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Della Corte M, Viggiano D. Wall Tension and Tubular Resistance in Kidney Cystic Conditions. Biomedicines 2023; 11:1750. [PMID: 37371845 DOI: 10.3390/biomedicines11061750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
The progressive formation of single or multiple cysts accompanies several renal diseases. Specifically, (i) genetic forms, such as adult dominant polycystic kidney disease (ADPKD), and (ii) acquired cystic kidney disease (ACKD) are probably the most frequent forms of cystic diseases. Adult dominant polycystic kidney disease (ADPKD) is a genetic disorder characterized by multiple kidney cysts and systemic alterations. The genes responsible for the condition are known, and a large amount of literature focuses on the molecular description of the mechanism. The present manuscript shows that a multiscale approach that considers supramolecular physical phenomena captures the characteristics of both ADPKD and acquired cystic kidney disease (ACKD) from the pathogenetic and therapeutical point of view, potentially suggesting future treatments. We first review the hypothesis of cystogenesis in ADPKD and then focus on ACKD, showing that they share essential pathogenetic features, which can be explained by a localized obstruction of a tubule and/or an alteration of the tubular wall tension. The consequent tubular aneurysms (cysts) follow Laplace's law. Reviewing the public databases, we show that ADPKD genes are widely expressed in various organs, and these proteins interact with the extracellular matrix, thus potentially modifying wall tension. At the kidney and liver level, the authors suggest that altered cell polarity/secretion/proliferation produce tubular regions of high resistance to the urine/bile flow. The increased intratubular pressure upstream increases the difference between the inside (Pi) and the outside (Pe) of the tubules (∆P) and is counterbalanced by lower wall tension by a factor depending on the radius. The latter is a function of tubule length. In adult dominant polycystic kidney disease (ADPKD), a minimal reduction in the wall tension may lead to a dilatation in the tubular segments along the nephron over the years. The initial increase in the tubule radius would then facilitate the progressive expansion of the cysts. In this regard, tubular cell proliferation may be, at least partially, a consequence of the progressive cysts' expansion. This theory is discussed in view of other diseases with reduced wall tension and with cysts and the therapeutic effects of vaptans, somatostatin, SGLT2 inhibitors, and potentially other therapeutic targets.
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Affiliation(s)
- Michele Della Corte
- Department of Translational Medical Sciences, University of Campania Luigi Vanvitelli, 80131 Naples, Italy
| | - Davide Viggiano
- Department of Translational Medical Sciences, University of Campania Luigi Vanvitelli, 80131 Naples, Italy
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2
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Glucose absorption drives cystogenesis in a human organoid-on-chip model of polycystic kidney disease. Nat Commun 2022; 13:7918. [PMID: 36564419 PMCID: PMC9789147 DOI: 10.1038/s41467-022-35537-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 12/08/2022] [Indexed: 12/24/2022] Open
Abstract
In polycystic kidney disease (PKD), fluid-filled cysts arise from tubules in kidneys and other organs. Human kidney organoids can reconstitute PKD cystogenesis in a genetically specific way, but the mechanisms underlying cystogenesis remain elusive. Here we show that subjecting organoids to fluid shear stress in a PKD-on-a-chip microphysiological system promotes cyst expansion via an absorptive rather than a secretory pathway. A diffusive static condition partially substitutes for fluid flow, implicating volume and solute concentration as key mediators of this effect. Surprisingly, cyst-lining epithelia in organoids polarize outwards towards the media, arguing against a secretory mechanism. Rather, cyst formation is driven by glucose transport into lumens of outwards-facing epithelia, which can be blocked pharmacologically. In PKD mice, glucose is imported through cysts into the renal interstitium, which detaches from tubules to license expansion. Thus, absorption can mediate PKD cyst growth in human organoids, with implications for disease mechanism and potential for therapy development.
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Lee K, Gusella GL, He JC. Epithelial proliferation and cell cycle dysregulation in kidney injury and disease. Kidney Int 2021; 100:67-78. [PMID: 33831367 PMCID: PMC8855879 DOI: 10.1016/j.kint.2021.03.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 03/05/2021] [Accepted: 03/11/2021] [Indexed: 02/08/2023]
Abstract
Various cellular insults and injury to renal epithelial cells stimulate repair mechanisms to adapt and restore the organ homeostasis. Renal tubular epithelial cells are endowed with regenerative capacity, which allows for a restoration of nephron function after acute kidney injury. However, recent evidence indicates that the repair is often incomplete, leading to maladaptive responses that promote the progression to chronic kidney disease. The dysregulated cell cycle and proliferation is also a key feature of renal tubular epithelial cells in polycystic kidney disease and HIV-associated nephropathy. Therefore, in this review, we provide an overview of cell cycle regulation and the consequences of dysregulated cell proliferation in acute kidney injury, polycystic kidney disease, and HIV-associated nephropathy. An increased understanding of these processes may help define better targets for kidney repair and combat chronic kidney disease progression.
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Affiliation(s)
- Kyung Lee
- Department of Medicine, Nephrology Division, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
| | - G Luca Gusella
- Department of Medicine, Nephrology Division, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - John Cijiang He
- Department of Medicine, Nephrology Division, Icahn School of Medicine at Mount Sinai, New York, New York, USA; Renal Program, James J. Peters Veterans Affairs Medical Center, Bronx, New York, USA.
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Automatic semantic segmentation of kidney cysts in MR images of patients affected by autosomal-dominant polycystic kidney disease. Abdom Radiol (NY) 2021; 46:1053-1061. [PMID: 32940759 PMCID: PMC7940295 DOI: 10.1007/s00261-020-02748-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 08/26/2020] [Accepted: 09/03/2020] [Indexed: 12/22/2022]
Abstract
PURPOSE For patients affected by autosomal-dominant polycystic kidney disease (ADPKD), successful differentiation of cysts is useful for automatic classification of patient phenotypes, clinical decision-making, and disease progression. The objective was to develop and evaluate a fully automated semantic segmentation method to differentiate and analyze renal cysts in patients with ADPKD. METHODS An automated deep learning approach using a convolutional neural network was trained, validated, and tested on a set of 60 MR T2-weighted images. A three-fold cross-validation approach was used to train three models on distinct training and validation sets (n = 40). An ensemble model was then built and tested on the hold out cases (n = 20), with each of the cases compared to manual segmentations performed by two readers. Segmentation agreement between readers and the automated method was assessed. RESULTS The automated approach was found to perform at the level of interobserver variability. The automated approach had a Dice coefficient (mean ± standard deviation) of 0.86 ± 0.10 vs Reader-1 and 0.84 ± 0.11 vs. Reader-2. Interobserver Dice was 0.86 ± 0.08. In terms of total cyst volume (TCV), the automated approach had a percent difference of 3.9 ± 19.1% vs Reader-1 and 8.0 ± 24.1% vs Reader-2, whereas interobserver variability was - 2.0 ± 16.4%. CONCLUSION This study developed and validated a fully automated approach for performing semantic segmentation of kidney cysts in MR images of patients affected by ADPKD. This approach will be useful for exploring additional imaging biomarkers of ADPKD and automatically classifying phenotypes.
