Anti-IL2 Induction in Liver Transplantation with 93% Rejection-Free Patient and Graft Survival at 18 Months

Abstract

Induction with the use of monoclonal antibodies targeting the alpha-chain (CD25) of the high-affinity IL2 receptor may avoid many of the adverse events associated with polyclonal antibodies and significantly impact on rejection-free long-term survival in orthotopic liver transplantation (OLT). Forty-two consecutive deceased donor primary OLT were retrospectively analyzed. All patients received two 20-mg doses of basiliximab (days 0 and 4 after OLT) followed by tacrolimus (0.15 mg/kg/day; 10-15 ng/mL target trough levels), and steroids (methylprednisolone 1 g intraoperatively followed by tapering doses). Mycophenolate mofetil (MMF) 1 g every 12 h was added to the drug combination as needed. The mean follow-up period was 19.3 months (range: 4.8-35.9 months). The average Model for End-Stage Liver Disease score was 26 (range: 15-40). A total of 39 patients (93%) remained rejection-free during follow-up with an actuarial rejection-free probability of 95% within 3 months. The actuarial patient and graft survival rate (Kaplan-Meier estimated) at 2 years was 93%. Twenty-five patients (60%) were completely off steroids within 3 months post-OLT (mean: 51.1 days, range: 10-90 days). By the 10th month post-OLT, 30/39 (77%) of the patients were completely off steroids. At last follow-up, 30/39 (77%) are on tacrolimus monotherapy with an average dose of 4 mg per day. Six patients (15%) are on double therapy, receiving a combination of tacrolimus and prednisone (two patients) or tacrolimus and MMF (two patients) or tacrolimus and mycophenolic acid (two patients). Only three patients (8%) are receiving triple therapy at last follow-up. Nine patients (21%) experienced at least one episode of infection. Only six (26%) of a total of 23 hepatitis C virus (HCV) recipients developed histology-proven HCV recurrence, with a mean onset of recurrence post-OLT of 3.2 months (range: 1.3-6.3 months). Of these six patients, two are presently undergoing treatment with interferon and ribavirin, one was treated and became HCV RNA negative, one was not treated, one declined treatment, and two died of HCV recurrence. None of the 42 study patients developed cytomegalovirus infection or posttransplant lymphoproliferative disease. These preliminary data suggest that basiliximab, given in combination with a tacrolimus-based immunosuppressive regimen, is safe and associated with a low incidence of acute rejection and excellent short-term rejection-free graft and patient survival rate after OLT.