Cho Chung Y, Oles Carolyn, Nowatzke William, Oliver Kerry, Garber Eric A E
Office of Regulatory Science, Center for Food Safety and Applied Nutrition (CFSAN), Food and Drug Administration, 5001 Campus Drive, College Park, MD, 20740, USA.
Radix® BioSolutions, 111 Cooperative Way #120, Georgetown, TX, 78626, USA.
Anal Bioanal Chem. 2017 Oct;409(25):5999-6014. doi: 10.1007/s00216-017-0528-y. Epub 2017 Aug 12.
The homology between proteins in legumes and tree nuts makes it common for individuals with food allergies to be allergic to multiple legumes and tree nuts. This propensity for allergenic and antigenic cross-reactivity means that commonly employed commercial immunodiagnostic assays (e.g., dipsticks) for the detection of food allergens may not always accurately detect, identify, and quantitate legumes and tree nuts unless additional orthogonal analytical methods or secondary measures of analysis are employed. The xMAP Multiplex Food Allergen Detection Assay (FADA) was used to determine the cross-reactivity patterns and the utility of multi-antibody antigenic profiling to distinguish between legumes and tree nuts. Pure legumes and tree nuts extracted using buffered detergent displayed a high level of cross-reactivity that decreased upon dilution or by using a buffer (UD buffer) designed to increase the stringency of binding conditions and reduce the occurrence of false positives due to plant-derived lectins. Testing for unexpected food allergens or the screening for multiple food allergens often involves not knowing the identity of the allergen present, its concentration, or the degree of modification during processing. As such, the analytical response measured may represent multiple antigens of varying antigenicity (cross-reactivity). This problem of multiple potential analytes is usually unresolved and the focus becomes the primary analyte, the antigen the antibody was raised against, or quantitative interpretation of the content of the analytical sample problematic. The alternative solution offered here to this problem is the use of an antigenic profile as generated by the xMAP FADA using multiple antibodies (bead sets). By comparing the antigenic profile to standards, the allergen may be identified along with an estimate of the concentration present. Cluster analysis of the xMAP FADA data was also performed and agreed with the known phylogeny of the legumes and tree nuts being analyzed. Graphical abstract The use of cluster analysis to compare the multi-antigen profiles of food allergens.
豆类和坚果中的蛋白质具有同源性，这使得食物过敏个体通常会对多种豆类和坚果过敏。这种致敏和抗原交叉反应的倾向意味着，除非采用额外的正交分析方法或二级分析措施，否则常用于检测食物过敏原的商业免疫诊断检测方法（如试纸条）可能无法始终准确地检测、识别和定量豆类和坚果。采用xMAP多重食物过敏原检测分析方法（FADA）来确定交叉反应模式以及多抗体抗原谱在区分豆类和坚果方面的效用。使用缓冲去污剂提取的纯豆类和坚果显示出高水平的交叉反应，在稀释或使用旨在提高结合条件严格性并减少植物源凝集素导致的假阳性发生的缓冲液（UD缓冲液）后，交叉反应会降低。检测意外的食物过敏原或筛查多种食物过敏原时，通常不知道存在的过敏原的身份、其浓度或加工过程中的修饰程度。因此，所测得的分析响应可能代表具有不同抗原性的多种抗原（交叉反应）。这种多种潜在分析物的问题通常无法解决，重点就变成了主要分析物、抗体所针对的抗原，或者分析样品含量的定量解释就会出现问题。这里针对这个问题提供的替代解决方案是使用由xMAP FADA使用多种抗体（磁珠组）生成的抗原谱。通过将抗原谱与标准进行比较，可以识别过敏原并估计其存在的浓度。还对xMAP FADA数据进行了聚类分析，结果与所分析的豆类和坚果的已知系统发育一致。图形摘要 使用聚类分析比较食物过敏原的多抗原谱。
