Seppälä U, Alenius H, Turjanmaa K, Reunala T, Palosuo T, Kalkkinen N
Institute of Biotechnology, University of Helsinki, Finland.
J Allergy Clin Immunol. 1999 Jan;103(1 Pt 1):165-71. doi: 10.1016/s0091-6749(99)70541-5.
Peeling of raw potatoes may cause allergic symptoms, such as sneezing, wheezing, and contact urticaria, for adults. For children, potatoes as food may cause various allergic reactions. However, the identity and molecular structure of the putative allergens in potato have remained unknown.
The aim of our study was to identify possible major allergens in potato by using sera of atopic children suspected of having food allergy and having positive skin prick test responses to raw potato.
Potato proteins were purified by standard methods of protein chemistry and characterized with amino-terminal sequencing and mass spectrometry. The IgE-binding ability of the purified proteins was verified by immunoblotting and ELISA with IgE antibodies from the sera of atopic children having positive skin prick test responses to raw potato.
Immunoblotting showed strong IgE binding to a 43-kd protein, identified as patatin, the main storage protein of potato tubers. In ELISA, 20 of 27 (74%) children with positive skin prick test responses to potato and none of the control subjects showed specific binding of IgE antibodies to purified patatin. A positive wheal-and-flare reaction was seen in 8 of 14 children prick tested with purified patatin.
These results show that patatin in potatoes is a significant, previously unrecognized,IgE-binding protein for children with a positive skin prick test response to raw potato. Further studies are needed to confirm the clinical importance of potatoes, and especially patatin, as a food allergen.
削生土豆皮可能会引发成年人的过敏症状，如打喷嚏、喘息和接触性荨麻疹。对儿童而言，土豆作为食物可能会引发各种过敏反应。然而，土豆中假定过敏原的身份和分子结构一直未知。
我们研究的目的是通过使用疑似食物过敏且对生土豆皮肤点刺试验呈阳性反应的特应性儿童的血清，来鉴定土豆中可能的主要过敏原。
采用标准蛋白质化学方法纯化土豆蛋白，并通过氨基末端测序和质谱进行表征。用对生土豆皮肤点刺试验呈阳性反应的特应性儿童血清中的IgE抗体，通过免疫印迹和酶联免疫吸附测定（ELISA）来验证纯化蛋白的IgE结合能力。
免疫印迹显示，IgE与一种43-kd的蛋白有强烈结合，该蛋白被鉴定为马铃薯块茎的主要贮藏蛋白——马铃薯Patatin。在ELISA中，27名对土豆皮肤点刺试验呈阳性反应的儿童中有20名（74%），而对照组中无人显示IgE抗体与纯化的Patatin有特异性结合。用纯化的Patatin对14名儿童进行点刺试验，其中8名出现了阳性风团和红晕反应。
这些结果表明，对于对生土豆皮肤点刺试验呈阳性反应的儿童，土豆中的Patatin是一种重要的、此前未被认识的IgE结合蛋白。需要进一步研究来证实土豆，尤其是Patatin作为食物过敏原的临床重要性。
