THYMOGLOBULIN SIGNIFICANTLY REDUCES THE RISK OF ACUTE REJECTION IN RIGHT LOBE LIVING-DONOR LIVER TRANSPLANT (LDLT) RECIPIENTS

Abstract

P514 Aims: Thymoglobulin (Thymo) has been reported to reduce the risk of rejection after transplantation, and may attenuate ischemic-reperfusion injury. The role of Thymo after LDLT, however, remains poorly defined Methods: We compared the outcome of patients that received no polyclonal antibody induction therapy (Group 1; n=36) with those that received a course of Thymo (Group 2; n=46). Thymo was initiated within the first 6 hrs after LDLT and continued for 3-7days; daily dosage was adjusted to maintain absolute lymphocyte counts of <0.2. All patients received a tapering dosage of methylprednisolone and tacrolimus (Tac; group 1, 84%; group 2, 90%) or Neoral cyclosporine (Cya; group 1, 16%; group 2, 10%; p=NS). In group 2, initiation of Cya/Tac was routinely delayed to the 3rd -5th post-op day. Ganciclovir was given for 3 mo. to all CMV+ recipients that received Thymo and to all CMV- recipients of CMV+ grafts. All complications were recorded prospectively. Results: Demographic characteristics (age, sex, cause of liver disease) were similar in both groups. Median follow-up was 996 days in group 1 and 429 days in group 2 (P<0.01). The proportion of patients free of rejection during the first 6 months was 62% in group 1 and 91% in group 2 (p <0.001 by Log rank test). Six patients in group 1 had steroid-resistant rejection requiring OKT3 (n=5) or thymo (n=1); all 6 of these patients were receiving tacrolimus. All rejection episodes in group 1 were mild and treated successfully with steroids. Thymo was well-tolerated in all patients. There was no significant difference in the incidence of bacterial, fungal, or CMV infection in the two groups. One patient in group 2 that acquired EBV from the graft developed PTLD, which has been treated successfully. Among Hepatitis C virus infected (HCV)-patients the incidence and severity of recurrent HCV was similar in group 1 and 2. Patient and graft survival at 2 years was 86% and 84% in group 1, and 86% and 86% in group 2, respectively. Causes of death in group 1 were small graft syndrome (n=2), myocardial infarction (1), and sepsis (2); and in group 2 were, recurrent hepatoma (1), lung cancer (1), and sepsis (3). Conclusions: Thymo significantly reduces the risk of acute rejection in LDLT recipients without increasing the risk of infectious complications. Reducing the risk of rejection may be valuable in recipients of marginal size grafts in whom rejection may compromise function, impair regeneration, and promote graft failure.