METHOD FOR DIAGNOSING REJECTION IN SMALL-BOWEL TRANSPLANTATION

Diagnosis of rejection in small bowel transplantation by the identific ation of a host-cell infiltrate is hampered by the physiological traff icking of host lymphocytes to the 'gut-associated lymphoid tissue' of the graft. This study compared physiological host-cell infiltration of small bowel grafts with that occurring in rejection and stable immuno suppression. Physiological host-cell infiltration, where the graft doe s not present an immune stimulus to the host, was assessed by transpla nting bowel from DA to (DA x PVG) F1 hybrid rats. The extent of host-c ell infiltration was determined by immunohistochemical analysis. In th e lamina propria, considerable infiltration by host cells was seen, al though it was significantly less than that in rejection or stable immu nosuppression. By contrast, host cells were seen in the intraepithelia l compartment only in rejection. Host-cell infiltration in the absence of an allogeneic stimulus suggests that histological identification o f host cells in the lamina propria is not necessarily indicative of re jection. However, the presence of host cells in the intraepithelial co mpartment is specific for rejection in small bowel transplantation.