Hepatitis C virus dynamics and cellular gene expression in uPA-SCID chimeric mice with humanized livers during intravenous silibinin monotherapy.

Legalon SIL (SIL) is a chemically hydrophilized version of silibinin, an extract of milk thistle (Silybum marianum) seeds that has exhibited hepatoprotective and antiviral effectiveness against hepatitis C virus (HCV) in patients leading to viral clearance in combination with ribavirin. To elucidate the incompletely understood mode of action of SIL against HCV, mathematical modelling of HCV kinetics and human hepatocyte gene expression studies were performed in uPA-SCID-chimeric mice with humanized livers. Chronically HCV-infected mice (n = 15) were treated for 14 days with daily intravenous SIL at 469, 265 or 61.5 mg/kg. Serum HCV and human albumin (hAlb) were measured frequently, and liver HCV RNA was analysed at days 3 and 14. Microarray analysis of human hepatocyte gene expression was performed at days 0, 3 and 14 of treatment. While hAlb remained constant, a biphasic viral decline in serum was observed consisting of a rapid 1st phase followed by a second slower phase (or plateau with the two lower SIL dosings). SIL effectiveness in blocking viral production was similar among dosing groups (median ε = 77%). However, the rate of HCV-infected hepatocyte decline, δ, was dose-dependent. Intracellular HCV RNA levels correlated (r = 0.66, P = 0.01) with serum HCV RNA. Pathway analysis revealed increased anti-inflammatory and antiproliferative gene expression in human hepatocytes in SIL-treated mice. The results suggest that SIL could lead to a continuous second-phase viral decline, that is potentially viral clearance, in the absence of adaptive immune response along with increased anti-inflammatory and antiproliferative gene expression in human hepatocytes.

Emergence of resistant variants detected by ultra-deep sequencing after asunaprevir and daclatasvir combination therapy in patients infected with hepatitis C virus genotype 1.

Daclatasvir (DCV) and asunaprevir (ASV) are NS5A and NS3 protease-targeted antivirals respectively, currently under development for the treatment of chronic hepatitis C virus (HCV) infection. We analysed the relationship between pre-existing drug-resistant variants and clinical outcome of the combination treatment with DCV and ASV. Ten patients with HCV genotype 1b were orally treated with a combination of ASV and DCV for 24 weeks. The frequencies of amino acid (aa) variants at NS3 aa positions 155, 156 and 168 and at NS5A aa31 and 93 before and after treatment were analysed by ultra-deep sequencing. We established a minimum variant frequency threshold of 0.3% based on plasmid sequencing. Sustained virological response (SVR) was achieved in 8 out of 10 patients (80%), and relapse of HCV RNA after cessation of the treatment and viral breakthrough occurred in the other two patients. Pre-existing DCV-resistant variants (L31V/M and/or Y93H; 0.9-99.4%) were detected in three out of eight patients who achieved SVR. Pre-existing DCV-resistant variants were detected in a relapsed patient (L31M, Y93H) and in a patient with viral breakthrough (Y93H); however, no ASV-resistant variants were detected. In these patients, HCV RNA rebounded with ASV- and DCV- double resistant variants (NS3 D168A/V plus NS5A L31M and Y93H). While pre-existing DCV-resistant variants might contribute to viral breakthrough in DCV and ASV combination therapy, the effectiveness of prediction of the outcome of therapy based on ultra-deep sequence analysis of pre-existing resistant variants appears limited.

Ribavirin dose reduction during telaprevir/ribavirin/peg-interferon therapy overcomes the effect of the ITPA gene polymorphism.

