Immunological Analysis During Interferon-Free Therapy for Chronic Hepatitis C Virus Infection Reveals Modulation of the Natural Killer Cell Compartment

Sofosbuvir (+) daclatasvir (+) ribavirin in Egyptian patients with hepatitis C virus: Therapeutic outcomes and the prognostic role of natural killer cells

BACKGROUND

One of the prominent causes of chronic liver disease worldwide is the hepatitis C virus (HCV). HCV believed that innate immunity contributes to a sustained virological response (SVR) to the treatment of Sofosbuvir (SOF) (+) Daclatasvir (DCV) (+) Ribavirin (RBV). This study aimed to evaluate the impact of SOF (+) DCV (+) RBV therapy and persistent HCV infection on the subset of natural killer cells (NK) in HCV genotype four patients from Egypt.

MATERIALS AND METHODS

One hundred and ten patients with persistent HCV infections requiring SOF (+) DCV (+) RBV therapy were grouped, and a flow cytometry (FCM) study of the NK cell subset in peripheral blood was performed. The assessment was performed before and after three and/or six months of the cessation of viral suppression therapy when a patient had a long-term viral response (SVR). One hundred and ten volunteers from the National Liver Institute's (NLI) blood bank were selected as controls.

RESULTS

Patients with chronic HCV infection before therapy had considerably lower CD16+ and CD3- CD56+ cells than controls. Their levels increase during SOF (+) DCV (+) RBV therapy. In patients with SVR during treatment, CD16+ and CD3- CD56+ cells increased significantly compared to those who did not get SVR. Furthermore, CD56+ cells were significantly higher in patients with persistent infection before treatment than controls but diminished with the response to treatment.

CONCLUSION

NK cell activation following SOF (+) DCV (+) RBV therapy and polarization to cytotoxicity occurred early in HCV antiviral therapy and was elevated in the respondents. Our data illustrated that establishing an inhibitory cytotoxic NK profile is related to therapeutic outcomes.

Revaccination for Hepatitis B in Previous Nonresponders Following Hepatitis C Eradication

BACKGROUND

Patients with chronic hepatitis C virus (HCV) do not respond to hepatitis B virus (HBV) vaccination as efficiently as the general population. We assessed if revaccination after HCV treatment resulted in improved response.

METHODS

Previous HBV vaccine nonresponders were prospectively recruited for revaccination after HCV eradication. Hepatitis B surface antibody (HBsAb) testing was performed 1 month after series completion.

RESULTS

Follow-up HBsAb testing was performed in 31 of 34 enrolled patients with 21 (67.7%) reactive results. There were no significant differences in HBsAb reactivity based on age, sex, race, or advanced fibrosis presence.

CONCLUSIONS

HBV vaccine nonresponders should be considered for revaccination following HCV cure.

Hepatitis C Virus and the Host: A Mutual Endurance Leaving Indelible Scars in the Host's Immunity

Hepatitis C virus (HCV) has spread worldwide, and it is responsible for potentially severe chronic liver disease and primary liver cancer. Chronic infection remains for life if not spontaneously eliminated and viral persistence profoundly impairs the efficiency of the host's immunity. Attempts have been made to develop an effective vaccine, but efficacy trials have met with failure. The availability of highly efficacious direct-acting antivirals (DAA) has created hope for the progressive elimination of chronic HCV infections; however, this approach requires a monumental global effort. HCV elicits a prompt innate immune response in the host, characterized by a robust production of interferon-α (IFN-α), although interference in IFN-α signaling by HCV proteins may curb this effect. The late appearance of largely ineffective neutralizing antibodies and the progressive exhaustion of T cells, particularly CD8 T cells, result in the inability to eradicate the virus in most infected patients. Moreover, an HCV cure resulting from DAA treatment does not completely restore the normal immunologic homeostasis. Here, we discuss the main immunological features of immune responses to HCV and the epigenetic scars that chronic viral persistence leaves behind.

