Ekstrand Ylva, Ternesten-Hasséus Ewa, Arvidsson Monica, Löfdahl Kerstin, Palmqvist Mona, Millqvist Eva
Department of Internal Medicine/Respiratory Medicine and Allergology, Sahlgrenska University Hospital, University of Gothenburg, Gothenburg, Sweden.
J Asthma. 2011 Jun;48(5):482-9. doi: 10.3109/02770903.2011.570405. Epub 2011 Apr 13.
Increasing evidence points to a potential role for members of the transient receptor potential family of cation channels on several features of asthmatic disease. The cough sensitivity to inhaled capsaicin is known to reflect the reactivity of these airway sensory nerves.
The aim was to study, among patients having a positive methacholine provocation and diagnosed with asthma, capsaicin cough sensitivity, sensitivity to methacholine, and levels of exhaled nitric oxide before and after treatment with inhaled steroids, and further, to measure the self-reported impact from environmental irritants.
Eighteen steroid-naïve patients with a positive methacholine test underwent capsaicin inhalation provocation on two occasions, before and after regular use of inhaled steroids over at least 3 months. Comparisons were made to 21 healthy controls. Sensitivity to methacholine and levels of exhaled nitric oxide were measured before and after the treatment. The participants also answered a validated questionnaire regarding environmental irritants.
The patients displayed higher capsaicin cough sensitivity than the controls before the treatment period, but not afterward. Before treatment, capsaicin cough answer correlated significantly with levels of exhaled nitric oxide, but not with methacholine sensitivity. After treatment with inhaled corticosteroids, the capsaicin cough sensitivity and the inflammatory parameters were normalized. In comparison to the control group, the patients reported more affective reactions to and behavioral disruptions induced by environmental irritants.
In steroid-naïve patients with a positive methacholine test, there is a link between that part of the airway inflammation that is reflected by exhaled nitric oxide and that followed by an augmented reactivity of capsaicin-sensitive sensory nerves. This association disappears after steroid treatment.
越来越多的证据表明，阳离子通道瞬时受体电位家族的成员在哮喘疾病的几个特征中可能发挥作用。已知对吸入辣椒素的咳嗽敏感性反映了这些气道感觉神经的反应性。
本研究旨在观察吸入性糖皮质激素治疗前后，对乙酰甲胆碱激发试验阳性且诊断为哮喘的患者，测定其辣椒素咳嗽敏感性、对乙酰甲胆碱的敏感性和呼出一氧化氮水平，并进一步评估环境刺激物对患者自我报告的影响。
18例未使用过糖皮质激素且乙酰甲胆碱试验阳性的患者，在至少3个月规范吸入糖皮质激素治疗前后，分别进行两次辣椒素吸入激发试验。与21名健康对照者进行比较。治疗前后测定对乙酰甲胆碱的敏感性和呼出一氧化氮水平。参与者还回答了一份关于环境刺激物的有效问卷。
治疗前患者的辣椒素咳嗽敏感性高于对照组，但治疗后则无差异。治疗前，辣椒素咳嗽反应与呼出一氧化氮水平显著相关，但与乙酰甲胆碱敏感性无关。吸入糖皮质激素治疗后，辣椒素咳嗽敏感性和炎症参数恢复正常。与对照组相比，患者报告对环境刺激物产生更多情感反应和行为干扰。
在未使用过糖皮质激素且乙酰甲胆碱试验阳性的患者中，呼出一氧化氮所反映的气道炎症部分与辣椒素敏感感觉神经反应性增强之间存在联系。激素治疗后这种关联消失。
