Enrique E, Alonso R, Bartolomé B, San Miguel-Moncín M, Bartra J, Fernández-Parra B, Tella R, Asturias J A, Ibarrola I, Martínez A, Cisteró-Bahíma A
Allergy Department, Institut Universitari Dexeus, Universitat Autònoma de Barcelona, Barcelona, Spain.
J Investig Allergol Clin Immunol. 2004;14(4):335-42.
The presence of profilin-specific IgE antibodies is a cause of cross-reactivity between botanically-unrelated allergen sources. Recently, the association between Platanus acerifolia pollinosis and plant-derived food allergy has been described. The aim of this study was to ascertain whether the P. acerifolia profilin is involved in such cross-reactivity.
Twenty-three patients suffering from Platanus acerifolia pollinosis and plant-derived food allergy were evaluated in an allergy department. Specific IgE levels to P. acerifolia pollen, P. acerifolia profilin and food extracts were measured. Molecular masses of IgE-binding proteins were calculated by Western blotting and cross-reactivity studies among P. acerifolia profilin and different food extracts were evaluated by Enzyme AllergoSorbent Test (EAST)-inhibition assays. Also, EAST-inhibition assays with the two known P. acerifolia allergens, Pla a 1 and Pla a 2, were performed.
Surprisingly, a high IgE-binding prevalence (90%) of P. acerifolia profilin was found. EAST-inhibition showed high inhibition values when Platanus acerifolia pollen extract was used as free phase and plant-derived food extracts as solid phase, whereas the other way round showed low inhibition values. IgE reactivity to profilin was studied using a pool of patient sera, by EAST-inhibition assays with hazelnut, apple peel, peanut, chickpea and peanut extracts as solid phase and no inhibition was obtained when P. acerifolia profilin was used as inhibitor phase. The same results were obtained when purified Pla a 1 and Pla a 2 were also used as inhibitor phase.
The clinical association observed between Platanus acerifolia pollen and plant-derived food could be explained by the in vitro IgE cross-reactivity detected by EAST-inhibition. However, it appears that neither P. acerifolia profilin nor the two major allergens described (Pla a 1 and Pla a 2) can explain such a strong cross-reactivity.
肌动蛋白结合蛋白特异性IgE抗体的存在是植物来源不相关的变应原之间发生交叉反应的原因。最近，已报道了悬铃木花粉症与植物源性食物过敏之间的关联。本研究的目的是确定悬铃木肌动蛋白结合蛋白是否参与这种交叉反应。
在过敏科对23例患有悬铃木花粉症和植物源性食物过敏的患者进行评估。测量了针对悬铃木花粉、悬铃木肌动蛋白结合蛋白和食物提取物的特异性IgE水平。通过蛋白质印迹法计算IgE结合蛋白的分子量，并通过酶变应原吸附试验（EAST）抑制试验评估悬铃木肌动蛋白结合蛋白与不同食物提取物之间的交叉反应性。此外，还进行了针对两种已知的悬铃木变应原Pla a 1和Pla a 2的EAST抑制试验。
令人惊讶的是，发现悬铃木肌动蛋白结合蛋白具有较高的IgE结合阳性率（90%）。当以悬铃木花粉提取物作为游离相、植物源性食物提取物作为固相时，EAST抑制试验显示出较高的抑制值，而反之则显示出较低的抑制值。使用患者血清池，通过以榛子、苹果皮、花生、鹰嘴豆和花生提取物作为固相的EAST抑制试验研究了对肌动蛋白结合蛋白的IgE反应性，当以悬铃木肌动蛋白结合蛋白作为抑制相时未获得抑制效果。当使用纯化的Pla a 1和Pla a 2作为抑制相时也得到了相同的结果。
悬铃木花粉与植物源性食物之间观察到的临床关联可以通过EAST抑制试验检测到的体外IgE交叉反应性来解释。然而，似乎悬铃木肌动蛋白结合蛋白和所描述的两种主要变应原（Pla a 1和Pla a 2）均无法解释这种强烈的交叉反应性。
