TIME-COURSE OF ADHESION MOLECULE EXPRESSION IN RECTAL MUCOSA OF GLUTEN-SENSITIVE SUBJECTS AFTER GLUTEN CHALLENGE

Adhesive interactions between endothelium and circulating cells, such as monocytes, neutrophils and lymphocytes, are crucial for localizing the inflammatory response. We investigated the inflammatory response o f rectal mucosa to local gluten challenge as a dynamic model of antige n-induced tissue injury, during which the expression of adhesion molec ules on leucocytes and endothelial cells could be sequentially observe d. Expression of ELAM-1, ICAM-1 and VCAM-1 was monitored in 10 treated and eight untreated patients with gluten sensitivity (coeliac disease ), and in five disease controls for up to 4 h (short challenge), while a further seven treated coeliacs were monitored for up to 24 h (long challenge) following rectal gluten challenge. In the former, the expre ssion of VCAM-1 and ELAM-1 was significantly raised 4 h after gluten c hallenge compared with controls. VCAM-1 and ELAM-1 expression was also increased in mucosae of treated patients, but to a lesser extent. VCA M-1 expression continued to increase for up to 24 h after gluten, whil e ELAM-1 had begun to wane by 4 h, reaching basal levels by 24 h. In c ontrast, the expression of ICAM-I did not change in any of the disease groups studied. These findings relate to significant increases in lym phocytes (CD3+ cells) after 8 h, and neutrophils (CD15+ cells) after 4 h in the lamina propria. This approach has permitted novel studies of the inflammatory response to a defined antigen in sensitized (gluten- sensitive) human patients.