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Torres JA, Rezaei M, Broderick C, Lin L, Wang X, Hoppe B, Cowley BD, Savica V, Torres VE, Khan S, Holmes RP, Mrug M, Weimbs T. Crystal deposition triggers tubule dilation that accelerates cystogenesis in polycystic kidney disease. J Clin Invest 2019; 129:4506-4522. [PMID: 31361604 PMCID: PMC6763267 DOI: 10.1172/jci128503] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 07/23/2019] [Indexed: 12/19/2022] Open
Abstract
The rate of disease progression in autosomal-dominant (AD) polycystic kidney disease (PKD) exhibits high intra-familial variability suggesting that environmental factors may play a role. We hypothesized that a prevalent form of renal insult may accelerate cystic progression and investigated tubular crystal deposition. We report that calcium oxalate (CaOx) crystal deposition led to rapid tubule dilation, activation of PKD-associated signaling pathways, and hypertrophy in tubule segments along the affected nephrons. Blocking mTOR signaling blunted this response and inhibited efficient excretion of lodged crystals. This mechanism of "flushing out" crystals by purposefully dilating renal tubules has not previously been recognized. Challenging PKD rat models with CaOx crystal deposition, or inducing calcium phosphate deposition by increasing dietary phosphorous intake, led to increased cystogenesis and disease progression. In a cohort of ADPKD patients, lower levels of urinary excretion of citrate, an endogenous inhibitor of calcium crystal formation, correlated with increased disease severity. These results suggest that PKD progression may be accelerated by commonly occurring renal crystal deposition which could be therapeutically controlled by relatively simple measures.
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Affiliation(s)
- Jacob A. Torres
- University of California Santa Barbara, Department of Molecular, Cellular, and Developmental Biology, and Neuroscience Research Institute, Santa Barbara, California, USA
| | - Mina Rezaei
- University of California Santa Barbara, Department of Molecular, Cellular, and Developmental Biology, and Neuroscience Research Institute, Santa Barbara, California, USA
| | - Caroline Broderick
- University of California Santa Barbara, Department of Molecular, Cellular, and Developmental Biology, and Neuroscience Research Institute, Santa Barbara, California, USA
| | - Louis Lin
- University of California Santa Barbara, Department of Molecular, Cellular, and Developmental Biology, and Neuroscience Research Institute, Santa Barbara, California, USA
| | - Xiaofang Wang
- Mayo Clinic College of Medicine, Division of Nephrology and Hypertension, Rochester, Minnesota, USA
| | - Bernd Hoppe
- University Children’s Hospital Bonn, Division of Pediatric Nephrology, Bonn, Germany
| | - Benjamin D. Cowley
- University of Oklahoma Health Sciences Center, Department of Medicine, Section of Nephrology, Oklahoma City, Oklahoma, USA
| | - Vincenzo Savica
- University of Messina, Department of Clinical and Experimental Medicine, Messina, Italy
| | - Vicente E. Torres
- Mayo Clinic College of Medicine, Division of Nephrology and Hypertension, Rochester, Minnesota, USA
| | - Saeed Khan
- University of Florida, Department of Pathology, Gainesville, Florida, USA
| | | | - Michal Mrug
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
- Department of Veterans Affairs Medical Center, Birmingham, Alabama, USA
| | - Thomas Weimbs
- University of California Santa Barbara, Department of Molecular, Cellular, and Developmental Biology, and Neuroscience Research Institute, Santa Barbara, California, USA
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Bae KT, Zhou W, Shen C, Landsittel DP, Wu Z, Tao C, Chapman AB, Torres VE, Yu ASL, Mrug M, Bennett WM, Harris PC. Growth Pattern of Kidney Cyst Number and Volume in Autosomal Dominant Polycystic Kidney Disease. Clin J Am Soc Nephrol 2019; 14:823-833. [PMID: 31088850 PMCID: PMC6556721 DOI: 10.2215/cjn.10360818] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 03/22/2019] [Indexed: 01/05/2023]
Abstract
BACKGROUND AND OBJECTIVES To evaluate the growth pattern of kidney cyst number and cyst volume in association with kidney size, demographics, and genotypes in autosomal dominant polycystic kidney disease. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Kidney cyst number and cyst volume were measured from serial magnetic resonance images, giving a maximum follow-up of 14.23 years, from 241 patients with autosomal dominant polycystic kidney disease (15-46 years old at baseline). The growth pattern was analyzed, in association with sex, age, height-adjusted total kidney volume, and genotype, using linear mixed models of repeated measurements and tests of interactions with age (as a time-dependent covariate) to assess rates of change over time. Models were also fit using Irazabal class. Genotypic groups were characterized as either (1) PKD1 truncating, PKD1 nontruncating, and PKD2 plus patients with no mutation detected; or (2) in combination with PKD1 mutation strength groups. RESULTS Imaging and genetic data were collected (at least one visit) for 236 participants. The mean height-adjusted total cyst number increased exponentially over time from a baseline value of 762 to 1715 at the last clinic visit, while the mean height-adjusted total cyst volume increased exponentially from 305 to 770 ml. Height-adjusted total kidney volume, height-adjusted total cyst number, and height-adjusted total cyst volume were all highly correlated over time. Female participants and participants with larger height-adjusted total kidney volume at baseline showed smaller rates of change in the log of height-adjusted total cyst number and cyst volume. PKD1 was associated with significant increases in both cyst number and volume at a given age, but genotype did not significantly affect the rate of growth. CONCLUSIONS Both height-adjusted total cyst number and height-adjusted total cyst volume increased exponentially and more than doubled over 14.23 years of follow-up. Compared with PKD2 plus no mutation detected, PKD1 was associated with a greater cyst number and volume at a given age, but no significant difference in the rate of growth.
