Exhaled nitric oxide levels in patients with atopic cough and cough variant asthma
Exhaled nitric oxide levels in patients with atopic cough and cough variant asthma
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DOI：
10.1111/j.1440-1843.2008.01273.x
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发表时间：
2008-05-01
期刊：
影响因子：
6.9
通讯作者：
Hara, Johsuke
中科院分区：
文献类型：
--
作者：
Fujimura, Masaki;Ohkura, Noriyuki;Hara, Johsuke
背景和目的：特应性咳嗽(AC)在日本是一种公认的临床疾病，患者表现为慢性持续性非生产性咳嗽。呼出的一氧化氮(NO)是嗜酸性气道炎的生物标志物。与咳嗽变异性哮喘(CVA)和哮喘(BA)相比，AC患者呼出的NO水平是否升高。方法：连续8周以上的患者出现单纯性咳嗽。慢性咳嗽的病因是根据日本呼吸学会的咳嗽管理指南确定的。在患者第一次就诊时，测量呼出的NO、辣椒素咳嗽敏感度(引起5次或5次以上咳嗽的辣椒素浓度(C5))和支气管可逆性。在为期6天的支气管扩张剂治疗结束后，第二次访问时测定其对乙酰胆碱的反应性(PC20)。结果：共纳入58名患者并进行了全面调查，其中9名和11名患者分别被诊断为AC和CVA是慢性咳嗽的单一原因。10例在过去4周内未接受过皮质类固醇治疗的BA患者作为对照。AC患者呼气NO水平明显低于CVA和BA患者。CVA患者呼出的NO水平与BA无显著差异。结论：呼出的NO可能反映了外周气道的嗜酸性炎症，其检测有助于CVA与AC及其他原因的慢性咳嗽的鉴别。
Background and objective: Atopic cough (AC) is an established clinical entity in Japan, in which patients present with a chronic persistent non-productive cough. Exhaled nitric oxide (NO) is a biomarker of eosinophilic airway inflammation. The present study examined whether exhaled NO levels were increased in AC in comparison with cough variant asthma (CVA) and bronchial asthma (BA).Methods: Consecutive patients presenting with an isolated cough lasting at least 8 weeks were enrolled in the study. The aetiology of the chronic cough was determined according to the Japanese Respiratory Society guidelines for management of cough. Exhaled NO, capsaicin cough sensitivity (capsaicin concentration eliciting five or more coughs (C5)) and bronchial reversibility were measured at the patients' first visit. Bronchial responsiveness (PC20 to methacholine) was measured at their second visit following a 6-day course of bronchodilator therapy.Results: There were 58 patients recruited and fully investigated; of these 9 and 11 patients were diagnosed with AC and CVA, respectively, as single causes of chronic cough. Ten patients with BA who had not received corticosteroid therapy in the previous 4 weeks and who attended the same clinic in the same time period acted as controls. Exhaled NO levels in patients with AC were significantly lower than those in patients with CVA and BA. There was no significant difference in the exhaled NO levels between patients with CVA and BA.Conclusions: Exhaled NO may reflect eosinophilic inflammation of peripheral airways and its measurement may be useful in differentiating CVA from AC and other causes of chronic non-productive cough.