title: Nasal potential difference in cystic fibrosis considering severe CFTR mutations.
abstract: The gold standard for diagnosing cystic fibrosis (CF) is a sweat chloride value above 60 mEq/L. However, this historical and important tool has limitations; other techniques should be studied, including the nasal potential difference (NPD) test. CFTR gene sequencing can identify CFTR mutations, but this method is time-consuming and too expensive to be used in all CF centers. The present study compared CF patients with two classes I-III CFTR mutations (10 patients) (G1), CF patients with classes IV-VI CFTR mutations (five patients) (G2), and 21 healthy subjects (G3). The CF patients and healthy subjects also underwent the NPD test. A statistical analysis was performed using the Mann-Whitney, Kruskal-Wallis, χ(2), and Fisher's exact tests, α = 0.05. No differences were observed between the CF patients and healthy controls for the PDMax, Δamiloride, and Δchloride + free + amiloride markers from the NPD test. For the finger value, a difference between G2 and G3 was described. The Wilschanski index values were different between G1 and G3. In conclusion, our data showed that NPD is useful for CF diagnosis when classes I-III CFTR mutations are screened. However, if classes IV-VI are considered, the NPD test showed an overlap in values with healthy subjects.
authors: Department of Otolaryngology, State University of Campinas (Unicamp), 13083-887 Campinas, SP, Brazil.
authors: Ronny Tah Yen
authors: RT
authors: Ng
authors: Department of Pediatrics, Center for Pediatrics Research (CIPED), State University of Campinas (Unicamp), 13083-887 Campinas, SP, Brazil ; Department of Medical Genetics, State University of Campinas (Unicamp), 13083-887 Campinas, SP, Brazil.
authors: Fernando Augusto de Lima
authors: FA
authors: Marson
authors: Department of Pediatrics, Center for Pediatrics Research (CIPED), State University of Campinas (Unicamp), 13083-887 Campinas, SP, Brazil.
authors: Jose Dirceu
authors: JD
authors: Ribeiro
authors: Department of Pediatrics, Center for Pediatrics Research (CIPED), State University of Campinas (Unicamp), 13083-887 Campinas, SP, Brazil.
authors: Antonio Fernando
authors: AF
authors: Ribeiro
authors: Department of Medical Genetics, State University of Campinas (Unicamp), 13083-887 Campinas, SP, Brazil.
authors: Carmen Silvia
authors: CS
authors: Bertuzzo
authors: Department of Pediatrics, Center for Pediatrics Research (CIPED), State University of Campinas (Unicamp), 13083-887 Campinas, SP, Brazil.
authors: Maria Angela Gonçalves de Oliveira
authors: MA
authors: Ribeiro
authors: Department of Pediatrics, Center for Pediatrics Research (CIPED), State University of Campinas (Unicamp), 13083-887 Campinas, SP, Brazil.
authors: Silvana Dalge
authors: SD
authors: Severino
authors: Department of Otolaryngology, State University of Campinas (Unicamp), 13083-887 Campinas, SP, Brazil.
authors: Eulalia
authors: E
authors: Sakano
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D003550:Cystic Fibrosis / Q000175:diagnosis* / Q000235:genetics; D004568:Electrodiagnosis / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008564:Membrane Potentials; D009154:Mutation; D009297:Nasal Mucosa / Q000378:metabolism / Q000502:physiology*