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Affiliation(s)
| | | | - Chengli Shen
- Biomedical Informatics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Douglas P Landsittel
- Biomedical Informatics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | | | | | - Arlene B Chapman
- Department of Internal Medicine, University of Chicago School of Medicine, Chicago, Illinois
| | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Alan S L Yu
- Department of Internal Medicine, Kansas University Medical Center, Kansas City, Kansas
| | - Michal Mrug
- Department of Medicine, The University of Alabama at Birmingham and.,Department of Veterans Affairs Medical Center, Birmingham, Alabama; and
| | | | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota
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7
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Zhang W, Blumenfeld JD, Prince MR. MRI in autosomal dominant polycystic kidney disease. J Magn Reson Imaging 2019; 50:41-51. [PMID: 30637853 DOI: 10.1002/jmri.26627] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 12/05/2018] [Accepted: 12/08/2018] [Indexed: 12/15/2022] Open
Affiliation(s)
- Weiguo Zhang
- Department of Radiology, Weill Cornell Medicine New York New York USA
| | - Jon D. Blumenfeld
- Rogosin Institute, and Department of MedicineWeill Cornell Medicine New York New York USA
| | - Martin R. Prince
- Department of Radiology, Weill Cornell Medicine New York New York USA
- Columbia College of Physicians and Surgeons New York New York USA
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Deletion of Pkd1 in renal stromal cells causes defects in the renal stromal compartment and progressive cystogenesis in the kidney. J Transl Med 2017; 97:1427-1438. [PMID: 28892094 DOI: 10.1038/labinvest.2017.97] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 06/29/2017] [Accepted: 08/02/2017] [Indexed: 12/15/2022] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD), caused by PKD1 and PKD2 gene mutations, is one of the most common genetic diseases, affecting up to 1 in 500 people. Mutations of PKD1 account for over 85% of ADPKD cases. However, mechanisms of disease progression and explanations for the wide range in disease phenotype remain to be elucidated. Moreover, functional roles of PKD1 in the renal stromal compartment are poorly understood. In this work, we tested if Pkd1 is essential for development and maintenance of the renal stromal compartment and if this role contributes to pathogenesis of polycystic kidney disease using a novel tissue-specific knockout mouse model. We demonstrate that deletion of Pkd1 from renal stromal cells using Foxd1-driven Cre causes a spectrum of defects in the stromal compartment, including excessive apoptosis/proliferation and extracellular matrix deficiency. Renal vasculature was also defective. Further, mutant mice showed epithelial changes and progressive cystogenesis in adulthood modeling human ADPKD. Altogether, we provide robust evidence to support indispensable roles for Pkd1 in development and maintenance of stromal cell derivatives by using a novel ADPKD model. Moreover, stromal compartment defects caused by Pkd1 deletion might serve as an important mechanism for pathogenesis of ADPKD.
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Reddy BV, Chapman AB. The spectrum of autosomal dominant polycystic kidney disease in children and adolescents. Pediatr Nephrol 2017; 32:31-42. [PMID: 27034070 DOI: 10.1007/s00467-016-3364-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 02/02/2016] [Accepted: 03/02/2016] [Indexed: 12/19/2022]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary renal disorder. It is characterized by the development of renal cysts and kidney enlargement and ultimately leads to renal failure typically in the sixth decade of life. Although most patients are asymptomatic until well into adulthood, renal cysts develop much earlier, often in utero. Significant renal anatomic and cystic expansion typically occurs before clinical manifestations in children and young adults with AKPKD. The cyst burden detected by imaging represents the minority of cyst burden, and renal and cardiovascular abnormalities are the most common manifestations in children with ADPKD. Here we review the molecular pathogenesis of ADPKD, discuss the screening, diagnosis and clinical manifestations of this renal disorder in childhood and adolescents and review treatment options and potential therapies currently being tested.
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Affiliation(s)
- Bharathi V Reddy
- University of Chicago, 5841, S. Maryland Avenue Suite S-511, MC 5100, Chicago, IL, 60637, USA.
| | - Arlene B Chapman
- University of Chicago, 5841, S. Maryland Avenue Suite S-511, MC 5100, Chicago, IL, 60637, USA
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10
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Leonhard WN, Kunnen SJ, Plugge AJ, Pasternack A, Jianu SBT, Veraar K, El Bouazzaoui F, Hoogaars WMH, Ten Dijke P, Breuning MH, De Heer E, Ritvos O, Peters DJM. Inhibition of Activin Signaling Slows Progression of Polycystic Kidney Disease. J Am Soc Nephrol 2016; 27:3589-3599. [PMID: 27020852 PMCID: PMC5118473 DOI: 10.1681/asn.2015030287] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 02/10/2016] [Indexed: 12/31/2022] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD), characterized by the formation of numerous kidney cysts, is caused by PKD1 or PKD2 mutations and affects 0.1% of the population. Although recent clinical studies indicate that reduction of cAMP levels slows progression of PKD, this finding has not led to an established safe and effective therapy for patients, indicating the need to find new therapeutic targets. The role of TGF-β in PKD is not clearly understood, but nuclear accumulation of phosphorylated SMAD2/3 in cyst-lining cells suggests the involvement of TGF-β signaling in this disease. In this study, we ablated the TGF-β type 1 receptor (also termed activin receptor-like kinase 5) in renal epithelial cells of PKD mice, which had little to no effect on the expression of SMAD2/3 target genes or the progression of PKD. Therefore, we investigated whether alternative TGF-β superfamily ligands account for SMAD2/3 activation in cystic epithelial cells. Activins are members of the TGF-β superfamily and drive SMAD2/3 phosphorylation via activin receptors, but activins have not been studied in the context of PKD. Mice with PKD had increased expression of activin ligands, even at early stages of disease. In addition, treatment with a soluble activin receptor IIB fusion (sActRIIB-Fc) protein, which acts as a soluble trap to sequester activin ligands, effectively inhibited cyst formation in three distinct mouse models of PKD. These data point to activin signaling as a key pathway in PKD and a promising target for therapy.
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Affiliation(s)
| | | | | | - Arja Pasternack
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland; and
| | | | | | | | - Willem M H Hoogaars
- Department of Human Movement Sciences, Faculty of Behavior and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute, Amsterdam, The Netherlands
| | - Peter Ten Dijke
- Molecular Cell Biology and Cancer Genomics Centre Netherlands at the Leiden University Medical Center, Leiden, The Netherlands
| | | | | | - Olli Ritvos
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland; and
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11
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Leonhard WN, Happe H, Peters DJM. Variable Cyst Development in Autosomal Dominant Polycystic Kidney Disease: The Biologic Context. J Am Soc Nephrol 2016; 27:3530-3538. [PMID: 27493259 PMCID: PMC5118495 DOI: 10.1681/asn.2016040425] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Patients with autosomal dominant polycystic kidney disease (ADPKD) typically carry a mutation in either the PKD1 or PKD2 gene, which leads to massive cyst formation in both kidneys. However, the large intrafamilial variation in the progression rate of ADPKD suggests involvement of additional factors other than the type of mutation. The identification of these factors will increase our understanding of ADPKD and could ultimately help in the development of a clinically relevant therapy. Our review addresses the mechanisms by which various biologic processes influence cyst formation and cyst growth, thereby explaining an important part of the inter- and intrafamilial variability in ADPKD. Numerous studies from many laboratories provide compelling evidence for the influence on cyst formation by spatiotemporal gene inactivation, the genetic context, the metabolic status, the presence of existing cysts, and whether the kidneys were challenged by renal injury. Collectively, a solid basis is provided for the concept that the probability of cyst formation is determined by functional PKD protein levels and the biologic context. We model these findings in a graphic representation called the cystic probability landscape, providing a robust conceptual understanding of why cells sometimes do or do not form cysts.
