Catalytic hairpin assembly triggering amplified DNAzyme-feedback for sensitive detection of hepatitis C virus genotype 1b.

Developing a simple, reliable, and sensitive hepatitis C virus (HCV) genetic sensing platform is of great significance for diagnosing diseases and selecting appropriate antiviral treatments. Herein, a tandem nucleic acid amplification strategy for sensitive detection of HCV genotype 1b (HCV-1b) was developed by stringing the catalytic hairpin assembly (CHA) and the triggered DNAzyme amplifier. The hairpin reactants were initiated by the target to produce lots of triggering double-stranded DNA sequences which can efficiently activate the subsequent blocked DNAzyme. Thereby, the continuous cleavage of substrate was realized, resulting in the fluorescence signal amplification. The DNA-based isothermal CHA-DNAzyme (CDz) sensing platform was successfully applied for sensitive detection of HCV-1b with the limit of detection (84 pM) and showed good selectivity. Moreover, the practical detection of target DNA in the complex biologic matrix indicated that the developing strategy had good potential for early HCV infection diagnosis.

Best therapy for the easiest to treat hepatitis C virus genotype 1b-infected patients.

BACKGROUND: The revolution in treatment of patients with chronic hepatitis C virus (HCV) infection dates back to the introduction of direct-acting antivirals (DAAs). The increase in efficacy was most pronounced in patients infected with genotype (GT) 1b, as this was the most poorly responsive population to treatment during the interferon era. AIM: To identify the most effective interferon-free therapy for GT1b-infected patients and to determine positive and negative predictors of virological response. METHODS: This real-world retrospective analysis included patients chronically infected with GT1b HCV whose data were obtained from the multicenter observational EpiTer-2 database. Treatment effectiveness was evaluated for each therapeutic regimen as the percentage of sustained virological responses (SVR). Assessment of the safety was based on the evaluation of the course of therapy, the occurrence of adverse events including serious ones, deaths during treatment and in the post 12-wk follow-up period. RESULTS: The studied population consisted of 11385 patients with a mean age of 53 ± 14.8 years and a female predominance (53.4%). The majority of them were treatment-naïve (74.6%) and patients with cirrhosis accounted for 24.3%. Of the DAA regimens used, 76.9% were GT-specific with ombitasvir/paritaprevir/ritonavir + dasabuvir ± ribavirin being the most used option (32.4%). A total of 10903 patients responded to treatment resulting in a 98.1% in the per-protocol analysis after excluding 273 patients without SVR data. The effectiveness of all regimens exceeded 90% and the highest SVR of 98.9% was achieved in patients treated with a combination of glecaprevir/pibrentasvir. Logistic regression analyses showed that the virologic response was independently associated with female sex [odds ratio (OR) = 1.67], absence of decompensated cirrhosis at baseline (OR = 2.42) and higher baseline platelets (OR = 1.004 per 1000/µL increase), while the presence of human immunodeficiency virus (HIV) coinfection significantly decreased the odds of response (OR = 0.39). About 95%-100% of patients completed therapy irrespective of the drug regimen. At least one adverse effect occurred in 10.9%-36.3% and most of them were mild. No treatment related deaths have been reported. CONCLUSION: We documented very high effectiveness and a good safety profile across all DAA regimens. Positive predictors of SVR were female sex, absence of decompensated cirrhosis at baseline and higher platelet count while HIV coinfection reduced the effectiveness.

Identification of a novel replication-competent hepatitis C virus variant that confers the sofosbuvir resistance.

Despite the excellent antiviral potency of direct-acting antivirals (DAAs) against hepatitis C virus (HCV), emergence of drug-resistant viral mutations remains a potential challenge. Sofobuvir (SOF), a nucleotide analog targeting HCV NS5B - RNA-dependent RNA polymerase (RdRp), constitutes a key component of many anti-HCV cocktail regimens and confers a high barrier for developing drug resistance. The serine to threonine mutation at the amino acid position 282 of NS5B (S282T) is the mostly documented SOF resistance-associated substitution (RAS), but severely hampers the virus fitness. In this study, we first developed new genotype 1b (GT1b) subgenomic replicon cells, denoted PR52D4 and PR52D9, directly from a GT1b clinical isolate. Next, we obtained SOF-resistant and replication-competent PR52D4 replicon by culturing the replicon cells in the presence of SOF. Sequencing analysis showed that the selected replicon harbored two mutations K74R and S282T in NS5B. Reverse genetics analysis showed that while PR52D4 consisting of either single mutation K74R or S282T could not replicate efficiently, the engineering of the both mutations led to a replication-competent and SOF-resistant PR52D4 replicon. Furthermore, we showed that the K74R mutation could also rescue the replication deficiency of the S282T mutation in Con1, another GT1b replicon as well as in JFH1, a GT2a replicon. Structural modeling analysis suggested that K74R might help maintain an active catalytic conformation of S282T by engaging with Y296. In conclusion, we identified the combination of two NS5B mutations S282T and K74R as a novel RAS that confers a substantial resistance to SOF while retains the HCV replication capacity.

