BACKGROUND: The relationship between cough receptor sensitivity and eosinophilic inflammation of the airway in patients with asthma remains unclear. METHODS:Eighteen patients with asthma sensitised to house dust mite (HDM) were enrolled in a randomised parallel group study. Patients with asthma whose main symptom was cough were not enrolled in the study. Half the patients were randomly assigned to inhale saline and the other half to inhale HDM allergen. Cough receptor sensitivity to capsaicin, airway responsiveness to histamine, and sputum eosinophils analysed with hypertonic saline inhalation were investigated before and 24 hours after saline or HDM allergen bronchoprovocation. RESULTS: Patients inhaling saline showed no significant changes in sputum eosinophils (from 7.87% (95% confidence interval (CI) 5.08 to 12.19) to 8.60% (95% CI 3.03 to 14.18); p=0.97), airway responsiveness to histamine (from 726.68 micro g/ml (95% CI 251.90 to 2096.36) to 773.01 micro g/ml (95% CI 251.36 to 2377.23); p=0.96), or capsaicin sensitivity (from 7.23 micro M (95% CI 2.45 to 21.31) to 7.24 micro M (95% CI 2.46 to 21.31); p=0.96). Early asthmatic response was induced in all patients, and late asthmatic response was observed in six of nine patients inhaling HDM allergen. Although there were significant increases in sputum eosinophils (from 9.83% (95% CI 6.78 to 14.27) to 21.00% (95% CI 13.85 to 28.15); p<0.01) and airway responsiveness to histamine (from 784.16 micro g/ml (95% CI 318.24 to 1932.24) to 377.81 micro g/ml (95% CI 118.43 to 1205.24); p<0.05) 24 hours after HDM allergen inhalation compared with baseline levels, capsaicin sensitivity did not change significantly (from 5.75 micro M (95% CI 1.91 to 17.30) to 6.20 micro M (95% CI 2.21 to 17.38); p=0.77). CONCLUSIONS: These findings suggest that cough receptor sensitivity to capsaicin is not associated with eosinophilic inflammation of the airway in patients with allergic asthma whose main symptoms are wheezing and dyspnoea but not cough.
RCT Entities:
BACKGROUND: The relationship between cough receptor sensitivity and eosinophilic inflammation of the airway in patients with asthma remains unclear. METHODS: Eighteen patients with asthma sensitised to house dust mite (HDM) were enrolled in a randomised parallel group study. Patients with asthma whose main symptom was cough were not enrolled in the study. Half the patients were randomly assigned to inhale saline and the other half to inhale HDM allergen. Cough receptor sensitivity to capsaicin, airway responsiveness to histamine, and sputum eosinophils analysed with hypertonicsaline inhalation were investigated before and 24 hours after saline or HDM allergen bronchoprovocation. RESULTS:Patients inhaling saline showed no significant changes in sputum eosinophils (from 7.87% (95% confidence interval (CI) 5.08 to 12.19) to 8.60% (95% CI 3.03 to 14.18); p=0.97), airway responsiveness to histamine (from 726.68 micro g/ml (95% CI 251.90 to 2096.36) to 773.01 micro g/ml (95% CI 251.36 to 2377.23); p=0.96), or capsaicin sensitivity (from 7.23 micro M (95% CI 2.45 to 21.31) to 7.24 micro M (95% CI 2.46 to 21.31); p=0.96). Early asthmatic response was induced in all patients, and late asthmatic response was observed in six of nine patients inhaling HDM allergen. Although there were significant increases in sputum eosinophils (from 9.83% (95% CI 6.78 to 14.27) to 21.00% (95% CI 13.85 to 28.15); p<0.01) and airway responsiveness to histamine (from 784.16 micro g/ml (95% CI 318.24 to 1932.24) to 377.81 micro g/ml (95% CI 118.43 to 1205.24); p<0.05) 24 hours after HDM allergen inhalation compared with baseline levels, capsaicin sensitivity did not change significantly (from 5.75 micro M (95% CI 1.91 to 17.30) to 6.20 micro M (95% CI 2.21 to 17.38); p=0.77). CONCLUSIONS: These findings suggest that cough receptor sensitivity to capsaicin is not associated with eosinophilic inflammation of the airway in patients with allergic asthma whose main symptoms are wheezing and dyspnoea but not cough.
Authors: A Di Franco; F L Dente; D Giannini; B Vagaggini; I Conti; P Macchioni; L Scuotri; M Taccola; E Bacci; P L Paggiaro Journal: Pulm Pharmacol Ther Date: 2001 Impact factor: 3.410
Authors: Maria G Belvisi; Mark A Birrell; Saifudin Khalid; Michael A Wortley; Rachel Dockry; Julie Coote; Kimberley Holt; Eric Dubuis; Angela Kelsall; Sarah A Maher; Sara Bonvini; Ashley Woodcock; Jaclyn A Smith Journal: Am J Respir Crit Care Med Date: 2016-06-15 Impact factor: 21.405
Authors: Hajar Ali; Collin Brooks; Julian Crane; Richard Beasley; Stephen Holgate; Peter Gibson; Philip Pattemore; Yu-Chieh Tzeng; Thorsten Stanley; Neil Pearce; Jeroen Douwes Journal: BMJ Open Respir Res Date: 2021-11