Profile of the VERSANT HCV genotype 2.0 assay

EASL recommendations on treatment of hepatitis C: Final update of the series☆

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease, with approximately 71 million chronically infected individuals worldwide. Clinical care for patients with HCV-related liver disease has advanced considerably thanks to an enhanced understanding of the pathophysiology of the disease, as well as developments in diagnostic procedures and improvements in therapy and prevention. These therapies make it possible to eliminate hepatitis C as a major public health threat, as per the World Health Organization target, although the timeline and feasibility vary from region to region. These European Association for the Study of the Liver recommendations on treatment of hepatitis C describe the optimal management of patients with recently acquired and chronic HCV infections in 2020 and onwards.

Development and validation of a simple and rapid method for hepatitis C virus genotyping based on one-step RT-qPCR

Hepatitis C virus (HCV) infections caused by different subtypes require different treatments; therefore, rapid and cost-effective genotyping methods for the diagnosis of HCV are greatly needed. In the present study, a new method to diagnose HCV subtypes that depends on a one-step quantitative reverse transcription PCR (RT-qPCR) and TaqMan fluorescence probe technique is described. Five pairs of primers and five probes were designed, which were able to detect five genotypes in three reaction tubes. One reaction was used to detect the 1b subtype, one was used to detect the 2a and 6a subtypes, and the other was used to detect the 3a and 3b subtypes. Rigorous performance validation was implemented for five aspects: Precision, sensitivity, accuracy, specificity and anti-interference. The HCV subtype that infected 289 patients was evaluated in the present study via RT-qPCR and verified by sequencing. The results revealed that the 1b subtype accounted for 45% of infections, the 2a subtype accounted for 9% of infections, the 3a subtype accounted for 13% of infections, the 3b subtype accounted for 18% of infections, and the 6a subtype accounted for 15% of infections. The analytical sensitivity for the detection of each of the five HCV subtypes was 1,000 IU/ml. The new method performed well in the performance validation mentioned above, indicating its effectiveness as a HCV genotyping method. RT-qPCR has mitigated some of the former challenges of existing HCV genotyping methods, including the time commitment, expense, and inaccuracy of such methods. The performance validation of this new method showed that RT-qPCR is reliable enough to be widely applied in China for HCV genotyping.

Comparison of direct sequencing of the NS5B region with the Versant HCV genotype 2.0 assay for genotyping of viral isolates in Mexico

Hepatitis C virus (HCV) infection affects an estimated 71 million people worldwide. HCV is classified into eight genotypes and >70 subtypes. Determination of HCV genotype is important for selection of type and duration of antiviral therapy, and genotype is also a predictor of treatment response. The most commonly used HCV genotyping method in clinical laboratories is a hybridization-based line probe assay (LiPA; Versant HCV Genotype 2.0). However, these methods have a lack of specificity in genotype identification and subtype assignment. Here, we compared the performance of Versant HCV Genotype 2.0 with the gold standard direct sequencing of the NS5B region, in 97 samples from Mexican patients. We found a genotypic concordance of 63.9% between these methods. While 68 samples (70%) were classified into HCV genotype 1 (GT1) by NS5B sequencing, it was not true for 17 samples (17.5%), which were not match HCV subtype by LiPA. Furthermore, nine of the 33 samples classified by NS5B sequencing as GT1a were not identified by LiPA. Use of direct sequencing could improve selection of the optimal therapy, avoid possible failures of therapy and avoid high costs resulting from incorrect genotyping tests in settings without broad access to pangenotypic regimens.

Next-generation sequencing for the clinical management of hepatitis C virus infections: does one test fits all purposes?

While the prospect of viral cure is higher than ever for individuals infected with the hepatitis C virus (HCV) due to ground-breaking progress in antiviral treatment, success rates are still negatively influenced by HCV's high genetic variability. This genetic diversity is represented in the circulation of various genotypes and subtypes, mixed infections, recombinant forms and the presence of numerous drug resistant variants among infected individuals. Common misclassifications by commercial genotyping assays in combination with the limitations of currently used targeted population sequencing approaches have encouraged researchers to exploit alternative methods for the clinical management of HCV infections. Next-generation sequencing (NGS), a revolutionary and powerful tool with a variety of applications in clinical virology, can characterize viral diversity and depict viral dynamics in an ultra-wide and ultra-deep manner. The level of detail it provides makes it the method of choice for the diagnosis and clinical assessment of HCV infections. The sequence library provided by NGS is of a higher magnitude and sensitivity than data generated by conventional methods. Therefore, these technologies are helpful to guide clinical practice and at the same time highly valuable for epidemiological studies. The decreasing costs of NGS to determine genotypes, mixed infections, recombinant strains and drug resistant variants will soon make it feasible to employ NGS in clinical laboratories, to assist in the daily care of patients with HCV.

A novel point-of-care oral anti-HCV assay: Is it reliable for screening hepatitis C virus infection in the era of direct-acting antivirals?

Recent advance in the direct-acting antivirals (DAAs) offers the potentials to eradicate hepatitis C virus (HCV) worldwide and makes universal screening more urgent. A point-of-care (POC) oral anti-HCV assay, the Fortune assay, was developed and its performance was evaluated. Individuals with or without HCV infection were recruited in three Centers. Paired oral and serum samples were tested using the Fortune and InTec anti-HCV assays. The Kehua serum anti-HCV assay served as a supplemental test to verify the discordant results. Some oral samples were also tested using the OraQuick anti-HCV assay. Furthermore, the Fortune assay results were compared with the documented RNA results. Sensitivity, specificity, and accuracy of the Fortune assay was 93.11%, 98.48%, and 96.58%, respectively (n = 1,022). Consistency between the Fortune and OraQuick assays was 96.35% (264/274); the Fortune assay detected additional 8 positive oral samples missed by the OraQuick assay. The Fortune assay demonstrated a 97.46% (115/118) positivity among the viremic patients. Furthermore, its sensitivity was HCV genotype independent. In conclusion, the Fortune assay was highly specific and accurate. It had comparable sensitivity as the serum assays for the diagnosis of active HCV infection. It provides a completely non-invasive and reliable tool for HCV screening in the DAA era.