Fragments of e-Cadherin as Biomarkers of Non-erosive Reflux Disease.

Abstract

Approximately, 20% of patients with heartburn and normal endoscopic findings do not symptomatically improve on proton pump inhibitor (PPI) therapy making diagnosis and treatment uncertain. A biomarker distinguishing PPI-responsive from PPI-refractory heartburn is desirable. We performed a pilot study assessing whether carboxy(C)-terminal fragments (CTFs) of e-cadherin in esophageal biopsies or amino(N)-terminal fragments (NTFs) of e-cadherin in serum could serve this purpose. Twenty-nine patients with endoscopy-negative heartburn had esophageal biopsies for CTFs on Western blot and blood for serum NTFs on ELISA. All patients received dexlansoprazole 30mg daily for 4weeks, and heartburn was assessed by daily diary entry. Post-treatment blood samples were obtained for serum NTFs. A control group without GERD symptoms (n=6) had biopsies for CTFs and a second control group (n=20) blood serum for serum NTFs. Twenty-seven of 29 patients (93.1%) with endoscopy-negative heartburn, but 0 of 6 controls, were positive for CTFs. All patients and controls had measureable serum NTFs, but mean NTFs were significantly higher in those with PPI-responsive heartburn compared to those with PPI-refractory heartburn and controls. Following treatment, 24 of 29 (82.8) patients had relief of heartburn, which associated with a decline in mean NTFs compared to controls. NTFs in PPI-refractory patients (n=5) were similar to controls before and after PPI therapy. When heartburn responds to PPI, elevated serum NTFs decline to normal. These data suggest that cleaved products of e-cadherin may serve as biomarkers of NERD. Further data are needed to assess and confirm this concept.