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Affiliation(s)
- Wouter N Leonhard
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Hester Happe
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Dorien J M Peters
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
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12
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Rangan GK, Lee VW, Alexander SI, Patel C, Tunnicliffe DJ, Vladica P. KHA-CARI Autosomal Dominant Polycystic Kidney Disease Guideline: Screening for Polycystic Kidney Disease. Semin Nephrol 2016; 35:557-564.e6. [PMID: 26718159 DOI: 10.1016/j.semnephrol.2015.10.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Gopala K Rangan
- Department of Renal Medicine, Westmead Hospital, Western Sydney Local Health District, Sydney, Australia; Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Westmead, Sydney, Australia.
| | - Vincent W Lee
- Department of Renal Medicine, Westmead Hospital, Western Sydney Local Health District, Sydney, Australia; Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Westmead, Sydney, Australia
| | - Stephen I Alexander
- Centre for Kidney Research and the Department of Nephrology, The Children's Hospital at Westmead, Westmead, NSW, Australia
| | - Chirag Patel
- Genetic Health Queensland, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
| | - David J Tunnicliffe
- KHA-CARI Guidelines, Centre for Kidney Research, The Children's Hospital at Westmead, Westmead, Sydney, Australia; Sydney School of Public Health, University of Sydney, Sydney, Australia
| | - Philip Vladica
- Department of Radiology, Westmead Hospital, Western Sydney Local Health District, Westmead, Sydney, Australia
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13
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Rangan GK, Lopez-Vargas P, Nankivell BJ, Tchan M, Tong A, Tunnicliffe DJ, Savige J. Autosomal Dominant Polycystic Kidney Disease: A Path Forward. Semin Nephrol 2016; 35:524-37. [PMID: 26718155 DOI: 10.1016/j.semnephrol.2015.10.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the commonest inherited cause of renal failure in adults, and is due to loss-of-function mutations in either the PKD1 or PKD2 genes, which encode polycystin-1 and polycystin-2, respectively. These proteins have an essential role in maintaining the geometric structure of the distal collecting duct in the kidney in adult life, and their dysfunction predisposes to renal cyst formation. The typical renal phenotype of ADPKD is the insidious development of hundreds of renal cysts, which form in childhood and grow progressively through life, causing end-stage kidney failure in the fifth decade in about half affected by the mutation. Over the past 2 decades, major advances in genetics and disease pathogenesis have led to well-conducted randomized controlled trials, and observational studies that have resulted in an accumulation of evidence-based data, and raise hope that the lifetime risk of kidney failure due to ADPKD will be progressively curtailed during this century. This review will provide a contemporary summary of the current state of the field in disease pathogenesis and therapeutics, and also briefly highlights the importance of clinical practice guidelines, patient perspectives, patient-reported outcomes, uniform trial reporting, and health-economics in ADPKD.
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Affiliation(s)
- Gopala K Rangan
- Department of Renal Medicine, Westmead Hospital, Western Sydney Local Health District, Westmead, Sydney, Australia; Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Westmead, Sydney, Australia.
| | - Pamela Lopez-Vargas
- Sydney School of Public Health, The University of Sydney, Sydney, Australia; Centre for Kidney Research, The Children's Hospital at Westmead, Sydney, Australia
| | - Brian J Nankivell
- Department of Renal Medicine, Westmead Hospital, Western Sydney Local Health District, Westmead, Sydney, Australia; Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Westmead, Sydney, Australia
| | - Michel Tchan
- Department of Genetic Medicine, Westmead Hospital, Western Sydney Local Health District, Sydney, Australia
| | - Allison Tong
- Sydney School of Public Health, The University of Sydney, Sydney, Australia; Centre for Kidney Research, The Children's Hospital at Westmead, Sydney, Australia
| | - David J Tunnicliffe
- Sydney School of Public Health, The University of Sydney, Sydney, Australia; Centre for Kidney Research, The Children's Hospital at Westmead, Sydney, Australia
| | - Judy Savige
- The University of Melbourne, Department of Medicine, Melbourne Health and Northern Health, Melbourne, Australia; Department of Nephrology, The Royal Melbourne Hospital, Parkville, Victoria, Australia
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14
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Rangan GK, Alexander SI, Campbell KL, Dexter MAJ, Lee VW, Lopez-Vargas P, Mai J, Mallett A, Patel C, Patel M, Tchan MC, Tong A, Tunnicliffe DJ, Vladica P, Savige J. KHA-CARI guideline recommendations for the diagnosis and management of autosomal dominant polycystic kidney disease. Nephrology (Carlton) 2016; 21:705-16. [DOI: 10.1111/nep.12658] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 10/20/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Gopala K Rangan
- Centre for Transplant and Renal Research, Westmead Millennium Institute; The University of Sydney; Sydney New South Wales Australia
- Department of Renal Medicine; Westmead Hospital, Western Sydney Local Health District; Sydney New South Wales Australia
| | - Stephen I Alexander
- Centre for Kidney Research; The Children's Hospital at Westmead; Sydney New South Wales Australia
- Department of Nephrology; The Children's Hospital at Westmead; Sydney New South Wales Australia
| | - Katrina L Campbell
- Department of Nutrition and Dietetics; The Princess Alexandra Hospital; Brisbane Queensland Australia
- Faculty of Health Sciences and Medicine; Bond University; Brisbane Queensland Australia
| | - Mark AJ Dexter
- Department of Neurological Surgery; Westmead Private Hospital; Sydney New South Wales Australia
| | - Vincent W Lee
- Centre for Transplant and Renal Research, Westmead Millennium Institute; The University of Sydney; Sydney New South Wales Australia
- Department of Renal Medicine; Westmead Hospital, Western Sydney Local Health District; Sydney New South Wales Australia
| | - Pamela Lopez-Vargas
- Centre for Kidney Research; The Children's Hospital at Westmead; Sydney New South Wales Australia
- Sydney School of Public Health; The University of Sydney; Sydney New South Wales Australia
| | - Jun Mai
- Department of Nephrology; Liverpool Hospital and Bankstown Hospital; Sydney New South Wales Australia
| | - Andrew Mallett
- Kidney Health Service and Conjoint Kidney Research Laboratory; Royal Brisbane and Women's Hospital; Brisbane Queensland Australia
- Centre for Kidney Disease Research, Centre for Chronic Disease and CKD, QLD, School of Medicine; The University of Queensland; Brisbane Queensland Australia
