Background

The IgE- and IgG₄-binding patterns of the major fish allergen parvalbumins are not clearly understood. IgE antibody-binding to parvalbumin from Asian seabass, Lat c 1.01, is implicated in up to 90 % of allergic reactions, although the region of IgE or IgG4 epitopes are unknown. In the present study, we characterized the specific IgE- and IgG₄-binding regions of Lat c 1.01 using serum from pediatric and adult patients with clinically-confirmed fish allergy.

Methods

A comparative investigation of patient IgE- and IgG₄-binding to recombinant Lat c 1.01 was performed by immunoblotting and indirect ELISA using serum from 15 children and eight adults with clinically confirmed IgE-mediated reactions to fish. The IgE- and IgG₄-binding regions of Lat c 1.01 were determined by inhibition ELISA using seven overlapping peptides spanning the entire 102 amino acid sequence. Elucidated IgE-binding regions were modelled and compared to known antibody-binding regions of parvalbumins from five other fish species.

Results

Ninety five percent (22/23) patients demonstrated IgE-binding to rLat c 1.01, while fewer patients (10/15 children and 7/8 adults) demonstrated robust IgG₄ binding when determined by immunoblots. IgE-binding for both cohorts was significantly higher compared to IgG₄-binding by ELISA. All patients in this study presented individual IgE and IgG₄ epitope-recognition profiles. In addition to these patient-specific antibody binding sites, general IgE epitopes were also identified at the C- and N-terminal regions of this major fish allergen.

Conclusions and Clinical relevance

Our findings demonstrate two specific IgE epitopes on parvalbumin from Asian seabass, while IgG₄ binding is much lower and patient specific. This study highlights the importance of advancement in epitope analysis regardless of the age group for diagnostics and immunotherapies for fish allergy.

中文翻译：

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主要鱼类过敏原Lat c 1上显示IgE和IgG ₄表位

背景

主要鱼类过敏原小白蛋白的IgE和IgG ₄结合模式尚不清楚。尽管IgE或IgG4抗原决定簇的区域未知，但与90％的过敏反应都涉及与来自亚洲鲈鱼的小白蛋白的IgE抗体结合。在本研究中，我们使用来自临床确诊的鱼过敏的儿科患者和成年患者的血清，鉴定了Lat c 1.01的IgE和IgG ₄特异性结合区域。

方法

通过免疫印迹和间接ELISA方法，使用15位儿童和8位成年人的血清进行了IgE介导的对鱼类的临床确诊，通过免疫印迹和间接ELISA对患者IgE和IgG ₄结合重组Lat c 1.01进行了比较研究。Lat c 1.01的IgE和IgG ₄结合区是通过抑制ELISA使用覆盖整个102个氨基酸序列的七个重叠肽确定的。对已阐明的IgE结合区进行建模，并与来自其他5种鱼类的小白蛋白的已知抗体结合区进行比较。

结果

95％（22/23）的患者表现出IgE与rLat c 1.01的结合，而通过免疫印迹测定的患者（10/15的儿童和7/8的成年人）表现出强大的IgG ₄结合能力。与通过ELISA的IgG ₄结合相比，两个群组的IgE结合均显着更高。该研究中的所有患者均表现出各自的IgE和IgG ₄表位识别特征。除了这些患者特异性抗体结合位点外，在该主要鱼类过敏原的C和N端区域还发现了一般的IgE表位。

结论与临床意义

我们的发现表明，来自亚洲鲈鱼的小白蛋白上有两个特定的IgE表位，而IgG _4的结合率要低得多，并且对患者具有特异性。这项研究强调了表位分析的发展重要性，无论年龄大小如何，都可以用于鱼过敏的诊断和免疫治疗。