Kei Fujiwara

Detection of Anti-Hepatitis C Virus Effects of Interferon and Ribavirin by a Sensitive Replicon System

ABSTRACT Although combination therapy with interferon and ribavirin has improved the treatment for chronic hepatitis C virus (HCV) infection, the detailed anti-HCV effect of ribavirin in clinical concentrations remains uncertain. To detect the anti-HCV effect of ribavirin in lower concentrations, a sensitive and accurate assay system was developed using the reporter replicon system with an HCV genotype 2a subgenomic replicon (clone JFH-1) that exhibits robust replication in various cell lines. This reporter replicon was generated by introducing the luciferase reporter gene (instead of the neomycin resistance gene) into the subgenomic JFH-1 replicon. To assess the replication of this reporter replicon, luciferase activity was measured serially up to day 3 after transient transfection of Huh7 cells. The luciferase activity increased exponentially over the time course of the experiment. After adjustment for transfection efficiency and transfected cell viability, the impacts of interferon and ribavirin were determined. The administration of interferon and ribavirin resulted in dose-dependent suppression of replicon RNA replications. The 50% inhibitory concentration of interferon and ribavirin was 1.80 IU/ml and 3.70 μg/ml, respectively. In clinical concentrations, replications were reduced to 0.09% and 53.74% by interferon (100 IU/ml) and ribavirin (3 μg/ml), respectively. Combination use of ribavirin and interferon enhanced the anti-HCV effect of interferon by 1.46- to 1.62-fold. In conclusion, we developed an accurate and sensitive replicon system, and the antivirus effect of interferon and ribavirin was easily detected within their clinical concentrations by this replicon system. This system will provide a powerful tool for screening new antiviral compounds against HCV.

T1653 Mutation in the Box a Increases the Riskof Hepatocellular Carcinoma in Patients with Chronic Hepatitis B Virus Genotype C Infection

BACKGROUND Most patients with chronic hepatitis B virus infection become carriers of inactive virus after hepatitis B e antigen seroconversion; however, a subgroup of patients have persistent abnormal transaminase levels and develop hepatocellular carcinoma after seroconversion. METHODS In an age-matched case-control study, 40 carriers of inactive virus (mean age+/-standard deviation [SD], 50.9 +/- 11.1 years), 40 patients with chronic hepatitis (mean age+/-SD, 50.2 +/- 8.9 years), and 40 patients with hepatocellular carcinoma (mean age+/-SD, 50.7 +/- 9.4 years) who were infected with hepatitis B virus genotype C and had test results positive for antibody to hepatitis B e antigen were analyzed. RESULTS The prevalence of T1653 in the box alpha was significantly higher among patients with hepatocellular carcinoma than among carriers of inactive virus who did not have hepatocellular carcinoma (70% vs. 25%; P < .0001) or chronic hepatitis (70% vs. 35%; P = .003). Mutations in the basic core promoter region (T1762/A1764) were frequently found in all groups, regardless of clinical status (in 77.5% of carriers of inactive virus, 77.5% of patients with chronic hepatitis, and 90% of patients with hepatocellular carcinoma). In the multivariate analysis, the presence of T1653, an alanine aminotransferase level of > or = 37 U/L, and a platelet count of < 18 x 10(4) platelets/mm3 were independent predictive values for hepatocellular carcinoma (odds ratio [95% confidence interval], 5.05 [1.56-16.35], 12.56 [3.05-51.77], and 11.5 [3.47-38.21], respectively). High alpha -fetoprotein level was the only independent predictive value for T1653 in patients with hepatocellular carcinoma (odds ratio, 12.67; 95% confidence interval, 1.19-134.17]). Among patients with test results positive for antibody to hepatitis B e antigen who had hepatocellular carcinoma and were infected with different genotypes of hepatitis B virus, the prevalence of T1653 was 40%, 15%, 25%, 25%, 67%, and 23% in patients infected with hepatitis B virus genotypes Aa, Ae, Ba, Bj, C, and D, respectively (P<.05 for genotype C vs. genotypes Ae, Ba, Bj, or D). CONCLUSIONS Our data indicate that the addition of T1653 mutation in the box alpha to the basic core promoter mutation increases the risk of hepatocellular carcinoma in patients with hepatitis B virus genotype C.

Transforming growth factor-beta-1 genetic polymorphism in Japanese patients with chronic hepatitis C virus infection

Background and Aim:  Transforming growth factor beta‐1 (TGF‐β1) is one of the most dominant fibrogenic cytokines in hepatic fibrosis. The aim of the present study was to examine the effects of TGF‐β1 polymorphisms in Japanese patients with chronic hepatitis C virus (HCV) infection and in healthy control subjects.

