Lanz M J, Leung D Y, White C W
Department of Pediatrics, University of Colorado, Health Sciences Center, Denver, USA.
Ann Allergy Asthma Immunol. 1999 Feb;82(2):161-4. doi: 10.1016/S1081-1206(10)62591-4.
Asthma is characterized as a chronic inflammatory process; however, there is no easily measured marker for airway inflammation. Such a marker, particularly in children, would be very helpful in the management of asthma even in the acute setting.
The purposes of this study were to determine whether asthmatic children have (1) elevation of exhaled breath nitric oxide (ENO) during acute exacerbations when presenting to the emergency room, (2) reduction of ENO following glucocorticoid treatment, or (3) improvement in spirometry and clinical examination accompanying reduction of ENO levels.
Peak ENO levels were measured by chemiluminescence during exhalation into the NO analyzer. Ten asthmatic children (mean age 10 years) who presented to the Pediatric Special Care Unit at National Jewish Medical and Research Center in acute respiratory distress with an asthma exacerbation were studied. The subjects were recruited, after informed consent was obtained from the parent, on the basis of specific inclusion/exclusion criteria. Measurements of ENO in parts per billion (ppb) and spirometry, including percentiles of forced expiratory volume in one second (FEV1%) and peak expiratory flow (PEF%), were performed before and after at least 5 days of glucocorticoid therapy.
The mean ENO level in the asthmatic children prior to glucocorticoid treatment was 48 +/- 8ppb, and after glucocorticoid treatment the ENO level was 17 +/- 1ppb; (P < .002). Prior to glucocorticoid treatment, the mean FEV1% value was 68 +/- 3% compared with the postglucocorticoid treatment FEV1% value of 100 +/- 5%; (P < .0001). Prior to glucocorticoid treatment, the mean PEF% value was 81 +/- 7%, compared with the postglucocorticoid treatment PEF% value of 105 +/- 6%; (P < .02).
The mean peak ENO level after glucocorticoid therapy was significantly less than that measured before treatment in children with acute asthma exacerbations. Concomitant with the decrease in ENO levels, there was improvement in the spirometry values and physical examination in the asthmatic children; thus, ENO is a sensitive marker for response to anti-inflammatory treatment in children.
哮喘的特征是慢性炎症过程；然而，目前尚无易于测量的气道炎症标志物。这样一种标志物，尤其是对于儿童而言，即使在急性发作期，对哮喘的管理也会非常有帮助。
本研究的目的是确定哮喘儿童是否存在：（1）在因急性加重而到急诊室就诊时，呼出气一氧化氮（ENO）升高；（2）糖皮质激素治疗后ENO降低；或（3）随着ENO水平降低，肺功能测定和临床检查有所改善。
呼气时通过化学发光法在NO分析仪中测量ENO峰值水平。对10名患有哮喘的儿童（平均年龄10岁）进行了研究，这些儿童因哮喘加重而出现急性呼吸窘迫，就诊于国家犹太医学和研究中心的儿科特殊护理病房。在获得家长的知情同意后，根据特定的纳入/排除标准招募受试者。在至少5天的糖皮质激素治疗前后，分别测量以十亿分率（ppb）为单位的ENO以及肺功能，包括一秒用力呼气量百分比（FEV1%）和呼气峰值流速百分比（PEF%）。
糖皮质激素治疗前，哮喘儿童的平均ENO水平为48±8 ppb，治疗后ENO水平为17±1 ppb；（P < 0.002）。糖皮质激素治疗前，平均FEV1%值为68±3%，而治疗后FEV1%值为100±5%；（P < 0.0001）。糖皮质激素治疗前，平均PEF%值为81±7%，治疗后PEF%值为105±6%；（P < 0.02）。
糖皮质激素治疗后，急性哮喘加重患儿的平均ENO峰值水平显著低于治疗前测量值。随着ENO水平的降低，哮喘儿童的肺功能测定值和体格检查均有所改善；因此，ENO是儿童抗炎治疗反应的敏感标志物。
