Background

Fractional exhaled nitric oxide (FeNO) is a noninvasive biomarker of type 2 asthma that can predict response to inhaled corticosteroid therapy. Little is known regarding the magnitude of FeNO reduction after an oral corticosteroid (OCS) course, and less is known whether there are differential responses based on race in children with mild-to-moderate asthma.

Objective

To assess the effect of a short course of OCS on FeNO in children with asthma and to determine whether the effect is influenced by race.

Methods

Children presenting with an acute asthma exacerbation, who had a FeNO measurement within the past 6 months when clinically stable, were enrolled. Spirometry and FeNO were obtained at the time of exacerbation and after a short course of prednisone.

Results

A total of 92 children were identified (aged 11 ± 3.3 years; white, n = 46 [50%], Hispanics, n = 30 [33%], African Americans [AAs], n = 16 [7%]). At baseline, AAs were more atopic and had higher mean FeNO values than both white (48.9 vs 25.6 ppb; P < .05) and Hispanic children (22.5 ppb; P < .05), despite being prescribed similar inhaled corticosteroid doses. During the exacerbation, AAs had the highest FeNO values, whereas there was no difference in lung function between AAs and non-AAs. After prednisone therapy, there was a 56.6% reduction in FeNO, and although AAs maintained the highest FeNO levels, the relative reduction was similar between AAs and non-AAs (53.9% vs 57.8%, respectively).

Conclusion

FeNO levels reduced by more than 50% after an OCS course. African American children had a greater degree of type 2–driven airway inflammation at baseline, during an exacerbation and after a short course of OCS, compared with non-AAs, although the relative reduction in FeNO was similar between the groups.

中文翻译：

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轻度至中度哮喘患儿对口服皮质类固醇的呼出气一氧化氮分数响应：种族的影响。

背景

呼出气一氧化氮（FeNO）是2型哮喘的一种非侵入性生物标志物，可以预测对吸入糖皮质激素治疗的反应。关于口服皮质类固醇（OCS）疗程后FeNO降低的程度知之甚少，对于轻度至中度哮喘的儿童，是否存在基于种族的差异反应，对此知之甚少。

目的

评估OCS短疗程对哮喘患儿FeNO的影响，并确定该影响是否受种族影响。

方法

纳入表现为急性哮喘急性发作的儿童，在临床稳定后的过去6个月内进行FeNO测定。加重时和泼尼松短疗程后可测出肺活量和FeNO。

结果

总共确定了92名儿童（年龄11±3.3岁；白人，n = 46 [50％]，西班牙裔，n = 30 [33％]，非裔美国人[AAs]，n = 16 [7％]）。在基线时，尽管处方了相似的吸入糖皮质激素剂量，但AA的异位性更高，平均FeNO值也高于白人（48.9 vs 25.6 ppb；P <.05）和西班牙裔儿童（22.5 ppb；P <.05）。在急性发作期间，AA的FeNO值最高，而AAA和非AAA的肺功能没有差异。泼尼松治疗后，FeNO减少了56.6％，尽管AA维持最高的FeNO水平，但AA和非AAA的相对减少相似（分别为53.9％和57.8％）。

结论

OCS疗程后，FeNO含量降低了50％以上。与非AA相比，非洲裔美国儿童在基线，急性发作期间和OCS短疗程后，基线时由2型驱动的气道炎症的程度更高，尽管两组之间FeNO的相对减少相似。