was only induced by TNF-α. However, neither stimulant altered proliferation in any cell line. PDTC reduced TNF-α-stimulated NF-κB activity in HK-2 only., Conclusions: PDTC reduced proliferation in ADPKD cells but did not consistently alter NF-κB activation, suggesting that other signalling pathways are likely to be involved in its ability to attenuate renal cyst growth in vivo.

Microsphaeropsis arundinis, a dematiaceous mold, is emerging as a cause of skin and soft tissue infection in immunocompromised hosts. Diagnosis is challenging because of the difficulty in identifying Microsphaeropsis species morphologically and few data are available to guide optimal management. We report 3 renal transplant recipients with M. arundinis soft tissue infection, where the etiological agent was diagnosed using DNA sequencing, and who were successfully treated with prolonged courses of extended-spectrum triazole antifungal agents., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)