Total epithelial thickness is a robust histologic marker that can be used in detection of gastroesophageal reflux disease (GERD), researchers report in the November issue of Clinical Gastroenterology and Hepatology.
GERD can be a challenge to diagnose because its symptoms overlap with those of other disorders. Endoscopy and esophageal pH monitoring detect GERD with limited levels of sensitivity—there is no standard diagnostic test. Simple tests are needed that increase the accuracy of GERD detection and are suitable for routine clinical practice—especially for patients with reflux disease who do not have visible esophageal erosions or ulcerations, and in settings in which pH monitoring is not widely available.
There are some systems for grading histologic parameters of the distal esophageal mucosa in individuals with GERD, but the diagnostic utility of these has not been established. Furthermore, the correlation of histologic criteria with clinical variables, such as esophageal acid exposure and reflux esophagitis, has not been systematically assessed.
Michael Vieth et al aimed to evaluate the accuracy of these criteria for the diagnosis of GERD, using endoscopy and pH monitoring as the standard. They also investigated inter-assessor agreement on histologic criteria, using a well-characterized primary care population with troublesome upper gastrointestinal symptoms.
Vieth et al performed a post hoc analysis of data from a clinical trial conducted in Europe and Canada on adults with frequent upper gastrointestinal symptoms who had not been treated with a proton pump inhibitor in the previous 2 months. Biopsies collected from 336 patients from 0.5 cm and 2.0 cm above the Z line were analyzed independently at separate pathology centers.
The authors found total epithelial thickness to be the best criterion for diagnosis of GERD; this also identified patients with nonerosive reflux disease, reflux esophagitis, and pathologic esophageal acid exposure at 0.5 cm and 2.0 cm above the Z line (see figure).
Basal cell layer thickness and presence of dilated intercellular spaces did not identify patients with GERD. Among the criteria tested, the best agreement between assessments carried out at the 2 pathology centers was for total epithelial thickness at 0.5 cm and 2.0 cm above the Z line.
Papillary length could identify patients with GERD in the overall population, more than half of whom had reflux esophagitis, but it did not predict the presence of reflux disease in the subgroup without endoscopically recognizable esophagitis.
The authors conclude that epithelial thickness of the distal esophageal mucosa is the most robust histologic marker for not the entire group of patients with investigation-defined GERD, but also for patients with nonerosive reflux disease, which is the important diagnostic challenge.
Vieth et al state that these findings are promising for clinical practice because, provided that the gastroesophageal junction is accurately identified, they suggest that evaluation of 1 easily assessed and standardized histologic marker can increase recognition of GERD when endoscopy shows no erosions. This measure may also be useful when pH testing is not available.
The authors state that the success of total epithelial thickness on its own as a predictor for GERD and its subgroups indicates the potential for this parameter to be incorporated as an additional or alternative marker in endoscopic biopsy assessments in clinical practice.