Clinical evaluation of a newly developed automated massively parallel sequencing assay for hepatitis C virus genotyping and detection of resistance-association variants. Comparison with a line probe assay

- The HCV genotype has been shown to compromise therapy. Genotype1 is important to select optimal drug regimens.
- This comparative evaluation between the two methods demonstrates an efficient method for accurate HCV genotyping.
- Sanger sequencing is a reference method that assists accurate HCV genotyping.
- The Q80K associates with reduced response to NS3 inhibitor, and Y93H with reduced response to NS5A inhibitor found frequently in Thai patients.

Hepatitis C virus (HCV) infection is a leading cause of chronic liver disease, cirrhosis and hepatocellular carcinoma. Recently, HCV was classified into 6 major genotypes (GTs) and 67 subtypes (STs). Efficient genotyping has become an essential tool for prognosis and indicating suitable treatment, prior to starting therapy in all HCV-infected individuals. The widely used genotyping assays have limitation with regard to genotype accuracy. This study was a comparative evaluation of exact HCV genotyping in a newly developed automated-massively parallel sequencing (MPS) system, versus the established Line probe assay 2.0 (LiPA), substantiated by Sanger sequencing, using 120 previously identified-HCV RNA positive specimens. LiPA gave identical genotypes in the majority of samples tested with MPS. However, as much as 25% of LiPA did not identify subtypes, whereas MPS did, and 0.83% of results were incompatible. Interestingly, only MPS could identify mixed infections in the remaining cases (1.67%). In addition, MPS could detect Resistance-Associated Variants (RAVs) simultaneously in GT1 in 56.82% of the specimens, which were known to affect drug resistance in the HCV NS3/NS4A and NS5A genomic regions. MPS can thus be deemed beneficial for guiding decisions on HCV therapy and saving costs in the long term when compared to traditional methods.