Immunohistochemical analysis of mucosal gamma-interferon production in coeliac disease

The role of gamma-interferon in the pathogenesis of enteropathies with an immunological basis such as coeliac disease, is unclear. Gamma-interferon immunoreactive lymphocytes were quantified in jejunal biopsies from patients with coeliac disease and from normal controls. In coeliac disease, there was an apparent decrease in the percentage of both intraepithelial (3.5% v 13.5%) and lamina propria (10.3% v 47.2%) lymphocytes expressing gamma-interferon compared with controls. In patients successfully treated with a gluten free diet, the percentage of gamma-interferon immunoreactive intra-epithelial lymphocytes was 10.3%. Intraepithelial lymphocytes were immunonegative for class II major histocompatibility complex, while epithelial cells showed increased expression of this product in coeliac disease. The results show that a relatively large proportion of lymphocytes in normal small bowel express gamma-interferon. They also indicate that in coeliac disease the major increase in the numbers of mucosal lymphocytes is the result of infiltration by lymphocytes not expressing gamma-interferon.