The protective effect of hepatic dysfunction on vascularized allograft survival

Recent studies have demonstrated that hepatic dysfunction, induced by experimental biliary ligation (EBL), impairs lymphocytic responsiveness to PHA stimulation in vitro and to cellular antigens in vivo. This suppression appears to be selective for T-cell mechanisms while B-cell-mediated functions remain intact. The purpose of this study was to determine whether coexisting hepatic insufficiency could exert a protective effect on vascularized or nonvascularized allograft survival in the transplanted recipient. Female Wistar-Furth (Rtl^w) 225 g rats were assigned randomly to three groups: EBL, sham operation (Sham) and normal control (NC). Fourteen days following operation animals received heterotopic cardiac or skin allografts from Buffalo (Rtl^b) donors. Cardiac and skin graft survival was determined daily, rejection was confirmed histologically, and technical failures were omitted from analysis. Allograft survival was expressed as median survival time ± SEM. Serum total bilirubin (mean ± SEM) was significantly elevated at Day 14 in EBL animals compared to Sham and NC groups (15.1 ± 1.0 vs 0.1 ± 0 and 0.2 ± 0.1 mg/dl, respectively, P < 0.01). Median cardiac allograft survival time by Probit was 10.6 ± 2.6 vs 5.6 ± 0.7 and 6.0 ± 0.9 days, respectively (P < 0.03). Skin graft survival (mean and range) was similar in all groups. These results demonstrate that EBL in the rat suppresses T-cell function and significantly prolongs vascularized allograft survival, but not skin allograft survival across the Rtl histocompatibility barrier. The mechanism whereby coexisting hepatic dysfunction exerts a protective effect on vascularized allograft survival warrants further investigation.