There is a significant unmet need for safe and effective therapeutic approaches to prevent immune-mediated graft injury and its complications in liver transplant (LT) recipients with autoimmune liver disease (AILD) including autoimmune hepatitis and primary sclerosing cholangitis. Siplizumab is an anti-cluster of differentiation 2 (CD2) monoclonal antibody that has demonstrated a favorable safety profile of siplizumab in over 779 human subjects and has been shown to target memory T cells-a key driver in the immune processes surrounding rejection and autoimmunity post LT in AILD. The purpose of this pilot, open-label phase 1 study is to determine the safety of siplizumab for induction in patients with AILD undergoing LT. Up to eight (8) subjects will receive siplizumab 0.6 mg/kg/dose on the day of transplant (Day 0) and Day 4 post-transplant, for a total of two doses. All subjects will be followed in the study for 12 months post-LT.