Short interferon and ribavirin treatment for HCV genotype 2 or 3 infection: NORDynamIC trial and real-life experience

A novel candidate hepatitis C virus genotype 4 subtype identified by next generation sequencing full-genome characterization in a patient from Saudi Arabia

Background and aim

Hepatitis C virus (HCV) infection is a major global public health concern, being a leading cause of chronic liver diseases such as chronic hepatitis, cirrhosis, and hepatocellular carcinoma. The virus is classified into 8 genotypes and 93 subtypes, each displaying distinct geographic distributions. Genotype 4 is the most predominant in the Middle East and Eastern Mediterranean and is associated with high rates of hepatitis C infection worldwide. This study used next-generation sequencing to fully characterize the HCV genome and identify a novel subtype within genotype 4 isolated from a 64-year-old Saudi man diagnosed with hepatitis C.

Methods

We analyzed the complete genome of the 141-HCV isolate using whole-genome sequencing.

Results

Our phylogenetic reconstructions, based on the entire genome of HCV-4 strains, revealed that the 141-HCV isolate formed a distinct group within the genotype 4 classification, providing valuable new insights into the variability of HCV.

Conclusion

This discovery of a previously unclassified HCV subtype within genotype 4 sheds light on the ongoing evolution and diversity of the virus. Such knowledge has significant implications for diagnostic and therapeutic approaches, as different subtypes may exhibit varying drug sensitivities and resistance profiles.

Controversies’ clarification regarding ribavirin efficacy in measles and coronaviruses: Comprehensive therapeutic approach strictly tailored to COVID-19 disease stages

BACKGROUND

Ribavirin is a broad-spectrum nucleoside antiviral drug with multimodal mechanisms of action, which supports its longevity and quality as a clinical resource. It has been widely administered for measles and coronavirus infections. Despite the large amount of data concerning the use of ribavirin alone or in combination for measles, severe acute respiratory syndrome, Middle East respiratory syndrome, and coronavirus disease 2019 (COVID-19) outbreaks, the conclusions of these studies have been contradictory. Underlying reasons for these discrepancies include possible study design inaccuracies and failures and misinterpretations of data, and these potential confounds should be addressed.

AIM

To determine the confounding factors of ribavirin treatment studies and propose a therapeutic scheme for COVID-19.

METHODS

PubMed database was searched over a period of five decades utilizing the terms “ribavirin” alone or combined with other compounds in measles, severe acute respiratory syndrome, Middle East respiratory syndrome, and COVID-19 infections. The literature search was performed and described according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Articles were considered eligible when they reported on ribavirin dose regimens and/or specified outcomes concerning its efficacy and/or possible adverse-effects. In vitro and animal studies were also retrieved. A chapter on ribavirin’s pharmacology was included as well.

RESULTS

In addition to the difficulties and pressures of an emerging pandemic, there is the burden of designing and conducting well-organized, double-blind, randomized controlled trials. Many studies have succumbed to specific pitfalls, one of which was identified in naturally ribavirin-resistant Vero cell lines in in vitro studies. Other pitfalls include study design inconsistent with the well-established clinical course of disease; inappropriate pharmacology of applied treatments; and the misinterpretation of study results with misconceived generalizations. A comprehensive treatment for COVID-19 is proposed, documented by thorough, long-term investigation of ribavirin regimens in coronavirus infections.

CONCLUSION

A comprehensive treatment strictly tailored to distinct disease stages was proposed based upon studies on ribavirin and coronavirus infections.

Ribavirin: pharmacology, multiple modes of action and possible future perspectives

Ribavirin is a unique guanosine analog with broad-spectrum activity against many RNA and DNA viruses. In addition to its mutational properties, ribavirin exerts extensive perturbation of cellular and viral gene expression. Furthermore, recent advances indicate that the impact of ribavirin on divergent cellular and viral pathways may be concentration dependent. This review aims at providing an overview of the pharmacology and multiple modes of action of ribavirin as well as pointing to possible novel future uses.

Inosine Triphosphate Pyrophosphatase Dephosphorylates Ribavirin Triphosphate and Reduced Enzymatic Activity Potentiates Mutagenesis in Hepatitis C Virus

