In Vitro Safety Assessment of Whey Hydrolysates

Antibody mediated allergy to Cow's milk can form a major threat to the infant's health. Infants with this type of allergy cannot consume normal milk from cow origin. Cow’s milk-derived whey hydrolysates are nutritional substitutes for children with this type of allergy. These hydrolysates can be regarded as degraded proteins of which the fragments will no longer to be recognized by the immune system of the allergic child. Cow's milk (or more specifically whey) hyrolyses therefore, will not trigger an allergic reaction. For the safety of the infant it is important to assess any residual allergenicity of the hydrolyses, before using these in infant food. 

Currently, rat immune cells expressing a human antibody receptor are used to perform this safety assessment. In this method serum antibodies from children that are allergic to cow's milk, are being used. However, limited availability and variation between children stand in the way of proper standardization of whey hydrolysate safety testing. Noteworthy is that every individual batch of whey hydrolysates has to be tested before it can be released onto the market. The safety testing of these kind of food subsititutes is stricly regulated. 

To address the issue of poorly available sera from allergic children, and to standardize and improve the method, multiple humanized antibodies against the cow protein b-lactoglobulin (a major allergen in whey) were generated. The new method with humanized antibodies turned out to be more specific, more robust and more sensitive. Usage of this ‘unlimited’ and well-defined source of b-lactoglobulin-specific antibodies in this new method showed to be a relevant and sensitive alternative for serum from allergic children. Currently, the method has been evaluated in a ring study with multiple laboratories. Participating laboratories are Bioceros in Utrecht; The Institute for Risk Assessment Sciences of the Utrecht University (IRAS); The Laboratory for Innovative Testing (INT) of the University of Applied Sciences in Utrecht and Nutricia Research in Utrecht. This validation study is one step further to general recognition of the value of this assay and is a crucial and initial small step toward implementation of this assay in the safety guidelines (in Europe). 

This reaseach has been published in the open access journal PLoS ONE (PLoS ONE 9(8): e106025. doi:10.1371/journal.pone.010602).  The validation study was presented at the World Congress on Alternatives and Animal Use in the Life Sciences, Prague, 24 - 28 August, 2014

This study was financially supported by Agentschap NL within the SLiM project in frame of ’Pieken in de Delta’ (PID101063) to improve fast implementation of alternatives for animal testing. 

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