特异性IgE对鸡蛋、牛奶过敏的诊断价值研究

The diagnostic capacity of serum food-specific Ig E in egg and cow's milk

目的通过对特异性Ig E与开放性食物激发试验的相关性研究,获得具有确诊食物过敏价值的特异性Ig E界值点,为简化临床诊断程序提供依据。方法选择徐州市妇幼保健院可疑食物过敏儿童289例,通过进行皮肤点刺试验、特异性Ig E的测定及开放性食物激发试验确诊食物过敏患儿。应用SPSS 13.0软件包分析特异性Ig E的敏感度、特异度、阳性预测值、阴性预测值;通过受试者工作特征曲线的曲线下面积评价特异性Ig E对食物过敏的诊断价值,并获得特异性Ig E的100%诊断界值点。结果蛋白、蛋黄、牛奶皮肤点刺试验的受试者工作特征曲线的曲线下面积分别为0.810、0.807及0.819。当蛋白、蛋黄、牛奶特异性Ig E分别≥8.5 k U/L、3.5 k U/L、5.0 k U/L时,特异性Ig E对食物过敏的诊断准确率可达100%。结论特异性Ig E对食物过敏的临床诊断准确性较好,通过其100%诊断界值点,可避免部分可疑食物过敏患儿进行食物激发试验。

Objective Serum food-specific IgE is the most common used parameter after skin prick test. We aimed to investigate the diagnostic capacity of serum food-specific IgE according to the outcome of oral food challenge, and to determine the cut-off points that could render food challenges unnecessary. Methods 289 children referred to the Maternal and Child Health of Xuzhou for the evaluation of suspected food allergy were prospectively studied. Children underwent skin prick test, serum food-specific IgE and open food challenge to the relevant food （s） in clinic. Diagnostic capacity （sensitivity, specificity, positive predictive value and negative predictive value）, area under curves （AUC） of the receiver operator characteristics （ROC） and predictive decision points were calculated by SPSS 13.0 package for the serum food-specific IgE. Results In 250 children, 160 skin prick test were performed with egg white, egg yolk and cow milk. The AUC of serum food-specific IgE was 0.810 for egg white, 0.807 for egg yolk and 0.819 for cow’s milk. We also defined serum food-specific IgE that were 100%diagnostic for allergy to egg white （≥8.5 kU/L）, egg yolk （≥3.5 kU/L）, cow milk （≥5.0 kU/L）. Conclusion Predictive decision points for a positive outcome of food challenges can be calculated for egg and cow’s milk using mean diameter. It may help to simplify the diagnostic procedure of food allergy.