Analytical and Bioanalytical Chemistry

, Volume 409, Issue 14, pp 3507–3514 | Cite as

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

  • Pavol Ďurč
  • František Foret
  • Eva Pokojová
  • Lukáš Homola
  • Jana Skřičková
  • Vladimír Herout
  • Milan Dastych
  • Hana Vinohradská
  • Petr Kubáň
Paper in Forefront


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.


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


Cystic fibrosis Capillary electrophoresis Sweat Skin wipe Ion ratio Diagnosis 



The authors acknowledge the financial support from the Grant Agency of the Czech Republic (grant no. P206/13/21919S). This research was conducted under the project CEITEC 2020 (LQ1601) with financial support from the Ministry of Education, Youth, and Sports of the Czech Republic under National Sustainability Programme II.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Research involving human participants

The study protocol was reviewed and approved by the Ethical Commission of University Hospital Brno (August 28, 2014).

Informed consent

Written informed consent was obtained from all participants.


  1. 1.
    Wilcken B, Wiley G, Sherry G, Bayliss U. Neonatal screening for cystic fibrosis: a comparison of two strategies for case detection in 1.2 million babies. J Pediatr. 1995;127:1229–56.CrossRefGoogle Scholar
  2. 2.
    Vertex Pharmaceuticals. KALYDECO® (ivacaftor). 2016. Accessed 29 Jan 2017.
  3. 3.
    Gibson LE, Cooke RE. A test for concentration of electrolytes in sweat in cystic fibrosis of the pancreas utilizing pilocarpine by iontophoresis. Pediatrics. 1959;23:545–9.Google Scholar
  4. 4.
    Hammond KB, Turcios NL, Gibson LE. Clinical evaluation of the macroduct sweat collection system and conductivity analyzer in the diagnosis of cystic fibrosis. J Pediatr. 1994;124:255–60.CrossRefGoogle Scholar
  5. 5.
    Itano M, Nussbaum E, Symons JL. Coulometric titration of sweat collected with the Webster collection system. Respiration. 1985;47:220–4.CrossRefGoogle Scholar
  6. 6.
    Heeley ME, Woolf DA, Heeley AF. Indirect measurements of sweat electrolyte concentration in the laboratory diagnosis of cystic fibrosis. Arch Dis Child. 2000;82:420–4.CrossRefGoogle Scholar
  7. 7.
    Mastella G, Di Cesare G, Borruso A, Menin L, Zanolla L. Reliability of sweat-testing by the macroduct((R)) collection method combined with conductivity analysis in comparison with the classic gibson and cooke technique. Acta Paediatr. 2000;89:933–7.CrossRefGoogle Scholar
  8. 8.
    Seia M, Costantino L, Paracchini V, Porcaro L, Capasso P, Coviello D, et al. Borderline sweat test: utility and limits of genetic analysis for the diagnosis of cystic fibrosis. Clin Biochem. 2009;42:611–6.CrossRefGoogle Scholar
  9. 9.
    Farrell PM, Rosenstein BJ, White TB, Accurso FJ, Castellani C, Cutting GR, et al. Guidelines for diagnosis of cystic fibrosis in newborns through older adults: cystic fibrosis foundation consensus report. J Pediatr. 2008;153:4–14.CrossRefGoogle Scholar
  10. 10.
    Massie J, Clements B. Diagnosis of cystic fibrosis after newborn screening: the australasian experience - twenty years and five million babies later: a consensus statement from the australasian paediatric respiratory group. Pediatr Pulmonol. 2005;39:440–6.CrossRefGoogle Scholar
  11. 11.
    Rosenstein BJ, Cutting GR. The diagnosis of cystic fibrosis: a consensus statement. J Pediatr. 1998;132:589–95.CrossRefGoogle Scholar
  12. 12.
    Bender LM, Cotton SW, Willis MS. Kids in America: newborn screening for cystic fibrosis. Labmedicine. 2011;42:595–601.Google Scholar
  13. 13.
    Gleeson M, Henry RL. Sweat sodium or chloride. Clin Chem. 1991;37:112.Google Scholar
  14. 14.
    Green A, Dodds P, Pennock C. A study of sweat sodium and chloride - criteria for the diagnosis of cystic fibrosis. Ann Clin Biochem. 1985;22:171–6.CrossRefGoogle Scholar
  15. 15.
    Naehrlich L, Bagheri-Behrouzi A. Misdiagnosis of cystic fibrosis - experience from Germany. J Cyst Fibros. 2013;12:68–73.CrossRefGoogle Scholar
  16. 16.
    Beauchamp M, Lands LC. Sweat-testing: a review of current technical requirements. Pediatr Pulmonol. 2005;39:507–11.CrossRefGoogle Scholar
  17. 17.
    Quinton PM. Cystic fibrosis - a disease in electrolyte transport. FASEB J. 1990;4:2709–17.Google Scholar
  18. 18.
    Bijman J. Transport processes in the eccrine sweat gland. Kidney Int. 1987;32:109–12.Google Scholar
  19. 19.
    Hodson ME, Beldon I, Power R, Duncan FR, Bamber M, Batten JC. Sweat tests to diagnose cystic fibrosis in adults. Br Med J. 1983;286:1381–3.CrossRefGoogle Scholar
  20. 20.
    Reddy MM, Quinton PM. Cytosolic potassium controls CFTR deactivation in human sweat duct. Am J Phys Cell Phys. 2006;291:122–9.CrossRefGoogle Scholar
  21. 21.
    Kuban P, Gregus M, Pokojova E, Skrickova J, Foret F. Double opposite end injection capillary electrophoresis with contactless conductometric detection for simultaneous determination of chloride, sodium and potassium in cystic fibrosis diagnosis. J Chromatogr A. 2014;1358:293–8.CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  • Pavol Ďurč
    • 1
    • 2
  • František Foret
    • 1
  • Eva Pokojová
    • 3
  • Lukáš Homola
    • 4
  • Jana Skřičková
    • 3
  • Vladimír Herout
    • 3
  • Milan Dastych
    • 5
  • Hana Vinohradská
    • 5
  • Petr Kubáň
    • 1
  1. 1.Department of Bioanalytical InstrumentationCEITEC Masaryk UniversityBrnoCzech Republic
  2. 2.Department of ChemistryMasaryk UniversityBrnoCzech Republic
  3. 3.Department of Respiratory Diseases and TBUniversity Hospital BrnoBrnoCzech Republic
  4. 4.Cystic Fibrosis Centre and Clinic of Pediatric Infectious DiseasesUniversity Hospital BrnoBrnoCzech Republic
  5. 5.Department of Clinical BiochemistryUniversity Hospital BrnoBrnoCzech Republic

Personalised recommendations