Onset of eosinophilic esophagitis during a clinical trial program of oral immunotherapy for peanut allergy

In this analysis of the PTAH clinical trial program, the overall incidence of EoE was approximately 1%, which is lower than previously reported rates of EoE with OIT for food allergies (2.7% in a meta-analysis and 5.1% in a recent retrospective review).1,6 The etiology of EoE pathogenesis in the cases reported in the PTAH clinical trial program is not definitively known, but may include EoE present and not diagnosed before OIT, EoE pre-existing but subclinical and exacerbated by OIT, or EoE triggered de novo by OIT. In a recent longitudinal placebo-controlled study examining serial endoscopic biopsies during peanut OIT, all the peanut-allergic participants had signs of epithelial barrier dysfunction at baseline and in some cases esophageal eosinophilia.8 The study demonstrated that most OIT-associated esophageal eosinophilia resolves during maintenance OIT and is not associated with clinical symptoms. Because the majority of participants in the PTAH clinical trials stopped the study drug around the time of EoE diagnosis, it is not known whether the eosinophilic infiltrate would have resolved with continued dosing. [...]the rate of developing EoE with PTAH in this clinical trial program was approximately 1%, not including the 5% of participants who discontinued PTAH treatment because of GI adverse events that were not further evaluated. Relevant medical history PTAH dose at EoE diagnosis (mg) Total exposure to PTAH (d) Symptoms Severity∗ Initial esophageal biopsy results Repeat esophageal biopsy results† Treatment Relatedness to PTAH∗ At first GI symptom onset At EoE diagnosis 1 12 58 58 Intermittent vomiting, abdominal pain, sore throat Mild EoE with peak eosinophil count of 92 eos/hpf Biopsy performed—results NA‡ Esomeprazole for vomiting; swallowed fluticasone after EoE diagnosis, elimination diet Related 2 Gastroesophageal reflux during infancy and chronic regurgitation 950§ 58 428 Frequent regurgitating/spitting up, gastric reflux Moderate The peak eosinophil count was 32 eos/hpf in the distal esophagus, 7 eos/hpf in the mid-esophagus, and up to 61 eos/hpf in the proximal esophagus NR Ranitidine, omeprazole, lansoprazole Related 3 Gastroesophageal reflux; recurrent nausea and cough 200 30 176 Gastroesophageal reflux,