The following is a summary of “Impact of using less objective symptoms to define tolerated dose during food challenges: A data-driven approach,” published in the JULY 2023 issue of Allergy & Immunology by Turner, et al.

Food challenges (FCs) are crucial in assessing efficacy outcomes in food allergy intervention studies. However, various criteria have been used to define a challenge reaction, leading to differences in their interpretation. Some criteria include subjective (nonobjective) symptoms from a single organ system as dose-limiting. For a secondary analysis, researchers sought to evaluate the impact of using less objective criteria to determine challenge-stop on reaction thresholds and their reproducibility in food allergy intervention studies.

Data from four interventional studies involving 592 participants were analyzed using three different challenge-stop criteria: PRACTALL consensus criteria; Consortium for Food Allergy Research version 3 (CoFAR v3) with at least one moderate- or severe-grade symptom; or CoFAR v3 with at least two mild symptoms occurring in different organ systems. The reproducibility of challenge thresholds was also assessed in participants undergoing subsequent repeat food challenges.

Applying CoFAR v3 definitions for dose-limiting symptoms resulted in underestimating reaction thresholds compared to PRACTALL criteria (P < .001), equivalent to almost a single dosing increment using a semi-log dosing regimen. When using CoFAR v3, reproducibility was similarly lowered (P <.001 [n = 223]). The least conservative interpretation of CoFAR v3 (2 minor symptoms occurring in distinct systems) led to a 15% overestimate when determining the effectiveness of oral immunotherapy. Significant gastrointestinal discomfort with apparent decreased activity continues to be a dose-limiting symptom, and a data-driven small update to CoFAR v3 produced a new set of challenge-stop criteria with similar validity to PRACTALL but easier to apply. 

Using less objective symptoms to define challenge-stop compromises the reproducibility of food challenges as a tool to assess efficacy outcomes in intervention studies and may overestimate the intervention’s efficacy. Researchers should consider using more standardized and objective criteria in food challenges for more accurate and reliable results.

Source: jacionline.org/article/S0091-6749(22)02591-X/fulltext