Clinical relevance of the HCV protease inhibitor-resistant mutant viral load assessed by ultra-deep pyrosequencing in treatment failure

Hepatitis C reinfection with protease inhibitor-resistant hepatitis C virus in an HIV-coinfected MSM

There is an ongoing global hepatitis C virus (HCV) epidemic mainly related to high-risk behaviour in persons who inject drugs (PWID) and in HIV-infected men who have sex with men (MSM) which continues to fuel the HCV epidemic. Treatment of HCV infection with direct antiviral therapy (DAA) has been very successful in the last decade. Main obstacles for HCV elimination are HCV reinfections observed in PWID and HIV-infected MSM. We present here an HIV-infected MSM patient who has been reinfected thrice with HCV. The virus which was investigated from his last reinfection episode reveals transmission of a newly acquired HCV protease inhibitor (PI) resistance, despite not having been exposed to HCV-PIs during his last DAA therapy.

Hepatitis C virus resistance to the new direct-acting antivirals

INTRODUCTION

The treatment of hepatitis C virus (HCV) infection has dramatically improved in recent years with the widespread use of interferon-free combination regimens. Despite the high sustained virological response (SVR) rates (over 90%) obtained with direct-acting antivirals (DAAs), drug resistance has emerged as a potential challenge. The high replication rate of HCV and the low fidelity of its RNA polymerase result in a high degree of genetic variability in the HCV population, which ultimately explains the rapid selection of drug resistance associated variants (RAVs).

AREAS COVERED

Results from clinical trials and real-world experience have both provided important information on the rate and clinical significance of RAVs. They can be present in treatment-naive patients as natural polymorphisms although more frequently they are selected upon treatment failure. In patients engaged in high-risk behaviors, RAVs can be transmitted.

EXPERT OPINION

Although DAA failures generally occur in less than 10% of treated chronic hepatitis C patients, selection of drug resistance is the rule in most cases. HCV re-treatment options are available, but first-line therapeutic strategies should be optimized to efficiently prevent DAA failure due to baseline HCV resistance. Considerable progress is being made and next-generation DAAs are coming with pangenotypic activity and higher resistance barrier.