Evaluation of Functional T-Cell Assays That Predict Causal Allergens in Eosinophilic Esophagitis

Background: Eosinophilic esophagitis (EoE) is a chronic, food antigen-driven disease of the esophagus that causes considerable morbidity. Elimination of allergenic foods from a patient's diet is a highly effective treatment. However, existing allergen testing modalities are not effective at identifying EoE-causal foods. We sought to determine the extent to which positive results for two functional T-cell assays, the EoE Milk Test and EoE Soy Test, associated with the clinical outcomes of EoE milk allergy and EoE soy allergy, respectively. Methods: Subjects were enrolled into one of two study designs: a prospective observational study or a retrospective case/control study. Additional control samples were obtained from an institutional core. The EoE Milk and Soy Tests were performed on peripheral blood samples, and the association between positive tests and clinical outcomes was determined using Receiver Operating Characteristic curves and other performance measures. Results: The EoE Milk Test maintained reliability regardless of disease activity or recent milk consumption and had 87% sensitivity and 83% specificity for EoE milk allergy in all study subjects (control and EoE). The EoE Soy Test had 90% sensitivity and 93% specificity in all subjects. Conclusions: Our evaluation of the EoE Milk and Soy Tests demonstrates that these functional T-cell assays hold promise as a predictive tool for identifying causal allergens in eosinophilic esophagitis patients.