been proposed to identify NOAELs for various food allergens, but few publicly available, peer-reviewed data of this nature are available at this time.
The specific criteria used to evaluate food challenge studies are shown in Table IV-4, and applied in Appendix 2.
Table IV-4. Specific Criteria for Evaluating Allergen Oral Challenge Studies
1. Has the study been published in a peer-
Published, peer-reviewed studies are
preferred although unpublished studies may be considered.
This information is needed to evaluate how the study results apply to at-risk populations (i.e., was the tested population allergic to the tested food?). This information is needed to determine the amount of allergenic protein in the test material. This information is needed to determine a NOAEL or LOAEL. This information is not needed for a safety assessment, but is needed for a risk assessment.
NOAELs and LOAELs cannot be determined in studies in which reactions occurred at the lowest dose tested. Objective reactions are preferred for both safety and risk assessments. This information is needed for a risk assessment.
7. Were the allergic reactions observed clearly described? 8. Were the data sufficient to describe the dose-response pattern for the population tested (e.g. for determining a cumulative dose- response curve)?
4. Was the lowest tested dose of allergen described, or can it be calculated? 5. Were the total number and progression of dose levels described, or can they be calculated? (i.e., can the entire dose series be explicitly determined?) 6. Did some of the test population respond to the lowest dose?
2. Were the criteria for selecting the test population clearly and completely described, and are they appropriate?
3. Was the test material clearly and completely described?
e. Differences Among Food Allergens. Allergens differ widely both in their potential to elicit allergic reactions and in the severity of these reactions. The simplest approach to dealing with these differences would be to establish a single threshold based on sensitivities to the most potent allergens. This threshold is likely to be unduly restrictive for many allergic consumers. Alternatively, separate thresholds could be established for each food allergen. However, the data needed for the separate threshold approach are not available for many allergens. The Threshold Working Group concluded that, to the extent possible, each food allergen should be treated independently but that a single threshold should be established if independent treatment is not possible. If a single threshold is established, it could be based on the allergenic food that elicits an allergenic reaction at the lowest total protein level.
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