Importance of environmental fungi and IgE non-mediated mechanism in atopic eough

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I. Clinical research1) Importance of environmental fungi, basidiomycetous fungi, in chronic cough(1) In previous studies basidiomycetous fungi had been documented as important environmental fungi in severer cases of atopic cough, The DNA sequence analysis revealed that the fungi which were cultured from sputum of patients with intractable chronic cough was Bjerkandera adusta.(2) Basidiomycetous fungi was detected from fungal culture of pharyngeal swab in 20% of patients with atopic cough. The rate was the second following Candida.(3) We succeeded to prepare the antigen extract of basidiomycetous fungi. Immediate type skin reaction using the antigen extract solution was positive in 20% of patients with atopic cough, which was significantly higher than that (5%) in non-atopic healthy subjects.(4) In 8 patients with intractable chronic cough whose sputum yielded Bjerkandera adusta cultured, lymphocyte stimulation test and inhalation provocation test using the fungal antigen were positive … More while the skin reaction was positive in only 3 patients. These findings suggest that lgE non-mediated allergic reaction is important in the fungal-associated chronic cough.2) Exhaled nitric oxide (NO) concentration in atopic coughExhaled nitric oxide (NO) is a biomarker of eosinophilic airway inflammation and the levels have been shown to be elevated in bronchial asthma, cough variant asthma and non-asthmatic eosinophilic bronchitis. We investigated whether the exhaled NO levels were increased in atopic cough in comparison with those in bronchial asthma and cough variant asthma. The exhaled NO levels were significantly lower in atopic cough compared with bronchial asthma and cough variant asthma.II. Basic research1) We developed guinea pig models of atopic cough and cough variant asthma. Neurokinins and histamine were important in the atopic cough model while leukotrienes were important in the cough variant asthma model.2) We hypothesized that cough attacks are mechanical stress to the airways and influence the cough reflex sensitivity. Transient rapid negative pressure was repeatedly given to anesthetized and artificially ventilated guinea pigs. Cough reflex sensitivity to inhaled capsaicin was increased 6 hours after the negative pressure stress which was associated with neutrophilic airway inflammation. Cough stress to airway makes a self-perpetuating cough-reflex cycle, in which antigen-induced increase in cough reflex sensitivity results in pathologic cough, and the cough in turn amplifies cough reflex sensitivity. Less