A third of humans carry genetic variants of the ITP pyrophosphatase (ITPase) gene (ITPA) that lead to reduced enzyme activity. Reduced ITPase activity was earlier reported to protect against ribavirin-induced hemolytic anemia and to diminish relapse following ribavirin and interferon therapy for hepatitis C virus (HCV) genotype 2 or 3 infections. While several hypotheses have been put forward to explain the antiviral actions of ribavirin, details regarding the mechanisms of interaction between reduced ITPase activity and ribavirin remain unclear. The in vitro effect of reduced ITPase activity was assessed by means of transfection of hepatocytes (Huh7.5 cells) with a small interfering RNA (siRNA) directed against ITPA or a negative-control siRNA in the presence or absence of ribavirin in an HCV culture system. Low ribavirin concentrations strikingly depleted intracellular GTP levels in HCV-infected hepatocytes whereas higher ribavirin concentrations induced G-to-A and C-to-U single nucleotide substitutions in the HCV genome, with an ensuing reduction of HCV RNA expression and HCV core antigen production. Ribavirin triphosphate (RTP) was dephosphorylated in vitro by recombinant ITPase to a similar extent as ITP, a naturally occurring substrate of ITPase, and reducing ITPA expression in Huh 7.5 cells by siRNA increased intracellular levels of RTP in addition to increasing HCV mutagenesis and reducing progeny virus production. Our results extend the understanding of the biological impact of reduced ITPase activity, demonstrate that RTP is a substrate of ITPase, and may point to personalized ribavirin dosage according to ITPA genotype in addition to novel antiviral strategies.IMPORTANCE This study highlights the multiple modes of action of ribavirin, including depletion of intracellular GTP and increased hepatitis C virus mutagenesis. In cell culture, reduced ITP pyrophosphatase (ITPase) enzyme activity affected the intracellular concentrations of ribavirin triphosphate (RTP) and augmented the impact of ribavirin on the mutation rate and virus production. Additionally, our results imply that RTP, similar to ITP, a naturally occurring substrate of ITPase, is dephosphorylated in vitro by ITPase.

Treatment of hepatitis C virus infection for adults and children: updated Swedish consensus guidelines 2017

AIM

Following the approval of two new therapeutic combinations within the European Union in 2017, the former Swedish recommendations for the treatment of hepatitis C virus (HCV) infection from 2016 were deemed in need of updating.

MATERIALS AND METHODS

An expert meeting to this end was held in Stockholm, Sweden in October 2017.

RESULTS AND CONCLUSIONS

An interferon-free combination of direct-acting antiviral agents is now recommended for all patients with chronic HCV infection, regardless of liver fibrosis stage, in order to limit morbidity and spread of the disease. An extended discussion of treatment for people who inject drugs in order to diminish transmission is included.

SVR Rates of HCV-infected population under PEG-IFN-α/R treatment in Northwest China

BACKGROUND

Chronic HCV Patients taking PEG-IFN-α/R from different ethnic groups have different probabilities of reaching a sustained viral response (SVR). There are many influence factors, such as HCV genotype, IL-28B single-nucleotide polymorphisms (SNP), Fibrosis 4 index (FIB-4), and aspartate aminotransferase-to-platelet ratio index (APRI) score. But the baseline factors in relation to treatment outcome was still not much clear.

METHODS

We evaluated data from 231 chronic HCV patients with or without liver fibrosis and their antiviral efficacy after treatment with pegylated interferon plus ribavirin (PEG-IFN-α/R) for 24-48 weeks. IL-28B SNP and HCV genotypes were analyzed with genome sequencing using pyrosequencing.

RESULTS

Sustained viral response (SVR) rates of patients with HCV 1b and 2a genotypes were 52.25% (58/111) and 75.28% (67/89) (P < 0.01). SVR rates of patients with IL-28B rs8099917 TT, rs12979860 CC and rs12980275 AA were 92.41% (25/27), 92.86% (26/28) and 88.89% (24/27) separately. We found that SVR rates in HCV 1b and 2a patients were only 31.0 and 39.4% if their FIB-4 > 3.25. In addition, when their APRI > 2, only 30.3% of HCV 1b patients and 50.2% of HCV 2a patients could obtain SVR.

CONCLUSIONS

There were high proportion of HCV genotype 1b and 2a in Northwest China. In both HCV 1b and 2a genotypes, patients with protective-genotype of IL-28B were more likely to obtain SVR. However, those with significant fibrosis or cirrhosis were less likely, no matter their genotype. Combined factors of HCV genotype, IL-28B genotype, FIB-4 and ARPI may indicate high prediction and clinical value regarding treatment with PEG-IFN-α/R and prognostic evaluation of chronic hepatitis C patients.

Treatment of hepatitis C virus infection: updated Swedish Guidelines 2016

In a recent expert meeting, Swedish recommendations for the treatment of hepatitis C virus (HCV) infection were updated. An interferon-free combination of direct-acting antiviral agents is considered and indicated for all patients with chronic HCV infection, but the ability to treat all is limited primarily by high cost of medication. The group of patients prioritized for therapeutic intervention has been extended to also include fertile women desiring to become pregnant. A more thorough discussion of treatment for people who inject drugs (PWIDs) in order to diminish transmission is included, and the clinical significance of baseline NS5A resistance associated variants (RAVs), also known as resistance associated substitutions (RASs), for the treatment of HCV genotype 1a or 3 infection is discussed.

