BACKGROUND: Unlike classic asthma, cough-variant asthma does not show any evidence of airway obstruction. The main symptom is a dry cough with little known pathophysiology. Hypersensitivity of the cough receptors in cough-variant asthma and an increase in the sensory nerve density of the airway epithelium in persistent dry cough patients have been reported. Therefore, it is possible that there is a higher sensory nerve density in cough-variant asthma patients than in classic asthma patients. OBJECTIVES: This study was undertaken to compare the substance P (SP)-immunoreactive nerve density in mucosal biopsies of cough-variant asthma patients, classic asthma patients, and in control subjects. METHODS: Bronchoscopic biopsies were performed in 6 cough-variant asthma patients, 14 classic asthma patients, and 5 normal controls. The tissues obtained were stained immunohistochemically. The SP-immunoreactive nerve density was measured in the bronchial epithelium using a light microscope at 400 x magnification. RESULTS: SP- immunoreactive nerve density for the cough-variant asthma group was significantly higher than that of the classic asthma group (p = 0.001), and of the normal control group (p = 0.006). CONCLUSIONS: It is possible that a sensory nerve abnormality within the airway may be related to hypersensitivity of the cough receptor, and that this may be one of the pathophysiologies of cough-variant asthma. Copyright 2003 S. Karger AG, Basel
BACKGROUND: Unlike classic asthma, cough-variant asthma does not show any evidence of airway obstruction. The main symptom is a dry cough with little known pathophysiology. Hypersensitivity of the cough receptors in cough-variant asthma and an increase in the sensory nerve density of the airway epithelium in persistent dry coughpatients have been reported. Therefore, it is possible that there is a higher sensory nerve density in cough-variant asthmapatients than in classic asthmapatients. OBJECTIVES: This study was undertaken to compare the substance P (SP)-immunoreactive nerve density in mucosal biopsies of cough-variant asthmapatients, classic asthmapatients, and in control subjects. METHODS: Bronchoscopic biopsies were performed in 6 cough-variant asthmapatients, 14 classic asthmapatients, and 5 normal controls. The tissues obtained were stained immunohistochemically. The SP-immunoreactive nerve density was measured in the bronchial epithelium using a light microscope at 400 x magnification. RESULTS: SP- immunoreactive nerve density for the cough-variant asthma group was significantly higher than that of the classic asthma group (p = 0.001), and of the normal control group (p = 0.006). CONCLUSIONS: It is possible that a sensory nerve abnormality within the airway may be related to hypersensitivity of the cough receptor, and that this may be one of the pathophysiologies of cough-variant asthma. Copyright 2003 S. Karger AG, Basel
Authors: Robert N Patterson; Brian T Johnston; Joy E S Ardill; Liam G Heaney; Lorcan P A McGarvey Journal: Thorax Date: 2007-01-24 Impact factor: 9.139
Authors: Brendan J Canning; Anne B Chang; Donald C Bolser; Jaclyn A Smith; Stuart B Mazzone; Lorcan McGarvey Journal: Chest Date: 2014-12 Impact factor: 9.410