Immunohistochemical detection of gastric mucin in normal and disease states

At least seven human mucin genes have been described, which express glycopr oteins MUC1-7 in various tissues. It has been shown that different mucins a re expressed in various gastric disease states compared to the normal. In t his study we used histochemical and immunohistochemical methods to determin e the type and pattern of mucin in 54 patients with a variety of gastric co nditions [i.e., normal controls, fetal stomachs, gastritis, low-grade dyspl asia, intestinal metaplasia (associated with gastritis, benign ulcers, dysp lasia, and cancer), early and advanced intestinal type adenocarcinoma, and diffuse adenocarcinoma]. We report for the first time the use of all seven MUC antibodies in the various conditions. Normal controls were immunoreacti ve for MUC4, 5, and 6, and gastritis specimens showed similar results, alth ough the latter showed more MUC1 immunoreactivity. Whereas early fetal stom ach showed no MUC immunoreactivity, MUC4, 5, and 6 were present from the ea rly second trimester onwards. There was no significant difference between d ysplasia and intestinal metaplasia, both categories showing the presence of MUC2 and 3 predominantly. Early intestinal type adenocarcinomas did not sh ow any mucins in the majority of cases. Advanced intestinal type adenocarci nomas showed immunoreactivity predominantly for MUC1, 5, and 6, as well as MUC2 in some cases. Diffuse adenocarcinomas showed strong positive MUC2 and 6 staining, and in some cases MUC5 and 7. In conclusion, we have shown dif ferent patterns of mucin immunoreactivity in various gastric disease states . Specimens with dysplasia, intestinal metaplasia, late intestinal type ade nocarcinoma, and diffuse gastric cancer were characterized by increased div ersity of mucin types, whereas early intestinal cancer showed loss of mucin immunoreactivity.