Jacquenet S, Morisset M, Battais F, Denery-Papini S, Croizier A, Baudouin E, Bihain B, Moneret-Vautrin D A
Genclis SAS, Vandoeuvre-lès-Nancy, France.
Int Arch Allergy Immunol. 2009;149(1):74-80. doi: 10.1159/000176309. Epub 2008 Nov 26.
omega-5 gliadin is a major allergen in exercise-induced wheat allergy (EIWA), but it is also implicated in immediate-type reactions to wheat. An ImmunoCAP assay to measure omega-5 gliadin-specific IgE has become available. This study aimed to evaluate this new biological test in wheat allergy diagnosis and to also determine if it was able to discriminate EIWA from other types of wheat allergy.
Sixty-one patients with wheat allergy were divided into 3 groups as a function of their symptoms (EIWA, immediate-type reactions and atopic dermatitis). These patients underwent skin prick tests with purified omega gliadins and ImmunoCAP to wheat flour, gluten and recombinant omega-5 gliadin.
The experimental data showed that 78% of EIWA patients had a positive skin prick test to natural omega-5 gliadin and the same proportion had detectable specific IgE to recombinant omega-5 gliadin, indicating that omega-5 gliadin is the main allergen, but not the only one, in our population. Additionally, we showed that this detection was not EIWA specific since omega-5 gliadin-specific IgE was detected in 30% of other patients who had a wheat allergy. These results lead to a positive predictive value of 37.5% and to a negative predictive value of 91%.
Although not specific to EIWA, the new ImmunoCAP omega-5 gliadin is an important biological test because of its negative predictive value. In case of food-dependent exercise-induced allergy, the absence of omega-5 gliadin-specific IgE will almost completely exclude the implication of wheat.
ω-5麦醇溶蛋白是运动诱发的小麦过敏（EIWA）中的主要过敏原，但它也与小麦的速发型反应有关。一种用于测量ω-5麦醇溶蛋白特异性IgE的免疫捕获检测方法已经问世。本研究旨在评估这项新的生物学检测在小麦过敏诊断中的作用，并确定它是否能够区分EIWA与其他类型的小麦过敏。
61名小麦过敏患者根据其症状分为3组（EIWA、速发型反应和特应性皮炎）。这些患者接受了用纯化的ω-麦醇溶蛋白以及针对小麦粉、麸质和重组ω-5麦醇溶蛋白的免疫捕获检测进行的皮肤点刺试验。
实验数据显示，78%的EIWA患者对天然ω-5麦醇溶蛋白的皮肤点刺试验呈阳性，相同比例的患者对重组ω-5麦醇溶蛋白检测到可检测的特异性IgE，这表明ω-5麦醇溶蛋白是我们研究人群中的主要过敏原，但不是唯一的过敏原。此外，我们还表明这种检测并非EIWA所特有，因为在30%的其他小麦过敏患者中检测到了ω-5麦醇溶蛋白特异性IgE。这些结果导致阳性预测值为37.5%，阴性预测值为91%。
尽管新的免疫捕获ω-5麦醇溶蛋白检测并非EIWA所特有，但由于其阴性预测值，它是一项重要的生物学检测。在食物依赖型运动诱发过敏的情况下，不存在ω-5麦醇溶蛋白特异性IgE几乎可以完全排除小麦的影响。
