MORPHOMETRIC ANALYSIS OF INTESTINAL-MUCOSA .5. QUANTITATIVE HISTOLOGICAL AND IMMUNOCYTOCHEMICAL STUDIES OF RECTAL MUCOSAE IN GLUTEN SENSITIVITY

To study changes in rectal mucosa that might be attributable to the ef fects of gluten, rectal biopsy specimens from untreated and treated gl uten sensitised subjects were analysed morphometrically and by immunoh istochemical techniques and were compared with a series of disease con trol mucosae. Although morphometry showed increased populations of pla sma cells, lymphocytes, and mast cells in the mucosae of untreated pat ients, which were reduced (except for mast cells) by dietary gluten re striction, immunohistochemical techniques were far more sensitive in d efining these changes. There were highly significant increases in CD3 and gammadelta+ lymphocytes within both the lamina propria and the ep ithelium while neutrophils (CD15+ cells) were not at all prominent. Ac tivated (CD25+) lymphocytes expressing interleukin (IL)-2 receptors we re increased in lamina propria, usually subjacent to basal lamina, alt hough a few IL-2R+ intra-epithelial lymphocytes were found: other IL-2 R+ cells were deemed to be macrophages (CD68+). These results clearly indicate that in untreated, gluten sensitised subjects the rectal muco sa shows a lymphoplasmacytoid reaction that is responsive to gluten re striction. The absence of neutrophilia suggests that this lesion is no t a conventional inflammatory type proctitis, but rather one presumed to be induced by gluten antigen(s) present in the faecal stream - that is, a cell mediated form of response.