Piboonpocanun Surapon, Thongngarm Torpong, Wongsa Chamard, Pacharn Punchama, Reamtong Onrapak, Sompornrattanaphan Mongkhon
Institute of Molecular Biosciences, Mahidol University, Salaya, Nakhonpathom, Thailand.
Division of Allergy and Clinical Immunology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
J Asthma Allergy. 2021 Jul 15;14:907-917. doi: 10.2147/JAA.S315202. eCollection 2021.
Various clinical patterns based on routes of sensitization and sensitized allergens are reported in adult-onset IgE-mediated wheat allergy. There is still a paucity of data on IgE-bound wheat allergen profiles in wheat challenge-proven adult-onset wheat allergic cases. Therefore, we aim to identify the major sensitized allergens in Thai adult-onset wheat allergic patients whose first symptom occurred after the age of 18 years despite previous tolerance.
This cross-sectional pilot study recruited patients from the Thai Adult-onset IgE-mediated Wheat Allergy Cohort (TAWAC). The sera of patients with mostly challenge-proven cases were selected for allergen study, including ImmunoCAP and IgE-bound gliadins along with glutenins profiles. The IgE-bound proteins were identified by liquid chromatography-tandem mass spectrophotometry (LC-MS/MS). Direct binding of IgE to recombinant gliadin and glutenin was performed to confirm the results of immunoblot and LC-MS/MS.
Eleven wheat-dependent exercise-induced anaphylaxis (WDEIA) and 4 typical wheat allergy (WA) patients were enrolled. Serum IgE from >50% of bound proteins had a molecular weight ranging from 35 to 55 kDa in both gliadin and glutenin extracts. Further, ELISA demonstrated that γ-gliadin and ω5-gliadin were the most important major allergens. Other major allergens include α/β-gliadin, HMW glutenin, and possibly α-amylase inhibitor or LWM glutenin. Gamma-gliadin sensitization was found in all WA patients (4/4), while ω-5 gliadin was found in all WDEIA patients (11/11) from ELISA.
Wheat γ-gliadin and ω-5 gliadin are major wheat allergens among adult-onset wheat allergy patients in Thailand. Component-resolved diagnosis using γ-gliadin might be helpful in high suspicion of wheat allergy.
成人起病的IgE介导的小麦过敏有基于致敏途径和致敏过敏原的多种临床模式报道。在小麦激发试验证实的成人起病的小麦过敏病例中，关于IgE结合的小麦过敏原谱的数据仍然匮乏。因此，我们旨在确定泰国成人起病的小麦过敏患者中的主要致敏过敏原，这些患者尽管既往耐受，但首次症状出现在18岁之后。
这项横断面试点研究从泰国成人起病的IgE介导的小麦过敏队列（TAWAC）中招募患者。选择大多数激发试验证实的病例的血清进行过敏原研究，包括免疫捕获法和IgE结合的醇溶蛋白以及谷蛋白谱。通过液相色谱-串联质谱法（LC-MS/MS）鉴定IgE结合的蛋白质。进行IgE与重组醇溶蛋白和谷蛋白的直接结合以确认免疫印迹和LC-MS/MS的结果。
纳入了11例小麦依赖运动诱发的过敏反应（WDEIA）患者和4例典型小麦过敏（WA）患者。在醇溶蛋白和谷蛋白提取物中，超过50%的结合蛋白的血清IgE分子量范围为35至55 kDa。此外，酶联免疫吸附测定（ELISA）表明γ-醇溶蛋白和ω5-醇溶蛋白是最重要的主要过敏原。其他主要过敏原包括α/β-醇溶蛋白、高分子量谷蛋白，以及可能的α-淀粉酶抑制剂或低分子量谷蛋白。ELISA发现所有WA患者（4/4）均有γ-醇溶蛋白致敏，而所有WDEIA患者（11/11）均有ω-5醇溶蛋白致敏。
小麦γ-醇溶蛋白和ω-5醇溶蛋白是泰国成人起病的小麦过敏患者中的主要小麦过敏原。对于高度怀疑小麦过敏的情况，使用γ-醇溶蛋白进行组分解析诊断可能会有帮助。