Proteomics reveals a global phenotypic shift of NK cells in HCV patients treated with direct-acting antivirals

Chronic hepatitis C virus (HCV) infections compromise natural killer (NK)-cell immunity. Direct-acting antivirals (DAA) effectively eliminate HCV, but the long-term effects on NK cells in cured patients are debated. We conducted a proteomic study on CD56+ NK cells of chronic HCV-infected patients before and 1 year after DAA therapy. Donor-variation was observed in NK-cell proteomes of HCV-infected patients, with 46 dysregulated proteins restored after DAA therapy. However, 30% of the CD56+ NK-cell proteome remained altered 1 year post-therapy, indicating a phenotypic shift with low donor-variation. NK cells from virus-negative cured patients exhibited global regulation of RNA-processing and pathways related to "stimuli response", "chemokine signaling", and "cytotoxicity regulation". Proteomics identified downregulation of vesicle transport components (CD107a, COPI/II complexes) and altered receptor expression profiles, indicating an inhibited NK-cell phenotype. Yet, activated NK cells from HCV patients before and after therapy effectively upregulated IFN-γ and recruited CD107a. Conversely, reduced surface expression levels of Tim-3 and 2B4 were observed before and after therapy. In conclusion, this study reveals long-term effects on the CD56+ NK-cell compartment in convalescent HCV patients 1 year after therapy, with limited abundance of vesicle transport complexes and surface receptors, associated with a responsive NK-cell phenotype.

NK cell subsets and dysfunction during viral infection: a new avenue for therapeutics?

In the setting of viral challenge, natural killer (NK) cells play an important role as an early immune responder against infection. During this response, significant changes in the NK cell population occur, particularly in terms of their frequency, location, and subtype prevalence. In this review, changes in the NK cell repertoire associated with several pathogenic viral infections are summarized, with a particular focus placed on changes that contribute to NK cell dysregulation in these settings. This dysregulation, in turn, can contribute to host pathology either by causing NK cells to be hyperresponsive or hyporesponsive. Hyperresponsive NK cells mediate significant host cell death and contribute to generating a hyperinflammatory environment. Hyporesponsive NK cell populations shift toward exhaustion and often fail to limit viral pathogenesis, possibly enabling viral persistence. Several emerging therapeutic approaches aimed at addressing NK cell dysregulation have arisen in the last three decades in the setting of cancer and may prove to hold promise in treating viral diseases. However, the application of such therapeutics to treat viral infections remains critically underexplored. This review briefly explores several therapeutic approaches, including the administration of TGF-β inhibitors, immune checkpoint inhibitors, adoptive NK cell therapies, CAR NK cells, and NK cell engagers among other therapeutics.

Spontaneous Rupture of Hepatocellular Carcinoma With Fatal Outcome in a Patient Taking Direct-Acting Antivirals

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors globally. Many complications are attributed to it, including spontaneous rupture, which is a serious and rare complication that can be life-threatening. Managing and detecting this condition might pose challenges, especially when there is no prior history of liver cirrhosis or tumor. We report on a 57-year-old man followed as an outpatient for chronic hepatitis C who presented to the emergency department for abdominal pain with abdominal distention and jaundice, occurring two months after treatment by direct-acting antiviral (DAA). He was not known to have a liver tumor on the ultrasound performed before the start of treatment. Therefore, the diagnosis of tumor rupture was not very clear. The evolution was fatal, and death occurred quickly. Although the association between DAA treatment and hepatocarcinogenesis and its possible complications is unknown, close monitoring by high-performance imaging is probably required in patients under DAA.

Immunological scars after cure of hepatitis C virus infection: Long-HepC?

Hepatitis C virus (HCV) infection provides a unique opportunity to study the effects of spontaneous or treatment-induced viral elimination on the human immune system. Twenty to 50% of patients with acute HCV infection spontaneously clear the virus, which is related to the quality of the individual's immune response, while the chronic infection is associated with an altered and impaired immune response. Direct-acting antiviral agents are now available that provide sustained viral elimination in more than 95% of patients with chronic HCV infection. Viral elimination leads to a decrease in disease sequelae such as cirrhosis and hepatocellular carcinoma, and extrahepatic manifestations also improve. However, some patients may still experience long-term complications, and viral elimination does not protect against HCV reinfection. This review addresses the question of whether the altered and impaired immune response caused by HCV normalizes after viral elimination and if this may affect the long-term clinical course after HCV cure.

Innate-like T lymphocytes in chronic liver disease

In addition to its metabolic activities, it is now clear that the liver hosts a number of diverse immune cell types that control tissue homeostasis. Foremost among these are innate-like T lymphocytes, including natural killer T (NKT) and mucosal-associated innate T (MAIT) cells, which are a population of specialized T cells with innate characteristics that express semi-invariant T cell receptors with non-peptide antigen specificity. As primary liver residents, innate-like T cells have been associated with immune tolerance in the liver, but also with a number of hepatic diseases. Here, we focus on the biology of NKT and MAIT cells and how they operate during the course of chronic inflammatory diseases that eventually lead to hepatocellular carcinoma.

