Gene Expression Profiling of Inflammatory Cytokines in Esophageal Biopsies of Different Phenotypes of Gastroesophageal Reflux Disease: a cross-sectional study

Background: Patients clinical phenotypes in gastroesophageal reflux disease (GERD) are classified as: Barrett's esophagus (BE), erosive esophagitis (EE) and non-erosive gastroesophageal reflux disease (NERD). The aim of this study was to characterize genes involved in the pathophysiology and immune response of GERD.Methods: This is an observational and cross-sectional study. All patients with BE, EE, NERD and the control group were subjected to a superior endoscopy (with biopsies of esophageal mucosa). The cytokine mRNA relative quantification of target genes was conducted by RT-PCR. Changes in gene expression were assessed of the genes associated with inflammation in each disease phenotype. Statistical analysis of differential gene expression was performed by using Dunn's Test for Multiple Comparisons. A p value < 0.05 was considered as significant. Results: A Total of 98 patients were included and they were divided into the following groups: Group BE 16 (16.33%), Group EE 23 (23.47%), Group NERD 42 (42.86%) and Control Group 17 (17.35%). When comparing with control group we found: patients with BE showed an increased expression of IL-8 (P<0.005) and higher levels of: IL-1β, NF-κβ, IL-10 and MMP-3, MMP-9 as well; patients with EE had higher levels of IL-1B, IL-6, IL-8 and IL-10 (P<0.005) and patients with NERD showed a differential gene expression of cytokines Th1, particularly TNF-α and IL-1B (P<0.005) and decreased gene expression of Th2 cytokines such as IL-10, IL-8 and MMP9. Conclusions: This study demonstrates the differential expression of mediators of inflammation in the esophageal mucosa of patients with the EE and BE phenotype.