The effect of soy processing on its allergenicity: Discrepancy between IgE binding and basophil stimulation tests

Presently, many studies assess allergenicity via IgE immunoblotting and IgE binding tests; however, IgE detection does not always signal the manifestation of a clinical allergy. However, the capacity of food allergens to trigger basophils makes it possible to use the in vitro functional basophil activation test (BAT) to assess allergenicity. The effect of the Maillard reaction (MR) on the allergenic potential of processed soy proteins was evaluated by two IgE binding tests (Competitive ELISA and Inhibition ImmunoCAP), a Western Blot and a functional BAT; with the aim to analyze whether the sIgE binding results correspond to the functional assay results. The results between the IgE binding tests and the functional assay were in-line for 2 of the 6 studied patients. For one patient there was no correlation between any of the results. For the raw soy protein extract heated with glucose for 10 and 30 min (SH SPE + Glu and LH SPE + Glu, respectively), the results were in-line for only 3 out of the 6 patients. Thus, the present study shows a discrepancy between IgE binding tests and basophil stimulation when assessing the effect of soy processing on its allergenicity. Since IgE-binding capacity does not always correlate to IgE cross-linking capacity, the conclusions of the allergenic potential based on the IgE binding tests alone should be drawn with care and further studies on this matter would benefit from the inclusion of a functional assay such as the BAT.