Division of Paediatric and Adolescent Medicine, Oslo University Hospital, Oslo, Norway.
Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
Clin Exp Allergy. 2018 Apr;48(4):415-423. doi: 10.1111/cea.13078. Epub 2018 Jan 25.
Peanut allergy necessitates dietary restrictions, preferably individualized by determining reactivity threshold through an oral food challenge (OFC). However, risk of systemic reactions often precludes OFC in children with severe peanut allergy.
We aimed to determine whether clinical and/or immunological characteristics were associated with reactivity threshold in children with anaphylaxis to peanut and secondarily, to investigate whether these characteristics were associated with severity of the allergic reaction during OFC.
A double-blinded placebo-controlled food challenge (DBPCFC) with peanut was performed in 96 5- to 15-year-old children with a history of severe allergic reactions to peanut and/or sensitization to peanut (skin prick test [SPT] ≥3 mm or specific immunoglobulin E [s-IgE] ≥0.35 kUA/L). Investigations preceding the DBPCFC included a structured interview, SPT, lung function measurements, serological immunology assessment (IgE, IgG and IgG ), basophil activation test (BAT) and conjunctival allergen provocation test (CAPT). International standards were used to define anaphylaxis and grade the allergic reaction during OFC.
During DBPCFC, all 96 children (median age 9.3, range 5.1-15.2) reacted with anaphylaxis (moderate objective symptoms from at least two organ systems). Basophil activation (CD63 basophils ≥15%), peanut SPT and the ratio of peanut s-IgE/total IgE were significantly associated with reactivity threshold and lowest observed adverse events level (LOAEL) (all P < .04). Basophil activation best predicted very low threshold level (<3 mg of peanut protein), with an optimal cut-off of 75.8% giving a 93.5% negative predictive value. None of the characteristics were significantly associated with the severity of allergic reaction.
In children with anaphylaxis to peanut, basophil activation, peanut SPT and the ratio of peanut s-IgE/total IgE were associated with reactivity threshold and LOAEL, but not with allergy reaction severity.
花生过敏需要饮食限制，最好通过口服食物挑战（OFC）确定反应阈值来实现个体化。然而，在严重花生过敏的儿童中，全身性反应的风险通常排除了 OFC 的可能性。
我们旨在确定在对花生发生过敏反应的儿童中，临床和/或免疫学特征是否与反应阈值相关，其次，研究这些特征是否与 OFC 期间过敏反应的严重程度相关。
对 96 名 5 至 15 岁的儿童进行了双盲安慰剂对照的花生食物挑战（DBPCFC），这些儿童有严重花生过敏反应和/或对花生致敏的病史（皮肤点刺试验 [SPT]≥3 毫米或特异性免疫球蛋白 E [s-IgE]≥0.35 kUA/L）。DBPCFC 之前的研究包括结构化访谈、SPT、肺功能测量、血清免疫学评估（IgE、IgG 和 IgG ）、嗜碱性粒细胞活化试验（BAT）和结膜过敏原激发试验（CAPT）。采用国际标准定义过敏反应和 OFC 期间过敏反应的严重程度。
在 DBPCFC 期间，所有 96 名儿童（中位数年龄 9.3 岁，范围 5.1-15.2 岁）均出现过敏反应（至少两个器官系统的中度客观症状）。嗜碱性粒细胞活化（CD63 嗜碱性粒细胞≥15%）、花生 SPT 和花生 s-IgE/总 IgE 比值与反应阈值和最低观察到的不良事件水平（LOAEL）显著相关（均 P<.04）。嗜碱性粒细胞活化最能预测极低阈值水平（<3 毫克花生蛋白），最佳截断值为 75.8%，阴性预测值为 93.5%。没有任何特征与过敏反应的严重程度显著相关。
在对花生过敏的儿童中，嗜碱性粒细胞活化、花生 SPT 和花生 s-IgE/总 IgE 比值与反应阈值和 LOAEL 相关，但与过敏反应严重程度无关。
