Analysis of the United Network for Organ Sharing database comparing renal allografts and patient survival in combined liver-kidney transplantation with the contralateral allografts in kidney alone or kidney-pancreas transplantation

BACKGROUND: Combined liver-kidney transplantation (LKT) is the accepted treatment for patients with liver failure and irreversible renal insufficiency. Controversy exists as to whether simultaneous LKT with organs from the same donor confers immunologic and graft survival benefit to the kidney allograft. This study compares the outcomes of simultaneous LKT with the contralateral kidneys used for kidney alone transplantation (KAT) or combined pancreas-kidney transplantation (PKT) to understand the factors that account for the differences in survival. METHODS: From October 1987 to October 2001, LKTs with organs from 899 cadaver donors were reported to the United Network for Organ Sharing; 800 contralateral kidneys from these donors were used in 628 KAT and 172 PKT recipients. These 800 paired control patients were the basis of this analysis. RESULTS: Graft and patient survival rates were lower among LKT recipients compared with KAT (P<0.001) and PKT recipients (P<0.001), because of a higher patient mortality rate during the first 3 months posttransplant. Among human leukocyte antigen-mismatched transplants, LKT recipients demonstrated the highest 1-year rejection-free survival rate (LKT 70%, KAT 61%, and PKT 57% ) (P=0.005 vs. KAT, P=0.005 vs. PKT). There was a lower incidence of renal graft loss resulting from chronic rejection among LKT recipients (LKT 2% vs. KAT 8% vs. PKT 6%, P<0.0001). CONCLUSIONS: Patients undergoing LKT exhibit a higher rate of mortality during the first year posttransplant compared with patients undergoing KAT and KPT. Analysis of the data indicates an allograft-enhancing effect of liver transplantation on the renal allograft.