IGHE and eosinophilic esophagitis: However, in 2010 the ImmunoCAP assay was adapted by Phadia to assay specific IgG4 antibodies using the same allergen caps that are used for the IgE assays: This is the same IgG4 assay that we used for measuring specific IgG4 antibodies to milk and wheat proteins in sera from patients with Eosinophilic Esophagitis (31, 37).