A clinicopathologic study of isolated intestinal allografts with preformed IgG lymphocytotoxic antibodies

Abstract

m Humoral rejection of human small bowel allografts has not been ell documented. The aim of this study was to determine the signifcance of preformed IgG lymphocytotoxic antibodies, as determined y the modified Amos crossmatch technique, in 6 of 28 (21.4%) adult solated intestinal allograft recipients treated with tacrolimus basal mmunosuppression. The crossmatch with dithiothreitol (DTT) was trongly positive in 5 grafts and weakly positive in the remaining one. he strongly positive crossmatch grafts (n 5) developed severe ucosal injuries immediately after reperfusion. Within the first 10 ays after transplantation, 3 of the 5 strongly positive crossmatch rafts developed clinically and endoscopically documented severe ucosal congestion, cyanotic discoloration, and focal hemorrhage ithin the allograft. Simultaneous mucosal biopsy specimens demontrated severe congestion, neutrophilic margination, and fibrin-plateet thrombi within the lamina propria microvasculature, along with ocal hemorrhage, but with no histological neutrophilic or necrotizng arteritis, and the immunofluorescent findings were unremarkable. he other 2 strongly positive crossmatch allograft recipients develped macroscopic congestion of mucosa with microscopic foci of ongestion and hemorrhage. In contrast, the recipient with a weakly