Comparison of direct sequencing and Invader assay for Y93H mutation and response to interferon-free therapy in hepatitis C virus genotype 1b

Prognosis of Patients with Chronic Hepatitis C Genotype 1b Infection Treated Using Daclatasvir/Asunaprevir after Sustained Virologic Response: A 6-Year Multicenter Prospective Observational Study

Aim and Objectives: Direct-acting antiviral (DAA) therapy can cure chronic hepatitis C (CHC), and daclatasvir (DCV)/asunaprevir (ASV) was the first interferon-free DAA therapy introduced in Korea. Patients who achieve sustained virologic response (SVR) after DAA treatment are expected to have good prognoses. Therefore, in this study, we aimed to investigate the prognosis of these patients. Materials and Methods: This multicenter prospective observational study included patients with CHC who achieved SVR after DCV/ASV treatment. The primary endpoint was hepatocellular carcinoma (HCC) occurrence, which was reviewed annually. Results: We included 302 patients (median follow-up duration: 38 [16.5-60.0] months; median age: 58 [49-67] years) in the study. Cirrhosis was observed in 103 patients (34.1%), and the median Child-Pugh score was 5.0. HCC occurred in 16 patients (5.3%) within six years post-SVR; these patients were older and had higher cirrhosis prevalence, alpha-fetoprotein levels, and fibrosis-4 index scores than did those without HCC development. Cox proportional hazards analysis revealed that age > 71 years (p = 0.005) and cirrhosis (p = 0.035) were significant risk factors for HCC occurrence. Conclusions: Although the prognoses of patients who achieved SVR with DCV/ASV therapy were generally good, the risk for HCC was present, especially in older patients and in those with cirrhosis. Hence, early treatment at younger ages and regular follow-up surveillance after achieving SVR are warranted.

Hepatitis C virus enhances Rubicon expression, leading to autophagy inhibition and intracellular innate immune activation

Autophagy, a degradation system, works to maintain cellular homeostasis. However, as the impact of Hepatitis C virus (HCV) infection on hepatocyte autophagy and its effect on HCV replication remain unclear, we examined them. HCV infection suppressed late-stage autophagy and increased Rubicon. siRNA-mediated knockdown of Rubicon promoted autophagy in HCV-infected cells. In Huh-7 cells harbouring the HCV replicon, Rubicon knockdown downregulated the expression of type 1 interferon (IFN)-related genes and upregulated HCV replication. Rubicon overexpression or administration of bafilomycin A1 or chloroquine, an inhibitor of late-stage autophagy, suppressed autophagy and activated the type 1 IFN pathway. On the other hand, Atg7 knockout suppressed early-stage autophagy and did not activate the type 1 IFN pathway. In livers of humanized liver chimeric mice, HCV infection increased Rubicon and enhanced type 1 IFN signalling. Elimination of HCV in the mice reduced the increase in Rubicon due to HCV infection. The expression levels of Rubicon and IFN-stimulated genes in chronic hepatitis C patients were higher than those in non-B, non-C hepatitis patients. HCV infection increased Rubicon and suppressed hepatocyte autophagy, leading to activation of the intracellular immune response. Rubicon induction is involved in HCV replication via activation of the intracellular immune response.

Glecaprevir/pibrentasvir+sofosbuvir: an optimal retreatment strategy in the setting of HCV NS5A resistance

Some individuals do not achieve a cure of their hepatitis C virus (HCV) infection due to non-adherence or resistance associated substitutions. Salvage options that are optimised for resistance profiles are essential. We report a 56-year-old Caucasian man with fatigue, depression and confusion in the setting of untreated HCV genotype 3a infection. He received ruzasvir and uprifosbuvir for 12 weeks within a clinical trial. The patient relapsed 4 weeks after the end of treatment and at this time resistance testing showed multiple resistances including a NS5A Y93H mutation. Given that this mutation confers resistance to first line salvage options, sofosbuvir and glecaprevir/pibrentasvir was used for 12 weeks and the patient was cured of HCV infection 12 weeks after the end of treatment. This shows that sofosbuvir and glecaprevir/pibrentasvir is a viable, effective option for second line/salvage therapy of HCV infection in the setting of resistance to NS5A inhibitors with the Y93H mutation.

