Liver is an organ that is well-known for its immune tolerant capacity. However, there were still controversial issues about the impact of immunologic challenge after liver transplantation on the graft function. Different results of graft function affected by immunologic factors such as pre-transplant panel reactive antibody (PRA) status, pre-transplant positive lymphocyte cross match (LCM), or post-transplant circulating donor specific antibody (DSA) has been reported according to individual institutes. There was no trial for presenting anti-donor lymphocyte antibody change after liver transplantation.

The investigators designed this study to analyze the correlation between pre- and post-transplant immune status (PRA, LCM), and graft survival / rejection episode. Also, the investigators will find aspects of anti-donor lymphocyte antibody change after liver transplantation.

Study Design: Target study population is forty patients who will undergo liver transplantation for 1 year in YUHS. Pediatric and early mortality cases will be excluded. Blood sample will be collected at pre-transplant period, post-transplant 7, 14, 21 day, 3 month and 6 month.

Inclusion Criteria:

• Liver recipients who undergo liver transplantation between Mar, 2011 and Feb, 2012
• Patients who can be followed for more than 3 months after transplantation

Exclusion Criteria:

• Age under 20 years
• Multi-organ transplantation
• Not agree with informed consent
• Patient who had plant to be transferred to other country or center

Adult recipients who will undergo liver transplantation during study period