- Centre for Rare Diseases Research, Institute for Molecular Bioscience; The University of Queensland; Brisbane Queensland Australia
| | - Chirag Patel
- Genetic Health Queensland; Royal Brisbane and Women's Hospital; Brisbane Queensland Australia
| | - Manish Patel
- Discipline of Surgery, Western Clinical School; The University of Sydney; Sydney New South Wales Australia
- Department of Urology; Westmead Hospital; Sydney New South Wales Australia
| | - Michel C Tchan
- Department of Genetic Medicine; Westmead Hospital; Sydney New South Wales Australia
- Sydney Medical School; The University of Sydney; Sydney New South Wales Australia
| | - Allison Tong
- Centre for Kidney Research; The Children's Hospital at Westmead; Sydney New South Wales Australia
- Sydney School of Public Health; The University of Sydney; Sydney New South Wales Australia
| | - David J Tunnicliffe
- Centre for Kidney Research; The Children's Hospital at Westmead; Sydney New South Wales Australia
- Sydney School of Public Health; The University of Sydney; Sydney New South Wales Australia
| | - Philip Vladica
- Department of Radiology; Westmead Hospital, Western Sydney Local Health District; Sydney New South Wales Australia
| | - Judy Savige
- Department of Nephrology; The Royal Melbourne Hospital; Parkville Victoria Australia
- Department of Medicine; The University of Melbourne; Victoria Australia
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15
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Abstract
OBJECTIVE To review the relationship between lithium-related renal dysfunction and microcysts. METHOD Electronic databases (PubMed and Google Scholar) were queried. RESULTS From a total of 12,425 publications, 76 were reviewed. DISCUSSION Glomerular renal dysfunction occurs after an average of 20 years of continuous lithium treatment, and the severity is related to the total lithium load as measured by dose and duration. Recently, several reports have highlighted the relationship between renal microcyst formation and significant reductions in glomerular filtration rate. Radiologically visible lithium-related microcysts are usually 1-2 mm and occasionally 3 mm. Smaller cysts, which are impossible to resolve, are probably more common than the visible cysts, based on observations of renal needle biopsies. Increases in the number of microcysts and the space they occupy within kidney volume appear to be related to both the duration of lithium treatment and the reduction in kidney function. The proposed mechanism of microcyst formation is related to the antiapoptotic effect of lithium. Specifically, by preventing renal tubular epithelial cells from undergoing apoptosis as part of the process of normal renal maintenance, lithium may be allowing the inappropriate growth of the surface area of tubules to form invaginations and ultimately cysts. It is proposed that the physical space occupied by these cysts in the limited volume within the renal capsule compromises the function of otherwise healthy renal tissue. Monitoring of kidneys utilizing radiographic imaging may be more sensitive than monitoring laboratory values. Additional research is required to optimize this new monitoring tool.
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Affiliation(s)
- Mashal Khan
- Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, KY, USA
| | - Rif S El-Mallakh
- Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, KY, USA
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16
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Turco D, Severi S, Mignani R, Magistroni R, Corsi C. Geometry-independent assessment of renal volume in polycystic kidney disease from magnetic resonance imaging. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:3081-4. [PMID: 26736943 DOI: 10.1109/embc.2015.7319043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Total renal volume (TRV) is an important quantitative indicator of the progression of autosomal dominant polycystic kidney disease (ADPKD). The Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease proposes a method for TRV computation based on manual tracing and geometric modeling. We developed a fast and nearly-automated technique for kidney segmentation and automatically compute TRV. In this study we aim to compare TRV estimates derived from these two different approaches. The highly-automated technique for the analysis of MR images was tested on 30 ADPKD patients. TRV was computed from both axial and coronal acquisitions, and compared to measurements based on geometric modeling by linear regression and Bland Altman analysis. In addition, to assess reproducibility, intra-observer and inter-observer variabilities were computed. The results of this study provide the feasibility of using a nearly-automated approach for accurate and fast evaluation of TRV also in markedly enlarged ADPKD kidneys.
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17
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Reliability of Total Renal Volume Computation in Polycystic Kidney Disease From Magnetic Resonance Imaging. Acad Radiol 2015; 22:1376-84. [PMID: 26276168 DOI: 10.1016/j.acra.2015.06.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 06/10/2015] [Accepted: 06/30/2015] [Indexed: 02/02/2023]
Abstract
RATIONALE AND OBJECTIVES Total renal volume (TRV) is an important quantitative indicator of the progression of autosomal dominant polycystic kidney disease (ADPKD). The Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease proposes a method for TRV computation based on manual tracing and geometric modeling. Alternative approaches for TRV computation are represented by the application of advanced image processing techniques. In this study, we aimed to compare TRV estimates derived from these two different approaches. MATERIALS AND METHODS The nearly automated technique for the analysis of magnetic resonance (MR) images was tested on 30 ADPKD patients. TRV was computed from both axial (KVax) and coronal (KVcor) acquisitions and compared to measurements based on geometric modeling (KVap) by linear regression and Bland-Altman analysis. In addition, to assess reproducibility, intraobserver and interobserver variabilities were computed. RESULTS Linear regression analysis between KVax and KVcor resulted in an excellent correlation (KVax = 1KVcor - 0.78; r(2) = 0.997). Bland-Altman analysis showed a negligible bias and narrow limits of agreement (bias: -11.7 mL; SD: 54.3 mL). Similar results were obtained by comparison of volumes obtained applying the nearly automated method and the one based on geometric modeling (y = 0.98x + 75.9; r(2) = 0.99; bias: -53.7 mL; SD: 108.1 mL). Importantly, geometric modeling does not provide reliable TRV estimates in huge kidney affected by regional deformation. Intraobserver and interobserver variability resulted in very small percentage error <2%. CONCLUSIONS The results of this study provide the feasibility of using a nearly automated approach for accurate and fast evaluation of TRV also in markedly enlarged ADPKD kidneys including exophytic cysts.