Investigation of residual hepatitis C virus in presumed recovered subjects

Recent studies have found hepatitis C virus (HCV) RNA in peripheral blood mononuclear cells (PBMCs) of the majority of presumed recovered subjects. We investigated this unexpected finding using samples from patients whose HCV RNA and anti‐HCV status had been serially confirmed. HCV RNA was detected in PBMCs from 66 of 67 chronic HCV carriers. Subpopulation analysis revealed that the viral load (log copies/106 cells) in B cells (4.14 ± 0.71) was higher than in total PBMCs (3.62 ± 0.71; P < 0.05), T cells (1.67 ± 0.88; P < 0.05), and non‐B/T cells (2.48 ± 1.15; P < 0.05). HCV negative‐strand RNA was not detected in PBMCs from any of 25 chronically infected patients. No residual viral RNA was detected in total PBMCs or plasma of 59 presumed recovered subjects (11 spontaneous and 48 treatment induced) using nested real‐time polymerase chain reaction with a detection limit of 2 copies/μg RNA (from ∼1 × 106 cells). PBMCs from 2 healthy HCV‐negative blood donors became HCV RNA positive, with B‐cell predominance, when mixed in vitro with HCV RNA–positive plasma, thus passively mimicking cells from chronic HCV carriers. No residual HCV was detected in liver or other tissues from 2 spontaneously recovered chimpanzees. Conclusion: (1) HCV RNA was detected in PBMCs of most chronic HCV carriers and was predominant in the B‐cell subpopulation; (2) HCV detected in PBMCs was in a nonreplicative form; (3) HCV passively adsorbed to PBMCs of healthy controls in vitro, becoming indistinguishable from PBMCs of chronic HCV carriers; and (4) residual HCV was not detected in plasma or PBMCs of any spontaneous or treatment‐recovered subjects or in chimpanzee liver, suggesting that the classic pattern of recovery from HCV infection is generally equivalent to viral eradication. (HEPATOLOGY 2013)

Combination of hepatitis B viral antigens and DNA for prediction of relapse after discontinuation of nucleos(t)ide analogs in patients with chronic hepatitis B

Aim:  The factors associated with hepatitis recurrence after discontinuation of nucleos(t)ide analogs (NAs) in patients with chronic hepatitis B were analyzed to predict the risk of relapse more accurately.

Novel Type of Hepatitis B Virus Mutation: Replacement Mutation Involving a Hepatocyte Nuclear Factor 1 Binding Site Tandem Repeat in Chronic Hepatitis B Virus Genotype E

ABSTRACT The genetic diversity of hepatitis B virus (HBV) strains has evolved through mutations such as point mutations, deletions or insertions, and recombination. We identified and characterized a novel type of mutation which is a complex of external insertion, deletion, and internal duplication in sequences from one of six patients with chronic hepatitis B virus genotype E (HBV/E). We provisionally named this mutation a “replacement mutation”; the core promoter upstream regulatory sequence/basic core promoter was replaced with a part of the S1 promoter covering the hepatocyte nuclear factor 1 (HNF1) binding site, followed by a tandem repeat of the HNF1 site. A longitudinal analysis of the HBV population over 6 years showed the clonal change from wild-type HBV/E to replacement-mutant type, resulting in a lower hepatitis B (HB) e antigen titer, a high HBV DNA level in serum, and progression of liver fibrosis. In an in vitro study using a replication model, the replacement-mutant HBV showed higher replication levels than the wild-type HBV/E replicon, probably mediated by altered transcription factor binding. Additionally, this HNF1 site replacement mutation was associated with excessive HB nucleocapsid protein expression in hepatocytes, in both in vivo and in vitro studies. This novel mutation may be specific to HBV genotype E, and its prevalence requires further investigation.

Lack of association between occult hepatitis B virus DNA viral load and aminotransferase levels in patients with hepatitis C virus-related chronic liver disease

Background and Aim:  Occult hepatitis B virus (HBV) infection in hepatitis C virus (HCV)‐infected patients might enhance the severity of chronic liver disease (CLD). To elucidate the correlation between occult HBV infection and the clinical course of HCV‐related CLD, we evaluated whether the fluctuation of occult HBV‐DNA directly affects the serum alanine aminotransferase (ALT) level.

Clinical Evaluation of Sofosbuvir/Ledipasvir in Chronic Hepatitis C Genotype 1 with and without Prior Daclatasvir/Asnaprevir Therapy.

This study explored treatment outcomes of sofosbuvir (SOF)/ledipasvir (LDV) therapy for chronic hepatitis C patients with and without prior daclatasvir (DCV)/asunaprevir (ASV) therapy.

Clinical evaluation of sofosbuvir/ledipasvir in patients with chronic hepatitis C genotype 1 with and without prior daclatasvir/asunaprevir therapy

This study explored treatment outcomes of sofosbuvir (SOF)/ledipasvir (LDV) therapy for chronic hepatitis C patients with and without prior daclatasvir (DCV)/asunaprevir (ASV) therapy.

Noninvasive evaluation of hepatic fibrosis in hepatitis C virus‐infected patients using ethoxybenzyl‐magnetic resonance imaging

Liver biopsy is the gold standard test to determine the grade of fibrosis, but there are associated problems. Because gadolinium‐ethoxybenzyl‐diethylenetriamine pentaacetic acid is secreted partially in hepatocytes and bile, it is possible that ethoxybenzyl‐magnetic resonance imaging (EOB‐MRI) correlates with liver function and liver fibrosis. The aim of this study was to compare the fibrosis seen in liver biopsy samples to the signal intensity of the hepatobiliary phase measured on EOB‐MRI in hepatitis C virus (HCV)‐infected patients.