Direct-acting Antiviral-induced Transient Recovery of NK Cells in Early-stage Treatment of Chronic Hepatitis C Patients

BACKGROUND AND AIMS

The rapid clearance of hepatitis C virus induced by direct-acting antivirals (DAAs) affects natural killer (NK) cells, but the reported results are not consistent, and the relative mechanism was unclear. This study focused on the dynamic changes of NK cells during and after DAA treatment and analyzed the reasons.

METHODS

Peripheral blood from 35 chronic hepatitis C patients who were treated with DAAs were collected at baseline and weeks 1, 2, 4, 12, and post-treatment week-12. The frequency, subset, and phenotype of NK cells were assayed by flow cytometry. Lactate dehydrogenase assays were used to evaluate the cytotoxicity of NK cells. Cytokine concentrations were measured with Luminex kits.

RESULTS

All patients achieved a sustained viral response (SVR), and the NK cell frequencies were not changed significantly during DAA therapy. However, the cytotoxicity of NK cells recovered significantly early in week 1, and then continuously decreased below normal levels. The changes of genotypes including NKp30⁺, NKp46⁺, and NKG2A⁺ NK cells were parallel to NK function. The subset of CD56^dim NK cells continuously increased and did not return to normal even at 12 weeks after treatment. Interleukin (IL)-2, IL10, IL15, interferon-gamma, and tumor necrosis factor-alpha all increased after week 4, peaked at the end of therapy, and then exhibited varying degrees of reduction with time.

CONCLUSIONS

DAA treatment led to transient functional recovery of NK cells in the early stage of treatment, and then continuously decreased to below normal levels. Alterations of NK subsets, phenotypes, and the microenvironment may be involved in the changes.

Soluble Immune Checkpoint Protein CD27 Is a Novel Prognostic Biomarker of Hepatocellular Carcinoma Development in Hepatitis C Virus-Sustained Virological Response Patients

Factors affecting the probability of hepatocellular carcinoma (HCC) development even after sustained virological response (SVR) following anti-hepatitis C virus (HCV) therapy remain unelucidated. This study characterized the role of 16 soluble (s) immune checkpoint proteins in 168 HCV-SVR patients, with 47 developing HCC at the study end point. At baseline, high concentrations of 10 immune checkpoint proteins were found in the sera of the HCC group. At the study end point, levels of sCD27, sCD28, sCD40, and sCD86 in the HCC group, which were depleted following SVR, returned to higher levels than those in the non-HCC group. More importantly, patients with baseline levels of sCD27 ≥ 4104 pg/mL, sCD28 ≥ 1530 pg/mL, and sCD40 ≥ 688 pg/mL predicted a significantly greater HCC cumulative rate. Although sCD27 was elevated in patient sera, its membrane-bound form, mCD27, accumulated in the tumor and peritumor area, mainly localized in T cells. Interestingly, T-cell activation time dependently induced sCD27. Furthermore, CD70, the ligand of CD27, was robustly expressed in HCC area in which CD70 promoter methylation analysis indicated the hypomethylation compared with the nontumor pairs. Recombinant human CD27 treatment induced the proliferation of CD70-bearing HepG2 cells via the mitogen-activated protein kinase (MEK)-extracellular signal-regulated kinase pathway, but not NF-κB or p38 pathway. In conclusion, these data indicate that baseline sCD27, sCD28, and sCD40 levels could be used as HCC prognostic markers in HCV-SVR patients. sCD27 likely promotes HepG2 cell growth via the CD27-CD70 axis.

