title: Rationale, design and objectives of ARegPKD, a European ARPKD registry study.
abstract: BACKGROUND
  Autosomal recessive polycystic kidney disease (ARPKD) is a rare but frequently severe disorder that is typically characterized by cystic kidneys and congenital hepatic fibrosis but displays pronounced phenotypic heterogeneity. ARPKD is among the most important causes for pediatric end stage renal disease and a leading reason for liver-, kidney- or combined liver kidney transplantation in childhood. The underlying pathophysiology, the mechanisms resulting in the observed clinical heterogeneity and the long-term clinical evolution of patients remain poorly understood. Current treatment approaches continue to be largely symptomatic and opinion-based even in most-advanced medical centers. While large clinical trials for the frequent and mostly adult onset autosomal dominant polycystic kidney diseases have recently been conducted, therapeutic initiatives for ARPKD are facing the challenge of small and clinically variable cohorts for which reliable end points are hard to establish.
  
  
  METHODS
  ARegPKD is an international, mostly European, observational study to deeply phenotype ARPKD patients in a pro- and retrospective fashion. This registry study is conducted with the support of the German Society for Pediatric Nephrology (GPN) and the European Study Consortium for Chronic Kidney Disorders Affecting Pediatric Patients (ESCAPE Network). ARegPKD clinically characterizes long-term ARPKD courses by a web-based approach that uses detailed basic data questionnaires in combination with yearly follow-up visits. Clinical data collection is accompanied by associated biobanking and reference histology, thus setting roots for future translational research.
  
  
  CONCLUSIONS
  The novel registry study ARegPKD aims to characterize miscellaneous subcohorts and to compare the applied treatment options in a large cohort of deeply characterized patients. ARegPKD will thus provide evidence base for clinical treatment decisions and contribute to the pathophysiological understanding of this severe inherited disorder.
authors.affiliation: Department of Pediatrics, University Hospital of Cologne, Kerpener Str. 62, 50937, Cologne, Germany. kathrin.ebner@uk-koeln.de.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Ebner
authors.affiliation: Department of Pediatrics, University Hospital Bonn, Adenauerallee 119, 53113, Bonn, Germany. markus.feldkoetter@ukb.uni-bonn.de.
authors.forename: Markus
authors.initials: M
authors.lastname: Feldkoetter
authors.affiliation: Department of Pediatric Nephrology, University Hospital Vall d'Hebron, Pg/Vall d' Hebron 119-129, 08034, Barcelona, Spain. gariceta@vhebron.net.
authors.forename: Gema
authors.initials: G
authors.lastname: Ariceta
authors.affiliation: Bioscientia Center for Human Genetics, Konrad-Adenauer-Straße 17, 55218, Ingelheim, Germany. Carsten.Bergmann@bioscientia.de.|Renal Division, Department of Medicine, University Freiburg Medical Center, Hugstetter Straße 55, 79106, Freiburg, Germany. Carsten.Bergmann@bioscientia.de.
authors.forename: Carsten
authors.initials: C
authors.lastname: Bergmann
authors.affiliation: Institute of Pathology, University Hospital of Cologne, Kerpener Str. 62, 50937, Cologne, Germany. reinhard.buettner@uk-koeln.de.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Buettner
authors.affiliation: Division of Pediatric Nephrology, University Children's Hospital Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany. anke.doyon@med.uni-heidelberg.de.
authors.forename: Anke
authors.initials: A
authors.lastname: Doyon
authors.affiliation: Department of Pediatrics, Division of Pediatric Nephrology, Hacettepe University Faculty of Medicine, Sihhiye, 06100, Ankara, Turkey. aduzova@hacettepe.edu.tr.
authors.forename: Ali
authors.initials: A
authors.lastname: Duzova
authors.affiliation: Institute of Pathology, University Hospital of Cologne, Kerpener Str. 62, 50937, Cologne, Germany. heike.goebel@uk-koeln.de.
authors.forename: Heike
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authors.lastname: Goebel
authors.affiliation: Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany. Haffner.Dieter@mh-hannover.de.
authors.forename: Dieter
authors.initials: D
authors.lastname: Haffner
authors.affiliation: Department of Pediatrics, University Hospital of Cologne, Kerpener Str. 62, 50937, Cologne, Germany. barbara.hero@uk-koeln.de.
authors.forename: Barbara
authors.initials: B
authors.lastname: Hero
authors.affiliation: Department of Pediatrics, University Hospital Bonn, Adenauerallee 119, 53113, Bonn, Germany. bernd.hoppe@ukb.uni-bonn.de.
authors.forename: Bernd
authors.initials: B
authors.lastname: Hoppe
authors.affiliation: Hannover Unified Biobank, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany. Illig.Thomas@mh-hannover.de.|Institute for Human Genetics, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany. Illig.Thomas@mh-hannover.de.
