DEFECTIVE HCV SPECIFIC T CELL RESPONSE IN LIVER TRANSPLANTED RECIPIENTS

Abstract

O32 Aims: To evaluate HCV specific immune responses in liver transplanted patients chronically HCV infected and to determine the impact of the immunosuppression on HCV specific T cell responses. Methods: A total of 40 patients were studied. The frequency of interferon γ (IFN γ) secreting T cells by ELIspot assay was determined in the blood of 12 patients HCV infected who underwent liver transplantation (more than 12 months after the graft) and in 28 chronically HCV infected non-transplanted patients. Determination of the HCV-specific T cell response was performed prior to the initiation of antiviral therapy. In all cases HCV-specific T cell responses were characterised following antigen-specific stimulation using a total of 728 overlapping peptides spanning the entire HCV genome (15-mers overlapping of 11 amino acids) diluted in 54 pools. Results: The 12 transplanted patients had recurrent HCV infection with elevated transaminases, high HCV RNA titres in serum (60% >500 kU) and signs of fibrosis at the biopsy. In the transplanted patients HCV specific T cell responses were detected only in 1 out of 12 patients (8%) whereas they were detected in 12 out 28 (42%) non-transplanted patients (p<0.05). Conclusions: These results suggest that immunosuppressive therapy in transplanted patients may severely curtail the generation of HCV specific immune response. The lack of HCV specific immune response may be at least in part responsible for the rapid progression of HCV infection in transplanted patients.