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18
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Mai J, W. Lee V, Lopez-Vargas P, Vladica P, Rangan GK. KHA-CARI Autosomal Dominant Polycystic Kidney Disease Guideline: Monitoring Disease Progression. Semin Nephrol 2015; 35:565-571.e18. [DOI: 10.1016/j.semnephrol.2015.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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19
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Grantham JJ. Rationale for early treatment of polycystic kidney disease. Pediatr Nephrol 2015; 30:1053-62. [PMID: 25022529 DOI: 10.1007/s00467-014-2882-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 05/29/2014] [Accepted: 06/05/2014] [Indexed: 12/12/2022]
Abstract
In hereditary cystic disorders, renal injury begins with the formation of the first cyst. Renal injury may manifest as large kidneys, abdominal pain, hypertension and hematuria in children and young adults with autosomal dominant polycystic kidney disease (ADPKD). In autosomal recessive PKD (ARPKD) and ADPKD, cysts form primarily in collecting ducts and expand progressively. Collecting duct cysts that block urine flow have the potential to block urine formation in large numbers of upstream nephrons. In an ARPKD rat congenitally lacking vasopressin, only a few cysts developed until exogenous arginine vasopressin (AVP) was administered. AVP elevates cyclic AMP in vulnerable tubule cells to stimulate mitogenesis and fluid secretion, thereby causing cysts to form and enlarge indefinitely. The administration of an AVP-V2 receptor inhibitor or the consumption of sufficient water to persistently lower plasma AVP levels will ameliorate disease progression. Renal volume measurements provide the most reliable way to forecast long-term outcome in individual children and adult patients with ADPKD. Many drugs that have demonstrated efficacy in small clinical trials, preclinical trials and cell-based studies are in the treatment pipeline. Counseling, regular exercise, limitation of dietary calories, salt, protein and fat, increased fluid intake throughout the day and treatment of hypertension are components of a rational treatment program that can be offered at an early age to those with, or at risk for developing PKD.
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Affiliation(s)
- Jared J Grantham
- The Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS, 66160, USA,
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20
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Leonhard WN, Zandbergen M, Veraar K, van den Berg S, van der Weerd L, Breuning M, de Heer E, Peters DJM. Scattered Deletion of PKD1 in Kidneys Causes a Cystic Snowball Effect and Recapitulates Polycystic Kidney Disease. J Am Soc Nephrol 2015; 26:1322-33. [PMID: 25361818 PMCID: PMC4446864 DOI: 10.1681/asn.2013080864] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 07/23/2014] [Indexed: 12/21/2022] Open
Abstract
In total, 1 in 1000 individuals carries a germline mutation in the PKD1 or PKD2 gene, which leads to autosomal dominant polycystic kidney disease (ADPKD). Cysts can form early in life and progressively increase in number and size during adulthood. Extensive research has led to the presumption that somatic inactivation of the remaining allele initiates the formation of cysts, and the progression is further accelerated by renal injury. However, this hypothesis is primarily on the basis of animal studies, in which the gene is inactivated simultaneously in large percentages of kidney cells. To mimic human ADPKD in mice more precisely, we reduced the percentage of Pkd1-deficient kidney cells to 8%. Notably, no pathologic changes occurred for 6 months after Pkd1 deletion, and additional renal injury increased the likelihood of cyst formation but never triggered rapid PKD. In mildly affected mice, cysts were not randomly distributed throughout the kidney but formed in clusters, which could be explained by increased PKD-related signaling in not only cystic epithelial cells but also, healthy-appearing tubules near cysts. In the majority of mice, these changes preceded a rapid and massive onset of severe PKD that was remarkably similar to human ADPKD. Our data suggest that initial cysts are the principal trigger for a snowball effect driving the formation of new cysts, leading to the progression of severe PKD. In addition, this approach is a suitable model for mimicking human ADPKD and can be used for preclinical testing.
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Affiliation(s)
| | | | | | | | - Louise van der Weerd
- Departments of Human Genetics, Radiology, Leiden University Medical Center, Leiden, The Netherlands
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21
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Riegersperger M, Herkner H, Sunder-Plassmann G. Pulsed oral sirolimus in advanced autosomal-dominant polycystic kidney disease (Vienna RAP Study): study protocol for a randomized controlled trial. Trials 2015; 16:182. [PMID: 25899445 PMCID: PMC4423136 DOI: 10.1186/s13063-015-0692-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 03/30/2015] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Autosomal-dominant polycystic kidney disease (ADPKD) is a hereditary illness that causes renal tubular epithelial cells to form cysts that proliferate and destroy renal tissue. This usually leads to a decline in renal function, and often to terminal kidney failure, with need for renal replacement therapy. There is currently no causative therapy. The mammalian target of rapamycin (mTOR) inhibitor sirolimus (SIR) is an immunosuppressant with strong antiproliferative effects, and is potentially able to stop or reduce cyst growth and preserve renal function in ADPKD. Continuous mTOR exposure results in a loss of its antiproliferative effects on renal tubular cells. With a half-life of roughly 60 hours, pulsed (weekly) administration of SIR may be an effective way to reduce cyst growth and preserve excretory renal function in ADPKD. METHODS/DESIGN The Vienna RAP Study is a randomized, double-blind, placebo-controlled trial, funded by the Anniversary Fund of the Oesterreichische Nationalbank. We will investigate the effects of a weekly dose of 3 mg SIR on kidney function in 34 patients with advanced ADPKD, compared to a placebo equivalent in 34 patients with advanced ADPKD, over 24 months. The primary endpoint is creatinine level (less or equal than 1.5-fold increase in serum creatinine without initiation of dialysis over two years) and dialysis, renal transplantation, or death. The secondary endpoints are safety, change in proteinuria (as indicated by albumin/creatinine- and protein/creatinine ratio, respectively), and creatinine clearance. DISCUSSIONS The Vienna RAP Study is, to the best of our knowledge, the first study to investigate the effects of a pulsed (weekly) dose of SIR on renal function in ADPKD. TRIAL REGISTRATION This trial was registered with EudraCT (identifier: 2012-000550-60 (EU)) on 27 November 2013 and with ClinicalTrials.gov (identifier: NCT02055079 (USA)) on 3 February 2014.
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Affiliation(s)
- Markus Riegersperger
- Department of Medicine III, Division of Nephrology and Dialysis, Medical University of Vienna, Währinger Gürtel 18-20, A-1090, Vienna, Austria.
| | - Harald Herkner
- Department of Emergency Medicine, Medical University of Vienna, Währinger Gürtel 18-20, A-1090, Vienna, Austria.
| | - Gere Sunder-Plassmann
- Department of Medicine III, Division of Nephrology and Dialysis, Medical University of Vienna, Währinger Gürtel 18-20, A-1090, Vienna, Austria.
