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Novel ‘genotype 8’ surfaces among four patients with HCV

Researchers identified four patients with a novel hepatitis C genotype, according to study published in The Journal of Infectious Diseases.

Despite the genotype’s genetic distinction from previously identified HCV genotypes 1 through 7, all four patients achieved sustained virologic response with direct-acting antivirals.

“Seven major genotypes (GTs) have been recognized to date, the complete genomes of which dier from each other by at least 30% at the nucleotide level,” Sergio M. Borgia, MD, FRCP(C), from the Brampton Civic Hospital in Ontario, Canada, and colleagues wrote.

The study comprised four patients with HCV who were originally diagnosed with genotype 5 by commercial assays. The patients resided in Canada and were originally from Punjab, India.

“The discovery of a novel HCV GT8 confirms the endemic nature of HCV in the Indian subcontinent, particularly in the Punjab State, which has one of the highest prevalence rates in the country and has important implications for the genetic and epidemiological characterization of the HCV epidemic worldwide,” Borgia and colleagues wrote.

Based on maximum likelihood phylogenetic analysis, the researchers concluded that the patients were infected with a novel, distinct HCV genotype referred to as “genotype 8.” Compared with previously identified HCV genotypes, genotype 8 had an average 67% to 71% similar sequence identity across the NS3, NS5A and NS5B genes.

Two patients underwent treatment with Vosevi (sofosbuvir/velpatasvir/voxilaprevir, Gilead Sciences) for 8 weeks, one patient underwent treatment with combination Sovaldi (sofosbuvir, Gilead Sciences) and Daklinza (daclatasvir, Bristol-Myers Squibb) for 12 weeks, and one patient underwent a 6-month treatment course with Harvoni (sofosbuvir/ledipasvir, Gilead Sciences).

“Because GTs, in addition to being vital for the characterization of the epidemiology and evolution of HCV, are also important in determining the treatment regimen, the inaccurate identification of infecting GTs may place patients at risk of treatment failure, if non-pangenotypic regimens are used,” the researchers wrote. “Further research into the discovery and characterization of additional cohorts of patients with HCV GT8 infection, and yet unidentified GTs, will enhance the confidence in pangenotypic treatments as well as help to better understand the role of HCV GT in a highly mobile global population.” – by Talitha Bennett

Disclosure: Borgia reports he has received research and study agreement grants from and is on the advisory boards for AbbVie, Gilead Sciences and Merck; and he has consultancy agreements with Gilead Sciences and Merck. Please see the full study for the other authors’ relevant financial disclosures.