Genetically Modified Organisms (GMO)
Biomarkers of Disease
The most successful approach for assessing the allergenicity of GMO foods was developed by the International Life Sciences Institute (ILSI) in collaboration with the International Food Biotechnology Council. These organizations have developed three main approaches for identifying biomarkers of allergenicity, which are currently used in the evaluation of proteins in GMOs. The first approach involves the examination of the structural similarity of the protein of interest and comparing it with known allergens.
The second approach involves characterizing the susceptibility of the protein of interest to digestion in a simulated gastric fluid. This is done because there is thought to be a correlation between the resistance to digestion and the induction of allergic responses by proteins.
The third approach involves the use of animal models and the detection of elevated IgE antibodies as biomarkers, although there are currently no widely accepted or thoroughly evaluated animal models for the identification of protein allergens.
Although these approaches have been tested, none of these tests are fully predictive of human allergenic responses to GMO proteins. Therefore, more progress needs to be made in developing definitive methods for the identification of protein allergens in GMOs (Hollingworth, 2002). The only definitive proof that a protein is a food allergen would be the observation of a clinical allergic reaction after ingestion of the GM food. However, a more practical and safe method used directly on humans would be to measure antigen-specific serum IgE after exposure to the protein of interest or a positive skin test to the protein. However, even these tests on humans produce a large number of false-positive and false-negative results (Germolec et al., 2003).