Comparison of gene expression profiles in eosinophilic esophagitis (EoE) between Japan and Western countries

Background: The prevalence rate of eosinophilic esophagitis (EoE) between Japan and Western countries is quite different. Although multiple factors, including the genetic background, lifestyle and dietary habits, may account for the difference, the pathogenic mechanism of EoE has not been fully clarified in Japanese. To elucidate whether EoE's pathogenic mechanisms differ between those populations, we performed transcriptome analysis of esophageal biopsy specimens from Japanese EoE patients and compared the identified gene signatures with published microarray data for EoE patients in the US.

Methods: We prospectively enrolled adult Japanese EoE patients (n = 4) according to the 2011 consensus guidelines for diagnosis of EoE. Age-matched healthy volunteer subjects (n = 4) were also enrolled as controls. We assessed the gene expression profiles of esophageal biopsies using microarray technology and then compared the identified gene signatures with earlier data generated in the US.

Results: Of 42,545 transcripts represented on the microarray, 385 were differentially expressed between the EoE and control samples (≥2 fold change and adjusted p-value of <0.05). Our microarray data showed strong overlapping with the data from US patients with EoE. An EoE-specific-transcript signature is typically composed of IL-13-inducible and eosinophil-related genes, including eotaxin-3/C-C chemokine ligand 26 (CCL26).

Conclusions: This transcriptome study suggests that the pathogenetic mechanisms of EoE in Japan and Western countries are similar. Our findings may contribute to a better understanding of the pathogenesis of EoE and to more accurate diagnosis of this disease in Japanese individuals.