Background

Fractional exhaled nitric oxide (FE_NO) is a marker of type 2 airway inflammation used in clinical practice in asthma. However, reference values are needed to broaden the clinical use of FE_NO and this is within the scope of a newly started Global Lung Function Initiative task force. We aim to study FE_NO levels with special emphasis on the upper limit of normal (ULN) in relation to the type and degree of IgE sensitisation.

Methods

FE_NO was measured in 1855 non-smoking, respiratory healthy subjects from the Swedish CArdioPulmonary bioImage Study (SCAPIS). Atopic subjects (n = 424), defined as being IgE-sensitised to aeroallergens (ImmunoCAP Phadiatop™, ≥0.35 PAU/l) were compared to non-atopic subjects (<0.35 PAU/l, n = 1431). Atopic subjects were further characterised according to their grade of IgE sensitisation (IgE antibody tertiles: (T1<1.16, T2 1.16–3.72 and T3 >3.72 PAU/l) and sensitisation to perennial (cat or mite) or seasonal (birch) allergens.

Results

Subjects IgE-sensitised to cat or mite had higher FE_NO compared to non-atopic subjects (FE_NO (ppb): median 20.0 vs. 15.0, and ULN 50.4 vs. 33.0, p < 0.001). This was seen to a lesser extent for subjects IgE-sensitised to birch only (median 18.0 vs. 15.0, and ULN 38.0 vs. 33.0, p = 0.048). Atopic subjects with a high degree of IgE sensitisation (Phadiatop: >3.72 PAU/l) had the highest FE_NO compared to non-atopic subjects (median 20.0 vs. 15.0, and ULN 56.0 vs. 33.0, p < 0.001).

Conclusions

The type and degree of IgE sensitisation should be considered in generating FE_NO reference values.

中文翻译：

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IgE 致敏类型和程度对于定义呼出气一氧化氮参考值的重要性

背景

呼出气一氧化氮分数 (FE _NO ) 是哮喘临床实践中使用的 2 型气道炎症的标志物。然而，需要参考值来扩大 FE _NO的临床使用，这在新成立的全球肺功能倡议工作组的范围内。我们的目标是研究 FE _NO水平，特别强调与 IgE 致敏类型和程度相关的正常上限 (ULN)。

方法

FE _NO是在瑞典心肺生物影像研究 (SAPIS) 的 1855 名不吸烟、呼吸系统健康的受试者中测量的。将特应性受试者 (n = 424) 与非特应性受试者 (<0.35 PAU/l, n = 1431) 进行比较，定义为对气源性过敏原 IgE 敏感（ImmunoCAP Phadiatop™，≥0.35 PAU/l）。特应性受试者根据其 IgE 致敏等级（IgE 抗体三分位数：（T1<1.16，T2 1.16–3.72 和 T3 >3.72 PAU/l）和对多年生（猫或螨）或季节性（桦木）过敏原的敏感性进一步表征。

结果

与非特应性受试者相比，对猫或螨虫过敏的IgE 受试者具有更高的 FE _{NO （FE NO} (ppb)：中位数 20.0 对 15.0，ULN 50.4 对 33.0，p < 0.001）。这在 IgE 仅对桦木敏感的受试者中出现的程度较小（中位数 18.0 对 15.0，ULN 38.0 对 33.0，p = 0.048）。与非特应性受试者相比，具有高度 IgE 致敏性（Phadiatop：>3.72 PAU/l）的特应性受试者具有最高的 FE _NO（中位数 20.0 对 15.0，ULN 56.0 对 33.0，p < 0.001）。

结论

_{在生成 FE NO}参考值时应考虑 IgE 致敏的类型和程度。