Impaired HBsAg release and antiproliferative/antioxidant cell regulation by HBeAg-negative patient isolates reflects an evolutionary process.

BACKGROUND: The hepatitis B e antigen (HBeAg)-negative infection Phase 3 is characterized by no or minimal signs of hepatic inflammation and the absence of hepatic fibrosis. However, underlying molecular mechanisms leading to this benign phenotype are poorly understood. METHODS: Genotype A, B and D HBeAg-negative patient isolates with precore mutation G1896A from Phase 3 were analysed in comparison with respective HBeAg-positive rescue mutant and HBeAg-positive wild-type reference genomes regarding differences in viral replication, morphogenesis, infectivity and impact on NF-E2-related factor 2 (Nrf2)/antioxidant response element (ARE)-dependent gene expression and cellular kinome. RESULTS: In comparison with reference genomes, the patient isolates are characterized by a lower intra- and extracellular hepatitis B surface antigen (HBsAg)-amount, and HBsAg-retention in the endoplasmic reticulum. Rescue of HBeAg expression increased HBsAg-amount but not its release. Expression of the isolated genomes is associated with a higher Nrf2/ARE-dependent gene expression as compared to reference genomes independent of HBeAg expression. Kinome analyses revealed a decreased activity of receptors involved in regulation of proliferative pathways for all patient isolates compared to the reference genomes. No specific conserved mutations could be found between all genomes from Phase 3. CONCLUSIONS: HBeAg-negative genomes from Phase 3 exhibit distinct molecular characteristics leading to lower HBsAg synthesis and release, enhanced oxidative stress protection and decreased activity of key kinases, triggering an antiproliferative stage, which might contribute to the lower probability of hepatocellular carcinoma. The observed differences cannot be associated with loss of HBeAg or specific mutations common to all analysed isolates, indicating the phenotype of Phase 3 derived genomes to be the result of a multifactorial process likely reflecting a conserved natural selection process.

[The status of national and global hepatitis C elimination]. / Stand der nationalen und globalen Hepatitis-C-Elimination.

BACKGROUND: In 2016, the World Health Organization propagated the elimination of hepatitis C virus (HCV) by 2030 in order to address the public health threat posed by viral hepatitis. This article looks at the progress that has been made globally and in Germany since 2016. METHODS: A selective literature search was conducted, with particular focus on studies and reviews relating to the elimination of hepatitis C infection both globally and in Germany. RESULTS: In 2020, 56.8 million HCV infections were counted worldwide, which corresponds to a decline of 6.8 million since 2015. Countries that made a significant contribution to the elimination figures during this period included Egypt, Georgia, and Iceland, which were able to drastically reduce the number of HCV infections by means of national commitment in politics and healthcare. With regard to the status of elimination in Germany, the inclusion of screening for viral hepatitis in the general health check-up ("Check-up 35") in 2022/2023 has led to a significant increase in HCV case numbers. Globally and in Germany, men who have sex with men, intravenous drug users, migrants, and prison inmates are particularly vulnerable groups with regard to HCV infection. CONCLUSION: In order to sustainably eliminate HCV, it is necessary to optimize education and prevention strategies in risk groups. With regard to the subgroup of prison inmates, political measures must be used to create a standardized approach in prison medicine. At a global level, elimination in low- and middle-income countries needs to be promoted in the future.

[Hepatitis C: From diagnosis to global virus elimination]. / Hepatitis C: von der Diagnose zur weltweiten Virus-Elimination.

Chronic infection with hepatitis C virus (HCV) is a common cause of complications such as liver cirrhosis and hepatocellular carcinoma (HCC). It is one of the most significant infectious diseases worldwide, posing a substantial health burden. Since the introduction of direct-acting antiviral agents (DAAs), the treatment landscape has undergone a revolution. HCV infection is curable, and the treatment is safe and well tolerated. Due to the availability of this effective therapeutic option, the World Health Organization (WHO) set an ambitious goal in 2015 to eliminate Hepatitis C by 2030, a goal that the German government also embraced in 2016. The key tasks involve identifying previously undiagnosed cases and ensuring they receive antiviral treatment. Addressing at-risk populations through specific measures, including micro-elimination projects and population-wide campaigns, is essential to achieving the WHO's target both in Germany and globally.

Real-world effectiveness of voxilaprevir/velpatasvir/sofosbuvir in patients following DAA failure.

