Abstract:Objective To investigate the expression of 8-hydroxy-2′ deoxyguanosine (8-OHdG) and inflammatory cytokines in esophageal mucosa of patients with gastroesophageal reflux disease (GERD) complicated with atrial fibrillation (AF) and their significance in the development of AF. Methods According to the inclusion and exclusion criteria,67 patients with GERD hospitalized in Xinjiang Uygur Autonomous Region People′s Hospital from January 2017 to November 2018 were selected as research group,and 23 healthy subjects were served as control group at the same time.All patients were given 24-hour dynamic electrocardiogram,24-hour pH monitoring,high-resolution esophageal manometry(HRM)monitoring,meanwhile endoscopy was performed to take the local mucosa at 3 cm of the dentate line of the esophagus as specimens.Using HE staining,immunohistochemistry,RT-PCR and ELISA,the degree of tissue inflammation,the expressions of 8-OHdG and inflammatory factors ［monocyte chemoattractant protein-1(MCP-1),interleukin-8(IL-8),tumor necrosis factor-α(TNF-α)］ and their concentrations in blood were analyzed. Results Based on the clinical examinations,the patients in research group were subdivided into AF group (GERD combined with AF) and non-AF group (GERD without AF).24 h pH monitoring showed that the numbers of weak acid reflux (4P<0.05).There were no significant differences in HRM monitoring among three groups (all P>0.05).Light microscopy showed that the mucosa was basically intact without edema or neutrophil infiltration in control group;moderate neutrophil infiltration and inflammatory reaction were observed in non-AF group;inflammatory pathological changes of infiltration of neutrophils,eosinophils and other immune cells in different degrees,prolongation of papillae and edema were observed in AF group.The inflammatory score in AF group was significantly higher than that in non-AF group (P<0.01).Immunohistochemistry showed that 8-OHdG expression in control group was mainly localized in the esophageal epithelium,mucosa and submucosa,while 8-OHdG expression in AF group almost covered the whole mucosa,indicating severe tissue oxidative damage in AF patients.RT-PCR and ELISA showed that the relative mRNA expression levels of 8-OHdG,MCP-1,IL-8 and TNF-α and their concentrations in serum increased significantly in non-AF group and AF group(peak in AF group)compared with the control group(all P<0.01).Pearson correlation analysis showed that the serum concentration of 8-OHdG was positively correlated with Demeester score and serum MCP-1,IL-8,TNF-α levels in AF group (P<0.01). Conclusion The expression of 8-OHdG and inflammatory factors (MCP-1,IL-8,TNF-α) and the concentration of blood in the esophageal mucosa of GERD complicated with AF patients were significantly increased,which may be closely related to the occurrence of AF induced by acid reflux.