Background: 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.
Methods: 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.
Results: 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 ω 5-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.
Conclusion: 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.



中文翻译：

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Omega-5 和 γ 麦醇溶蛋白是成人发病的 IgE 介导的小麦过敏的主要过敏原：泰国口服食物挑战队列的结果


背景：在成人发病的 IgE 介导的小麦过敏中，报道了基于致敏途径和致敏过敏原的各种临床模式。在经小麦挑战证明的成年发病小麦过敏病例中，关于 IgE 结合小麦过敏原谱的数据仍然很少。因此，我们的目标是确定泰国成人小麦过敏患者的主要致敏过敏原，尽管之前有耐受性，但其首次症状出现在 18 岁之后。

方法：这项横断面试点研究从泰国成人发病 IgE 介导的小麦过敏队列 (TAWAC) 中招募患者。选择大多数经挑战证明病例的患者血清进行过敏原研究，包括ImmunoCAP和IgE结合的麦醇溶蛋白以及麦谷蛋白谱。 IgE 结合蛋白通过液相色谱-串联质谱 (LC-MS/MS) 进行鉴定。进行 IgE 与重组麦醇溶蛋白和麦谷蛋白的直接结合以确认免疫印迹和 LC-MS/MS 的结果。

结果： 11 名小麦依赖性运动诱发过敏反应 (WDEIA) 和 4 名典型小麦过敏 (WA) 患者入组。在麦醇溶蛋白和麦谷蛋白提取物中，超过 50% 的结合蛋白的血清 IgE 的分子量范围为 35 至 55 kDa。此外，ELISA证明γ-麦醇溶蛋白和ω 5-麦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-麦醇溶蛋白、HMW 麦谷蛋白，可能还包括 α-淀粉酶抑制剂或 LWM 麦谷蛋白。通过 ELISA，在所有 WA 患者 (4/4) 中发现了 γ-麦醇溶蛋白致敏，而在所有 WDEIA 患者 (11/11) 中发现了 ω-5 麦醇溶蛋白。

结论：小麦γ-麦醇溶蛋白和ω-5麦醇溶蛋白是泰国成人小麦过敏患者的主要小麦过敏原。使用 γ-麦醇溶蛋白进行成分解析诊断可能有助于高度怀疑小麦过敏。