Correlation of Probe-Based Confocal Laser Endomicroscopy (pCLE) and Mucosal Integrity Testing (MIT) with Epithelial Barrier Function and Presence of Gastroesophageal Reflux Disease (GERD).
INTRODUCTION
Epithelial barrier function (EBF) disruption is a key mechanism underlying gastroesophageal reflux disease (GERD). Our aim was to assess whether two novel technologies, probe-based confocal laser endomicroscopy (pCLE) and mucosal integrity testing (MIT), could assess EBF.


METHODS
We prospectively enrolled patients undergoing upper endoscopy for refractory GERD or non-GERD conditions. Patients underwent esophagogastroduodenoscopy, pCLE, MIT, esophageal biopsy at 2 cm and 6 cm above the esophagogastric junction, and wireless pH testing. To assess EBF in vitro, biopsies were mounted in a mini-Ussing chamber, 1 ml of fluorescein was instilled on the mucosal side, and concentration of fluorescein on the serosal side was measured at 3 h.


RESULTS
We enrolled 54 subjects (28 GERD, 26 non-GERD based on Lyon consensus criteria). In vivo permeability assessed by pCLE did not differ significantly between GERD vs. non-GERD patients and did not correlate with in vitro permeability. Mean MIT at 2 cm was lower in GERD compared to non-GERD (1914 vs. 3727 ohms). MIT correlated inversely with in vitro permeability at 2 cm and at 6 cm. Using a predictive model that used slope and intercept of MIT at 2 cm and 6 cm, sensitivity and specificity of MIT at identifying GERD was 76% and 72%, respectively.


CONCLUSION
pCLE did not differentiate GERD vs non-GERD and did not correlate with EBF measured in vitro. MIT, on the other hand, may be more promising as it differentiated GERD vs non-GERD and correlated with EBF measured in vitro.
['Mutha|Pritesh R|PR|http://orcid.org/0000-0002-7749-6097', 'Fasullo|Matthew|M|', 'Chu|Shijian|S|', 'Schubert|Mitchell L|ML|', 'Zfass|Alvin|A|', 'Cooper|Patricia|P|', 'Gill|Mankanchan|M|', 'Kang|Le|L|', 'Vaezi|Michael|M|', 'Wildhorn|Stu|S|', 'Slaughter|Chris|C|', 'Shah|Tilak|T|']
Gastroesophageal reflux Barrett esophagus Diagnostic technique, Digestive system Electric impedance Microscopy, Confocal