Introduction and objectives

The diagnosis of IgE-mediated cow's milk allergy (CMA) is often based on clinical history and on specific IgE levels and/or skin-prick tests (SPT), both of which are sensitive but not specific. The gold standard, oral food challenge (OFC), is expensive and time-consuming and involves a risk of severe allergic reactions. This study aimed to determine the value of specific IgEs, ratios of specific IgEs for cow's milk and its components to total IgE, and wheal size on SPT for predicting a positive OFC for CMA.

Material and methods

We retrospectively studied 72 patients [median age, four years; age range 0.75–15 years] sensitized to cow's milk who underwent OFCs to milk. predictive variables between patients with positive and negative OFCs were compared. Receiver operator characteristic (ROC) curves were uses to assess variables’ discriminatory capacity and Youden's index to determine the best cut-offs for predicting CMA.

Results

The OFC was positive in 39 (54%) patients. Wheal size on SPT and all specific IgEs and specific-to-total IgE ratios were significantly different between patients with positive OFCs and those with negative OFCs (p < 0.001). The variable with the greatest area under the ROC curve was casein-specific IgE (0.98), followed by β-lactoglobulin-specific IgE (0.923), casein-specific-to-total-IgE ratio (0.919), and α-lactalbumin-specific IgE (0.908). Casein-specific IgE ≥0.95 kU/L yielded 88.9% sensitivity and 90.9% specificity.

Conclusions

In our center, casein-specific IgE >0.95 kU/L can obviate an OFC to cow's milk for the diagnosis of CMA in patients sensitized to cow's milk with a compatible history.

中文翻译：

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对牛奶敏感的儿童对牛奶进行口服食物阳性挑战的预测因素。

介绍和目标

IgE 介导的牛奶过敏 (CMA) 的诊断通常基于临床病史和特定的 IgE 水平和/或皮肤点刺试验 (SPT)，这两者都很敏感但不具有特异性。金标准，口服食物挑战 (OFC)，既昂贵又费时，并涉及严重过敏反应的风险。本研究旨在确定特定 IgE 的值、牛奶及其成分的特定 IgE 与总 IgE 的比率以及 SPT 上的风团大小，以预测 CMA 的阳性 OFC。

材料与方法

我们回顾性研究了 72 名患者 [中位年龄，4 岁；年龄范围 0.75-15 岁] 对牛奶敏感的接受 OFC 对牛奶的人。比较了阳性和阴性 OFC 患者之间的预测变量。接收者操作特征 (ROC) 曲线用于评估变量的判别能力和 Youden 指数，以确定预测 CMA 的最佳临界值。

结果

39 名 (54%) 患者的 OFC 呈阳性。OFC 阳性患者和 OFC 阴性患者之间 SPT 上的风团大小和所有特定 IgE 以及特定与总 IgE 的比率显着不同（p  < 0.001）。ROC 曲线下面积最大的变量是酪蛋白特异性 IgE (0.98)，其次是 β-乳球蛋白特异性 IgE (0.923)、酪蛋白特异性与总 IgE 之比 (0.919) 和 α-乳白蛋白-特异性 IgE (0.908)。酪蛋白特异性 IgE ≥0.95 kU/L 产生 88.9% 的灵敏度和 90.9% 的特异性。

结论

在我们的中心，酪蛋白特异性 IgE >0.95 kU/L 可以避免对牛奶进行 OFC 用于诊断对牛奶敏感且具有相容病史的患者的 CMA。