Division of Allergy & Immunology, Mount Sinai School of Medicine, New York, NY 10029, USA.
Clin Exp Allergy. 2012 Feb;42(2):293-304. doi: 10.1111/j.1365-2222.2011.03920.x. Epub 2011 Dec 22.
Shrimp is a frequent cause of severe allergic reactions world-wide. Due to issues such as cross-reactivity, diagnosis of shrimp allergy is still inaccurate, requiring the need for double-blind, placebo-controlled food challenges (DBPCFC). A better understanding of the relationship between laboratory findings and clinical reactivity is needed.
To determine whether sensitization to certain shrimp allergens or recognition of particular IgE epitopes of those allergens are good biomarkers of clinical reactivity to shrimp.
Thirty-seven consecutive patients were selected with clinical histories of shrimp allergy. Skin prick test, specific IgE determinations, DBPCFC and immunoblot assays to shrimp extract were performed. IgE binding to synthetic overlapping peptides representing the sequence of the four allergens from the Pacific white shrimp (Litopenaeus vannamei) identified to date (Lit v1, Lit v2, Lit v3 and Lit v4) was analysed.
Of 37 (46%) patients, 17 had a positive challenge to shrimp (11 children and 6 adults). By microarray, patients with positive challenges showed more intense binding to shrimp peptides than those with negative challenges. Statistically significant differences in terms of the frequency and intensity of IgE binding to some epitopes were observed between the two groups. Diagnostic efficiency was higher for individual epitopes than for proteins. Particularly, efficiency was highest for certain Lit v 1 and Lit v 2 epitopes, followed by Lit v 3 and Lit v 4 epitopes.
Patients with positive shrimp challenges present in general more intense and diverse epitope recognition to all four shrimp allergens. IgE antibodies to these shrimp epitopes could be used as biomarkers for prediction of clinical reactivity in subjects with sensitization to shrimp. Patients with positive shrimp challenges show more intense sensitization and more diverse epitope recognition. Several IgE-binding shrimp epitopes could be used as biomarkers for predicting clinical reactivity in subjects with sensitization to shrimp.
虾是全球范围内引起严重过敏反应的常见原因。由于交叉反应等问题，虾过敏的诊断仍然不够准确，需要进行双盲、安慰剂对照食物挑战（DBPCFC）。需要更好地了解实验室结果与临床反应之间的关系。
确定对某些虾过敏原的致敏或对这些过敏原特定 IgE 表位的识别是否是对虾临床反应的良好生物标志物。
选择 37 例有虾过敏病史的连续患者。进行皮肤点刺试验、特异性 IgE 测定、DBPCFC 和虾提取物免疫印迹分析。分析针对迄今为止从太平洋白虾（Litopenaeus vannamei）鉴定的四种过敏原（Lit v1、Lit v2、Lit v3 和 Lit v4）的序列的合成重叠肽的 IgE 结合。
在 37 例（46%）患者中，有 17 例对虾有阳性挑战（11 例儿童和 6 例成人）。通过微阵列，阳性挑战患者对虾肽的结合强度比阴性挑战患者更强。两组之间在某些表位的 IgE 结合的频率和强度方面观察到统计学上的显著差异。与蛋白质相比，个别表位的诊断效率更高。特别是某些 Lit v1 和 Lit v2 表位以及 Lit v3 和 Lit v4 表位的效率最高。
阳性虾挑战患者通常对所有四种虾过敏原表现出更强烈和多样化的表位识别。针对这些虾表位的 IgE 抗体可用作预测对虾致敏的临床反应的生物标志物。对虾有阳性挑战的患者表现出更强的致敏和更多样化的表位识别。一些 IgE 结合的虾表位可用作预测对虾致敏患者临床反应的生物标志物。
