S394 Esophageal Cytology Collection Device for Assessment of Esophageal Eosinophilia in Eosinophilic Esophagitis: Real World Experience

Abstract

Introduction: Eosinophilic esophagitis (EoE) is a chronic condition characterized by symptoms of esophageal dysfunction and tissue eosinophilia. One barrier to clinical care in EoE is the need for repeat upper endoscopy (EGD) with biopsies to assess for tissue esophageal eosinophilia. A non-endoscopic esophageal cytology collection device (CytospongeTM) may be a viable alternative to assess for esophageal eosinophilia, but few studies have examined its use in EoE. Methods: We first performed a pilot study in which individuals with confirmed EoE underwent CytospongeTM procedure prior to a clinically-indicated EGD. The cytology results were compared to histology obtained via EGD (gold standard). Cytology and histology from mucosal biopsies were classified as active disease (≥1 eos/hpf cytology; ≥15 eos/hpf, respectively) or remission (0 eos/hpf; < 15 eos/hpf, respectively). The eosinophil-associated protein, eosinophil-derived neurotoxin (EDN) was assayed in the supernatant using ELISAs. We subsequently used the CytospongeTM to assess for mucosal eosinophils, in place of standard EGD with biopsy, in a subset of patients for clinical care. Results: For the pilot study, 7 patients (ages 20-53; 57% males) underwent the CytospongeTM procedure 1 hour prior to EGD. When using a cut-off of 1 eos/hpf on cytology, there was 100% concordance between the CytospongeTM cytology and esophageal biopsies for identifying active EoE and remission (3 active, 4 remission). There was also a trend towards higher concentrations of EDN in the CytospongeTM supernatant of active EoE (median 34.11 ng/mL) versus remission (median 9.5 ng/mL, p=0.057). Between September 2020 and May 2022, 15 CytospongeTM procedures were performed for clinical care (9 patients; ages 30-61; 56% male). Eight patients were undergoing food elimination diets and one was undergoing surveillance after sustained deep remission. No eosinophilia was seen in 10/15 cytology specimens and 5/15 had eosinophilia (range 1-15 eos)(Table). One patient underwent EGD shortly after CytospongeTM (1 eos on cytology), which demonstrated 10-30 eos/hpf on mucosal biopsy. The CytospongeTM procedure was well-tolerated with no significant adverse events. (Figure) Conclusion: The CytospongeTM is a novel mucosal assessment tool that is easily performed and correlates well with gold standard esophageal biopsies in EoE. It should be considered for use in eosinophilic esophagitis to avoid numerous EGD procedures.Figure 1.: a) Esophageal cytology collection device (CytospongeTM), b) Histology from standard esophageal biopsy, c) Cytology from CytospongeTM (same patient as b). Arrows point to eosinophils. Note: images previously published in McGowan EC, Aceves SS, CME Review: Noninvasive tests for eosinophilic esophagitis: Ready for use?. Ann Allergy Asthma Immunol 129 (2022); 27-34. Table 1. - Esophageal Cytology Collection Device (CytospongeTM) Results in Clinical Use Patient Age/Sex Current Treatment CytospongeTM Results Interpretation 1 61M Food Elimination Diet - reintroduced soy 0 eos/hpf Soy is not a trigger 2 50F Food Elimination Diet - reintroduced dairy 2 eos/hpf Dairy is a trigger 3a 30F Food elimination diet - reintroduced soy 0 eos/hpf Soy is not a trigger 3b Food elimination diet - reintroduced egg 0 eos/hpf Egg is not a trigger 3c Food elimination diet - reintroduced wheat 0 eos/hpf Wheat is not a trigger 4 44F Food elimination diet - four food elimination (4FED) 3 eos/hpf Not in remission on 4FED 5a 40F Food elimination diet - reintroduced wheat 0 eos/hpf Wheat is not a trigger 5b Food elimination diet - reintroduced dairy 1 eos/hpf Dairy is a trigger 6a 32M Food elimination diet - two food elimination (2FED) 0 eos/hpf Remission on 2FED Food elimination diet - reintroduced wheat 0 eos/hpf Wheat is not a trigger 7a 43M Food elimination diet - reintroduced fish 0 eos/hpf Fish is not a trigger Food elimination diet - reintroduced soy 0 eos/hpf Soy is not a trigger 8a 39M Food elimination diet - two food elimination (2FED) 6 eos/hpf Not in remission on 2FED Food elimination diet - four food elimination (4FED) 15 eos/hpf Not in remission on 4FED 9 36M Swallowed steroids twice daily and PPI 0 eos/hpf Maintenance of remission