Hsieh K-Y, Tsai C-C, Wu C H Herbert, Lin R-H
Graduate Institute of Immunology, College of Medicine, National Taiwan University, Taipei, Taiwan.
Clin Exp Allergy. 2003 Aug;33(8):1067-75. doi: 10.1046/j.1365-2222.2003.01724.x.
The aetiology of food allergy remains unclear. Although failure to develop or breakdown in oral tolerance has been proposed, the existence of physiologic sensitization routes other than the gastrointestinal tract cannot be excluded.
The purpose of this study is to clarify whether or not exposure to allergen through the skin can promote food allergy.
BALB/c mice were shaved on the back, and a patch impregnated with 100 micro g of ovalbumin (OVA) was applied to the dorsal skin for a 1-week period and then removed. After three courses of sensitization, OVA-specific antibodies in sera were measured, and then mice were orally challenged with 50 mg of OVA. Anaphylactic symptoms, plasma histamine levels, and histology of intestines and lungs after oral challenge were examined.
Epicutaneous (EC) sensitization of mice to OVA induced a high level of OVA-specific IgE. Subsequent oral challenge with OVA resulted in symptoms of systemic anaphylaxis with elevated levels of plasma histamine as well as histological changes in both intestines and lungs. In the presence of anti-IL-4 antibodies, EC sensitization failed to provoke an IgE response, but still induced a Th2-predominant cellular immune response in lungs after oral challenge.
We demonstrated for the first time that food allergy can be induced by allergen exposure through the skin. Our results identify a novel role of EC sensitization in the pathogenesis of food allergy.
食物过敏的病因仍不清楚。虽然有人提出是口服耐受未能形成或遭到破坏，但不能排除存在胃肠道以外的生理性致敏途径。
本研究旨在阐明经皮肤接触变应原是否会促进食物过敏。
将BALB/c小鼠背部毛发剃除，在其背部皮肤贴敷浸有100μg卵清蛋白（OVA）的贴片，持续1周后移除。经过三个疗程的致敏后，检测血清中OVA特异性抗体，然后给小鼠口服50mg OVA进行激发试验。观察口服激发试验后的过敏症状、血浆组胺水平以及肠道和肺部的组织学变化。
小鼠经皮（EC）致敏OVA可诱导产生高水平的OVA特异性IgE。随后口服OVA进行激发试验，出现全身过敏症状，血浆组胺水平升高，肠道和肺部均有组织学变化。在存在抗IL-4抗体的情况下，经皮致敏未能引发IgE反应，但在口服激发试验后仍在肺部诱导出以Th2为主的细胞免疫反应。
我们首次证明经皮肤接触变应原可诱发食物过敏。我们的研究结果确定了经皮致敏在食物过敏发病机制中的新作用。