Response of Human Liver Tissue to Innate Immune Stimuli

Precision-cut human liver slice cultures (PCLS) have become an important alternative immunological platform in preclinical testing. To further evaluate the capacity of PCLS, we investigated the innate immune response to TLR3 agonist (poly-I:C) and TLR4 agonist (LPS) using normal and diseased liver tissue. Pathological liver tissue was obtained from patients with active chronic HCV infection, and patients with former chronic HCV infection cured by recent Direct-Acting Antiviral (DAA) drug therapy. We found that hepatic innate immunity in response to TLR3 and TLR4 agonists was not suppressed but enhanced in the HCV-infected tissue, compared with the healthy controls. Furthermore, despite recent HCV elimination, DAA-cured liver tissue manifested ongoing abnormalities in liver immunity: sustained abnormal immune gene expression in DAA-cured samples was identified in direct ex vivo measurements and in TLR3 and TLR4 stimulation assays. Genes that were up-regulated in chronic HCV-infected liver tissue were mostly characteristic of the non-parenchymal cell compartment. These results demonstrated the utility of PCLS in studying both liver pathology and innate immunity.

Surveillance for hepatocellular carcinoma: current status and future perspectives for improvement

INTRODUCTION

Hepatocellular carcinoma (HCC) is a globally relevant medical problem. Fortunately, risk factors for this tumor have been identified, and surveillance protocols developed. Patients with liver cirrhosis have the highest risk of developing HCC and have historically been included in surveillance programs. Special categories have also emerged in recent years, especially patients with eradicated HCV infection or nonalcoholic fatty liver disease. Novel serum biomarkers and magnetic resonance imaging protocols are currently being proposed to refine existing surveillance protocols.

AREAS COVERED

We discuss the rationale of surveillance programs for HCC and report the most recent recommendations from international guidelines about this topic. Gray areas, such as nonalcoholic fatty liver disease and the role of intrahepatic cholangiocellular carcinoma, are also discussed.

EXPERT OPINION

Surveillance is recognized as a tool to favor early diagnosis of HCC, access to curative treatment, and increase survival, even if the supporting evidence is mainly based on observational studies. As new randomized clinical trials are difficult to propose, future challenges will include optimizing implementation in the primary care setting and a more personalized approach, balancing the opportunities and risks of overdiagnosis of novel techniques and biomarkers.

Imprint of unconventional T-cell response in acute hepatitis C persists despite successful early antiviral treatment

Unconventional T cells (UTCs) are a heterogeneous group of T cells that typically exhibit rapid responses toward specific antigens from pathogens. Chronic hepatitis C virus (HCV) infection causes dysfunction of several subsets of UTCs. This altered phenotype and function of UTCs can persist over time even after direct-acting antiviral (DAA)-mediated clearance of chronic HCV. However, it is less clear if and how UTCs respond in acute, symptomatic HCV infection, a rare clinical condition, and if rapid DAA treatment of such patients reverses the caused perturbations within UTCs. Here, we comprehensively analyzed the phenotype and reinvigoration capacity of three major UTC populations, mucosal-associated invariant T (MAIT) cells, γδ T cells, and CD4 and CD8 double-negative αβ T cells (DNT cells) before, during, and after DAA-mediated clearance of acute symptomatic HCV infection. Furthermore, MAIT cell functionality was systematically studied. We observed a reduced frequency of MAIT cells. However, remaining cells presented with a near-to-normal phenotype in acute infection, which contrasted with a significant dysfunction upon stimulation that was not restored after viral clearance. Notably, DNT and γδ T cells displayed a strong activation ex-vivo in acute HCV infection, which subsequently normalized during the treatment. In addition, DNT cell activation was specifically associated with liver inflammation and inflammatory cytokines. Altogether, these data provide evidence that UTCs respond in a cell type-specific manner during symptomatic HCV infection. However, even if early treatment is initiated, long-lasting imprints within UTCs remain over time.

Crosstalk between tumor-associated macrophages and neighboring cells in hepatocellular carcinoma

The tumor microenvironment generally shows a substantial immunosuppressive activity in hepatocellular carcinoma (HCC), accounting for the suboptimal efficacy of immune-based treatments for this difficult-to-treat cancer. The crosstalk between tumor cells and various cell types in the tumor microenvironment is strongly related to HCC progression and treatment resistance. Monocytes are recruited to the HCC tumor microenvironment by various factors and become tumor-associated macrophages (TAMs) with distinct phenotypes. TAMs often contribute to weakened tumor-specific immune responses and a more aggressive phenotype of malignancy. Recent single-cell RNA-sequencing data have demonstrated the central roles of specific TAMs in tumorigenesis and treatment resistance by their interactions with various cell populations in the HCC tumor microenvironment. This review focuses on the roles of TAMs and the crosstalk between TAMs and neighboring cell types in the HCC tumor microenvironment.