authors.forename: Thomas
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authors.affiliation: Vilnius University Hospital, Center for Pediatrics, Santariskiu, 08406, Vilnius, Lithuania. augustina.jankauskiene@mf.vu.lt.
authors.forename: Augustina
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authors.lastname: Jankauskiene
authors.affiliation: Hannover Unified Biobank, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany. Klopp.Norman@mh-hannover.de.
authors.forename: Norman
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authors.affiliation: Department of General Pediatrics, University Hospital Münster, Waldeyerstr. 22, 48149, Muenster, Germany. Jens.koenig@ukmuenster.de.
authors.forename: Jens
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authors.affiliation: The Children's Memorial Health Institute, Al. Dzieci Polskich 20, 04-730, Warsaw, Poland. m.litwin@czd.pl.
authors.forename: Mieczyslaw
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authors.lastname: Litwin
authors.affiliation: Department of Pediatric Nephrology, University Hospitals Leuven, Herestrtaat 49, 3000, Leuven, Belgium. Djalila.mekahli@uzleuven.be.
authors.forename: Djalila
authors.initials: D
authors.lastname: Mekahli
authors.affiliation: Service de Néphrologie Pédiatrique, Hospices Civils de Lyon, Université de Lyon, Hôpital Femme Mère Enfant, 69677, Bron, France. bruno.ranchin@chu-lyon.fr.
authors.forename: Bruno
authors.initials: B
authors.lastname: Ranchin
authors.affiliation: Institute of Medical Biometry and Informatics, University of Heidelberg, Im Neuenheimer Feld 305, 69120, Heidelberg, Germany. sander@imbi.uni-heidelberg.de.
authors.forename: Anja
authors.initials: A
authors.lastname: Sander
authors.affiliation: Pediatric Nephrology Unit, Fondazione IRCCS Ca Granda Ospedale Maggiore Polic, Via della Commenda 9, 20122, Milano, Italy. saratesta72@gmail.com.
authors.forename: Sara
authors.initials: S
authors.lastname: Testa
authors.affiliation: Department of Pediatrics, University Hospital of Cologne, Kerpener Str. 62, 50937, Cologne, Germany. lutz.weber@uk-koeln.de.
authors.forename: Lutz Thorsten
authors.initials: LT
authors.lastname: Weber
authors.affiliation: The Children's Memorial Health Institute, Al. Dzieci Polskich 20, 04-730, Warsaw, Poland. dorotawicher01@gmail.com.
authors.forename: Dorota
authors.initials: D
authors.lastname: Wicher
authors.affiliation: Department of Medical Biology, Center for Biobanking and Genomics, Hacettepe University, Ankara, Turkey. ayuzbasi@hacettepe.edu.tr.
authors.forename: Ayse
authors.initials: A
authors.lastname: Yuzbasioglu
authors.affiliation: Institute of Human Genetics, RWTH University Hospital Aachen, Pauwelsstrasse 30, 52074, Aachen, Germany. kzerres@ukaachen.de.
authors.forename: Klaus
authors.initials: K
authors.lastname: Zerres
authors.affiliation: Department of Pediatrics, University Hospital of Cologne, Kerpener Str. 62, 50937, Cologne, Germany. joerg.doetsch@uk-koeln.de.
authors.forename: Jörg
authors.initials: J
authors.lastname: Dötsch
authors.affiliation: Division of Pediatric Nephrology, University Children's Hospital Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany. franz.schaefer@med.uni-heidelberg.de.
authors.forename: Franz
authors.initials: F
authors.lastname: Schaefer
authors.affiliation: Department of Pediatrics, University Hospital of Cologne, Kerpener Str. 62, 50937, Cologne, Germany. max.liebau@uk-koeln.de.|Center for Molecular Medicine, University Hospital of Cologne, Robert-Koch-Str. 21, 50931, Cologne, Germany. max.liebau@uk-koeln.de.|Nephrology Research Laboratory, Department II of Internal Medicine, University Hospital of Cologne, CECAD Building, Joseph-Stelzmann-Str. 26, 50931, Cologne, Germany. max.liebau@uk-koeln.de.
authors.forename: Max Christoph
authors.initials: MC
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mesh_terms: D000328:Adult; D018070:Biological Specimen Banks / Q000458:organization & administration*; D002648:Child; D018450:Disease Progression; D005060:Europe; D005260:Female; D030342:Genetic Diseases, Inborn / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D006801:Humans; D038622:Internationality; D020407:Internet; D007676:Kidney Failure, Chronic / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy; D008103:Liver Cirrhosis / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D008297:Male; D017044:Polycystic Kidney, Autosomal Recessive / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy*; D011786:Quality Control; D012042:Registries; D012107:Research Design; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index