Genetic Determinants in a Critical Domain of NS5A Correlate with Hepatocellular Carcinoma in Cirrhotic Patients Infected with HCV Genotype 1b.

HCV is an important cause of hepatocellular carcinoma (HCC). HCV NS5A domain-1 interacts with cellular proteins inducing pro-oncogenic pathways. Thus, we explore genetic variations in NS5A domain-1 and their association with HCC, by analyzing 188 NS5A sequences from HCV genotype-1b infected DAA-naïve cirrhotic patients: 34 with HCC and 154 without HCC. Specific NS5A mutations significantly correlate with HCC: S3T (8.8% vs. 1.3%, p = 0.01), T122M (8.8% vs. 0.0%, p < 0.001), M133I (20.6% vs. 3.9%, p < 0.001), and Q181E (11.8% vs. 0.6%, p < 0.001). By multivariable analysis, the presence of >1 of them independently correlates with HCC (OR (95%CI): 21.8 (5.7-82.3); p < 0.001). Focusing on HCC-group, the presence of these mutations correlates with higher viremia (median (IQR): 5.7 (5.4-6.2) log IU/mL vs. 5.3 (4.4-5.6) log IU/mL, p = 0.02) and lower ALT (35 (30-71) vs. 83 (48-108) U/L, p = 0.004), suggesting a role in enhancing viral fitness without affecting necroinflammation. Notably, these mutations reside in NS5A regions known to interact with cellular proteins crucial for cell-cycle regulation (p53, p85-PIK3, and ß-catenin), and introduce additional phosphorylation sites, a phenomenon known to ameliorate NS5A interaction with cellular proteins. Overall, these results provide a focus for further investigations on molecular bases of HCV-mediated oncogenesis. The role of theseNS5A domain-1 mutations in triggering pro-oncogenic stimuli that can persist also despite achievement of sustained virological response deserves further investigation.

Incidence and predictors of direct-acting antiviral treatment failure in Turkish patients with chronic hepatitis C genotype 1b infection.

Evaluation of the incidence and predictors of failure of direct-acting antiviral treatment for hepatitis C virus genotype 1b patients is important. Our retrospective cohort study assessed 172 Turkish patients who had received a full course of such treatment and could be checked for sustained virologic response. The overall treatment failure rate was 2.9% (5/172), all of whom relapsed. In three of these cases with sequencing data available, all had NS5A resistance-associated substitution. Multivariate analysis revealed that a 1 mg/dL increase in pre-treatment total bilirubin level was associated with a sevenfold increased likelihood of treatment failure. The baseline level of total bilirubin was the only significant independent predictor of direct-acting antiviral treatment failure.

Comparative effectiveness of 8 versus 12 weeks of Ombitasvir/Paritaprevir/ritonavir and Dasabuvir in treatment-naïve patients infected with HCV genotype 1b with non-advanced hepatic fibrosis.

PURPOSE: Since 2017 treatment-naïve patients infected with genotype 1b of hepatitis C virus and minimal or moderate fibrosis can be treated with Ombitasvir/Paritaprevir/ritonavir + Dasabuvir (OPrD) for 8 weeks according to updated Summary of Product Characteristics. The aim of our study was to assess the comparative efficacy of 8 and 12-weeks therapy with OPrD in large cohort of patients eligible for 8 weeks regimen treated in real-world setting. MATERIALS AND METHODS: We analysed data of 3067 HCV genotype 1b infected patients treated with OPrD between 2015 and 2017. Final analysis included patients with none, minimal or moderate fibrosis (F0-F2). RESULTS: A total of 771 patients were enrolled in the study, including 197 (26%) treated for 8-weeks and 574 patients fulfilling criteria for 8-weeks but assigned to 12-weeks regimen. Majority of patients had no or minimal fibrosis (F0-F1). Longer treatment duration was more often administered in patients with moderate fibrosis, comorbidities, concomitant medications. SVR was achieved in 186 (94%) patients treated for 8 weeks and 558 (97%) for 12 weeks (p = 0.07). After exclusion of lost to follow-up patients, sustained virological response (SVR) rate reached 95% and 99%, respectively (p = 0.01). We were not able to identify factors associated with non-response. CONCLUSIONS: This real-word experience study confirmed similar, high effectiveness of 8 and 12-weeks regimens of OPrD in genotype 1b HCV infected patients with non-advanced fibrosis. Despite of reduced SVR rate after 8-weeks regimen, there is no need to extend therapy to 12-weeks in vast majority of such patients and no need to add ribavirin.

