SUBCUTANEOUS IMMUNOTHERAPY – A DOUBLE-EDGED SWORD IN EOSINOPHILIC ESOPHAGITIS? A SYSTEMATIC LITERATURE REVIEW

Introduction

Eosinophilic esophagitis (EoE) is marked by histological eosinophilic infiltration and may have concurrent aero-allergen sensitization. While evidence suggests oral and sublingual immunotherapy (SLIT) may instigate EoE, data on subcutaneous immunotherapy (SCIT) is lacking.

Methods

A literature review of PubMed, Science Direct, and Embase was conducted in May 2024 for unique case reports, controlled clinical trials, and observational studies regarding SCIT in EoE patients with endoscopic or clinical follow-up.

Results

From an initial 152 results, nine studies were relevant: four retrospective cohorts, three case reports, one longitudinal-observational study, and one prospective cohort. The four retrospective cohorts showed histologic improvement post-SCIT-treatment compared with initial endoscopy. Fewer topical steroids were required post-SCIT compared to controls. Two cases described improvement in EoE symptoms after achieving maintenance phase and in one case showed complete clinical and histologic remission. The remaining case report described recurrence of EoE with SCIT; however, this was after initial use and cessation of SLIT. The observational study assessed patients given either SCIT or SLIT who had positive IgE to grass or wheat while following dietary recommendations and were monitored for three years with endoscopy and clinical follow-up clinical follow-up; these patients had reduced steroid-use. The prospective cohort assessed 39 EoE patients for two years treated with SCIT and elimination diet who had allergies to group 1 grasses and lipid transfer proteins (hazelnut, walnut, mugwort, peach), showing clinical EoE improvement at two-years.

Conclusion

Significant subjective and histologic improvement in coexisting allergy and EoE is documented in the evaluated reports; SCIT requires further consideration in EoE patients.