Researchers Identify Food Allergen Linked to Eosinophilic Esophagitis

A study led by researchers at Children’s Hospital of Philadelphia (CHOP) has identified a specific food allergen responsible for eosinophilic esophagitis (EoE), an inflammatory condition of the esophagus. This research, published in the Journal of Allergy and Clinical Immunology, marks the first time that a food allergen associated with EoE has been identified at the molecular level. The findings may contribute to improved diagnostic methods and further research into other allergens linked to this condition.

EoE, first recognized approximately 30 years ago, affects about one in every 2,000 children. Unlike some food allergies that children may outgrow, EoE persists into adulthood. The condition can be triggered by various foods, including milk, soy, eggs, and wheat, with different triggers varying among individuals. Without proper management, EoE can lead to esophageal scarring and food impaction, where food becomes trapped in the esophagus. Current treatments include dietary adjustments and immunosuppressive medications, though these approaches are not always effective.

The research team, led by Dr. David A. Hill of CHOP’s Division of Allergy and Immunology, sought to understand how the immune system recognizes food antigens. Using advanced sequencing techniques, including single-cell RNA sequencing, T-cell receptor sequencing, and tetramer-based diagnostics, the researchers identified the specific milk protein, β-casein AA 59-78, as a trigger for EoE in one patient. Tetramer-based diagnostics, traditionally used in cancer research, allowed the team to pinpoint antigen-specific T cells responsible for the allergic response.

Although the study focused on a single patient, the approach provides a framework for identifying other food allergens associated with EoE. Researchers aim to expand the study to examine additional food triggers, with the goal of developing more accurate diagnostic tools and treatment strategies for individuals with EoE.

The study was supported by several research grants and organizations, including the American Partnership for Eosinophilic Disorders, the Food Allergy Fund, The Hartwell Foundation, and the Children’s Hospital of Philadelphia Endowed Chair in Genomic Research.