The purpose of this study is to compare kidney function, long term patient and graft survival, and incidence of acute rejection in liver transplant recipients between one group receiving thymoglobulin induction and delayed initiation of tacrolimus and another group of liver transplant recipients having immediate administration of tacrolimus without any induction immunosuppression.

Renal insufficiency following liver transplantation in adult recipients is a major cause of morbidity and a major contributor to mortality. One of the key factors contributing to this renal dysfunction is the use of calcineurin inhibitors. There is some evidence to suggest that the first 7-10 days following liver transplantation are crucial in terms of renal function and the ability to avoid the use of nephrotoxic agents such as calcineurin inhibitors may have a significant impact on long-term outcome.

Inclusion Criteria:

• Primary liver transplant recipient with Model for End Stage Liver Disease (MELD) criteria documentation
• Over 18 years of age
• Signed informed consent form
• if female of childbearing potential: Must not be lactating Must have negative serum pregnancy test on study day 0 Must have agreed on a reliable and acceptable form of contraception during the study
• sexually active males must be practicing an acceptable form of contraception

Exclusion Criteria:

• Multiple organ transplants
• Prior solid organ or bone marrow transplant recipients
• Fulminant hepatic failure
• Status 1 transplants
• Liver transplant candidates with greater than 6 weeks of dialysis
• Patients who in the opinion of the Investigator are not eligible for thymo induction at the time of transplant
• Recipients of investigational therapy within 90 days prior to transplant
• Know contraindication to administration of rabbit anti-thymocyte globulin
• Patients whose medical condition is such that the physician feels it would not be in their best interest to participate in the study
• Patients who are unwilling to have a Glofil nuclear medicine scan at specified time points
• History of malignancy within 5 years with the exception of:
• Adequately treated localized squamous or basal cell carcinoma of the skin without evidence of recurrence, and /or
• Hepatocellular carcinoma