What is required for a good prognosis on liver transplant?

Before an allograft is attempted, the ABO blood group system and other blood group antigens of donor and recipient must be determined, because these antigens are also present on most body cells. the recipient and donor tissues are typed to determine their major histocompatibility complex (MHC) antigen match. MHC variation among human tissues is tremendous, so matching for all MHC antigens is impossible. The closer the match the less likely the transplant will be rejected. (Marieb 793)