Abstract Objective: To assess intra- and interobserver agreement among non-expert pathologists in identifying features of the eosinophilic esophagitis histologic scoring system (EoEHSS) in pediatric patients. Patients and methods: The authors used 50 slides from patients (aged 1-15 years; 72% male) with EoE. EoEHSS evaluates eosinophilic inflammation and other features including epithelial basal zone hyperplasia, eosinophilic abscesses, eosinophil surface layering, dilated intercellular spaces, surface epithelial alteration, dyskeratotic epithelial cells, and lamina propria fibrosis. Grade and stage of abnormalities are scored using a 4-point scale (0 normal; 3 maximum change). Four pathologists determined EoEHSS findings on two occasions. Intra- and interobserver agreement was assessed using Kappa (κ) statistics and intra-class correlation coefficients. Results: Intra- and interobserver agreement for the identification of eosinophil counts ≥ 15/high power field (HPF) was excellent, however varied when assessing additional features of the EoEHSS. For the more experienced pathologist, agreement for most EoEHSS items and the composite scores was substantial to excellent. For the less experienced pathologists, intraobserver agreement ranged from absent to substantial for individual features and ranged from moderate to substantial for the composite scores. Conclusion: Most items of the EoEHSS had substantial to excellent reliability when assessed by a pathologist experienced in the diagnosis of EoE but presented lower repeatability among less experienced pathologists. These findings suggest that specific training of pathologists is required for the identification of EoEHSS characteristics beyond eosinophil count, as these features are considered useful in the evaluation of response to treatment and correlation with clinical manifestations and endoscopic findings.

Resumo Objetivo: Comparar características endoscópicas e histológicas entre pacientes com esofagite eosinofílica responsiva (EoERIBP) e não responsiva (EoENRIBP) ao tratamento com inibidores de bomba de prótons. Métodos: Avaliados laudos e imagens endoscópicas de pacientes com sintomas de disfunção esofágica associados a contagem ≥ 15 eosinófilos por campo de grande aumento (eos/CGA) em biópsia do esôfago. Os pacientes foram classificados em responsivos (EoERIBP) ou não responsivos (EoENRIBP) aos inibidores de bomba de prótons conforme resposta ao tratamento na segunda endoscopia (< 15 eos/CGA) após 8 semanas. Resultados: Dos 231 pacientes (72,3% masculino), 64 (27,7%) foram responsivos aos inibidores de bomba de prótons. Edema (77,3% vs. 62,5%, p = 0,031) e linhas verticais (69,5% vs. 51,6%, p = 0,014) foram mais frequentes nos EoENRIBP. A contagem de eosinófilos em esôfago médio ≥ 35 eos/CGA (25,1% vs. 12,5%) foi mais frequente nesses pacientes (p = 0,001). Os que apresentaram contagem de eosinófilos < 15 eos/CGA no esôfago médio à primeira endoscopia apresentaram maior chance de responder ao tratamento com inibidores de bomba de prótons em comparação aos pacientes com 15-34 eos/CGA (p = 0,004; OR: 3,26; IC95%: 1,46-7,24) e aos pacientes com ≥ 35 eos/CGA (p = 0,006; OR: 3,20; IC95%: 1,39-7,41). Conclusão: Edema e linhas verticais à endoscopia e maior contagem de eosinófilos em esôfago médio foram mais frequentes nos pacientes não responsivos aos inibidores de bomba de prótons. Uma vez que não houve diferenças significativas nos outros achados entre os grupos, não se pode afirmar que essas características sejam suficientes para distinguir pacientes com EoENRIBP dos pacientes com EoERIBP.

Abstract Objective: To compare endoscopic and histologic features of pediatric patients with eosinophilic esophagitis (EoE) responding to proton pump inhibitor (PPI) to those not responding to PPI. Methods: Endoscopic reports and photographs of patients with symptoms of esophageal dysfunction and ≥15 eosinophils per high-powered field (eos/hpf) in esophageal biopsies prior to PPI trial were reviewed. Patients were classified as responsive to PPI (PPIREoE) or non-responsive to PPI (PPINREoE) according to response totreatment (<15 eos/hpf) at second endoscopy after 8 weeks. Results: Of the 231 patients (72.3% male), 64 (27.7%) were responsive to the proton pump inhibitors. Edema (77.3% vs. 62.5%, p = 0.031) and vertical lines (69.5% vs. 51.6%, p = 0.014) were more frequent in PPINREoE patients. An eosinophil count in the mid-esophagus ≥ 35 eos/HPF (25.1% vs. 12.5%) was more frequent in these patients (p = 0.001). Those with eosinophil count < 15 eos/HPF in the mid-esophagus at the first endoscopy were more likely to respond to treatment with proton pump inhibitors compared to patients with 15-34 eos/HPF (p = 0.004, OR: 3.26, 95% CI: 1.46-7.24) and to patients with ≥ 35 eos/HPF (p = 0.006, OR: 3.20, 95% CI: 1.39-7.41). Conclusion: Edema and vertical lines at the endoscopy and a higher eosinophil count in the mid-esophagus were more frequent in patients who were non-responsive to proton pump inhibitors. As there were no significant differences in the other findings between the groups, it cannot be affirmed that these characteristics are sufficient to differentiate between PPINREoE and PPIREoE patients.