Background: Increasing evidence points to a potential role for members of the transient receptor potential family of cation channels on several features of asthmatic disease. The cough sensitivity to inhaled capsaicin is known to reflect the reactivity of these airway sensory nerves.
Objective: The aim was to study, among patients having a positive methacholine provocation and diagnosed with asthma, capsaicin cough sensitivity, sensitivity to methacholine, and levels of exhaled nitric oxide before and after treatment with inhaled steroids, and further, to measure the self-reported impact from environmental irritants.
Methods: Eighteen steroid-naïve patients with a positive methacholine test underwent capsaicin inhalation provocation on two occasions, before and after regular use of inhaled steroids over at least 3 months. Comparisons were made to 21 healthy controls. Sensitivity to methacholine and levels of exhaled nitric oxide were measured before and after the treatment. The participants also answered a validated questionnaire regarding environmental irritants.
Results: The patients displayed higher capsaicin cough sensitivity than the controls before the treatment period, but not afterward. Before treatment, capsaicin cough answer correlated significantly with levels of exhaled nitric oxide, but not with methacholine sensitivity. After treatment with inhaled corticosteroids, the capsaicin cough sensitivity and the inflammatory parameters were normalized. In comparison to the control group, the patients reported more affective reactions to and behavioral disruptions induced by environmental irritants.
Conclusions: In steroid-naïve patients with a positive methacholine test, there is a link between that part of the airway inflammation that is reflected by exhaled nitric oxide and that followed by an augmented reactivity of capsaicin-sensitive sensory nerves. This association disappears after steroid treatment.
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http://dx.doi.org/10.3109/02770903.2011.570405 | DOI Listing |
ERJ Open Res
November 2024
Division of Infection, Immunity and Respiratory Medicine, University of Manchester and Manchester Academic Health Science Centre, Manchester, UK.
https://bit.ly/45P1X8V.
View Article and Find Full Text PDFSci Rep
November 2024
Department of Respiratory Medicine, Allergy, and Clinical Immunology, Graduate school of Medical Sciences, Nagoya City University, Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi, Japan.
Sensitization to Staphylococcus aureus (S. aureus) enterotoxins (SEs) A (SEA) and B (SEB) is associated with the pathogenesis of several chronic airway diseases, including asthma and chronic rhinosinusitis, but its role in chronic obstructive pulmonary disease (COPD) remains unclear. This cohort study aimed to investigate the impact of sensitization to SEs on total IgE levels, and capsaicin cough reflex sensitivity (C-CS) in COPD.
View Article and Find Full Text PDFOtolaryngol Head Neck Surg
November 2024
Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Innovation (Camb)
November 2024
National Institute of Biological Sciences, Beijing 102206, China.
J Ethnopharmacol
February 2025
School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang, 310013, China; Key Laboratory of Neuropsychiatric Drug Research of Zhejiang Province, Hangzhou Medical College, Hangzhou, Zhejiang, 311300, China. Electronic address:
Ethnopharmacological Relevance: Cough variant asthma (CVA), a prevalent chronic inflammatory disease, is the most common cause of chronic cough. Over the years, the aqueous extract of Quzhou Aurantii Fructus (QAFA) has been widely used to treat respiratory diseases, particularly cough.
Aim Of The Study: This study aimed to elucidate the therapeutic effect of QAFA on allergen-induced CVA, providing deep insights into the underlying mechanisms.
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