HCV Q80K/R/L simeprevir resistance mutation: longitudinal surveillance by next-generation sequencing in HIV-coinfected patients during unsuccessful pegylated interferon and ribavirin therapy

SEDE M, LAUFER NL, QUARLERI J

Amsterdam

Congreso; 3rd. International Congress on Antivirals; 2014

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Background. Hepatitis C virus resistance variants confer a spectrum of decreased sensitivity to protease inhibitors. Such variants have a lower fitness than wild-type virus which correlates with the low frequency at which they are observed in untreated patients. However, the Q80K/R/L variants were reported for up to 48% of patients with HCV-1 infection. They appears to decrease sensitivity to simeprevir by 7-fold or 9-fold. Methodology. Viral RNA was extracted from plasma samples obtained from 18 patients (17 males) previous and during peg-IFN+RBV therapy. During median period of 168 days (IQR105-168) 4 sampling times were analyzed. Their mean HCV plasma viral load was 6.6±0.5 log IU/ml. HCV isolates were typed as genotype 1. Next-generation sequencing (NGS) was used for in-depth resolution of heterogeneous intra-patient viral populations. NGS (454 FLX, Roche) was performed on HCV-1 RNA populations using NS3 PCR-amplified coding region (amino acid 32-to-175) detecting resistance at frequencies below 1%. Results. The presence of Q80R/K/L was detected in 16 out of 18 patients (89%). Nevertheless in most of them (14/18) they appeared only transiently and with very low frequency (≤1%) into the viral population. The remaining two exhibited high frequencies (100% and 85%) of simeprevir-associated resistance mutations (Q80L and Q80K, respectively) from baseline for up to one year. For both, a high level of HCV replication (5.6 and 6.7 log IU/ml, respectively) was observed. Conclusions. A high natural prevalence of Q80R/K/L resistant variants has been observed in HCV-1/HIV coinfected patients who failed to peg-IFN+ribavirin therapy. Mostly they appeared as minority-variants detected ephemerally by NGS that may be outcompeted by wild-type virus. Occasionally, in spite of their presence, the level of viral replication was preserved. Since their impact on simeprevir therapy, baseline screening for the Q80R/K/L variants in HCV-1 patients may be warranted before treatment.