Ho L P, Innes J A, Greening A P
Respiratory Unit, Western General Hospital NHS Trust, Edinburgh, UK.
Eur Respir J. 1998 Dec;12(6):1290-4. doi: 10.1183/09031936.98.12061290.
Airways inflammation has been associated with increased nitric oxide (NO) in the exhaled breath. It was, therefore, questioned whether exhaled NO could act as an indicator of the severity of airways inflammation in the chronic suppurative lung diseases cystic fibrosis (CF) and bronchiectasis. NO levels in a single exhalation were measured using a chemiluminescence analyser. Thirty-six patients with CF and 16 with bronchiectasis were studied and compared with 22 normal subjects and 35 asthmatic patients. All subjects were nonsmokers and all measurements were made when patients were clinically stable. In addition, exhaled NO was measured in 10 CF patients at the time of onset of an acute infective exacerbation and followed for 7 days during the treatment of the exacerbation in eight of the 10 patients. No significant differences were found in NO levels in patients with CF or bronchiectasis compared with normals (median 4.0, 5.5 and 4.4 parts per billion (ppb), respectively), but all were lower than in asthma patients (10.4 ppb). The NO levels in the CF patients at time of exacerbation were not increased and did not change during treatment. These data show that nitric oxide levels in the exhaled breath of patients with chronic suppurative lung diseases, in contrast to asthma, are not elevated, despite the presence of substantial airways inflammation. Possible explanations include poor diffusion of nitric oxide across increased and viscous airway secretions, removal of nitric oxide by reaction with reactive oxygen species in the inflamed environment and failure of upregulation of epithelial inducible nitric oxide synthase in chronic suppurative conditions.
气道炎症与呼出气体中一氧化氮（NO）增加有关。因此，有人质疑呼出的NO是否可作为慢性化脓性肺部疾病囊性纤维化（CF）和支气管扩张症中气道炎症严重程度的指标。使用化学发光分析仪测量单次呼气中的NO水平。对36例CF患者和16例支气管扩张症患者进行了研究，并与22名正常受试者和35名哮喘患者进行了比较。所有受试者均不吸烟，所有测量均在患者临床稳定时进行。此外，在10例CF患者急性感染加重发作时测量呼出的NO，并在其中8例患者加重发作治疗期间随访7天。与正常人相比，CF患者或支气管扩张症患者的NO水平没有显著差异（中位数分别为4.0、5.5和4.4十亿分之一（ppb）），但均低于哮喘患者（10.4 ppb）。CF患者加重发作时的NO水平没有升高，治疗期间也没有变化。这些数据表明，与哮喘不同，慢性化脓性肺部疾病患者呼出气体中的一氧化氮水平并未升高，尽管存在大量气道炎症。可能的解释包括一氧化氮在增加且粘稠的气道分泌物中扩散不佳、在炎症环境中与活性氧反应导致一氧化氮被清除以及在慢性化脓性疾病中上皮诱导型一氧化氮合酶上调失败。
