Lehtimäki Lauri, Kankaanranta Hannu, Saarelainen Seppo, Turjanmaa Väinö, Moilanen Eeva
Immunopharmacological Research Group, Medical School, University of Tampere, Finland.
J Asthma. 2005 Sep;42(7):605-9. doi: 10.1080/02770900500294678.
Some patients with asthmatic symptoms and eosinophilic airway inflammation have normal lung function and thus do not meet the current diagnostic criteria of asthma. Exhaled nitric oxide (NO) measurement at multiple exhalation flow rates can be used to assess alveolar and bronchial NO output and inflammation. We tested whether alveolar or bronchial NO output is increased in subjects having asthmatic symptoms but normal lung function. Exhaled NO concentration was measured at three exhalation flow rates (100, 175, and 370 mL/s) to assess alveolar NO concentration and bronchial NO flux in 23 patients with asthmatic symptoms but normal lung function ("asthmatic symptoms group"), 40 patients with asthma, and 40 healthy control subjects. The asthmatic symptoms group had increased bronchial NO flux (1.7 +/- 0.3 nL/s, p = 0.016) and alveolar NO concentration (1.8 +/- 0.2 parts per billion (ppb), p = 0.010) compared with healthy controls (0.7 +/- 0.1 nL/s and 1.0 +/- 0.1 ppb, respectively). Patients with asthma had even higher bronchial NO flux (2.5 +/- 0.3 nL/s, p = 0.024) but normal alveolar NO concentration (1.1 +/- 0.2 ppb, p = 0.664). In asthmatic symptoms group, alveolar NO concentration correlated positively with blood eosinophil count and negatively with small airway function (FEF50% and FEF75%). In conclusion, patients with asthmatic symptoms but normal lung function have increased alveolar NO concentration and mildly elevated bronchial NO flux suggesting a more peripheral inflammation than in patients with asthma.
一些有哮喘症状和嗜酸性粒细胞气道炎症的患者肺功能正常，因此不符合目前哮喘的诊断标准。在多个呼气流量下测量呼出一氧化氮（NO）可用于评估肺泡和支气管的NO输出及炎症情况。我们测试了有哮喘症状但肺功能正常的受试者的肺泡或支气管NO输出是否增加。在23名有哮喘症状但肺功能正常的患者（“哮喘症状组”）、40名哮喘患者和40名健康对照者中，以三种呼气流量（100、175和370 mL/s）测量呼出NO浓度，以评估肺泡NO浓度和支气管NO通量。与健康对照者（分别为0.7±0.1 nL/s和1.0±0.1 ppb）相比，哮喘症状组的支气管NO通量增加（1.7±0.3 nL/s，p = 0.016），肺泡NO浓度增加（1.8±0.2十亿分之一（ppb），p = 0.010）。哮喘患者的支气管NO通量更高（2.5±0.3 nL/s，p = 0.024），但肺泡NO浓度正常（1.1±0.2 ppb，p = 0.664）。在哮喘症状组中，肺泡NO浓度与血液嗜酸性粒细胞计数呈正相关，与小气道功能（FEF50%和FEF75%）呈负相关。总之，有哮喘症状但肺功能正常的患者肺泡NO浓度增加，支气管NO通量轻度升高，提示其炎症比哮喘患者更外周。
