Fecal IgE Analyses Reveal a Role for Stratifying Peanut-Allergic Patients

Area of Science:

• Immunology
• Gastroenterology
• Microbiome Research

Background:

• Peanut allergy (PA) is an IgE-mediated food allergy with diverse clinical manifestations, frequently involving the gastrointestinal tract.
• The specific role of intestinal IgE in gastrointestinal PA symptoms remains poorly understood.
• This study investigated fecal IgE as a novel approach for patient endotyping in PA.

Purpose of the Study:

• To examine fecal IgE responses in children with peanut allergy.
• To explore the relationship between fecal IgE, gut microbiome, and clinical symptoms.
• To investigate potential mechanisms underlying gastrointestinal PA symptoms.

Main Methods:

• Collected fecal and serum samples from peanut-allergic and healthy children.
• Utilized multiplex assays to identify IgE and cytokines.
• Employed shotgun metagenomics DNA sequencing and allergen database comparisons to identify microbial peptides homologous to known allergens.

Main Results:

• Fecal IgE signatures in PA patients showed increased levels for 13 allergens, differing significantly from serum IgE patterns.
• Bacterial homologs with high identity to allergens were identified in the gut microbiome of PA patients.
• PA patients exhibited higher levels of fecal IgA, IL-22, and auto-IgE binding, with fecal IgE levels correlating with abdominal pain scores.

Conclusions:

• Fecal IgE release from the intestinal mucosa may contribute to severe abdominal pain in PA.
• This mechanism could involve leaky gut epithelia and anti-commensal T-helper 2 (TH2) responses.
• Fecal IgE analysis offers a novel approach for understanding and potentially endotyping PA.