title: Nasal potential difference measurements in diagnosis of cystic fibrosis: an international survey.
abstract: BACKGROUND
  The role of nasal potential difference (NPD) measurement as a diagnostic test for cystic fibrosis (CF) is a subject of global controversy because of the lack of validation studies, clear reference values, and standardized protocols for diagnostic NPD.
  
  
  METHODS
  To determine diagnostic NPD frequency, protocols, interpretation, and rater agreement, we surveyed the 18 NPD centres of the European Cystic Fibrosis Society Diagnostic Network Working Group.
  
  
  RESULTS
  Fifteen centres reported performing 373 diagnostic NPDs in 2012. Most use the CFF-TDN-SOP (67%) and the chloride-free + isoproterenol response of the side with the largest response (47%) as diagnostic criteria and use centre-specific reference ranges. Rater agreement for five NPD tracings - in general - was good, but poor in tracings with different responses between the two nostrils.
  
  
  CONCLUSIONS
  NPD is frequently used as a diagnostic and research tool for CF. Performance is highly standardized, centre-specific reference ranges are established, and rater agreement - in general - is good. Centre-independent diagnostic criteria and reference ranges must be defined by multicentre validation studies to improve standardized interpretation for diagnostic use.
authors.affiliation: Department of Pediatrics, Justus-Liebig-University Giessen, Giessen, Germany. Electronic address: lutz.naehrlich@paediat.med.uni-giessen.de.
authors.forename: Lutz
authors.initials: L
authors.lastname: Naehrlich
authors.affiliation: Ruhr University Paediatric Clinic at St Josef Hospital, Bochum, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Ballmann
authors.affiliation: Paediatric Respiratory Medicine, Royal Brompton and Harefield NHS Foundation Trust, United Kingdom; Respiratory Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, United Kingdom; Department of Gene Therapy, Imperial College London, United Kingdom.
authors.forename: Jane
authors.initials: J
authors.lastname: Davies
authors.affiliation: CFTR Biomarker Centre and Translational CF Research Group Christiane Herzog Cystic Fibrosis Centre, Paediatric Pulmonology and Immunology, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Nico
authors.initials: N
authors.lastname: Derichs
authors.affiliation: Hospital for Sick Children, Toronto, Canada.
authors.forename: Tanja
authors.initials: T
authors.lastname: Gonska
authors.affiliation: Stockholm Cystic Fibrosis Center, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: Lena
authors.initials: L
authors.lastname: Hjelte
authors.affiliation: CF Centre Cologne, Children's Hospital, University of Cologne, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: van Konigsbruggen-Rietschel
authors.affiliation: Louvain Centre for Toxicology and Applied Pharmacology (LTAP), Université catholique de Louvain, Brussels, Belgium.
authors.forename: Teresinha
authors.initials: T
authors.lastname: Leal
authors.affiliation: Cystic Fibrosis Center, Azienda Ospedaliera Universitaria Integrata di Verona, Verona, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Melotti
authors.affiliation: Cystic Fibrosis Unit, Ludwig Engel Centre for Respiratory Research, Westmead Millennium Institute, University of Sydney at Westmead, Westmead, NSW, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Middleton
authors.affiliation: Klinik für Pädiatrische Pneumologie, Allergologie und Neonatologie, OE 6710, Medizinische Hochschule Hannover, Hannover, Germany.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Tümmler
authors.affiliation: Cystic Fibrosis Reference Centre, University Hospital Gasthuisberg, Catholic University of Leuven, Leuven, Belgium.
authors.forename: Francois
authors.initials: F
authors.lastname: Vermeulen
authors.affiliation: Pediatric Gastroenterology, Hadassah University Hospital, Jerusalem, Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Wilschanski
mesh_terms: D000318:Adrenergic beta-Agonists; D000584:Amiloride; D002712:Chlorides / Q000378:metabolism; D003550:Cystic Fibrosis / Q000175:diagnosis* / Q000378:metabolism; D003948:Diagnostic Techniques, Respiratory System / Q000592:standards* / Q000706:statistics & numerical data; D004568:Electrodiagnosis / Q000379:methods / Q000592:standards* / Q000706:statistics & numerical data; D062686:Epithelial Sodium Channel Blockers; D005060:Europe; D019538:Health Care Surveys; D006801:Humans; D038622:Internationality; D007545:Isoproterenol; D008564:Membrane Potentials; D009297:Nasal Mucosa / Q000378:metabolism*; D015588:Observer Variation; D012016:Reference Values; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires
chemical_list: D000318:Adrenergic beta-Agonists; D002712:Chlorides; D062686:Epithelial Sodium Channel Blockers; D000584:Amiloride; D007545:Isoproterenol
keywords: Cystic fibrosis; Diagnosis; Nasal potential difference