Mei Lu and Richard E Goodman

　　Department of Food Science and Technology, University of Nebraska-Lincoln, USA

　　Background: The Codex Alimentarius Guideline (2003) for food safety assessment

　　of GM plants recommends evaluating potential changes in endogenous allergen expression if the plant is a common source of food allergy. The European Food Safety Authority (EFSA) now asks for direct enzyme-linked immunosorbent assay (ELISA) and both 1D and 2D immunoblotting using individual allergic sera for IgE binding comparisons to evaluate diverse epitope recognition. Because the natural variability in the expression of endogenous allergens between varieties is unknown, a new pest-resistant genetically modified (GM) soybean, a near-isogenic line and five non-GM commercial lines of soybeans grown in multiple geographical regions were compared for IgE binding.

　　Method: Qualitative differences were evaluated from IgE binding to proteins separated under reducing and non-reducing 1D-SDS-PAGE and 2D-IEF x SDSPAGE. Quantitative differences were compared by direct ELISA. Eleven individual soybean allergic sera and five non-soybean allergic control sera were tested.

　　Results: Minor IgE binding differences were observed between the GM and nearisogenic soybeans as well as some commercial lines for some subjects by immunoblotting.

　　The IgE binding measured by ELISA was not statistically different between the GM and near-isoline control soybeans and was within the range of variation of the other commercial soybeans lines with different genetic backgrounds.

　　Conclusion: The evidence suggests that this GM soybean line does not present an increased risk of allergy as the variation in IgE binding was similar to commercial soybean lines. More importantly, soybean allergic consumers should avoid consumption of foods containing any soybeans, thus the relevance of the required testing is not clear.