D3.271 - Development of a multiplex assay to assess the risk of IgE cross-reactivity to new protein sources

To address demographic and climate challenges, the global food system seeks to promote the consumption of more sustainable sources of protein as alternatives to animal-based proteins. Alongside changes of eating habits, new food allergens could also be introduced into the diet. Assessing the safety and allergenic potential of new protein sources includes evaluating the risk of cross-reactivity with immunoglobulin E (IgE) specific to known allergenic foods. We thus aimed to develop a multiplex approach to assess IgE cross-reactivity between major allergenic sources and alternative protein sources.

Extracts from different allergenic and alternative protein sources were prepared and characterized by electrophoretic analysis. The IgE immunoreactivity of known allergenic foods was then measured by ELISA and using commercial plasmas from a large panel of sensitized individuals. Based on the sensitization profile toward the different food protein extracts, plasmas were then selected to develop a multiplex assay. This assay evaluated the ability of a protein source to inhibit the IgE binding to different major allergenic foods conjugated to distinct fluorescent-coded magnetic beads.

Using a competitive binding format, the assay can currently assess the capacity of a food source to simultaneously and distinctly inhibit the IgE binding to milk, peanut, soybean, chickpea, cashew or shrimp proteins. Notably, this test evidenced the risk of IgE cross-reactivity between proteins from different legumes (chickpea, lentil, fava bean) and between proteins from shrimp and insects.

The multiplex screening test is functional and provides a promising method for a preliminary risk assessment of IgE cross-reactivity between alternative protein sources and sources already known to be allergenic. Its application to the detection of multiple contaminations by different major allergens in food products could also be considered.