Isothermal Amplification Methods for the SNP Genotyping

The demands for genotyping techniques with acceptable precision, accuracy, cost-effectiveness in high throughput formats made driving forces for continuous development of novel technologies. A wide range of mutation detection techniques based on polymerase chain reaction (PCR) have been introduced. The best alternatives were the isothermal amplification technologies that those did not require a thermal cycler. In this review, we aimed to describe the most known isothermal amplification techniques for SNP genotyping.

Late relapse of hepatitis C virus in patients with sustained virological response after daclatasvir and asunaprevir therapy

The optimal term of follow-up for patients who achieve sustained virological responses (SVR) is an important topic because of the widespread use of direct-acting antivirals (DAA), which achieve a high SVR rate. Investigations of long-term follow-up among patients with SVR after interferon (IFN) therapy have reported that approximately 80%-100% of patients maintained SVR. However, the long-term durability of SVR to DAA treatment is unknown. The aim of this study was to evaluate the incidence of late relapse in patients who achieved SVR with daclatasvir (DCV) and asunaprevir (ASV). Four hundred and thirteen patients infected with hepatitis C virus (HCV) genotype 1b who completed ASV and DCV treatment and achieved SVR were selected. Patients who were persistently negative for serum HCV RNA at 24 weeks after withdrawal of DCV and ASV were considered to have SVR24. Mean follow-up period was 21.5 months (range, 4.8-30.3 months) after SVR24. Four patients redeveloped HCV RNA in serum at 6, 12, 12 and 26 months, respectively, after achieving SVR24. Results of molecular analysis by phylogenetic tree of HCV nonstructural protein 3 and 5A regions from late relapse indicated that the same strain was present at pretreatment and late relapse. In conclusion, late relapse by the original HCV strain was confirmed by direct sequencing in 4 of 413 patients with SVR to ASV and DCV. Although a few patients may develop late relapse, SVR achieved with all oral DAA therapy is as durable as that with IFN therapy.

Systematic review with meta-analysis: effectiveness and tolerability of interferon-free direct-acting antiviral regimens for chronic hepatitis C genotype 1 in routine clinical practice in Asia

BACKGROUND

Direct-acting antiviral (DAA) regimens have shown high efficacy and tolerability for patients with HCV genotype 1/1b (GT1/1b) in clinical trials. However, robust real-world evidence of interferon (IFN)-free DAA treatment for HCV GT1-infected patients in Asia is still lacking.

AIM

To systematically review and meta-analyse the effectiveness and tolerability of IFN-free DAA therapy for HCV GT1 infection in Asia.

METHODS

We included studies that enrolled adult patients with HCV GT1 infection in routine clinical practice in Asia, using IFN-free DAA regimens, and reported sustained virological response (SVR) after 12/24 weeks end-of-treatment by 31 May 2017. The pooled SVR rates were computed with a random-effects model. Subgroup analysis and meta-regression as previously registered in PROSPERO were performed to determine how pre-planned variables might have affected the pooled estimates.

RESULTS

We included 41 studies from eight countries and regions, comprising of 8574 individuals. The pooled SVR rates for GT1 were 89.9% (95% CI 88.6-91.1, I2  = 55.1%) with daclatasvir/asunaprevir (DCV/ASV) and 98.1% (95% CI 97.0-99.0, I2  = 41.0%) with ledipasvir/sofosbuvir ± ribavirin (LDV/SOF ± RBV). Baseline cirrhosis but not prior treatment history and age, attenuated the effectiveness of both regimens. Baseline resistance associated substitutions (RASs) severely attenuated SVR of DCV/ASV (65.4% vs 94.3%, P < 0.001) and only minimally with LDV/SOF ± RBV (94.5% vs 99.2%, P = 0.003). Patients with renal dysfunction treated with DCV/ASV showed a higher SVR rate (93.9% vs 89.8%, P = 0.046). Patients with hepatocellular carcinoma (HCC) LDV/SOF ± RBV achieved a lower SVR than those without HCC (94.1% vs 98.7%, P = 0.001).

CONCLUSION

All oral DAA treatment of HCV GT1 resulted in high cure rates in Asian patients in routine clinical practice setting including elderly patients and those with end-stage renal disease.