MONITORING OF ACUTE ALLOGRAFT-REJECTION BY CYTOLOGICAL, IMMUNOCYTOCHEMICAL, AND IMMUNOHISTOCHEMICAL STUDIES FOLLOWING RAT SMALL-BOWEL TRANSPLANTATION

We investigated the role of graft luminal fluid cytology for immunolog ical monitoring of rat small-bowel allograft recipients. Allogeneic tr ansplantation from WKAM (RT1(u)) to Lewis recipients and syngeneic tra nsplantation using Lewis (RT1(l)) rats were carried out. Twenty centim eters of the proximal jejunum was transplanted as a Thiry-Vella loop. The luminal fluid on days 0, 3, and 6 was examined cytologically using Papanicolaou, periodic acid-Schiff, and Giemsa staining, and immunocy tochemically with monoclonal antibodies for macrophages (ED1 and ED2), Full thickness biopsies of graft tissue were evaluated by both immuno fluorescence (ED1 and ED2) and by standard histological methods. The c ytological examination on day 6 revealed an increase in the number of enterocytes, lymphocytes, and neutrophils, the presence of bacteria, a nd the depletion of goblet cells in the allografts, Histologically, si gnificant morphological changes of acute rejection were first seen on day 6, Immunofluorescence predicted the acute rejection of the allogra fts earlier than a histological examination by shelving an increase in the number of ED1- and Ed2-positive cells on day 3, Graft luminal flu id cytology and immunofluorescence analysis of ED1 and ED2 cells could thus be used to recognize early acute allograft rejection following s mall-bowel transplantation.