Endoscopic findings in transplanted allo-intestine of rats after discontinuance of immunosuppressive agent.

ABSTRACT

In clinical practice, graft rejection in small-bowel transplantation should be diagnosed before irreversible condition of the graft. We have already reported the usefulness of endoscopic examination for the early detection of acute rejection in a rat model. Here we evaluated rejection after discontinuance of methyl-deoxyspergualin by endoscopy. Heterotopic small-bowel transplantation was performed by the cuff method from a DA to a LEW rat. Endoscopic and histological examinations were performed through the stomas. Two-week administration of methyl-deoxyspergualin significantly prolonged graft survival. Graft rejection after discontinuance of the agent occurred much more slowly than rejection without the immunosuppressive drug. Erosive mucosal changes were endoscopically observed in the early phase of rejection in rats that did not receive the immunosuppressant. However, endoscopic findings after discontinuance of methyl-deoxyspergualin indicated edematous changes and thickening of the wall without erosion, and, histologically, the grafted intestine showed slowly-progressing rejection with flattened villi. If we pay attention to edematous changes and hardening of intestinal wall, and take selective biopsies, endoscopic examination may improve the early diagnosis of slowly progressive rejection in the clinical setting.