Bruijnzeel-Koomen C A, Mudde G C, Bruijnzeel P L
Swiss Institute of Allergy and Asthma Research, Davos Platz, Switzerland.
Allerg Immunol (Paris). 1989 Jun;21(6):219-23.
Aeroallergens can induce a delayed patch test reaction, which is specific for patients with atopic dermatitis (AD). Histopathology of this aeroallergen induced skin reaction suggests the involvement of Langerhans cells (LC), T cells and eosinophils. Since LC from AD patients may bear Fc sigma, R-bound IgE molecules, it was hypothesized that aeroallergens after contact with the skin bind to allergen-specific IgE on LC leading to efficient presentation to T cells. In vitro studies show that LC from AD patients can indeed present aeroallergens to T cells, provided LC-bound IgE molecules are present. These results, firstly, explain the reaction mechanism behind the patch test reaction to aeroallergens; secondly, they point to a new allergic reaction mechanism in which a link is provided between type I and type IV allergic reactions according to Gell and Coombs; thirdly, they throw a new light on the role of aeroallergens in the pathogenesis of AD. Aeroallergens may after contact with skin of AD patients not only induce eczematous skin lesions but also be involved in the induction of the synthesis of allergen specific IgE molecules. From a practical point of view, the results of this study show that aeroallergens play a more important role in the pathogenesis of AD than has been accepted so far.
气传变应原可诱发迟发性斑贴试验反应，这是特应性皮炎（AD）患者所特有的。这种气传变应原诱发的皮肤反应的组织病理学提示朗格汉斯细胞（LC）、T细胞和嗜酸性粒细胞参与其中。由于AD患者的LC可能携带FcσR结合的IgE分子，因此推测气传变应原与皮肤接触后会与LC上的变应原特异性IgE结合，从而有效地呈递给T细胞。体外研究表明，只要存在LC结合的IgE分子，AD患者的LC确实可以将气传变应原呈递给T细胞。这些结果，首先，解释了针对气传变应原的斑贴试验反应背后的反应机制；其次，它们指出了一种新的过敏反应机制，根据盖尔和库姆斯的分类，在该机制中I型和IV型过敏反应之间建立了联系；第三，它们为气传变应原在AD发病机制中的作用提供了新的线索。气传变应原与AD患者的皮肤接触后，不仅可能诱发湿疹性皮肤病变，还可能参与变应原特异性IgE分子合成的诱导。从实际角度来看，这项研究的结果表明，气传变应原在AD发病机制中所起的作用比目前所公认的更为重要。