Clinical outcomes after the introduction of direct antiviral agents for patients infected with genotype 1b hepatitis C virus depending on the regimens: A multicenter study in Korea.

BACKGROUND: A real-life study is essential outside clinical trials. The aim is to evaluate the clinical outcomes of direct acting agents (DAA) for patients with chronic hepatitis C (CHC) in real practice. METHODS: We analyzed 590 consecutively enrolled patients with CHC-1b who received DAAs since 2015, when DAAs were introduced in Korea. The patients were checked for resistance-associated variants (RAV) against nonstructural protein 5A inhibitors and then daclatasvir/asunaprevir or sofosbuvir based regimens were chosen. RESULTS: The frequency of patients with cirrhosis and prior hepatocellular carcinoma (HCC) was 29.2% and 4.7%, respectively. For the RAV test, 10% were positive and in 3.6% the result was "indeterminate." Overall, 518 patients were treated with a 24-week regimen of daclatasvir/asunaprevir, 72 patients (RAV positive 75%) were treated with 12 weeks regimen of ledipasvir/sofosbuvir or daclatasvir/sofosbuvir. The SVR12 was 94.0% in the daclatasvir/asunaprevir, 98.2% in the ledipasvir/sofosbuvir, and 100% in the daclatasvir/sofosbuvir group. A total of 93.3% of SVR12 in the RAV-"indeterminate" patients was not difference 95.0% in the RAV-negative patients. Up to 1 year, de novo HCC occurrence and recurrence developed in 2.6% and 17.8%, respectively. HCC was more frequent in cirrhotic patients than in noncirrhotic patients (P = 0.000). α Fetoprotein (AFP) level at the end of treatment was a predicting factor for de novo HCC. CONCLUSIONS: Optimizing the choice of DAAs according to RAV test resulted in high SVR among CHC-1b Korean patients. This real practice multicenter cohort study suggests the importance of AFP and HCC surveillance in cirrhotic patients even after successful HCV therapy.

Efficacy and safety of elbasvir plus grazoprevir combination therapy in Japanese patients infected with hepatitis C virus genotype 1b.

AIM: Treatment with all-oral direct-acting antiviral agents (DAAs) elbasvir/grazoprevir (EBR/GZR) is associated with high sustained virologic response (SVR). The aim of this study was to evaluate the safety and treatment efficacy of EBR/GZR in hepatitis C virus (HCV)-infected patients. METHODS: This retrospective cohort study included 147 consecutive patients with chronic HCV genotype 1b infection who were treated with EBR (50 mg) plus GZR (100 mg) once daily for 12 weeks. The rates of SVR at 12 weeks after the end of treatment (SVR12) were evaluated based on patient baseline characteristics. Treatment efficacy was analyzed according to background chronic kidney disease (CKD), and retreatment efficacy in patients who failed to respond to previous DAAs. RESULTS: The SVR12 was 94% (138 of 147 patients), based on intention-to-treat analysis. Rates of SVR12 were 97% (131 of 135) and 58% (7 of 12) in cases naïve to DAA treatment and failure to respond to prior DAAs, respectively. The SVR12 rates in patients with CKD stage 4-5 was 100% (8 of 8). All patients (4 of 4 patients) with stage 4-5 and advanced fibrosis (Fibrosis-4 index ≥3.25) also achieved SVR12. Multivariate analysis that included the above variables identified pretreatment with other DAAs as an independent factor that was significantly and independently associated with non-SVR12 (odds ratio, 97.5; P < 0.001). Relapsers of first DAAs, excluding the combination of ledipasvir and sofosbuvir, achieved SVR12. Characteristic novel non-structural protein 5A substitutions were not detected after failure of retreatment with EBR/GZR. CONCLUSION: Treatment with EBR/GZR was highly efficacious with acceptable safety, even in patients with CKD stage 4-5. Retreatment of relapsers to prior DAAs, excluding ledipasvir and sofosbuvir, achieved SVR12.