Direct-Acting Antivirals Improve Treatment Outcomes in Patients with Hepatitis C Virus-Related Hepatocellular Carcinoma Treated with Transarterial Chemoembolization: A Nationwide, Multi-center, Retrospective Cohort Study

BACKGROUND AND AIMS

The influence of direct-acting antivirals (DAAs) on chronic hepatitis C (CHC)-related hepatocellular carcinoma (HCC) remains controversial. We investigated the effect of eradicating CHC using DAAs on treatment outcomes in patients with CHC-related HCC treated with transarterial chemoembolization (TACE).

METHODS

This nationwide, multi-center, retrospective study recruited patients with CHC-related HCC treated with TACE as the first-line anti-cancer treatment, and who achieved a sustained virological response (SVR) using DAAs (DAA group) between 2006 and 2017. Patients achieving an SVR following interferon-based treatment (IFN group) and those without treatment (control group) were also recruited for comparison.

RESULTS

A total of 425 patients were eligible for the study. Of these, 356 (83.8%), 26 (6.1%), and 43 (10.1%) were allocated to the control, IFN, and DAA groups, respectively. A multivariate analysis showed that liver cirrhosis, segmental portal vein thrombosis, and larger maximal tumor size independently predicted an increased risk of progression (all p < 0.05), whereas, the DAA group (vs. IFN and control groups) independently predicted a reduced risk of progression (hazard ratio (HR) = 0.630, 95% confidence interval 0.411-0.966, p = 0.034). The cumulative incidence rate of HCC progression in the DAA group was significantly lower than that in the IFN and control groups (p = 0.033, log-rank test). In addition, the DAA group (vs. IFN and control groups) was independently associated with a reduced risk of mortality (p = 0.042).

CONCLUSIONS

DAA treatment provided significantly prolonged progression-free survival in patients with CHC-related HCC treated with TACE compared to that in patients administered IFN or no treatment.

Signatures of immune dysfunction in HIV and HCV infection share features with chronic inflammation in aging and persist after viral reduction or elimination

Chronic inflammation is thought to be a major cause of morbidity and mortality in aging, but whether similar mechanisms underlie dysfunction in infection-associated chronic inflammation is unclear. Here, we profiled the immune proteome, and cellular composition and signaling states in a cohort of aging individuals versus a set of HIV patients on long-term antiretroviral therapy therapy or hepatitis C virus (HCV) patients before and after sofosbuvir treatment. We found shared alterations in aging-associated and infection-associated chronic inflammation including T cell memory inflation, up-regulation of intracellular signaling pathways of inflammation, and diminished sensitivity to cytokines in lymphocytes and myeloid cells. In the HIV cohort, these dysregulations were evident despite viral suppression for over 10 y. Viral clearance in the HCV cohort partially restored cellular sensitivity to interferon-α, but many immune system alterations persisted for at least 1 y posttreatment. Our findings indicate that in the HIV and HCV cohorts, a broad remodeling and degradation of the immune system can persist for a year or more, even after the removal or drastic reduction of the pathogen load and that this shares some features of chronic inflammation in aging.

Hepatitis C Virus Relapse After Ultrashort Direct-Acting Antiviral Therapy Associates With Expression of Genes Involved With Natural Killer-Cell and CD8+ T-Cell Function

To identify immunologic correlates of hepatitis C virus (HCV) relapse after direct-acting antiviral (DAA) therapy, we quantified select immune transcripts in whole blood from noncirrhotic HCV subjects treated with 4-6 weeks of DAAs. We identified specific markers of natural killer-cell and CD8+ T-cell function (GZMB, PRF1, NKp46) with higher expression in subjects who relapsed. These findings suggest a role for host immunity in HCV eradication with ultrashort DAA therapy. We quantified whole blood immune transcripts in noncirrhotic HCV subjects treated with shortcourse antiviral therapy. Markers of natural killer-cell and CD8+ T-cell function had higher expression in virologic relapsers, suggesting a role for host immunity in HCV eradication.

Hepatitis C Virus (HCV) Direct-Acting Antiviral Therapy in Persons With Human Immunodeficiency Virus-HCV Genotype 1 Coinfection Resulting in High Rate of Sustained Virologic Response and Variable in Normalization of Soluble Markers of Immune Activation

BACKGROUND

Hepatitis C virus (HCV) direct-acting antivirals are highly effective. Less is known about changes in markers of immune activation in persons with human immunodeficiency virus (HIV) in whom a sustained virologic response (SVR) is achieved.

