• To assess whether in-vitro donor-specific immune reactivity patterns are indicative of rate of HCV recurrence [ Time Frame: Baseline prior to surgery, Weeks 1, 2; Months 1, 2, 3, 4, 5, 6, 12, 18 ] [ Designated as safety issue: No ]
  

• To compare in-vitro donor-specific immune reactivity patterns and rejection episodes in liver transplant recipients [ Time Frame: Baseline prior to surgery, Weeks 1, 2; Months 1, 2, 3, 4, 5, 6, 12, 18 ] [ Designated as safety issue: No ]
  
• To establish immune monitoring protocol for HCV+ liver transplant recipients that will aid in tailoring immunosuppression protocols for these patients and in devising strategies to treat patients with recurrent hepatitis C post-liver transplantation. [ Time Frame: Baseline prior to surgery, Weeks 1, 2; Months 1, 2, 3, 4, 5, 6, 12, 18 ] [ Designated as safety issue: No ]
  

To establish whether in-vitro donor-specific immune reactivity patterns can differentiate between those liver transplant recipients who are positive for the Hepatitis C virus (HCV) who are at high risk and those who are at low risk for graft loss secondary to early recurrence of HCV.

An assessment of the recipient's donor-specific immune status can be achieved by measuring T-cell activity, specifically alloreactive primed (donor-specific) T cell activity. It has been shown that detection of IFN-y in short-term enzyme-linked-immunosorbent-spot (ELISPOT) assay is consistent with the presence of primed memory T cells (6). In the transplantation setting, T cells of an allograft recipient that secret IFN-y after short in-vitro exposure to donor cells represent a prior sensitization of recipient to donor antigens in vivo. Clinically interpreted - this priming event may signify the presence of an up-coming, or an on-going, rejection episode. Our limited preliminary data suggest an additional potential clinical value for the in-vitro assessment of donor-specific IFN-y production in predicting those liver transplant recipients at higher risk for recurrence of Hepatitis C.