Monday, August 30, 2010

HCV treatment

Michael Carter for Aidsmap (30 August 2010)

HCV protease inhibitors likely to work for co-infected patients previously treated for HCV

Previous treatment with pegylated interferon and ribavirin will not reduce the effectiveness of hepatitis C protease inhibitors in HIV-positive patients, US investigators report in the September 15th edition of the Journal of Infectious Diseases.

The study involved 26 HIV/hepatitis-co-infected patients. The genetic diversity of hepatitis C was evaluated in patients before and after they started treatment for this infection with pegylated interferon and ribavirin. This analysis showed that it was similar in patients who achieved a sustained virologic response to such treatment and those who did not.

“These results suggest that prior HCV [hepatitis C virus] treatment with interferon-ribavirin would not markedly impact the potential efficacy of subsequent HCV PI [protease inhibitor] treatment in coinfected patients”, comment the investigators.

Liver disease caused for hepatitis C is now an important cause of death in HIV-positive patients who are co-infected with this virus.

Hepatitis C can be treated. The current standard of care is pegylated interferon combined with ribavirin. The goal of treatment is a cure (or sustained virologic response), defined as an undetectable hepatitis C viral 24 weeks after the completion of therapy.

However, only a minority of HIV-positive patients who are chronically infected with hepatitis C clear the infection with this treatment.

It is hoped that more effective anti-hepatitis C drugs will soon become available, and the protease inhibitors boceprevir and telaprevir have shown good results in clinical trials involving both treatment-naïve and treatment experienced hepatitis C monoinfected patients.

Anti-hepatitis C protease inhibitors target a crucial step in the replication of the virus called the N-terminal domain of nonstructural protein 3 (NS3). High levels of genetic diversity at the amino acid and nucleotide levels have been observed in NS3. It is possible that previous therapy for hepatitis C could increase diversity within this gene, thereby reducing the effectiveness of protease inhibitors.

Reference

Impact of interferon-ribavirin treatment on hepatitis C virus (HCV) protease quasispecies diversity in HIV- and HCV-coinfected patients.
Aarthi Chary, Mark A. Winters, Shyam Kottilil, Alison A. Murphy, Michael A. Polis, and Mark Holodniy
Journal of Infectious Diseases 202: 889-93, 2010. DOI: 10.1086/655784

Link to JID abstract

Link to Aidsmap article

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