Abstract: Gastroesophageal reflux disease (GERD) is a group of diseases caused by reflux of gastric contents, no single biomarker can reflect the whole spectrum of disease. GERD biomarkers are valuable for the diagnosis of esophageal disease without abnormal endoscopic and conventional pH impedance monitoring. Histopathological markers,baseline impedance and serological tests (reflecting esophageal mucosal integrity), quantifying the degree of mucosal integrity impairment of the baseline mucosal impedance, reflecting the proteolytic fragments of connexins have become a promising group of GERD biomarkers.

Key words: gastroesophageal reflux, cell adhesion molecules, immunohistochemistry