Abstract

The purpose of this study is to evaluate the change of mucosal immunity in gastric diseases. A quantative analysis of IgA and secretory component(SC) in gastric diseases by immunohistochemical method was performed in 110 specimens. The results are as follows: 1) In normal gastric mucosa, all of 10 cases revealed a negative reaction to antihuman SC but 4 cases were positive for IgA. 2) In chronic superficial gastritis and chronic atrophic gastritis with intestinal metaplasia, the metaplastic cells except for the goblet cells were positive for both IgA and SC. 3) The dysplastic cells were also positive for both IgA and SC, and the regenerating cells in ulcer as well. 4) All of the well differentiated or moderately well differentiated adenocarcinomas showed positive reactions to antihuman IgA and antihuman SC, and the intensity appeared to be stronger in the former. However, among 10 cases of poorly differentiated adenocarcinoma SC was not demonstrated in 5 cases, and no IgA was present in one case. In 10 cases of signet ring cell carcinoma, 6 cases revealed a negative reaction to antihuman IgA and 6 cases to antihuman SC. The above results suggest that the secretory immunity is not essential in normal gastric mucosa. The intestinal metaplasia in chronic gastritis is considered as an adaptive response to chronic inflammation. The degree of differentiation in adenocarcinoma may be related to the mucosal immunity.

• Keywords: IgA;Secretory component;Mucosal immunity;