Background: Measurement of sputum is used to define airway inflammatory phenotypes. Cough variant asthma (CVA) is considered to be the initial stage of classic asthma (CA). The aim of this study was to describe the association between the different subtypes of CVA and CA.
Methods: A total of 459 patients with CVA and CA were screened for the study. All included patients performed spirometry, underwent a bronchial challenge with methacholine and induced sputum according to the guidelines.
Results: A higher frequency of female patients were found with CVA and the eosinophilic airway inflammation of CVA than in CA and the noneosinophilic airway inflammation of CA (p=0.004 and p=0.024, respectively). Bronchial hyper-responsiveness (BHR) was lower in eosinophilic CVA and CA (p=0.006), while no difference was found in noneosinophilic CVA and CA. Association between the percentage of sputum eosinophils and the FEV₁ level fell below 20% of the baseline value (PD₂₀) in CVA and CA (r= − 0.1245, p=0.0357 and r= − 0.2148, p=0.0014, respectively).
Conclusion: Eosinophilia may be associated with more severe disease, yet there was no difference in spirometry between the eosinophilic and noneosinophilic groups, and the BHR difference was not dramatic.



中文翻译：

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经典哮喘和咳嗽变异型哮喘的炎症亚型

背景：痰液的测量用于定义气道炎症表型。咳嗽变异性哮喘（CVA）被认为是典型哮喘（CA）的初始阶段。本研究的目的是描述 CVA 和 CA 不同亚型之间的关联。
方法：本研究共筛选了 459 名 CVA 和 CA 患者。根据指南，所有纳入的患者都进行了肺活量测定，接受了乙酰甲胆碱的支气管激发和诱导痰。
结果：女性患者出现 CVA 和 CVA 嗜酸性气道炎症的频率高于 CA 和 CA 非嗜酸性气道炎症（p = 0.004 和p= 0.024，分别）。嗜酸性CVA和CA的支气管高反应性（BHR）较低（p = 0.006），而非嗜酸性CVA和CA无差异。在 CVA 和 CA中，痰嗜酸性粒细胞百分比与 FEV ₁水平之间的关联降至基线值 (PD _{20 ) 的 20% 以下（分别为 r= - 0.1245，} p = 0.0357 和 r= - 0.2148，p = 0.0014）。
结论：嗜酸性粒细胞增多可能与更严重的疾病有关，但嗜酸性粒细胞和非嗜酸性粒细胞组之间的肺活量测定无差异，BHR差异不显着。