检测呼出气体中的一氧化氮不能预测慢性咳嗽患者对糖皮质激素吸入治疗的反应
2009/07/10
背景：糖皮质激素吸入（ICS）治疗反应较好的慢性咳嗽患者中呼出气体中的一氧化氮（ENO）浓度增加。本研究旨在评价ENO在预测慢性咳嗽患者对ICS治疗反应中的作用，研究乙酰甲胆碱或单磷酸腺苷反应性与ICS治疗反应的相关性。
方法：共纳入43名慢性咳嗽患者。在基线状态下，检测ENO、呼吸量测定以及采用乙酰甲胆碱或单磷酸腺苷检测浓度-反应曲线。接下的4周里，患者接受每天2次100 mg丙酸氟替卡松治疗。基线状态下（第1周）和4周的治疗期内，患者每天对白天与夜间的咳嗽症状进行评分。
结果：19名（44%）患者对氟替卡松治疗有反应，受试者操作特征曲线（ROC）分析显示，基线状态下，ENO在鉴别患者对ICS的反应中准确性较差。ENO（20 ppb ENO为截断点）预测患者ICS治疗反应的敏感性和特异性分别为53%和63%。对氟替卡松治疗有效者和无效者气道对乙酰甲胆碱或单磷酸腺苷的反应率和反应的强度也无显著差异。
结论：虽然大部分慢性咳嗽患者对ICS治疗有反应，但基线状态下的ENO水平或AMP反应性并不能鉴别这些患者。
（刘国梁 审校）
Prieto L, et al. Chest. 2009 May 1. [Epub ahead of print]
Exhaled Nitric Oxide Measurement Is Not Useful for Predicting the Response to Inhaled Corticosteroids in Subjects With Chronic Cough
Prieto L, Ferrer A, Ponce S, Palop J, Marín J.
Background: Increased concentrations of exhaled nitric oxide (ENO) are identified predominantly in subjects with chronic cough due to conditions that habitually respond well to inhaled corticosteroids (ICS). The aim of this study was to assess the usefulness of ENO in predicting the response to ICS therapy in subjects with chronic cough, and to determine the relationship between either methacholine or adenosine 5;-monophosphate (AMP) responsiveness and the response to ICS therapy.
Methods: A total of 43 patients with chronic cough were studied. During the baseline period, ENO measurement, spirometry, and concentration-response studies with both methacholine and AMP were performed. For the next 4 weeks, patients were treated with inhaled fluticasone propionate 100 |gmg twice daily. At baseline (1 week) and during the 4 weeks treatment period, patients completed a diary twice daily recording daytime and nighttime cough symptom scores.
Results: Nineteen patients (44%) responded well to fluticasone therapy. The receiver operating characteristic (ROC) curve analysis showed that the accuracy to identify the response to ICS for ENO at baseline was poor. The sensitivity and specificity of ENO for predicting the response to ICS, using 20 ppb as the ENO cut off point, were 53% and 63%, respectively. Differences in both prevalence and degree of airway responsiveness to either methacholine or AMP between fluticasone responsive and nonresponsive subjects were also not significant.
Conclusions: Although a significant proportion of subjects with chronic cough respond well to ICS therapy, these patients cannot be identified by ENO levels or AMP responsiveness at baseline.
