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End-stage liver disease secondary to hepatitis C virus (HCV) infection is the leading indication for liver transplantation in the UnitedSubsequent to the initial cloning of and the development of diagnostic tests for the hepatitis C virus (HCV) in 1989, 1,2 hepatitis C has emerged as a major cause of liver disease. It is estimated that there are approximately four million individuals infected with HCV in the United States, where HCV infection causes 20% of acute and 70% of chronic hepatitis. 3,4 While published data give conflicting estimates of the proportion of HCV-infected individuals who go on to develop cirrhosis, the number of patients with HCV infection requiring liver transplantation has grown steadily. In 1991, when screening for HCV infection first became widely available, 17.8% of liver transplantations were performed for end-stage liver disease associated with HCV infection. This proportion has increased every year following 1991 and is currently over 30%, making end-stage liver disease associated with HCV infection the leading indication for liver transplantation in the United States. 5 Recurrence of HCV infection in liver allograft recipients is nearly universal. 6,7 In the setting of an increasing donor organ shortage, these facts have raised pressing questions about liver transplantation for liver disease associated with HCV infection. In 1990, the Liver Transplantation Database (LTD) was established by the National Institutes of Diabetes and Digestive and Kidney Diseases (NIDDK). Three prominent liver transplantation centers prospectively contributed serum, tissue, clinical, and demographic information from patients being evaluated for liver transplantation, the purpose of which was to pool collective experience in liver transplantation to answer questions that could not readily be addressed by single centers. Transplantation for HCV-associated liver disease poses several important such questions. Although patients undergoing liver transplantation for HCV have been reported to have comparable overall patient and graft survival to most other indications, it is not known whether a subset of HCV-infected recipients exists who are at increased risk for poor patient or graft survival. To date, no viral, donor, recipient, or therapeutic variables identifying a cohort of HCV-infected recipients with poor patient and/or graft survival have been defined. We report the experience of the NIDDK LTD in the identification of risk factors for adverse outcomes following liver transplantation for HCV. PATIENTS AND METHODS Study PatientsThe LTD is a 7-year prospective study of patients who underwent liver transplantation at three medical centers. 8 The three participating centers were: Mayo Clinic and Foundation, Rochester, MN; the University of Nebraska, Omaha, NE; and the University of California, San Francisco, CA. The study was approved by the Institutional

In 1999, the Institute of Medicine suggested that instituting a continuous disease severity score that de-emphasizes waiting time could improve the allocation of cadaveric livers for transplantation. This report describes the development and initial implementation of this new plan. The goal was to develop a continuous disease severity scale that uses objective, readily available variables to predict mortality risk in patients with end-stage liver disease and reduce the emphasis on waiting time. Mechanisms were also developed for inclusion of good transplant candidates who do not have high risk of death but for whom transplantation may be urgent. The Model for End-Stage Liver Disease (MELD) and Pediatric End-Stage Liver Disease (PELD) scores were selected as the basis for the new allocation policy because of their high degree of accuracy for predicting death in patients having a variety of liver disease etiologies and across a broad spectrum of liver disease severity. Except for the most urgent patients, all patients will be ranked continuously under the new policy by their MELD/PELD score. Waiting time is used only to prioritize patients with identical MELD/PELD scores. Patients who are not well served by the MELD/PELD scores can be prioritized through a regionalized peer review system. This new liver allocation plan is based on more objective, verifiable measures of disease severity with minimal emphasis on waiting time. Application of such risk models provides an evidenced-based approach on which to base further refinements and improve the model. (Liver Transpl2002;8:851-858.)

This year was notable for changes to exception points determined by the geographic median allocation Model for End‐Stage Liver Disease (MELD) and implementation of the National Liver Review Board, which took place on May 14, 2019. The national acuity circle liver distribution policy was also implemented but reverted to donor service area‐ and region‐based boundaries after 1 week. In 2019, growth continued in the number of new waiting list registrations (12,767) and transplants performed (8,896), including living‐donor transplants (524). Compared with 2018, living‐donor liver transplants increased 31%. Women continued to have a lower deceased­donor transplant rate and a higher pretransplant mortality rate than men. The median waiting time for candidates with a MELD of 15‐34 decreased, while the number of transplants performed for patients with exception points decreased. These changes may have been related to the policy changes that took effect in May 2019, which increased waiting list priority for candidates without exception status. Hepatitis C continued to decline as an indication for liver transplant, as the proportion of liver transplant recipients with alcohol‐related liver disease and clinical profiles consistent with non‐alcoholic steatohepatitis increased. Graft and patient survival have improved despite changing recipient demographics including older age, higher MELD, and higher prevalence of obesity and diabetes.

A national conference was held to better characterize the long-term outcomes of liver transplantation (LT) for patients with hepatocellular carcinoma (HCC) and to assess whether it is justified to continue the policy of assigning increased priority for candidates with early-stage HCC on the transplant waiting list in the United States. The objectives of the conference were to address specific HCC issues as they relate to liver allocation, develop a standardized pathology report form for the assessment of the explanted liver, develop more specific imaging criteria for HCC designed to qualify LT candidates for automatic Model for End-Stage Liver Disease (MELD) exception points without the need for biopsy, and develop a standardized pretransplant imaging report form for the assessment of patients with liver lesions. At the completion of the meeting, there was agreement that the allocation policy should result in similar risks of removal from the waiting list and similar transplant rates for HCC and non-HCC candidates. In addition, the allocation policy should select HCC candidates so that there are similar posttransplant outcomes for HCC and non-HCC recipients. There was a general consensus for the development of a calculated continuous HCC priority score for ranking HCC candidates on the list that would incorporate the calculated MELD score, alpha-fetoprotein, tumor size, and rate of tumor growth. Only candidates with at least stage T2 tumors would receive additional HCC priority points. Liver Transpl 16:262-278,