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1.  Hepatitis C virus resistance to new specifically-targeted antiviral therapy: A public health perspective 
World Journal of Virology  2013;2(1):6-15.
Until very recently, treatment for chronic hepatitis C virus (HCV) infection has been based on the combination of two non-viral specific drugs: pegylated interferon-α and ribavirin, which is effective in, overall, about 40%-50% of cases. To improve the response to treatment, novel drugs have been designed to specifically block viral proteins. Multiple compounds are under development, and the approval for clinical use of the first of such direct-acting antivirals in 2011 (Telaprevir and Boceprevir), represents a milestone in HCV treatment. HCV therapeutics is entering a new expanding era, and a highly-effective cure is envisioned for the first time since the discovery of the virus in 1989. However, any antiviral treatment may be limited by the capacity of the virus to overcome the selective pressure of new drugs, generating antiviral resistance. Here, we try to provide a basic overview of new treatments, HCV resistance to new antivirals and some considerations derived from a Public Health perspective, using HCV resistance to protease and polymerase inhibitors as examples.
PMCID: PMC3785043  PMID: 24175225
Specifically-targeted antiviral therapy; Direct-acting antiviral; Protease inhibitors; Polymerase inhibitors; Viral resistance
2.  New developments in the management of hepatitis C virus infection: focus on boceprevir 
Chronic hepatitis C virus infection is an important public health problem, and the standard treatment (combination of pegylated interferon-α and ribavirin) has an effectiveness rate of only 40%–50%. Novel virus-specific drugs have recently been designed, and multiple compounds are under development. The approval for the clinical use of direct-acting antivirals in 2011 (boceprevir [BOC] and telaprevir, viral NS3 protease inhibitors) has increased recovery rates by up to 70%. Therefore, a highly effective treatment has been envisioned for the first time. This paper focuses on BOC and the implementation of new BOC-based treatment regimes.
PMCID: PMC3421477  PMID: 22904616
HCV; antiviral therapy; protease inhibitors; viral resistance
3.  Recombination in Hepatitis C Virus 
Viruses  2011;3(10):2006-2024.
Hepatitis C virus (HCV) is a Flavivirus with a positive-sense, single-stranded RNA genome of about 9,600 nucleotides. It is a major cause of liver disease, infecting almost 200 million people all over the world. Similarly to most RNA viruses, HCV displays very high levels of genetic diversity which have been used to differentiate six major genotypes and about 80 subtypes. Although the different genotypes and subtypes share basic biological and pathogenic features they differ in clinical outcomes, response to treatment and epidemiology. The first HCV recombinant strain, in which different genome segments derived from parentals of different genotypes, was described in St. Petersburg (Russia) in 2002. Since then, there have been only a few more than a dozen reports including descriptions of HCV recombinants at all levels: between genotypes, between subtypes of the same genotype and even between strains of the same subtype. Here, we review the literature considering the reasons underlying the difficulties for unequivocally establishing recombination in this virus along with the analytical methods necessary to do it. Finally, we analyze the potential consequences, especially in clinical practice, of HCV recombination in light of the coming new therapeutic approaches against this virus.
PMCID: PMC3205392  PMID: 22069526
phylogenetic tree; congruence; breakpoint; superinfection; homoplasy
Virus research  2007;130(1-2):285-291.
Chronic infection by Hepatitis C virus (HCV) causes liver fibrosis, which is accelerated by unknown mechanisms in patients with HIV-1 coinfection. The evolution of HCV quasispecies in this setting of coinfection is not fully understood. To compare HCV quasispecies between HIV-HCV coinfection and HCV monoinfection, we sequenced 340 HCV clones from the HVR-1 and NS3 regions at two different time points in two groups of treatment-naïve patients with HCV-1a infection: (1) HIV-HCV positive (n=6); and (2) HIV negative-HCV positive (n=3). In HCV/HIV coinfection, we found a trend for reduced HCV genetic complexity and diversity, and a trend towards reduced dN/dS ratios in the HVR-1 region, especially in those patients with CD4<200 cells/mm3, who lost positive selective immune pressure in the HVR-1 region. Differences in immune regulation of HCV quasispecies in HIV coinfected individuals deserve further exploration to clarify the different outcomes of chronic hepatitis C noted between the immunocompromised and the immunocompetent host.
PMCID: PMC2919681  PMID: 17601623
Immune pressure; coinfection; AIDS; envelope; NS3; CD4 counts

Results 1-4 (4)