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Background: It has been reported that nasal allergy influences the lower airway inflammation and functions. We elucidated whether nasal allergy would contribute to lower airway inflammation and functions., Methods: 266 subjects aged 21-39 years were interviewed with special emphasis on history of asthma and nasal allergies (perennial allergic rhinitis (PAR) and seasonal allergic rhinitis (Japanese cedar pollinosis; PO)). Symptomatic subject was defined when nasal symptoms were present during a 3-week study period. Pulmonary function, provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 s (PC20), capsaicin cough threshold defined as capsaicin concentration eliciting 5 or more coughs (C5) and eosinophil percentage in hypertonic saline-induced sputum were measured., Results: Based on the interview, 232 subjects without asthma were divided into symptomatic (n = 25) and asymptomatic (n = 22) PAR, PO on-season (n = 15) and off-season (n = 36), and non-nasal allergy subjects (control) (n = 134). Sputum eosinophils were significantly greater in symptomatic PAR than another four groups (p < 0.01). FEV1/FVC ratio was significantly lower in PAR than control (p < 0.05). Maximum mean expiratory flow was lower in PAR than control (asymptomatic: p < 0.05, symptomatic: p = 0.06). C5 was not different among groups. PAR tended to have a lower PC20 compared to control (symptomatic: p = 0.078; asymptomatic: p = 0.086)., Conclusions: These results suggest that eosinophilic inflammation occurred in symptomatic period of PAR may contribute to development of lower airway remodeling and bronchial hyperresponsiveness. Reversely, PO may not be associated with lower airway eosinophilic inflammation or abnormal bronchial functions. Nasal allergy dose not influence the cough reflex sensitivity., (Copyright 2006 S. Karger AG, Basel.)

Aims: Cough, one of the main symptoms of bronchial asthma, is a chronic airway inflammatory disease with functionally damaged bronchial epithelium. Recently, we established an animal model with cough hypersensitivity after antigen challenge and clearly showed the protective effect of carbocysteine in this model. This study was designed to investigate the clinical effect of carbocysteine for cough sensitivity in patients with bronchial asthma., Methods: The effects of the two orally active mucoregulatory drugs, carbocysteine and ambroxol hydrochloride, on cough response to inhaled capsaicin were examined in 14 patients with stable asthma. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of airway cough sensitivity., Results: Geometric mean values of the cough threshold at run-in (baseline) and after 4 weeks' treatment of placebo, 1500 mg day-1 of carbocysteine and 45 mg day-1 of ambroxol hydrochloride were 12.8 micro M (95% confidence interval [CI] 5.5, 29.6), 11.0 micro M (95% CI 4.4, 27.5), 21.0 micro M (95% CI 8.8, 50.2) and 11.6 micro M (95% CI 5.8, 23.3), respectively. The cough threshold for carbocysteine was significantly greater than those of ambroxol hydrochloride (P = 0.047) and placebo (P = 0.047), respectively., Conclusions: These findings indicate that carbocysteine administration may be a novel therapeutic option for asthmatic patients, especially with cough variant asthma.

Inflammatory mediators are involved in the pathogenesis of airway inflammation, but the role of prostaglandin I2 (PGI2) remains obscure. This study was designed to investigate the role of PGI2 in cough reflex sensitivity of the asthmatic airway, which is characterized by chronic eosinophilic airway inflammation. The effect of beraprost, a chemically and biologically stable analogue of PGI2, on cough response to inhaled capsaicin was examined in 21 patients with stable asthma in a randomized, placebo-controlled cross over study. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of airway cough reflex sensitivity. The cough threshold was significantly (p < 0.05) decreased after two weeks of treatment with beraprost [17.8 (GSEM 1.20) μM] compared with placebo [30.3 (GSEM 1.21) μM]. PGI2 increases cough reflex sensitivity of the asthmatic airway, suggesting that inhibition of PGI2 may be a novel therapeutic option for patients with asthma, especially cough predominant asthma. [ABSTRACT FROM AUTHOR]

Background: Late asthmatic response is observed following antigen challenge in actively, but not passively, sensitized guinea pigs. Although cough reflex sensitivity is increased after antigen challenge in actively sensitized guinea pigs, it is unknown whether the antigen-induced increase in cough reflex sensitivity develops in passively sensitized animals. The aim of this study was to compare the cough reflex sensitivity to inhaled capsaicin after an inhaled antigen challenge between actively and passively sensitized guinea pigs. Methods: Measurement of number of coughs elicited by increasing concentrations of capsaicin (10-6 and 10-4 M) and bronchial responsiveness to ascending concentrations of methacholine, and analysis of bronchoalveolar lavage fluid (BALF) were separately performed 24 h after an antigen challenge in actively and passively sensitized guinea pigs. Results: Percentage of eosinophils in BALF and bronchial responsiveness to methacholine were increased 24 h after the antigen challenge in both actively and passively sensitized animals compared with saline-challenged actively and passively sensitized animals, respectively. Absolute number of eosinophils in BALF from actively sensitized and antigen-challenged guinea pigs was significantly greater than that from passively sensitized and antigen-challenged animals. Cough response to capsaicin and concentration of substance P in BALF were increased 24 h after the antigen challenge in actively sensitized guinea pigs, but not in passively sensitized guinea pigs. Bronchial responsiveness, cough reflex sensitivity and substance P concentration and total cells in BALF were increased in actively sensitized and saline challenged guinea pigs compared with passively sensitized and saline challenged animals. Conclusion: The results suggest that active sensitization per se increases cough reflex sensitivity accompanied by increased inflammatory cells and substance P level in BALF, and antigen challenge further increases them, while simple IgE- and/or IgG-mediated allergic reaction per se or the low intensity of eosinophil infiltration in the airway itself may not affect cough reflex sensitivity in guinea pigs. [ABSTRACT FROM AUTHOR]