Reekers R, Busche M, Wittmann M, Kapp A, Werfel T
Department of Dermatology and Allergology, Hannover Medical University, Hannover, Germany.
J Allergy Clin Immunol. 1999 Aug;104(2 Pt 1):466-72. doi: 10.1016/s0091-6749(99)70395-7.
Patients with inhalant allergy caused by birch pollen frequently demonstrate immediate symptoms to cross-reactive fruits, vegetables, or both. The nature of late eczematous reactions to pollen related food antigens has not been investigated in detail.
The purpose of this study was to find out whether isolated late eczematous reactions to birch pollen-related food antigens can be observed in patients with atopic dermatitis (AD) who are highly sensitized to birch pollen antigens. A possible linkage of such reactions with specific T-cell responses to birch pollen antigens in the blood and lesional skin was examined as well.
We examined 37 adult patients with AD and hypersensitivity to birch pollen but without any history of immediate responses to food challenges. These patients underwent an elimination diet, including all birch pollen-related food antigens, followed by a double-blind, placebo-controlled, oral provocation. Blood and skin biopsy specimens were taken to examine a birch pollen-specific lymphocyte response.
Seventeen patients reacted with a deterioration of AD symptoms. Food- or birch pollen-specific IgE did not differentiate these patients from nonreactive patients. A significantly higher increase in the proportion of blood lymphocytes expressing the cutaneous lymphocyte antigen on incubation with birch pollen antigens was found in cells from reactive compared with nonreactive patients. The proliferative response of skin-derived T-cell lines from reactive patients to birch pollen extract or Bet v 1 was significantly higher than that of nonreactive patients. An enrichment of more than 25% of T-lymphocyte subpopulations defined by T-cell receptor-Vbeta elements was detected in the majority of such antigen-stimulated T-cell lines from responsive patients. A higher frequency of birch pollen-reactive T cells was calculated from limiting-dilution assays, and a higher rate of birch pollen-specific T-cell clones was generated from cultures with skin-derived T cells from reactive patients.
Our results show, for the first time, that a subpopulation of patients with hypersensitivity to birch pollen and AD reacts with worsening of eczema after oral challenge with birch pollen-related foods and that a birch pollen-specific T-cell response can be found in the lesional skin of these patients.
桦树花粉引起的吸入性过敏患者经常对交叉反应性水果、蔬菜或两者都表现出即时症状。对花粉相关食物抗原的迟发性湿疹反应的本质尚未进行详细研究。
本研究的目的是确定在对桦树花粉抗原高度敏感的特应性皮炎（AD）患者中是否能观察到对桦树花粉相关食物抗原的孤立迟发性湿疹反应。还检查了此类反应与血液和皮损中对桦树花粉抗原的特异性T细胞反应之间的可能联系。
我们检查了37名患有AD且对桦树花粉过敏但没有任何食物激发即时反应史的成年患者。这些患者接受了排除饮食，包括所有桦树花粉相关的食物抗原，随后进行双盲、安慰剂对照的口服激发试验。采集血液和皮肤活检标本以检查桦树花粉特异性淋巴细胞反应。
17名患者的AD症状恶化。食物或桦树花粉特异性IgE无法区分这些患者与无反应患者。与无反应患者相比，反应性患者的细胞在与桦树花粉抗原孵育时，表达皮肤淋巴细胞抗原的血液淋巴细胞比例显著更高。反应性患者皮肤来源的T细胞系对桦树花粉提取物或Bet v 1的增殖反应显著高于无反应患者。在大多数来自反应性患者的此类抗原刺激的T细胞系中，检测到由T细胞受体-Vβ元件定义的T淋巴细胞亚群富集超过25%。通过有限稀释试验计算出更高频率的桦树花粉反应性T细胞，并且从反应性患者的皮肤来源T细胞培养物中产生了更高比例的桦树花粉特异性T细胞克隆。
我们的结果首次表明，对桦树花粉和AD过敏的患者亚群在口服桦树花粉相关食物激发后湿疹恶化，并且在这些患者的皮损中可以发现桦树花粉特异性T细胞反应。
