Preliminary results of a "prope" tolerogenic regimen with thymoglobulin pretreatment and hepatitis C virus recurrence in liver transplantation

Background. Recent reports demonstrate the efficacy of induction immunosuppression with Thymoglobulin, a potent antithymocyte polyclonal antibody, in allowing acquired tolerance by means of a tolerogenic regimen of recipient pretreatment and low-dose postoperative immunosuppression. The effect of this novel approach on recurrence of hepatitis C viral disease after liver transplantation has never been investigated. We report the preliminary results of a retrospective analysis aimed at discovering any relationship between Thymoglobulin immunosuppression and the pattern of recurrence of hepatitis C. Methods. Thymoglobulin induction plus tacrolimus monotherapy was used in a group of 22 hepatitis C virus (HCV) + patients receiving liver transplantation; 30 HCV+ patients receiving transplants within the same year received conventional tacrolimus plus steroid immunosuppression and represented the comparison group. Results. Patient survival and acute rejection rate did not differ between the two groups. Significantly lower dosages and levels of tacrolimus were possible with Thymoglobulin, and a progressive weaning of tacrolimus monotherapy was accomplished in most patients, without major rejection complications. The HCV recurrence rate was similar in both groups, although significantly lower HCV RNA loads were obtained with Thymoglobulin pretreatment. The mean time to histologic recurrence was shorter in Thymoglobulin-treated patients; however, no significant difference was observed in mean Ishak's histologic grading and staging of HCV recurrence. Conclusions. In our preliminary experience, a "prope" tolerogenic regimen with Thymoglobulin pretreatment and low-dose immunosuppression in liver-transplant recipients gave good protection against rejection and permitted lower HCV viral loads, whose significance in the long-term outcome of HCV patients deserves further investigation.