IGHE and immunoglobulin G4-related sclerosing disease: Subsequent retrospective studies reported an elevated IgE in 34%–86% of patients with AIP.2, 3 In our prospective study of IgG4-RD, an elevated IgE was found in 57% at diagnosis, and a positive correlation was shown between IgE and both IgG4 and eosinophils count.