Foetisch Kay, Westphal Sandra, Lauer Iris, Retzek Mechthild, Altmann Fritz, Kolarich Daniel, Scheurer Stephan, Vieths Stefan
Department of Allergology, Paul-Ehrlich-Institut, Langen, Germany.
J Allergy Clin Immunol. 2003 Apr;111(4):889-96. doi: 10.1067/mai.2003.173.
The clinical relevance of IgE specific for cross-reactive carbohydrate determinants (CCDs) has been a matter of controversy. Until now, no convincing experiments have been performed to test the biologic significance of individual multivalent allergens that carry multiple carbohydrate epitopes.
We sought to contribute to the understanding of the role of CCD-specific IgE antibodies and to study whether CCD-specific IgE antibodies are able to activate basophils using different multivalent glycoproteins as antigens.
Purified natural tomato beta-fructofuranosidase (nLyc e 2) and rLyc e 2.02 expressed in Escherichia coli were compared by means of histamine release tests. In addition, native and deglycosylated horseradish peroxidase and a neoglycoprotein consisting of a defined glycopeptide (Manalpha1-6[Xylbeta1-2]Manbeta1-4GlcNAcbeta1-4[Fucalpha1-3]GlcNAc) coupled to BSA were used in histamine release assays using stripped basophils from normal donors resensitized with IgE from CCD-reactive patients with food allergy to tomato.
Ten CCD-positive and 2 CCD-negative sera from patients with tomato allergy underwent histamine release testing by using the glycoproteins and nonglycosylated controls as antigens, respectively. All sera induced histamine release with tomato extract (up to 100%), confirming the allergic status of the donors. Four of the CCD-positive sera induced releases ranging from 12% to 82% with all of the glycoproteins but not with the nonglycosylated or monovalent controls. All other sera showed no response or only very weak response to the glycoproteins.
Approximately one third of the CCD-positive sera from patients with tomato allergy have biologically relevant CCD-specific IgE antibodies. Therefore the general claim that CCD-specific IgE is clinically irrelevant has to be reconsidered critically. Hence IgE specific for CCDs should be taken into consideration in the diagnosis and therapy of certain allergies. In the subgroup of patients sensitized to CCDs, the use of natural allergens should be preferred over the use of recombinant allergens expressed in prokaryotic organisms.
针对交叉反应性碳水化合物决定簇（CCDs）的特异性IgE的临床相关性一直存在争议。到目前为止，尚未进行令人信服的实验来测试携带多个碳水化合物表位的单个多价变应原的生物学意义。
我们试图促进对CCDs特异性IgE抗体作用的理解，并研究CCDs特异性IgE抗体是否能够使用不同的多价糖蛋白作为抗原激活嗜碱性粒细胞。
通过组胺释放试验比较了纯化的天然番茄β-呋喃果糖苷酶（nLyc e 2）和在大肠杆菌中表达的rLyc e 2.02。此外，天然和去糖基化的辣根过氧化物酶以及由定义的糖肽（Manα1-6[Xylβ1-2]Manβ1-4GlcNAcβ1-4[Fucα1-3]GlcNAc）与牛血清白蛋白偶联而成的新糖蛋白，用于组胺释放试验，该试验使用来自对番茄食物过敏的CCDs反应性患者的IgE重新致敏的正常供体的脱颗粒嗜碱性粒细胞。
分别使用糖蛋白和非糖基化对照作为抗原，对10例番茄过敏患者的CCDs阳性血清和2例CCDs阴性血清进行组胺释放试验。所有血清均能诱导番茄提取物释放组胺（高达100%），证实了供体的过敏状态。4例CCDs阳性血清对所有糖蛋白诱导的组胺释放率为12%至82%，但对非糖基化或单价对照无反应。所有其他血清对糖蛋白无反应或仅有非常微弱的反应。
约三分之一的番茄过敏患者的CCDs阳性血清具有生物学相关的CCDs特异性IgE抗体。因此，必须严格重新考虑关于CCDs特异性IgE在临床上无关的普遍说法。因此，在某些过敏的诊断和治疗中应考虑CCDs特异性IgE。在对CCDs致敏的患者亚组中，应优先使用天然变应原而非原核生物中表达的重组变应原。