Treatment success of chronic hepatitis C virus genotype 1 infection has improved with the advent of telaprevir plus peg-interferon/ribavirin triple combination therapy. However, the effect of inosine triphosphatase (ITPA) polymorphism on dose reduction during triple therapy, especially during the postmarketing phase, has not been sufficiently evaluated. We analysed 273 patients with genotype 1 infection who were treated with triple therapy and assessed the effect of the ITPA polymorphism on dose reduction. ITPA and IFNL4 SNP genotypes were determined by the Invader assay. A stepwise multivariate regression analysis was performed to identify factors associated with outcome of the therapy. The overall sustained viral response (SVR) rate 12 weeks after the end of therapy was 80.2% (219/273). Decline of haemoglobin was significantly faster, and ribavirin was more extensively reduced in patients with ITPA SNP rs1127354 genotype CC than CA/AA. Extensive reduction of ribavirin resulted in mild reduction of telaprevir and peg-interferon, but no significant increase in viral breakthrough. Although the amount of telaprevir given was slightly higher in CA/AA patients, the total dose of peg-interferon and the SVR rate did not differ between the two groups. Multivariate analysis showed that IFNL4 but not ITPA SNP genotype, platelet count and peg-interferon adherence were significantly associated with outcome of therapy. Postmarketing-phase triple therapy resulted in a high SVR rate in spite of extensive ribavirin dose reduction in a diverse patient population, indicating the importance of treatment continuation and appropriate management of adverse events.

Human microRNA hsa-miR-1231 suppresses hepatitis B virus replication by targeting core mRNA.

Pathogen-specific miRNA profiles might reveal potential new avenues for therapy. To identify miRNAs directly associated with hepatitis B virus (HBV) in hepatocytes, we performed a miRNA array analysis using urokinase-type plasminogen activator (uPA)-severe combined immunodeficiency (SCID) mice where the livers were highly repopulated with human hepatocytes and human immune cells are absent. Mice were inoculated with HBV-infected patient serum samples. Eight weeks after HBV infection, human hepatocytes were collected from liver tissues, and miRNAs were analysed using the Toray 3D array system. The effect of miRNAs on HBV replication was analysed using HBV-transfected HepG2 cells. Four miRNAs, hsa-miR-486-3p, hsa-miR-1908, hsa-miR-675 and hsa-miR-1231 were upregulated in mouse and human livers with HBV infection. These miRNAs were associated with immune response pathways such as inflammation mediated by chemokine and cytokine signalling. Of these miRNAs, hsa-miR-1231, which showed high homology with HBV core and HBx sequences, was most highly upregulated. In HBV-transfected HepG2 cells, overexpression of hsa-miR-1231 resulted in suppression of HBV replication with HBV core reduction. In conclusion, a novel interaction between hsa-miR-1231 and HBV replication was identified. This interaction might be useful in developing new therapeutic strategies against HBV.

IL28B polymorphism may guide pegylated interferon plus ribavirin therapy even after curative treatment for hepatitis C virus-related hepatocellular carcinoma.

The present study was designed to determine the predictive factors for the viral response to pegylated interferon-alpha plus ribavirin combination therapy (PEGIFN/RBV) administered after curative treatment for hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). The study group was 78 patients treated between January 2005 and January 2009. The sustained viral response (SVR) rate was 25.8% (15/58) in patients infected with HCV-genotype 1 and 55.0% (11/20) in those with genotype 2. Among the 78 patients, 32 (41.0%) could not complete the treatment protocol, and this was because of HCC recurrence in 17 (53%) of them. Multivariate analysis identified partial early viral response (pEVR) as the only independent determinant of SVR [odds ratio (OR) 14.73, P = 0.013] for patients with genotype 1. Multivariate analysis identified male gender (OR 8.72, P = 0.001) and interleukin-28B (IL-28B) genotype (rs8099917) TT (OR 7.93, P = 0.007) as independent predictors of pEVR. Multivariate analysis also identified IL-28B genotype GG+TG (OR 14.1, P = 0.021) and α-fetoprotein >30 (OR 5.4, P = 0.031) as independent predictors of null response. Patients with SVR showed a better survival rate than those without SVR (P = 0.034). The second HCC recurrence rate tended to be lower in patients with SVR than in those without SVR (P = 0.054). With regard to the prognosis of patients with SVR, it is desirable to achieve SVR with interferon therapy even when administered after HCC treatment. IL-28B genotype is a potentially useful marker for the response to PEGIFN/RBV therapy administered after curative treatment of HCV-related HCC.