In Vitro Study on Anti-Hepatitis C Virus Activity of Spatholobus suberectus Dunn

Hepatitis C virus (HCV) infects 200 million people worldwide, and 75% of HCV cases progress into chronic infections, which consequently cause cirrhosis and hepatocellular carcinoma. HCV infection is treated with currently considered standard drugs, including direct anti-viral agents (DAAs), alone or in combination with peginterferon-α plus ribavirin. However, sustained viral responses vary in different cohorts, and high costs limit the broad use of DAAs. In this study, the ethanol and water extracts of 12 herbs from Lingnan in China were examined in terms of their inhibitory effect on HCV replication. Among the examined extracts, Spatholobus suberectus ethanol extracts suppressed HCV replication. By comparison, Extracts from Fructus lycii, Radix astragali (root), Rubus chingii Hu (fruit), Flos chrysanthemi Indici (flower), Cassia obtusifolia (seed), Lonicera japonica Thunb (flower), Forsythia suspense Thunb (fruit), Poria cocos (sclerotia), Carthamus tinctorius L. (flower), Crataegus pinnatifida Bge. (fruit), and Leonurus japonicas Houtt. (leaf) extracts failed to show a similar activity. Active S. suberectus fractions containing tannins as the major component also inhibited the in vitro translation of HCV RNA. The combination treatments of single compounds, such as epigallocatechin gallate and epicatechin gallate, were not as potent as crude S. suberectus fractions; therefore, crude S. suberectus extract may be a potential alternative treatment against HCV either alone or in combination with other agents.

Predictors of sustained virological response in patients with hepatitis C virus genotype 3 infection

Aim of the study

To assess predictors of sustained virological response (SVR) in patients with chronic hepatitis C virus (HCV) genotype 3 treated with standard therapy.

Material and methods

We retrospectively investigated data of 116 consecutive treatment-naïve patients chronically infected with HCV genotype 3, treated with pegylated interferon alpha (PegIFNα) and ribavirin (RBV) for 24 weeks. HCV RNA at week 4 (rapid virological response – RVR) and week 12 (early virological response – EVR) were measured in 85 and 105 patients respectively. Liver biopsy data were available for 103 patients. The variables were compared between patients with an SVR and those without.

Results

Overall 70.7% of patients achieved an SVR. Pretreatment factors including younger age, mild liver fibrosis as well as normal values of gamma-glutamyl transferase (GGT) and platelet count were significantly associated with higher SVR rate in univariate analysis. In the multivariate analysis only baseline platelet count > 140 000/µl and normal GGT activity were correlated with higher SVR rate. At weeks 4 and 12 HCV RNA was undetectable in 34.1% and 84.8% of patients respectively. The SVR rate was significantly higher in patients with an RVR compared to those without (p = 0.002). Only 2 patients with a rapid and early virological response did not achieve an SVR; both had negative pretreatment prognostic factors.

Conclusions

In treatment-naïve patients with genotype 3 HCV infection, low baseline platelet count and elevated GGT activity were significantly associated with poor response to PegIFNα and RBV. Achieving a rapid and early virological response was associated with higher likelihood of an SVR.

[The efficiency of antiviral therapy in patients with chronic -hepatitis C infected with hepatitis C virus recombinants]

The review gives the data available in the literature in the efficiency of treatment in patients with chronic hepatitis C infected with hepatitis C virus.(HCV) recombinants, by applying various antiviral therapy regimens. The low efficiency of treatment with- pegylated interferons (PEG IFN) + ribavirin (RIB) and sofosburin (SOF) +RIB in this patient group (a sustained virologic response was achieved in 22 and 30.7%, respectively) compared with the efficiency of treatment (87-97 and 83-97%, respectively) inpatients infected with HCV genotype 2 does not allow the 2015 EASL HCV genotype 2 treatment regimens to be used in. such patients. In this connection, subtyping genotype 2 isolates by NS5B sequencing should be introduced into clinical laboratory practice to successfully detect recombinant HCVs and to enhance the efficiency of antiviral therapy.

Community-based seroepidemiological survey of HCV infection in Catalonia, Spain

In a recent expert meeting, Swedish recommendations for the treatment of HCV infection were updated. An interferon-free combination of direct-acting antiviral agents was recommended as the first line standard-of-care treatment for chronic HCV infection. Interferon-based therapy should be considered as a second line option after an individual benefit-risk assessment. Treatment is strongly recommended for HCV infected patients with bridging fibrosis or cirrhosis (Metavir stages F3–4), before and after liver transplantation, and in the presence of extra-hepatic manifestations. Additionally, patients with moderate liver fibrosis (stage F2) as well as women in need of in vitro fertilisation should be prioritised for therapeutic intervention. Treatment indications for people who inject drugs, children, chronic kidney disease and HIV co-infection are also discussed.