Introduction We previously found that FK did not induce a severe reduction of immune response compared to other clacineurin inhibitor (ILTS 2009 oral presentation).

Aim We aimed to evaluate the in vitro effect of tacrolimus on hepatitis C virus (HCV)-specific immune response by ELISpot to establish early the possible effect of immunosuppression and so tailoring immunosuppressive schedule before OLTx to minimize or delay HCV recurrence.

Method Twenty-five HCV+ve patients (20 male and 5 female) on waiting list were enrolled. Blood samples were taken and at least on 2–2.5×10⁵ cells per well ELISpot was performed to evaluate IFN-specific response after coculturing with 1 ng/ml or 5 ng/ml of FK for 24 h. CMV and a specific stimulation with PMI-Ionomicin were used as control on HCV patients. Ten healthy donors were used as control.

Results After 24 h of FK stimulation, PMA-Ion IFN-response was reduced in all patients (p<0.05) compared to basal values both with 1 ng/ml that 5 ng/ml while CMV- specific showed reduction only when cocultured with 5 ng/ml. Among patients on waiting list, we had that 8 out 25 had a major reduction of HCV and CMV specific response (p <0.05) while 17 out 25 had no statistical significant changes in their IFN response.

Conclusion Based on these results and our previous data, ELISpot assay before OLTx may useful to establish the impact of immunosuppressive schedule. In those having a major reduction of HCV specific immune response after CNI stimulation (FK) a different drug should be used to minimize or delay the possible HCV recurrence. Further studies are required to establish in vitro effects.