title: New approach for cystic fibrosis diagnosis based on chloride/potassium ratio analyzed in non-invasively obtained skin-wipe sweat samples by capillary electrophoresis with contactless conductometric detection.
abstract: A new approach for sweat analysis used in cystic fibrosis (CF) diagnosis is proposed. It consists of a noninvasive skin-wipe sampling followed by analysis of target ions using capillary electrophoresis with contactless conductometric detection (C4D). The skin-wipe sampling consists of wiping a defined skin area with precleaned cotton swab moistened with 100 μL deionized water. The skin-wipe sample is then extracted for 3 min into 400 μL deionized water, and the extract is analyzed directly. The developed sampling method is cheap, simple, fast, and painless, and can replace the conventional pilocarpine-induced sweat chloride test commonly applied in CF diagnosis. The aqueous extract of the skin-wipe sample content is analyzed simultaneously by capillary electrophoresis with contactless conductometric detection using a double opposite end injection. A 20 mmol/L L-histidine/2-(N-morpholino)ethanesulfonic acid and 2 mmol/L 18-crown-6 at pH 6 electrolyte can separate all the major ions in less than 7 min. Skin-wipe sample extracts from 30 study participants-ten adult patients with CF (25-50 years old), ten pediatric patients with CF (1-15 years old), and ten healthy control individuals (1-18 years old)-were obtained and analyzed. From the analyzed ions in all samples, a significant difference between chloride and potassium concentrations was found in the CF patients and healthy controls. We propose the use of the Cl-/K+ratio rather than the absolute Cl-concentration and a cutoff value of 4 in skin-wipe sample extracts as an alternative to the conventional sweat chloride analysis. The proposed Cl-/K+ion ratio proved to be a more reliable indicator, is independent of the patient's age, and allows better differentiation between non-CF individuals and CF patients having intermediate values on the Cl-sweat test. Figure New approach for cystic fibrosis diagnosis based on skin-wipe sampling of forearm and analysis of ionic content (Cl-/K+ratio) in skin-wipe extracts by capillary electrophoresis with contactless conductometric detection.
authors.affiliation: Department of Bioanalytical Instrumentation, CEITEC Masaryk University, Veveří 97, 602 00, Brno, Czech Republic.|Department of Chemistry, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic.
authors.forename: Pavol
authors.initials: P
authors.lastname: Ďurč
authors.affiliation: Department of Bioanalytical Instrumentation, CEITEC Masaryk University, Veveří 97, 602 00, Brno, Czech Republic.
authors.forename: František
authors.initials: F
authors.lastname: Foret
authors.affiliation: Department of Respiratory Diseases and TB, University Hospital Brno, Jihlavská 20, 625 00, Brno, Czech Republic.
authors.forename: Eva
authors.initials: E
authors.lastname: Pokojová
authors.affiliation: Cystic Fibrosis Centre and Clinic of Pediatric Infectious Diseases, University Hospital Brno, Jihlavská 20, 625 00, Brno, Czech Republic.
authors.forename: Lukáš
authors.initials: L
authors.lastname: Homola
authors.affiliation: Department of Respiratory Diseases and TB, University Hospital Brno, Jihlavská 20, 625 00, Brno, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Skřičková
authors.affiliation: Department of Respiratory Diseases and TB, University Hospital Brno, Jihlavská 20, 625 00, Brno, Czech Republic.
authors.forename: Vladimír
authors.initials: V
authors.lastname: Herout
authors.affiliation: Department of Clinical Biochemistry, University Hospital Brno, Jihlavská 20, 625 00, Brno, Czech Republic.
authors.forename: Milan
authors.initials: M
authors.lastname: Dastych
authors.affiliation: Department of Clinical Biochemistry, University Hospital Brno, Jihlavská 20, 625 00, Brno, Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Vinohradská
authors.affiliation: Department of Bioanalytical Instrumentation, CEITEC Masaryk University, Veveří 97, 602 00, Brno, Czech Republic. petr.kuban@gmail.com.
authors.forename: Petr
authors.initials: P
authors.lastname: Kubáň
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002712:Chlorides / Q000032:analysis*; D003550:Cystic Fibrosis / Q000175:diagnosis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D007223:Infant; D008875:Middle Aged; D011188:Potassium / Q000032:analysis*; D025341:Principal Component Analysis; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods; D013542:Sweat / Q000737:chemistry*
chemical_list: D002712:Chlorides; D011188:Potassium
keywords: Capillary electrophoresis; Cystic fibrosis; Diagnosis; Ion ratio; Skin wipe; Sweat