A 40-year-old man with a history of gastroesophageal reflux disease (GERD) undergoes esophageal sampling for Barrett esophagus (BE). An increase in the presence of which biomarker would indicate the presence of this condition?A. Trefoil factor 1 (TFF1)
Correct Answer: D
BE is defined as intestinal metaplasia from squamous to columnar epithelium and is a risk factor for the development of EA. However, the majority of EA occurs de novo, and the prevalence of BE is reported to be between 1% and 8% calling into question the cost-effectiveness of routine endoscopy screening programs. Consequently, nonendoscopic methods for screening are also being employed. One method uses a device called a capsule sponge combined with an immunohistochemical biomarker (TFF3). The patient ingests the capsule that is attached to a string and contains a compressed mesh. The mesh is exposed when the gelatin capsule dissolves in the stomach. The mesh is then withdrawn through the esophagus where it collects samples of the cells lining the esophageal lumen. The biomarker is then used to differentiate Barrett epithelial cells from gastric columnar and esophageal squamous cells. An increase in the biomarker trefoil factor indicates an increase in columnar epithelium with intestinal metaplasia compared to normal esophagus. The expression of the biomarkers TFF1, FBP1, FMO5, and FOXA3 is increased in BE, but the levels are similar to those observed in the gastric mucosa.