Taylor D Robin
Department of Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
J Allergy Clin Immunol. 2006 Feb;117(2):259-62. doi: 10.1016/j.jaci.2005.11.010.
Asthma is a pathologically heterogeneous disease, and the phenotype is characterized by different types of airway inflammation. Exhaled nitric oxide (F(E)NO) measurements are a surrogate marker specific for eosinophilic airway inflammation. The latter is usually associated with steroid responsiveness, and hence, F(E)NO may be used to guide steroid requirements in certain clinical situations. High F(E)NO levels may be used to predict likely benefits with inhaled corticosteroid (ICS) therapy. Both high and low F(E)NO levels are prognostically significant when withdrawal of ICS treatment is being considered. Studies have shown that, just as for induced sputum, repeated F(E)NO measurements improve the cost-effectiveness of ICS therapy when used to guide dose requirements. In practice, F(E)NO measurements are useful in the management of severe or difficult asthma. High and low F(E)NO levels in symptomatic patients provide the clinician with information that enables active eosinophilic airway inflammation to be included or excluded. Either outcome is helpful in decision making. F(E)NO measurements complement the use of other tests in asthma, but more work is required to determine reference values and cut-points for appropriate interpretation.
哮喘是一种病理上异质性的疾病，其表型以不同类型的气道炎症为特征。呼出一氧化氮（F（E）NO）测量是嗜酸性粒细胞气道炎症的特异性替代标志物。后者通常与类固醇反应性相关，因此，F（E）NO可用于在某些临床情况下指导类固醇的使用需求。高F（E）NO水平可用于预测吸入性糖皮质激素（ICS）治疗可能带来的益处。在考虑停用ICS治疗时，高和低F（E）NO水平都具有预后意义。研究表明，与诱导痰检测一样，重复进行F（E）NO测量在用于指导剂量需求时可提高ICS治疗的成本效益。在实践中，F（E）NO测量对重度或难治性哮喘的管理很有用。有症状患者的高和低F（E）NO水平为临床医生提供了信息，使其能够判断是否存在活跃的嗜酸性粒细胞气道炎症。这两种结果都有助于决策。F（E）NO测量补充了哮喘中其他检测方法的应用，但需要更多工作来确定合适解读的参考值和切点。
