Nonepithelial Gene Expression Correlates With Symptom Severity in Adults With Eosinophilic Esophagitis

The mechanistic basis of the variable symptomatology seen in eosinophilic esophagitis (EoE) remains poorly understood.

We examined the correlation of a validated, patient-reported outcome metric with a broad spectrum of esophageal transcripts to uncover potential symptom pathogenesis.

We extracted data from 146 adults with EoE through the Consortium of Eosinophilic Gastrointestinal Disease Researchers. Patients were subgrouped by esophageal dilation history. We compared a validated patient-reported outcome metric, the EoE Activity Index (EEsAI), with a set of transcripts expressed in the esophagus of patients with EoE, the EoE Diagnostic Panel (EDP). We used single-cell RNA sequencing data to identify the cellular source of EEsAI-related EDP genes and further analyzed patients with mild and severe symptoms.

The EEsAI correlated with the EDP total score, especially in patients without recent esophageal dilation (r = -0.31; P = .003). We identified 14 EDP genes that correlated with EEsAI scores (r ≥ 0.3; P < .05). Of these, 11 were expressed in nonepithelial cells and three in epithelial cells. During histologic remission, only four of 11 nonepithelial genes (36%) versus all three epithelial genes (100%) had decreased expression to less than 50% of that in active EoE. Fibroblasts expressed five of 11 nonepithelial EEsAI-associated EDP genes (45%). A subset of nonepithelial genes (eight of 11; 73%), but not EoE-representative genes (none of four; 0%; CCL26, CAPN14, DSG1, and SPINK7), was upregulated in patients with EoE with the highest versus lowest symptom burden.

The correlation of symptoms and nonepithelial esophageal gene expression substantiates that nonepithelial cells (eg, fibroblasts) likely contribute to symptom severity.