Animal food allergens

Kimber, I. and Dearman, R.J., Can animal models predict food allergenicity Nutr. Bull., 26, 127, 2001. 

ANIMAL MODELS IN FOOD ALLERGEN ANALYSIS AND INVESTIGATING THE MECHANISMS OF ALLERGY... 

Jenkins, J.A., Breiteneder, H., and Mills, E.N.C. 2007. Evolutionary distance from human homologs reflects allergenicity of animal food proteins. J Allergy Clin Immunol 120 1399-1405. 

For food allergens, validated animal models for dose-response assessment are not available and human studies (double-blind placebo-controlled food challenges [DBPCFCs]) are the standard way to establish thresholds. It is practically impossible to establish the real population thresholds this way. Such population threshold can be estimated, but this is associated with major statistical and other uncertainties of low dose-extrapolation and patient recruitment and selection. As a matter of fact, uncertainties are of such order of magnitude that a reliable estimate of population thresholds is currently not possible. The result of the dose-response assessment can also be described as a threshold distribution rather than a single population threshold. Such distribution can effectively be used in probabilistic modeling as a tool in quantitative risk assessment (see Section 15.2.5)... 

Chicken (Callus domesticus) eggs have been used as a nutrient source throughout human history. Egg is an inherent ingredient in human and animal food and is most difficult to exclude from the diet. Several studies have documented the major allergens in eggs (26-28). Egg white (albumin) is more allergenic than egg yolk. Egg yolk, which can be separated into two fractions by ultracentrifugation. 

Plants used to produce PRPs should be amenable to confinement . Isolation distances were increased, and the cultivation of food and feed crops following a PRP crop was discouraged. New hazard and exposure data for human and livestock health assessment may also be required from PRP-containing traditional food or feed crops prior to the approval of field trials. Exposure risk concerns the potential for PRPs to be present in human food or animal feed, and where exposure can occur, what mechanisms are used to limit biological activity. Hazards included direct toxicity and allergenicity in humans or animals as well as hazards presented by the coproduct streams that result from processing. These latter requirements could place a major burden on proponents to prove their materials are safe prior to even confined field trials. 

The approach to safety assessment recommended by IFBC/ILSI [70] was somewhat guarded about the potential utility of animal models and noted at that time that there were available no suitable methods. However, a somewhat different view was expressed in 2001 in the recommendations deriving from the FAO/WHO joint consultation [71]. In this case one of the conclusions reached was that animal models might contribute valuable information on the likely allergenicity of foods derived from GM crops. Although progress in the development of animal models appropriate for safety assessment predated the publication of the FAO/WHO recommendations, further momentum was provided for research in this area [4, 9, 87-98],... 

Danielle, nine years old when interviewed, enjoys playing the piano and recorder, and making colorful origami animals. Ordinarily even-tempered, Danielle experiences dramatic physical and emotional reactions from exposure to perfumes and other chemicals, and from eating certain foods containing additives and allergens. Her reactions include nosebleeds, muscle aches, headaches, crying spells and irritability. 

Naturally, plant ingredients are not the only source of food and drinks. Actually, in advanced developed countries, food from animal source is dominating where milk and meat represent the most concrete examples of drink and food, respectively. Nevertheless, the prevalence of specific applications, such as protein components useful for human health, stimulates the development of plant consumption. As a counterpart, plants also contain threatening protein components (toxins and allergens) that require attention for an improved food security therefore, there is a need of detecting low-abundance proteins (the deep proteome) from plant tissues as schematically illustrated in Figure 1. It is within this context that this chapter purposely limits the discussion to plant proteomics. The description about the situation of low-abundance animal-derived food proteomics has been made by the same authors in various other documents (3-6). 

Proteins being at the center of cellular metabolism and development, it is to be expected that they focus a lot of interest in food safety assessment. They actually could negatively impact on human or animal health if they comprise, for example, polypeptidic allergens, proteinaceous toxins, and antagonistic proteins such as special inhibitors. For all these compounds, genome analysis would not bring pertinent information contrary to an in-depth proteome investigation (73). 

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