| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS | REGISTER |
|
|
|
|
|||||||||||||
|
|
|||||||||||||||
COUGH |
Department of Thoracic Medicine, National Heart and Lung Institute, Imperial College and Royal Brompton Hospital, London, UK
Correspondence to:
Correspondence to:
Professor K F Chung
Department of Thoracic Medicine, National Heart and Lung Institute, Imperial College, Dovehouse Street, London SW3 6LY, UK; f.chung{at}imperial.ac.uk
Background: Increased hydrogen and reduced chloride ionic environments of the airways are conducive to the stimulation of cough. However, the constituents of the local milieu of the airways of patients with chronic cough are unknown.
Methods: The pH and chloride levels in exhaled breath condensate and capsaicin cough threshold (C5) were measured in 50 patients with chronic cough and in 16 healthy controls. pH and chloride measurements were repeated after capsaicin challenge in those with cough. The cause of cough was asthma (n = 13), postnasal drip/rhinitis (n = 7), gastro-oesophageal reflux (n = 5), bronchiectasis (n = 5), but remained unidentified in 20.
Results: Compared with controls, patients with chronic cough had lower pH (mean 7.9 v 8.3, 95% CI of difference –0.5 to –0.2, p<0.0001), chloride levels (median 4 v 6 mmol/l, 95% CI –3.1 to –0.2, p = 0.007), and C5 (median 3.9 v 125 µM, 95% CI –270.0 to –17.6, p = 0.002). The pH levels were different in the six subgroups including controls, and were reduced in all diagnostic subgroups of patients with cough compared with controls but did not differ between them. Chloride levels were significantly different in the six subgroups but were lower than controls in only the gastro-oesophageal reflux subgroup. There was a weak but significant correlation between chloride levels and C5 when all participants were analysed together, but not between pH and C5 or chloride levels. pH and chloride levels did not change after capsaicin challenge.
Conclusions: The epithelial lining fluid of patients with chronic cough has a reduced pH and reduced chloride levels which could contribute to the enhanced cough reflex.
Abbreviations: C2 and C5, concentration of capsaicin causing 
2 or 5 coughs; EBC, exhaled breath condensate; GOR, gastro-oesophageal reflux; PND, postnasal drip
Keywords: chronic cough; exhaled breath condensate; chloride; airway acidification
This article has been cited by other articles:
|
|
 |
|
  Z. L. Borrill, K. Roy, and D. Singh Exhaled breath condensate biomarkers in COPD Eur. Respir. J., August 1, 2008; 32(2): 472 - 486. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Chung Review Series: Chronic cough: Future directions in chronic cough: mechanisms and antitussives Chronic Respiratory Disease, August 1, 2007; 4(3): 159 - 165. [Abstract] [PDF]
|
|
|
|
|
|
S. Dodig, I. Cepelak, D. Plavec, Z. Vlasic, B. Nogalo, and M. Turkalj The effect of gas standardisation on exhaled breath condensate pH and PCO2 Eur. Respir. J., July 1, 2007; 30(1): 185 - 187. [Full Text] [PDF]
|
|
|
|
|
|
Z. L. Borrill, J. A. Smith, J. Naylor, A. A. Woodcock, and D. Singh The effect of gas standardisation on exhaled breath condensate pH. Eur. Respir. J., July 1, 2006; 28(1): 251 - 252. [Full Text] [PDF]
|
|
|
|
 |
|
 R. M. Effros, R. Casaburi, J. Su, M. Dunning, J. Torday, J. Biller, and R. Shaker The Effects of Volatile Salivary Acids and Bases on Exhaled Breath Condensate pH Am. J. Respir. Crit. Care Med., February 15, 2006; 173(4): 386 - 392. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. O. Paget-Brown, L. Ngamtrakulpanit, A. Smith, D. Bunyan, S. Hom, A. Nguyen, and J. F. Hunt Normative Data for pH of Exhaled Breath Condensate. Chest, February 1, 2006; 129(2): 426 - 430. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. F. Chung, M. Hew, J. Score, A. V. Jones, A. Reiter, N. C. P. Cross, and B. J. Bain Cough and hypereosinophilia due to FIP1L1-PDGFRA fusion gene with tyrosine kinase activity Eur. Respir. J., January 1, 2006; 27(1): 230 - 232. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A P. S Hungin, A. S Raghunath, and I. Wiklund Beyond heartburn: a systematic review of the extra-oesophageal spectrum of reflux-induced disease Fam. Pract., December 1, 2005; 22(6): 591 - 603. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Horvath, J. Hunt, P. J. Barnes, and On behalf of the ATS/ERS Task Force on Exhaled Bre Exhaled breath condensate: methodological recommendations and unresolved questions Eur. Respir. J., September 1, 2005; 26(3): 523 - 548. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A Morice, C F Everett, S A Mulrennan, K F Chung, and A Niimi Exhaled breath condensate in chronic cough * Authors' reply Thorax, March 1, 2005; 60(3): 259 - 259. [Full Text] [PDF]
|
|
|
|
|
|
A Morice EBC pH and chronic cough Thorax, March 1, 2005; 60(3): 257 - 257. [Full Text] [PDF]
|
|
|
|
|
|
Z. Borrill, C. Starkey, J. Vestbo, and D. Singh Reproducibility of exhaled breath condensate pH in chronic obstructive pulmonary disease Eur. Respir. J., February 1, 2005; 25(2): 269 - 274. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A. Groneberg, A. Niimi, Q. T. Dinh, B. Cosio, M. Hew, A. Fischer, and K. F. Chung Increased Expression of Transient Receptor Potential Vanilloid-1 in Airway Nerves of Chronic Cough Am. J. Respir. Crit. Care Med., December 15, 2004; 170(12): 1276 - 1280. [Abstract] [Full Text] [PDF]
|
|
Read all eLetters
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS | REGISTER |