Daclatasvir and asunaprevir combination therapy for patients with chronic hepatitis C virus genotype 1b infection in real world.

BACKGROUND/AIMS: Previous studies have reported a high rate of sustained virologic response (SVR) and a low rate of serious adverse events with the use of daclatasvir (DCV) and asunaprevir (ASV) combination therapy. We evaluated the efficacy and safety of DCV and ASV combination therapy for patients with chronic hepatitis C virus (HCV) genotype 1b infection in real world. METHODS: We enrolled 278 patients (184 treatment-naïve patients) from five hospitals in Daegu and Gyeongsangbuk-do. We evaluated the rates of rapid virologic response (RVR), end-of-treatment response (ETR), and SVR at 12 weeks after completion of treatment (SVR12). Furthermore, we investigated the rate of adverse events and predictive factors of SVR12 failure. RESULTS: The mean age of patients was 59.5 ± 10.6 years, and 140 patients (50.2%) were men. Seventy-seven patients had cirrhosis. Baseline information regarding nonstructural protein 5A (NS5A) sequences was available in 268 patients. Six patients presented with pretreatment NS5A resistance-associated variants. The RVR and the ETR rates were 96.6% (258/267) and 95.2% (223/232), respectively. The overall SVR12 rate was 91.6% (197/215). Adverse events occurred in 17 patients (7.9%). Six patients discontinued treatment because of liver enzyme elevation (n = 4) and severe nausea (n = 2). Among these, four achieved SVR12. Other adverse events observed were fatigue, headache, diarrhea, dizziness, loss of appetite, skin rash, and dyspnea. Univariate analysis did not show significant predictive factors of SVR12 failure. CONCLUSION: DCV and ASV combination therapy showed high rates of RVR, ETR, and SVR12 in chronic HCV genotype 1b-infected patients in real world and was well tolerated without serious adverse events.

Efficacy of precision therapy with direct-acting antiviral drugs for patients with chronic HCV genotype 1b infection / 中华临床感染病杂志

Objective To evaluate the efficacy of precision therapy with direct-acting antiviral drugs (DAAs) for patients with chronic HCV gene type 1b infection.Methods One hundred and thirteen patients with chronic HCV genotype 1b infection admitted in the Department of Infectious Diseases of First Hospital of Shanxi Medical University from January 2018 to July 2019 were enrolled,including 89 patients with chronic hepatitis and 24 patients with cirrhosis.Different DAAs therapeutic schedule were taken based on liver function, kidney function, complication and treatment costs.Seventy-two patients were treated with pan-genotype drugs, including 43 patients treated with Sofosbuvir and Velpatasvir (SOF+VEL), 13 treated with Sofosbuvir and Ribavirin ( SOF +RBV), and 16 treated with Sofosbuvir and Daclatasvir ( SOF +DCV).Forty one patients were treated with specific genotype DAAs , including 15 treated with Ombitasvir and Dasabuvir (OBV+DSV), and 26 treated with Elbasvir and Grazoprevir tablets (EBR+GZR).Pair t test and Chi-square test were used to compare virological response rate , the liver function and the adverse reactions were observed.Results The super-rapid virological response (SRVR) rate with DAAs treatment at 1 week was 88.5%(100／113),and the rapid virological response ( RVR) at 4 weeks of treatment was 98.2%(111／113).There was no significant differences in SRVR and RVR among the patients treated with five treatment regimens (χ2 ＝5.95 and 1.04,P＞0.05), all the patients obtained complete early virological response (CEVR) at 12 weeks and sustained virological response ( SVR12) at 12 weeks after treatment. Besides, there were no significant differences in SRVR and RVR between pan-genotype and gene-specific drugs (χ2 ＝0.03 and 0.17, P＞0.05),both CEVR and SVR12 reached 100% in all patients.The liver transaminase levels were improved in patients undergoing pan-genotype or gene-specific drugs treatment. Mild adverse reactions were observed in 5 cases, hemolysis occurred in 1 patient and it was cured after replacement of drugs.Conclusion Both pan-genotype and specific genotypes of DAAs can achieve high virological response rates.Genotypic testing should be performed before antiviral therapy , in order to accurately select treatment options and to save costs.