Are we ready for marginal hepatitis B core antibody-positive living liver donors?

Adult-to-adult living donor liver transplantation (LDLT) is being performed in the United States with increasing frequency because of the severe shortage of cadaveric donor organs.1,2 For example, 42 of 89 Organ Procurement and Transplantation Network– certified liver transplant programs (47%) reported having performed at least one adult-to-adult LDLT in 2000, and 355 adult-to-adult LDLTs were performed in the United States in 2002, with the latter accounting for 6.6% of all liver transplantations.1,3 Patient and graft survival rates in carefully selected adult living donor liver transplant recipients have been similar to those for cadaveric recipients; however the number of patients and duration of follow-up are limited.4,5 In addition, greater rates of biliary, infectious, and vascular complications have been reported in adult living donor liver transplant recipients compared with cadaveric recipients.2-5 Information on outcomes of right-lobe liver donors is limited because of the lack of a standardized follow-up protocol and central registry. However, shortterm complications reported in adult living liver transplant donors include blood transfusion (10% to 15%), biliary complications (15% to 30%), and reoperation (5%), among others.1-7 Although most healthy adult living liver transplant donors regenerate the majority of their liver mass within 1 month of donation, liver failure requiring possible liver transplantation has been reported in three donors, and death, in three others.1,2,6 Although the need for adult-to-adult LDLT may decline with implementation of the Model for EndStage Liver Disease liver allocation policy, some critics have called for a moratorium on adult-to-adult LDLT until risks and benefits have been clarified in prospective studies.2,8,9 Many US liver transplant programs also have begun to use marginal cadaveric donor livers in selected liver transplant candidates with high medical urgency.10 Marginal cadaveric livers are variably defined as those with a greater risk for primary nonfunction or the potential to transmit disease. Preliminary data suggest that overall patient and graft survival rates have been acceptable using such carefully selected marginal donors as those older than 50 years and donor livers with less than 30% steatosis on biopsy.11,12 Conversely, results with non–heart-beating donors and severely steatotic livers have been less favorable.13,14 Hepatitis B core antibody–positive (HBcAb ) cadaveric donor livers also are considered marginal because of the 25% to 90% risk for hepatitis B virus (HBV) transmission to the recipient.15,16 However, outcomes in selected hepatitis B surface antigen (HBsAg) and seropositive (i.e., HBcAb or antibody to HBsAg [HBsAb] ) recipients generally have been favorable.15 Transplantation of HBcAb cadaveric livers to seronegative recipients is associated with a high rate of HBV transmission, which may lead to severe graft dysfunction in some recipients.16,17 Use of lamivudine and hepatitis B immunoglobulin (HBIG) immunoprophylaxis in recipients of HBcAb cadaveric livers appears to reduce the rate of HBV transmission; however, larger studies with longer follow-up are needed to determine the optimal prophylaxis strategy.18-20 In this issue of Liver Transplantation, Lo et al21 present outcomes of 54 consecutive adult living liver transplant donors from Hong Kong who were followed up for a median of 31 months postdonation. Although clinical outcomes of a limited number of recipients of HBcAb living donor liver grafts have been reported previously, the shortand long-term safety of partial hepatectomy in HBcAb adult living liver transplant donors has not been described previously.22,23 The majority of right-lobe liver donors in this series were women (65%), and mean donor graft weight was 574 g. The 24 HBcAb donors were significantly older than the 29 HBcAb donors (median age, 42 v 31 years). Interestingly, 80% of the HBcAb group were HBsAb , suggesting either previous HBV vaccination or exposure to HBV. However, serum HBV DNA was