Hepatitis C virus viral kinetics during α-2a or α-2b pegylated interferon plus ribavirin therapy in liver transplant recipients with different immunosuppression regimes

Disparity of basal and therapeutically activated interferon signalling in constraining hepatitis E virus infection

Hepatitis E virus (HEV) represents one of the foremost causes of acute hepatitis globally. Although there is no proven medication for hepatitis E, pegylated interferon-α (IFN-α) has been used as off-label drug for treating HEV. However, the efficacy and molecular mechanisms of how IFN signalling interacts with HEV remain undefined. As IFN-α has been approved for treating chronic hepatitis C (HCV) for decades and the role of interferon signalling has been well studied in HCV infection, this study aimed to comprehensively investigate virus-host interactions in HEV infection with focusing on the IFN signalling, in comparison with HCV infection. A comprehensive screen of human cytokines and chemokines revealed that IFN-α was the sole humoral factor inhibiting HEV replication. IFN-α treatment exerted a rapid and potent antiviral activity against HCV, whereas it had moderate and delayed anti-HEV effects in vitro and in patients. Surprisingly, blocking the basal IFN pathway by inhibiting JAK1 to phosphorylate STAT1 has resulted in drastic facilitation of HEV, but not HCV infection. Gene silencing of the key components of JAK-STAT cascade of the IFN signalling, including JAK1, STAT1 and interferon regulatory factor 9 (IRF9), stimulated HEV infection. In conclusion, compared to HCV, HEV is less sensitive to IFN treatment. In contrast, the basal IFN cascade could effectively restrict HEV infection. This bears significant implications in management of HEV patients and future therapeutic development.

Early predictors of antiviral treatment response in liver transplant recipients with recurrent hepatitis C genotype 1

The success of current antiviral treatment for hepatitis C virus (HCV) recurrence in liver transplant (LT) recipients remains limited. We aimed at evaluating the value of IL28B genotype and early viral kinetics to predict response to standard treatment in the transplant setting. We retrospectively evaluated 104 LT recipients treated for HCV genotype 1 recurrence between 2001 and 2010. Baseline variables, including IL28B genotype, and early viral kinetics were compared among patients who did or did not achieve a sustained virological response (SVR). Logistic regression analyses of candidate variables were conducted to generate a reliable predictive model based on the minimum set of variables. Twenty-nine (28%) achieved an SVR. On multivariate analysis, the magnitude of HCV RNA decline at 4 weeks (OR: 3.74, 95% CI: 1.64-9.39; P = 0.003) and treatment compliance (OR: 35.27, 95% CI: 3.35-365.54; P = 0.003) were the only independent predictors of SVR. Favourable recipient IL28B genotype significantly correlates with virological response at week 4 (OR 3.23; 95% CI, 1.12-9.15; P = 0.03). By logistic regression analysis, a model including donor age, recipient rs12979860 genotype and viral load at 4 weeks showed the best predictive value for SVR with an area under the receiver operating curve of 0.861. Favourable recipient IL28B genotype strongly correlates with the viral response at week 4 which is the strongest predictor of response. The combination of recipient IL28B genotype and donor age with the week 4 response reliably estimates the probability of SVR early on-treatment and may facilitate therapeutic strategies incorporating new antiviral agents.

Liver transplantation and hepatitis C

Hepatitis-C-virus- (HCV-) related end-stage cirrhosis is the primary indication for liver transplantation in many countries. Unfortunately, however, HCV is not eliminated by transplantation and graft reinfection is universal, resulting in fibrosis, cirrhosis, and finally graft decompensation. The use of poor quality organs, particularly from older donors, has a highly negative impact on the severity of recurrence and patient/graft survival. Although immunosuppressive regimens have a considerable impact on the outcome, the optimal regimen after liver transplantation for HCV-infected patients remains unclear. Disease progression monitoring with protocol biopsy and new noninvasive methods is essential for predicting patient/graft outcome and starting antiviral treatment with the appropriate timing. Antiviral treatment with pegylated interferon and ribavirin is currently considered the most promising regimen with a sustained viral response rate of around 30% to 35%, although the survival benefit of this regimen remains to be investigated. Living-donor liver transplantation is now widely accepted as an established treatment for HCV cirrhosis and the results are equivalent to those of deceased donor liver transplantation.