Intestinal response to immunologic insult

1. 1. Granulomatous lesions can be produced by injection of the appropriate antigen into the intestinal wall of previously sensitised animals. 2. 2. In untreated intestinal allografts the severity of the immunologic response usually results in massive necrosis of the graft approximately seven days after its insertion. 3. 3. Rejection follows widespread permeation of the allograft from “without in” by lymphocytes, plasma cells, and monocytes. The pattern closely resembles that seen in other allografts and the final process in the intestine appears to be one of haemorrhagic infarction due to extensive damage to small blood vessels. 4. 4. When the rejection process is delayed extensive fibrosis occurs in the allograft associated with disappearance of the mucosa and complete atrophy of the muscle layers. 5. 5. There is, as yet, insufficient evidence to indicate that these phenomena play a significant etiologic role in human alimentary granulomatous disease.