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22
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Liver involvement in early autosomal-dominant polycystic kidney disease. Clin Gastroenterol Hepatol 2015; 13:155-64.e6. [PMID: 25111236 PMCID: PMC4267913 DOI: 10.1016/j.cgh.2014.07.051] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 07/10/2014] [Accepted: 07/23/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Polycystic liver disease (PLD), the most common extrarenal manifestation of autosomal-dominant polycystic kidney disease (ADPKD), has become more prevalent as a result of increased life expectancy, improved renal survival, reduced cardiovascular mortality, and renal replacement therapy. No studies have fully characterized PLD in large cohorts. We investigated whether liver and cyst volumes are associated with volume of the hepatic parenchyma, results from liver laboratory tests, and patient-reported outcomes. METHODS We performed a cross-sectional analysis of baseline liver volumes, measured by magnetic resonance imaging, and their association with demographics, results from liver laboratory and other tests, and quality of life. The data were collected from a randomized, placebo-controlled trial underway at 7 tertiary-care medical centers to determine whether the combination of an angiotensin I-converting enzyme inhibitor and angiotensin II-receptor blocker was superior to the inhibitor alone, and whether low blood pressure (<110/75 mm Hg) was superior to standard blood pressure (120-130/70-80 mm Hg), in delaying renal cystic progression in 558 patients with ADPKD, stages 1 and 2 chronic kidney disease, and hypertension (age, 15-49 y). RESULTS We found hepatomegaly to be common among patients with ADPKD. Cysts and parenchyma contributed to hepatomegaly. Cysts were more common and liver and cyst volumes were greater in women, increasing with age. Patients with advanced disease had a relative loss of liver parenchyma. We observed small abnormalities in results from liver laboratory tests, and that splenomegaly and hypersplenism were associated with PLD severity. Higher liver volumes were associated with a lower quality of life. CONCLUSIONS Hepatomegaly is common even in early stage ADPKD and is not accounted for by cysts alone. Parenchymal volumes were larger, compared with liver volumes of patients without ADPKD or with those predicted by standardized equations, even among patients without cysts. The severity of PLD was associated with altered biochemical and hematologic features, as well as quality of life. ClinicalTrials.gov identifier: NCT00283686.
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23
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Abstract
The increasing use of medical imaging as an investigative tool is leading to the incidental and frequent finding of renal cysts in the general population. The presence of a solitary or multiple renal cysts has been generally considered benign in the absence of a family history of renal cystic disease or evidence of chronic kidney disease. Nonetheless, a number of recent studies have questioned this consensus by reported associations with the development of hypertension or malignant change. For these reasons, some clinicians consider the presence of renal cysts to be a contraindication to kidney donation. The situation is complicated by the different usage of the term 'simple' by some radiologists (to indicate non-complex lesions) or nephrologists (to indicate age-related non-hereditary lesions). We propose that the term 'simple' be replaced with the morphological description, Stage I renal cyst (Bosniak Classification). The presence of a Stage I renal cyst should not preclude kidney donation. However, occult renal disease should be excluded and appropriate donor assessment performed.
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Affiliation(s)
- Roslyn J Simms
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK Renal Unit, Freeman Hospital, Newcastle upon Tyne NE7 7DN, UK Kidney Genetics Group, Academic Nephrology Unit, Department of Infection and Immunity, University of Sheffield Medical School, Sheffield S10 2RX, UK Sheffield Kidney Institute, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield S5 7AU, UK
| | - Albert C M Ong
- Kidney Genetics Group, Academic Nephrology Unit, Department of Infection and Immunity, University of Sheffield Medical School, Sheffield S10 2RX, UK Sheffield Kidney Institute, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield S5 7AU, UK
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24
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Kurschat CE, Müller RU, Franke M, Maintz D, Schermer B, Benzing T. An approach to cystic kidney diseases: the clinician's view. Nat Rev Nephrol 2014; 10:687-99. [DOI: 10.1038/nrneph.2014.173] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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25
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Braun WE, Schold JD, Stephany BR, Spirko RA, Herts BR. Low-dose rapamycin (sirolimus) effects in autosomal dominant polycystic kidney disease: an open-label randomized controlled pilot study. Clin J Am Soc Nephrol 2014; 9:881-8. [PMID: 24721888 PMCID: PMC4011437 DOI: 10.2215/cjn.02650313] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 01/04/2014] [Indexed: 01/13/2023]
Abstract
BACKGROUND AND OBJECTIVES The two largest studies of mammalian target of rapamycin inhibitor treatment of autosomal dominant polycystic kidney disease (ADPKD) demonstrated no clear benefit on the primary endpoint of total kidney volume (TKV) or on eGFR. The present study evaluated two levels of rapamycin on the 12-month change in (125)I-iothalamate GFR (iGFR) as the primary endpoint and TKV secondarily. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS In a 12-month open-label pilot study, 30 adult patients with ADPKD were randomly assigned to low-dose (LD) rapamycin (rapamycin trough blood level, 2-5 ng/ml) (LD group, n=10), standard-dose (STD) rapamycin trough level (>5-8 ng/ml) (STD group, n=10), or standard care (SC group, n=10). They were evaluated with iGFR and noncontrast computed tomography. RESULTS Change in iGFR at 12 months was significantly higher in the LD group (7.7±12.5 ml/min per 1.73 m(2); n=9) than in the SC group (-11.2 ± 9.1 ml/min per 1.73 m(2); n=9) (LD versus SC: P<0.01). Change in iGFR at 12 months in the STD group (1.6 ± 12.1 ml/min per 1.73 m(2); n=8) was not significantly greater than that in the SC group (P=0.07), but it was in the combined treatment groups (LD+STD versus SC: P<0.01). Neither eGFR calculated by the CKD-Epidemiology Collaboration equation nor TKV (secondary endpoint) changed significantly from baseline to 12 months in any of the groups. On the basis of results of the mixed model, during the study, patients in the LD group had significantly lower trough blood levels of rapamycin (mean range ± SD, 2.40 ± 0.64 to 2.90 ± 1.20 ng/ml) compared with those in the STD group (3.93 ± 2.27 to 5.77 ± 1.06 ng/ml) (P<0.01). CONCLUSION Patients with ADPKD receiving LD rapamycin demonstrated a significant increase in iGFR compared with those receiving standard care, without a significant effect on TKV after 12 months.
