Protease-inhibitor based antiviral therapy of HCV reinfection after liver transplantation
constitutes a difficult task due to drug-drug interactions, reduced tolerance and
severe side effects.
The aim of the present study was to retrospectively analyze the clinical course, dose
adjustment and blood concentrations of immunosuppressive drugs as well as biomarkers
of immunosuppressive effects by immunomonitoring of nuclear factor of activated T
cells (NFAT) -regulated gene expression of HCV-positive liver transplant patients
during telaprevir containing triple therapy.
All 5 patients were HCV-RNA negative at treatment week 12 and stayed negative until
the end of observation. Safety was acceptable with minimal acute rejection and reactivation
of cytomegalovirus as the most serious adverse events. Anemia with a hemoglobin level
lower than 8.5 g/dL and grade 3 neutropenia were common. Cyclosporine (CsA) dose was
reduced to 30.8% and CsA drug-clearance was reduced to 38.5% by telaprevir. Despite
correctly adapted target trough levels, we observed a significant decrease in the
CsA peak trough level under telaprevir therapy. Immunomonitoring of NFAT regulated
genes Il-2, IFN-γ and GM-CSF revealed an inverse correlation with CsA blood levels
leading to markedly altered mRNA levels and an increase in residual gene activity.
That means that the main immunosuppressive effect is diminished during telaprevir
therapy and indicates an overestimation of the immunosuppressive CsA – effect if estimated
by blood trough levels during telaprevir therapy.
In conclusion, antiviral therapy with protease inhibitors seems feasible in liver
transplant patients under close monitoring. Immunomonitoring of NFAT – regulated genes
assesses the biological activity of cyclosporine and therefore helps to prevent over-
and under-immunosuppression during triple therapy