From the Journals

Genetic composition of HCV changes with HIV coinfection



Marked differences were seen in the composition of hepatitis C virus hypervariable region 1 (HVR1) when comparing HIV-coinfected (CIP) with HCV-monoinfected (MIP) individuals, according to the results of a genetic analysis of nearly 300 patients.

An enlargement of a hepatitis C vaccine is shown, Courtesy NIH

Intrahost HCV HVR1 evolution varies between these two groups, which suggests that HIV-inflicted changes in the host environment exact a strong HCV genetic response, according to a report published online in Infection, Genetics, and Evolution.

“A high prevalence of HIV-HCV coinfection and its impact on mortality among such populations groups as PWID [people who inject drugs] and MSM [men who have sex with men] is of major concern to public health,” according to the researchers.

Previous studies using the Global Hepatitis Outbreak and Surveillance Technology, a Web-based system for the detection of HCV transmission developed by the researchers, analyzed sequences of intrahost variants of the HVR1 region using next-generation sequencing. They found that genetic variation in the HVR1 of intrahost HCV variants was strongly associated with host sex and ethnicity, resistance to interferon, and stages of HCV infection.

In this particular study, the researchers assessed 28,622 nucleotide sequences of intrahost HCV HVR1 variants from 113 CIP and 176 MIP individuals.

They examined 148 physical-chemical indexes of DNA nucleotide dimers and found that there were significant differences in the means and frequency distributions of seven physical-chemical properties between HVR1 variants from both groups.

The significant majority of these profiles (98%-99%) were found to be specific to CIP or MIP, indicating that coevolution among HVR1 sites reflects HCV adaptation to HIV among coinfected individuals. “This observation suggests substantial differences in fitness between HVR1 variants circulating in infected hosts in the presence or absence of HIV, according to the researchers from the Centers for Disease Control and Prevention.

“HCV strains circulating in high-risk groups need to be carefully monitored for the identification of potentially new traits of clinical and public health relevance,” the researchers concluded.

This study was supported by CDC intramural funding. The authors reported that they had no disclosures.

SOURCE: Lara J et al. doi: 10.1016/j.meegid.2018.07.039.

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