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Affiliation(s)
- William E Braun
- Glickman Urological and Kidney Institute,, †Quantitative Health Sciences, and, ‡Imaging Institute, Cleveland Clinic, Cleveland, Ohio
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26
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Bae KT, Sun H, Lee JG, Bae K, Wang J, Tao C, Chapman AB, Torres VE, Grantham JJ, Mrug M, Bennett WM, Flessner MF, Landsittel DP. Novel methodology to evaluate renal cysts in polycystic kidney disease. Am J Nephrol 2014; 39:210-7. [PMID: 24576800 DOI: 10.1159/000358604] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 01/08/2014] [Indexed: 01/21/2023]
Abstract
AIM To develop and assess a semiautomated method for segmenting and counting individual renal cysts from mid-slice MR images in patients with autosomal dominant polycystic kidney disease (ADPKD). METHODS A semiautomated method was developed to segment and count individual renal cysts from mid-slice MR images in 241 subjects with ADPKD from the Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease. For each subject, a mid-slice MR image was selected from each set of coronal T2-weighted MR images covering the entire kidney. The selected mid-slice image was processed with the semiautomated method to segment and count individual renal cysts. The number of cysts from the mid-slice image of each kidney was also measured by manual counting. The level of agreement between the semiautomated and manual cyst counts was compared using intraclass correlation (ICC) and a Bland-Altman plot. RESULTS Individual renal cysts were successfully segmented using the semiautomated method in all 241 cases. The number of cysts in each kidney measured with the semiautomated and manual counting methods correlated well (ICC = 0.96 for the right or left kidney), with a small average difference (-0.52, with higher semiautomated counts, for the right kidney, and 0.13, with higher manual counts, for the left kidney) in the semiautomated method. However, there was substantial variation in a small number of subjects; 6 of 241 participants (2.5%) had a difference in the total cyst count of more than 15. CONCLUSION We have developed a semiautomated method to segment individual renal cysts from mid-slice MR images in ADPKD kidneys as a quantitative indicator of characterization and disease progression of ADPKD.
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Affiliation(s)
- Kyongtae T Bae
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pa., USA
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27
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Milutinović A, Zorc-Pleskovič R, Živin M, Vovk A, Seša I, Šuput D. Magnetic resonance imaging for rapid screening for the nephrotoxic and hepatotoxic effects of microcystins. Mar Drugs 2013; 11:2785-98. [PMID: 23921723 PMCID: PMC3766865 DOI: 10.3390/md11082785] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/04/2013] [Accepted: 07/19/2013] [Indexed: 01/08/2023] Open
Abstract
In vivo visualization of kidney and liver damage by Magnetic Resonance Imaging (MRI) may offer an advantage when there is a need for a simple, non-invasive and rapid method for screening of the effects of potential nephrotoxic and hepatotoxic substances in chronic experiments. Here, we used MRI for monitoring chronic intoxication with microcystins (MCs) in rat. Male adult Wistar rats were treated every other day for eight months, either with MC-LR (10 μg/kg i.p.) or MC-YR (10 μg/kg i.p.). Control groups were treated with vehicle solutions. T1-weighted MR-images were acquired before and at the end of the eight months experimental period. Kidney injury induced by the MCs presented with the increased intensity of T1-weighted MR-signal of the kidneys and liver as compared to these organs from the control animals treated for eight months, either with the vehicle solution or with saline. The intensification of the T1-weighted MR-signal correlated with the increased volume density of heavily injured tubuli (R2 = 0.77), with heavily damaged glomeruli (R2 = 0.84) and with volume density of connective tissue (R2 = 0.72). The changes in the MR signal intensity probably reflect the presence of an abundant proteinaceous material within the dilated nephrons and proliferation of the connective tissue. T1-weighted MRI-is a valuable method for the in vivo screening of kidney and liver damage in rat models of intoxication with hepatotoxic and nephrotoxic agents, such as microcystins.
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Affiliation(s)
- Aleksandra Milutinović
- Institute of Histology and Embryology, Faculty of Medicine, University of Ljubljana, Korytkova 2, Ljubljana 1000, Slovenia; E-Mails: (A.M.); (R.Z.-P.)
| | - Ruda Zorc-Pleskovič
- Institute of Histology and Embryology, Faculty of Medicine, University of Ljubljana, Korytkova 2, Ljubljana 1000, Slovenia; E-Mails: (A.M.); (R.Z.-P.)
| | - Marko Živin
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana 1000, Slovenia; E-Mails: (M.Z.); (A.V.)
| | - Andrej Vovk
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana 1000, Slovenia; E-Mails: (M.Z.); (A.V.)
- Centre for Clinical Physiology, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, Ljubljana 1000, Slovenia
| | - Igor Seša
- Institute Jožef Stefan, Jamova 23, Ljubljana 1000, Slovenia; E-Mail:
| | - Dušan Šuput
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana 1000, Slovenia; E-Mails: (M.Z.); (A.V.)
- Centre for Clinical Physiology, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, Ljubljana 1000, Slovenia
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Bae K, Park B, Sun H, Wang J, Tao C, Chapman AB, Torres VE, Grantham JJ, Mrug M, Bennett WM, Flessner MF, Landsittel DP, Bae KT. Segmentation of individual renal cysts from MR images in patients with autosomal dominant polycystic kidney disease. Clin J Am Soc Nephrol 2013; 8:1089-97. [PMID: 23520042 PMCID: PMC3700699 DOI: 10.2215/cjn.10561012] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 02/07/2013] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To evaluate the performance of a semi-automated method for the segmentation of individual renal cysts from magnetic resonance (MR) images in patients with autosomal dominant polycystic kidney disease (ADPKD). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This semi-automated method was based on a morphologic watershed technique with shape-detection level set for segmentation of renal cysts from MR images. T2-weighted MR image sets of 40 kidneys were selected from 20 patients with mild to moderate renal cyst burden (kidney volume < 1500 ml) in the Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease (CRISP). The performance of the semi-automated method was assessed in terms of two reference metrics in each kidney: the total number of cysts measured by manual counting and the total volume of cysts measured with a region-based thresholding method. The proposed and reference measurements were compared using intraclass correlation coefficient (ICC) and Bland-Altman analysis. RESULTS Individual renal cysts were successfully segmented with the semi-automated method in all 20 cases. The total number of cysts in each kidney measured with the two methods correlated well (ICC, 0.99), with a very small relative bias (0.3% increase with the semi-automated method; limits of agreement, 15.2% reduction to 17.2% increase). The total volume of cysts measured using both methods also correlated well (ICC, 1.00), with a small relative bias of <10% (9.0% decrease in the semi-automated method; limits of agreement, 17.1% increase to 43.3% decrease). CONCLUSION This semi-automated method to segment individual renal cysts in ADPKD kidneys provides a quantitative indicator of severity in early and moderate stages of the disease.
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Affiliation(s)
- Kyungsoo Bae
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
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