Role Of Immunoglobulin G4 In Pediatric Eosinophilic Esophagitis: Clinical, Endoscopic And Pathological Study

Abstract

Background: New studies demonstrate increased oesophageal IgG4 in cases with eosinophilic esophagitis (EoE), proposing a potential IgG4-involved process. The role of IgG4 in pediatric EoE hasn't been widely studied.

Objective: To analyze IgG4 immunohistochemistry staining in oesophageal biopsy specimens of children with EoE in comparison to that of specimens from children with gastroesophageal reflux disease (GERD).

Patients and Methods: In this retrospective study we conducted immunohistochemical staining of IgG4 in oesophageal biopsies from 48 children: Newly diagnosed children with EoE (n = 24), children with reflux oesophagitis (n = 24).

 Results: IgG4 presented in higher numbers in plasma cells of eosinophilic esophagitis cases compared to children with GERD (p ≤0.001). Also, IgG4 number in esophageal epithelial cells was significantly higher in EoE cases versus children with GERD (p value≤0.001). Furthermore, there were significant differences regarding IgG4 reaction in extracellular spaces. 23 EoE cases stained positively for IgG4 in extracellular spaces with different intensities of staining (11 weak, 12 strong) whereas only 13 of GERD children stained positively for IgG4 (10 weak, 3 strong). 11 GERD children versus only 1 EoE child showed negative staining for IgG4 in extracellular spaces (p value 0.002).

Conclusions: our study implicates the potential role of IgG4 in esophageal biopsies in children with EoE at diagnosis. Further pediatric studies are needed to confirm this finding which may help to tailor EoE therapies in the future.