Peanut allergy affects 3% of Australian children and has a higher risk of anaphylaxis than most food allergies. Predicting who is likely to develop anaphylaxis is still an inexact science. The fraction of exhaled nitric oxide (FeNO) shows promise as a biomarker involved in peanut allergy, as nitric oxide plays a role in inhibiting mast cell degranulation which is relevant in anaphylaxis, where mast cell degranulation plays a mediator role. The aim of this study was to assess the change in FeNO in children during peanut challenge. Thirty-six children aged from 5 to 17 years were recruited for open-labelled peanut challenge. Participants had skin prick test to peanut performed, and serum collected for Ara h2 specific IgE and peanut specific IgE. FeNO was measured by portable device (NIOX VERO) prior to and throughout the peanut challenge. When grouped according to reaction type at peanut challenge (anaphylaxis, clinical allergy not anaphylaxis and tolerant), there were significant differences in the mean change in FeNO measurement between the anaphylaxis group and the clinical allergy, not anaphylaxis group (p = 0.005), and between the anaphylaxis group and tolerant group (p < 0.0001). FeNO decreased more significantly in those who subsequently developed anaphylaxis than in those with clinical allergy, not anaphylaxis or negative peanut challenge (tolerance). As a bedside test that can be used in children, it has potential for further research into mechanisms of anaphylaxis in food allergy and potentially assists in predicting an imminent anaphylactic reaction in some patients. Trial registration ClinicalTrials.gov: PEAnut Anaphylaxis Predictors (PEAAP) NCT02424136.

中文翻译：

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花生挑战期间呼出一氧化氮的变化与反应的严重程度有关。

花生过敏影响 3% 的澳大利亚儿童，并且过敏反应的风险比大多数食物过敏更高。预测谁可能出现过敏反应仍然是一门不精确的科学。呼出的一氧化氮 (FeNO) 分数有望作为花生过敏的生物标志物，因为一氧化氮在抑制肥大细胞脱颗粒方面发挥着作用，而肥大细胞脱颗粒与过敏反应相关，而肥大细胞脱颗粒在过敏反应中起中介作用。本研究的目的是评估花生挑战期间儿童 FeNO 的变化。36 名 5 岁至 17 岁的儿童被招募参加开放标签花生挑战。参与者对花生进行皮肤点刺试验，并收集血清中的Ara h2特异性IgE和花生特异性IgE。在花生挑战之前和整个过程中，通过便携式设备 (NIOX VERO) 测量 FeNO。当根据花生挑战时的反应类型（过敏反应、非过敏反应的临床过敏和耐受）分组时，过敏反应组和临床过敏而非过敏反应组之间 FeNO 测量值的平均变化存在显着差异（p = 0.005），并且过敏反应组和耐受组之间的差异（p < 0.0001）。随后出现过敏反应的患者中 FeNO 的下降幅度比临床过敏患者的下降更为显着，而非过敏反应或花生激发试验（耐受性）阴性的患者。作为一种可用于儿童的床边测试，它有可能进一步研究食物过敏的过敏反应机制，并可能有助于预测某些患者即将发生的过敏反应。试验注册 ClinicalTrials.gov：PEAnut 过敏反应预测器 (PEAAP) NCT02424136。