Allergen immunotherapy shows promise for eosinophilic esophagitis

SAN ANTONIO — Allergen immunotherapy helped to relieve eosinophilic esophagitis symptoms and led to remission, according to results of a systematic review presented at the American Academy of Allergy, Asthma & Immunology Annual Meeting.

“Environmental allergens have been shown to trigger eosinophilic esophagitis (EoE); however, evidence of immunotherapy in achieving remission or relief of symptoms is limited,” Joshua Ang, DO, resident physician at Mountain Vista Medical Center, and colleagues wrote in their abstract.

Aimed at analyzing the effectiveness and safety of allergen immunotherapy for EoE, the researchers conducted a systematic review and synthesis of prior research spanning from 2007 to 2022. Researchers measured the efficacy of immunotherapy by eosinophil counts and reduction of dysphagia symptoms.

The review included three studies, one of which included a double-blind, randomized controlled trial featuring 20 children who received either epicutaneous immunotherapy (EPIT) or placebo.

Although there was no difference in the intent-to-treat population compared with the placebo group, 47% of patients in the per-protocol population treated with EPIT had less than 15 eosinophils per high powered field at the conclusion of the study.

Overall, researchers noted that symptoms appeared improved in the EPIT group compared with those receiving placebo. The placebo group also had one adverse event.

Meanwhile, an observational, longitudinal study involved targeted immunotherapy to certain environmental allergens for patients with EoE. Ang and colleagues found that at the end of follow-up, 75.2% of patients met the criteria for EoE discharge. Additionally, the immunotherapy group experienced no adverse events.

In the third study, a retrospective cohort study, researchers reported no significant differences between groups after allergen immunotherapy, as well as no adverse events.

The researchers concluded that although the results may be limited due to low study yield, they nonetheless support that immunotherapy could be beneficial in reducing EoE symptoms while helping patients reach remission.

Additionally, Ang and colleagues pointed out that allergen immunotherapy may be most useful for patients with EoE who experience seasonal exacerbations.