Immunoglobulin G4 in eosinophilic esophagitis: Immune complex formation and correlation with disease activity.

Background: Recent studies have shown deposition of immunoglobulin G4 (IgG4) and food proteins in the esophageal mucosa of eosinophilic esophagitis (EoE) patients. Our aims were to assess whether co-localization of IgG4 and major cow's milk proteins (CMPs) was associated with EoE disease activity and to investigate the proteins enriched in proximity to IgG4 deposits.

Methods: This study included adult subjects with EoE (n = 13) and non-EoE controls (n = 5).