Allergen challenge increases capsaicin-evoked cough responses in patients with allergic asthma.
Adult
Aged
Allergens
/ administration & dosage
Asthma
/ immunology
Capsaicin
/ administration & dosage
Cough
/ immunology
Cross-Over Studies
Eosinophils
/ immunology
Female
Forced Expiratory Volume
Humans
Leukocyte Count
Male
Middle Aged
Pulmonary Eosinophilia
/ immunology
Single-Blind Method
Sputum
/ immunology
Young Adult
Asthma
allergen
capsaicin
cough
transient receptor potential vanilloid type 1
Journal
The Journal of allergy and clinical immunology
ISSN: 1097-6825
Titre abrégé: J Allergy Clin Immunol
Pays: United States
ID NLM: 1275002
Informations de publication
Date de publication:
09 2019
09 2019
Historique:
received:
22
06
2018
revised:
24
10
2018
accepted:
30
11
2018
pubmed:
21
1
2019
medline:
30
5
2020
entrez:
21
1
2019
Statut:
ppublish
Résumé
Cough is a common and troublesome symptom in asthmatic patients, but little is known about the neuronal pathways that trigger cough. The mechanisms by which airway inflammation, airway hyperresponsiveness, and variable airflow obstruction cause cough are unclear. We sought to investigate the effects of allergen exposure on cough reflex sensitivity. We performed a 9-visit, randomized, single-blind, placebo-controlled, 2-way crossover study comparing cough responses to inhaled capsaicin in patients with mild atopic asthma after allergen challenge compared with diluent control. Full-dose capsaicin challenge was performed at screening to determine the capsaicin dose inducing a half-maximal response, which was subsequently administered at 30 minutes and 24 hours after inhaled allergen/diluent challenge. Spontaneous coughing was measured for 24 hours after allergen/diluent. Methacholine challenge and sputum induction were performed before and after allergen/diluent challenge. Twelve steroid-naive subjects completed the study (6 female subjects; mean age, 34.8 years). Allergen inhalation caused both an early (mean ± SD, 38.2% ± 13.0%) and late (mean ± SD, 23.7% ± 13.2%) decrease in FEV Allergen-induced bronchoconstriction and airway eosinophilia result in increased cough reflex sensitivity to capsaicin associated with an increase in 24-hour spontaneous coughing.
Sections du résumé
BACKGROUND
Cough is a common and troublesome symptom in asthmatic patients, but little is known about the neuronal pathways that trigger cough. The mechanisms by which airway inflammation, airway hyperresponsiveness, and variable airflow obstruction cause cough are unclear.
OBJECTIVE
We sought to investigate the effects of allergen exposure on cough reflex sensitivity.
METHODS
We performed a 9-visit, randomized, single-blind, placebo-controlled, 2-way crossover study comparing cough responses to inhaled capsaicin in patients with mild atopic asthma after allergen challenge compared with diluent control. Full-dose capsaicin challenge was performed at screening to determine the capsaicin dose inducing a half-maximal response, which was subsequently administered at 30 minutes and 24 hours after inhaled allergen/diluent challenge. Spontaneous coughing was measured for 24 hours after allergen/diluent. Methacholine challenge and sputum induction were performed before and after allergen/diluent challenge.
RESULTS
Twelve steroid-naive subjects completed the study (6 female subjects; mean age, 34.8 years). Allergen inhalation caused both an early (mean ± SD, 38.2% ± 13.0%) and late (mean ± SD, 23.7% ± 13.2%) decrease in FEV
CONCLUSION
Allergen-induced bronchoconstriction and airway eosinophilia result in increased cough reflex sensitivity to capsaicin associated with an increase in 24-hour spontaneous coughing.
Identifiants
pubmed: 30660644
pii: S0091-6749(19)30035-1
doi: 10.1016/j.jaci.2018.11.050
pii:
doi:
Substances chimiques
Allergens
0
Capsaicin
S07O44R1ZM
Banques de données
ISRCTN
['ISRCTN79930571']
Types de publication
Journal Article
Randomized Controlled Trial
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
788-795.e1Subventions
Organisme : Wellcome Trust
ID : 207504/B/17/Z
Pays : United Kingdom
Organisme : Medical Research Council
ID : MR/K015141/1
Pays : United Kingdom
Commentaires et corrections
Type : CommentIn
Informations de copyright
Copyright © 2019 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.