Schocker F, Lüttkopf D, Müller U, Thomas P, Vieths S, Becker W M
Forschungszentrum Borstel, Division of Allergology, Germany.
Eur J Nutr. 2000 Aug;39(4):172-80. doi: 10.1007/s003940070021.
Usually hazelnut allergic patients suffer from the tree pollen associated oral allergy syndrome (OAS) caused by cross-reactive structures. Anaphylactic reactions elicited by hazelnuts happen rarely but are of high clinical significance. Considering that hazelnuts are ingredients in processed foods, hazelnuts may play an important role as hidden allergens for these high risk patients. Therefore, we analyzed the IgE reactivity of a young woman with severe allergic reactions after ingestion of hazelnuts without any association to tree pollen allergy.
The aim of this study was to identify and characterize these potent hazelnut-specific allergens. We compared these allergens to structures displayed by sera from patients with a completely or partially non pollen-related hazelnut allergy and with birch pollen-related hazelnut allergy. None of the sera had a clinical history of anaphylaxis. Special emphasis was placed on the heat stability and cross-reactivity of these allergens.
METHODS/RESULTS: Using Western blotting with extract from birch pollen and EAST inhibition techniques we were able to show that the allergens in the serum sample of the young woman were not cross-reactive with birch pollen. Immunoblot experiments with extracts from native and heated hazelnuts and EAST inhibition tests further characterized these allergens to be heat-stable. Unlike the IgE binding pattern of the sera from the patients with pollen-related hazelnut allergy, low molecular weight proteins below 10 kDa were identified by the sera from the patients without pollinosis.
Since the binding pattern of the serum sample of the young woman was different from that of the sera from patients without pollen allergy but less severe symptoms, we assume an association between single non pollen-dependent hazelnut allergens in the low molecular range and severe allergic reactions. These results enable us to approach a subgroup of hazelnut allergens which we believe to be responsible for anaphylactic reactions in hazelnut allergic patients after ingestion of heat-stable hazelnut structures in processed food stuff, independent of pollinosis.
通常，榛子过敏患者会因交叉反应结构而患上与树花粉相关的口腔过敏综合征（OAS）。榛子引发的过敏反应很少见，但具有很高的临床意义。鉴于榛子是加工食品中的成分，对于这些高危患者而言，榛子可能作为隐藏的过敏原发挥重要作用。因此，我们分析了一名年轻女性在摄入榛子后出现严重过敏反应且与树花粉过敏无任何关联的血清中IgE的反应性。
本研究的目的是鉴定和表征这些强效的榛子特异性过敏原。我们将这些过敏原与完全或部分与花粉无关的榛子过敏患者以及与桦树花粉相关的榛子过敏患者血清所显示的结构进行了比较。所有血清均无过敏反应的临床病史。特别强调了这些过敏原的热稳定性和交叉反应性。
方法/结果：使用桦树花粉提取物进行蛋白质印迹法和酶联免疫斑点抑制技术，我们能够证明该年轻女性血清样本中的过敏原与桦树花粉无交叉反应。用天然和加热榛子提取物进行免疫印迹实验以及酶联免疫斑点抑制试验进一步表征这些过敏原具有热稳定性。与花粉相关的榛子过敏患者血清的IgE结合模式不同，无花粉症患者的血清鉴定出低于10 kDa的低分子量蛋白质。
由于该年轻女性血清样本的结合模式与无花粉过敏但症状较轻患者的血清不同，我们推测低分子范围内单一的非花粉依赖性榛子过敏原与严重过敏反应之间存在关联。这些结果使我们能够确定一类榛子过敏原，我们认为这类过敏原是导致榛子过敏患者在摄入加工食品中热稳定的榛子结构后发生过敏反应的原因，且与花粉症无关。
