Allen Nathan D, Davis Beth E, Cockcroft Donald W
Division of Respirology, Critical Care and Sleep Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Ann Allergy Asthma Immunol. 2008 Oct;101(4):413-8. doi: 10.1016/S1081-1206(10)60319-5.
One of the characteristic features of the hyperresponsive airway smooth muscle in asthma is the loss of deep-inhalation bronchoprotection and bronchodilation. The airway of individuals with asthma is also characterized by inflammation.
To evaluate whether the loss of deep-inhalation bronchoprotection is correlated with the degree of inflammation in the asthmatic airway.
Eighteen study participants performed 2 methacholine challenges (identical doses), 1 with deep inhalations and 1 without, separated by at least 24 hours. Airway inflammation was evaluated by measurement of fraction of exhaled nitric oxide (FE(NO)) and induced sputum eosinophils.
A significant negative correlation was found between the degree of deep-inhalation bronchoprotection and airway inflammation when measured by FE(NO) (P = .02, r = .54, n = 18) and by percentage of eosinophils (P = .002, r = .76, n = 12). A significant positive correlation was also found between the FE(NO) and percentage of eosinophils (P = .009, r = .68, n = 12).
Deep-inhalation bronchoprotection was significantly impaired in individuals with greater airway inflammation. This finding suggests that therapy directed at decreasing airway inflammation may promote the recovery of normal deep-inhalation bronchoprotection.
哮喘患者气道平滑肌高反应性的特征之一是深吸气支气管保护作用和支气管舒张作用丧失。哮喘患者的气道也具有炎症特征。
评估深吸气支气管保护作用的丧失是否与哮喘气道炎症程度相关。
18名研究参与者进行了2次乙酰甲胆碱激发试验（相同剂量），1次深吸气，1次不深吸气，两次试验间隔至少24小时。通过测量呼出一氧化氮分数（FE(NO)）和诱导痰嗜酸性粒细胞来评估气道炎症。
当通过FE(NO)（P = 0.02，r = 0.54，n = 18）和嗜酸性粒细胞百分比（P = 0.002，r = 0.76，n = 12）测量时，深吸气支气管保护程度与气道炎症之间存在显著负相关。FE(NO)与嗜酸性粒细胞百分比之间也存在显著正相关（P = 0.009，r = 0.68，n = 12）。
气道炎症较重的个体深吸气支气管保护作用明显受损。这一发现表明，针对减轻气道炎症的治疗可能促进正常深吸气支气管保护作用的恢复。