Background & Aims: Voxilaprevir/velpatasvir/sofosbuvir (VOX/VEL/SOF) is highly effective for re-treatment of direct-acting antiviral (DAA)-experienced patients with chronic HCV infection. In the present study, predictors of virologic treatment response were analyzed in an integrative analysis of three large real-world cohorts. Methods: Consecutive patients re-treated with VOX/VEL/SOF after DAA failure were enrolled between 2016 and 2021 in Austria, Belgium, Germany, Italy, Spain and Switzerland. Results: A total of 746 patients were included: median age was 56 (16-88) years and 77% were male. Most patients were infected with HCV genotype 1 (56%) and 3 (32%). 86% of patients carried resistance-associated substitutions in the NS3, NS5A or NS5B regions. Overall, 95.4% (683/716) of patients achieved a sustained virologic response. Treatment effectiveness was significantly affected by advanced liver disease (p <0.001), hepatocellular carcinoma (p <0.001), higher baseline ALT levels (p = 0.02), HCV genotype 3 (p <0.001), and prior VEL/SOF treatment (p = 0.01). In a multivariate analysis, only HCV genotype 3, hepatocellular carcinoma and cirrhosis turned out to be independent predictors of treatment failure. Resistance-associated substitutions, as well as the presence of rare genotypes, did not impact treatment outcome. The effectiveness of rescue therapy with glecaprevir/pibrentasvir and SOF, with or without ribavirin, for 12 to 24 weeks was found to be high (100%). Conclusions: Infection with HCV genotype 3, the presence of liver cancer and cirrhosis are independently associated with failure of VOX/VEL/SOF re-treatment. It is unclear whether the addition of ribavirin and/or extension of treatment duration may be effective to avoid virologic relapse on VOX/VEL/SOF. However, rescue treatment with glecaprevir/pibrentasvir+SOF seems to be effective. Impact and implications: Representative data on the effectiveness of voxilaprevir/velpatasvir/sofosbuvir (VOX/VEL/SOF) in clinical practice are still scarce and the collection of a larger number of patients with difficult-to-treat cofactors including the assessment of resistance-associated substitution profiles is required before more specific recommendations for optimal re-treatment in these patients can be given. Thus, we aimed to analyze treatment effectiveness and predictors of virologic response to VOX/VEL/SOF in an integrative analysis of three large real-word cohorts. The study results, derived from a multicenter cohort consisting of 746 patients, demonstrated that re-treatment with VOX/VEL/SOF is an effective salvage therapy associated with an overall per protocol sustained virologic response rate of 95%. Hepatocellular carcinoma onset, cirrhosis and HCV genotype 3 were identified as independent negative predictors of treatment response, whereas resistance-associated substitutions, as well as rare genotypes and chimera, did not impact sustained virologic response rates following re-treatment with VOX/VEL/SOF.

Rare HCV subtypes and retreatment outcomes in a cohort of European DAA-experienced patients.

Background and Aims: Data on the prevalence and characteristics of so-called rare HCV genotypes (GTs) in larger cohorts is limited. This study investigates the frequency of rare GT and resistance-associated substitutions and the efficacy of retreatment in a European cohort. Methods: A total of 129 patients with rare GT1-6 were included from the European resistance database. NS3, NS5A, and NS5B were sequenced and clinical parameters and retreatment efficacies were collected retrospectively. Results: Overall 1.5% (69/4,656) of direct-acting antiviral (DAA)-naive and 4.4% (60/1,376) of DAA-failure patients were infected with rare GT. Although rare GTs were almost equally distributed throughout GT1-6 in DAA-naive patients, we detected mainly rare GT4 (47%, 28/60 GT4; of these n = 17, subtype 4r) and GT3 (25%, 15/60 GT3, of these n = 8, subtype 3b) among DAA-failures. A total of 62% (37/60) of DAA failures had not responded to first-generation regimes and the majority was infected with rare GT4 (57%, 21/37). In contrast, among patients with failure to pangenotypic DAA regimens (38%, 23/60), infections with rare GT3 were overrepresented (57%, 13/23). Although NS5A RASs were uncommon in rare GT2, GT5a, and GT6, we observed combined RASs in rare GT1, GT3, and GT4 at positions 28, 30, 31, which can be considered as inherent. DAA failures with completed follow-up of retreatment, achieved a high SVR rate (94%, 45/48 modified intention-to-treat analysis; 92%, 45/49 intention-to-treat). Three patients with GT4f, 4r, or 3b, respectively, had virological treatment failure. Conclusions: In this European cohort, rare HCV GT were uncommon. Accumulation of specific rare GT in DAA-failure patients suggests reduced antiviral activities of DAA regimens. The limited global availability of pangenotypic regimens for first line therapy as well as multiple targeted regimens for retreatment could result in HCV elimination targets being delayed. Impact and implications: Data on the prevalence and characteristics of rare HCV genotypes (GT) in larger cohorts are still scarce. This study found low rates of rare HCV GTs among European HCV-infected patients. In direct-acting antiviral (DAA)-failure patients, rare GT3 subtypes accumulated after pangenotypic DAA treatment and rare GT4 after first generation DAA failure and viral resistance was detected at NS5A positions 28, 30, and 31. The limited global availability of pangenotypic DAA regimens for first line therapy as well as multiple targeted regimens for retreatment could result in HCV elimination targets being delayed.