Expression of MUC5AC and Trefoil Peptide 1 (TFF1) in the Subtypes of Intestinal Metaplasia

Alterations of the expression pattern of mucins and trefoil peptides have been described in gastric adenocarcinomas and in their precursor lesions. The aim of this study was to determine the progression patterns of intestinal metaplasia (IM) subtypes by analyzing the expression patterns of TFF1 and MUC5AC in different subtypes of IM of the stomach. Endoscopic gastric biopsies of the antrum and body were obtained from patients with dyspepsia and endoscopic IM. Alcian blue/periodic acid-Schiff staining and the high iron diamine technique were used to classify the subtypes of IM. Immunoreactivity for MUC5AC and TFF1 was estimated in different types of IM. IM was detected in 128 samples from 80 patients; type I was found in 48 samples, type II was found in 37 samples, and type III was found in 43 samples. There was a gradual decrease in MUC5AC and TFF1 expression during the progression of IM from type I to type III via the type II intermediate. This downregulation of MUC5AC and TFF1 expression may challenge the sequential progression of IM from type I to type III via the type II intermediate, and it might be associated with gastric carcinogenesis.