Paediatrics and Child Health, University College, Cork, Ireland.
Murdoch Childrens Research Institute, Department of Paediatrics, University of Melbourne, Melbourne, Australia; Department of Allergy and Immunology, Royal Children's Hospital, Melbourne, Australia.
J Allergy Clin Immunol. 2017 May;139(5):1583-1590. doi: 10.1016/j.jaci.2017.01.030. Epub 2017 Feb 24.
Eliciting doses (EDs) of allergenic foods can be defined by the distribution of threshold doses for subjects within a specific population. The ED is the dose that elicits a reaction in 5% of allergic subjects. The predicted ED for peanut is 1.5 mg of peanut protein (6 mg of whole peanut).
We sought to validate the predicted peanut ED (1.5 mg) with a novel single-dose challenge.
Consecutive eligible children with peanut allergy in 3 centers were prospectively invited to participate, irrespective of previous reaction severity. Predetermined criteria for objective reactions were used to identify ED single-dose reactors.
Five hundred eighteen children (mean age, 6.8 years) were eligible. No significant demographic or clinical differences were identified between 381 (74%) participants and 137 (26%) nonparticipants or between subjects recruited at each center. Three hundred seventy-eight children (206 male) completed the study. Almost half the group reported ignoring precautionary allergen labeling. Two hundred forty-five (65%) children experienced no reaction to the single dose of peanut. Sixty-seven (18%) children reported a subjective reaction without objective findings. Fifty-eight (15%) children experienced signs of a mild and transient nature that did not meet the predetermined criteria. Only 8 (2.1%; 95% CI, 0.6%-3.4%) subjects met the predetermined criteria for an objective and likely related event. No child experienced more than a mild reaction, 4 of the 8 received oral antihistamines only, and none received epinephrine. Food allergy-related quality of life improved from baseline to 1 month after challenge regardless of outcome (η = 0.2, P < .0001). Peanut skin prick test responses and peanut- and Ara h 2-specific IgE levels were not associated with objective reactivity to peanut ED.
A single administration of 1.5 mg of peanut protein elicited objective reactions in fewer than the predicted 5% of patients with peanut allergy. The novel single-dose oral food challenge appears clinically safe and patient acceptable, regardless of the outcome. It identifies the most highly dose-sensitive population with food allergy not otherwise identifiable by using routinely available peanut skin prick test responses or specific IgE levels, but this single-dose approach has not yet been validated for risk assessment of individual patients.
过敏原食物的激发剂量（ED）可以通过特定人群中阈值剂量的分布来定义。ED 是引起 5%过敏受试者反应的剂量。预测花生的 ED 为 1.5 毫克花生蛋白（6 毫克整粒花生）。
我们旨在通过新的单次剂量挑战来验证预测的花生 ED（1.5 毫克）。
在三个中心，连续邀请符合条件的花生过敏儿童前瞻性参与，无论以前的反应严重程度如何。使用客观反应的预定标准来识别 ED 单剂量反应者。
518 名儿童（平均年龄 6.8 岁）符合条件。在 381 名（74%）参与者和 137 名（26%）非参与者之间，以及在每个中心招募的受试者之间，没有发现显著的人口统计学或临床差异。378 名儿童（206 名男性）完成了研究。近一半的组报告忽略了预防性过敏原标签。245 名（65%）儿童对单剂量花生无反应。67 名（18%）儿童报告有主观反应但无客观发现。58 名（15%）儿童出现轻微且短暂的症状，但不符合预定标准。只有 8 名（2.1%；95%CI，0.6%-3.4%）受试者符合预定标准，出现客观且可能相关的事件。没有儿童出现更严重的反应，8 名儿童中有 4 名仅接受了口服抗组胺药治疗，没有儿童接受肾上腺素治疗。无论结果如何，食物过敏相关生活质量在挑战后 1 个月均从基线改善（η=0.2，P<.0001）。花生皮试反应和花生及 Ara h 2 特异性 IgE 水平与花生 ED 的客观反应无关。
单次给予 1.5 毫克花生蛋白引起的客观反应少于预测的 5%花生过敏患者。新的单次口服食物挑战在临床和患者可接受方面均安全，无论结果如何。它可以识别出对常规使用的花生皮试反应或特异性 IgE 水平无法识别的食物过敏中最敏感的人群，但这种单次剂量方法尚未针对个体患者的风险评估进行验证。
