Supplementary Material for: Component-Resolved Analyses for Diagnosis of Food Allergies in Infants and Young Children in Southern China

Introduction: Chicken eggs and cow’s milk are two of the most common foods that cause allergic reactions in infants and young children, and there is a lack of precise diagnostic methods to identify the allergic state of these patients. The recently developed food allergen component-resolved diagnosis (CRD) may be a more accurate diagnosis method for food allergies. Methods: One hundred children sensitized to egg white and milk crude extracts and diagnosed with or suspected allergic disease were included. The specific immunoglobulin E (sIgE) (s) of animal food allergen crude extracts (egg yolk, milk, shrimp, crab, cod, beef) and the main components of egg white and milk were tested. The sensitization characteristics, cross-reactivity, and clinical relevance were analyzed. Results: The results of egg white-sensitized patients showed that ovalbumin (Gal d 2) had the highest positive rate of 100%. Compared with other pairwise combinations of egg allergens, the combination of egg white and Gal d 2 had higher diagnostic accuracy, with an AUC of 0.876 (95% CI: 0.801–0.951), a sensitivity of 88.9%, and a specificity of 75.9%. The positive rates of beta-lactoglobulin (Bos d 5) and alpha-lactoglobulin (Bos d 4) in the milk-sensitized children were comparable, 92% and 91%, respectively. The combination of crude milk extract and Bos d 4 had the highest diagnostic accuracy, with an AUC of 0.969 (95% CI: 0.938–0.999), a sensitivity of 100%, and a specificity of 82.7%. Conclusion: Among these subjects, our study found the main allergenic component of egg white was Gal d 2, and the main allergenic components of milk were Bos d 4 and Bos d 5. CRD may help identify egg/milk allergies and non-allergies.

引言：鸡蛋与牛乳是引发婴幼儿最常见的两类食物过敏反应的食品，目前仍缺乏精准的诊断手段以明确此类患者的过敏状态。近年来新兴的食物过敏原组分解析诊断（component-resolved diagnosis, CRD）或可成为更为精准的食物过敏诊断方法。
方法：本研究纳入100名对蛋清与牛乳粗提物致敏，且已确诊或疑似罹患食物过敏性疾病的儿童。检测了动物性食物过敏原粗提物（蛋黄、牛乳、虾、蟹、鳕鱼、牛肉）及蛋清、牛乳主要组分的特异性免疫球蛋白E（specific immunoglobulin E, sIgE）水平，并分析了致敏特征、交叉反应性与临床相关性。
结果：针对蛋清致敏患者的分析显示，卵清蛋白（ovalbumin, Gal d 2）阳性率最高，达100%。相较于其他两两联用的蛋清过敏原组合，蛋清与Gal d 2的联合检测诊断准确性更高，其曲线下面积（Area Under Curve, AUC）为0.876（95%置信区间（Confidence Interval, CI）: 0.801–0.951），灵敏度为88.9%，特异度为75.9%。牛乳致敏儿童中，β-乳球蛋白（beta-lactoglobulin, Bos d 5）与α-乳白蛋白（alpha-lactalbumin, Bos d 4）的阳性率相当，分别为92%与91%。牛乳粗提物与Bos d 4的联合检测诊断准确性最优，AUC达0.969（95% CI: 0.938–0.999），灵敏度为100%，特异度为82.7%。
结论：本研究纳入的受试群体中，蛋清的主要致敏组分为Gal d 2，牛乳的主要致敏组分为Bos d 4与Bos d 5。组分解析诊断（CRD）可助力精准区分蛋/牛乳致敏与非致敏状态。