METHODS

We conducted a nonrandomized clinical trial of 12 or 24 weeks of paritaprevir-ritonavir-ombitasvir plus dasabuvir (PrOD) with or without ribavirin in persons with HCV-1/HIV coinfection suppressed with antiretroviral therapy. Plasma HCV, soluble CD14 (sCD14), interferon-inducible protein 10, soluble CD163 (sCD163), interleukin 6 (IL-6), interleukin 18, monocyte chemoattractant protein (MCP-1), autotaxin (ATX), and Mac2-binding protein (Mac2BP) were measured over 48 weeks.

RESULTS

Participants were treated with PrOD for 12 (n = 9) or 24 (n = 36) weeks; the SVR rate at 12 weeks was 93%. At baseline, cirrhosis was associated with higher ATX and MCP-1, female sex with higher ATX and IL-6, older age with higher Mac2BP, higher body mass index with higher ATX, and HIV-1 protease inhibitor use with higher sCD14 levels. In those with SVR, interferon-inducible protein 10, ATX, and Mac2BP levels declined by week 2, interleukin 18 levels declined by the end of treatment, sCD14 levels did not change, and sCD163, MCP-1, and IL-6 levels changed at a single time point.

CONCLUSIONS

During HIV/HCV coinfection, plasma immune activation marker heterogeneity is in part attributable to age, sex, cirrhosis, body mass index, and/or type of antiretroviral therapy. HCV treatment with paritaprevir-ritonavir-ombitasvir plus dasabuvir is highly effective and is associated with variable rate and magnitude of decline in markers of immune activation.

CLINICAL TRIALS REGISTRATION

NCT02194998.

Immunological Mechanisms for Hepatocellular Carcinoma Risk after Direct-Acting Antiviral Treatment of Hepatitis C Virus Infection

Direct-acting antiviral agents (DAAs) that allow for rapid clearance of hepatitis C virus (HCV) may evoke immunological changes. Some cases of rapid de novo hepatocellular carcinoma (HCC) development or early recurrence of HCC after DAA treatment have been reported. During chronic HCV infection, natural killer (NK) cells exhibited a deviant functional phenotype with decreased production of antiviral cytokines and increased cytotoxicity; however, DAA treatment rapidly decreased their cytotoxic function. Effective DAA therapy also suppressed the intrahepatic activation of macrophages/monocytes. This was followed by a decrease in mucosal-associated invariant T (MAIT) cell cytotoxicity without normalization of cytokine production. Rapid changes in the phenotypes of NK and MAIT cells after DAA treatment may attenuate the cytotoxicity of these cells against cancer cells. Moreover, DAA treatment did not normalize the increased frequencies of regulatory T cells even after clearance of HCV infection. Thus, the persistently increased frequency of regulatory T cells may contribute to a local immunosuppressive milieu and hamper the clearance of cancer cells. This review will focus on recent studies describing the changes in innate and adaptive immune responses after DAA treatment in patients with chronic HCV infection in the context of de novo occurrence or recurrence of HCC.

Adaptive Natural Killer Cell Functional Recovery in Hepatitis C Virus Cured Patients

BACKGROUND AND AIMS

Current evidence suggests that dysfunctional natural killer (NK) cell responses during hepatitis C virus (HCV) infection can be restored after viral eradication with direct acting antivirals (DAAs). However, the fate of the recently described adaptive NK cell population, endowed with increased ability to mediate antibody-dependent cell-mediated cytotoxicity (ADCC), during HCV infection is poorly defined, while no study has explored the effects of DAAs on this NK subset.

APPROACH AND RESULTS

We performed multicolor flow cytometry to investigate CD57⁺ FcεRIγ^neg adaptive and FcεRIγ^pos conventional NK cell phenotype and function before and after DAA treatment in 59 patients chronically infected with HCV, 39 with advanced liver fibrosis, and 20 with mild-moderate liver fibrosis. Moreover, bulk NK cell phenotype and function were analyzed after cytokine activation following contact with K562 target cells. The proportion of FcεRIγ^neg NK cells in patients with HCV was associated with increased HCV load at baseline, and it was significantly reduced after treatment. Patients with an advanced fibrosis stage displayed increased NK cell activation and exhaustion markers that normalized after therapy. Of note, adaptive NK cells from patients with HCV were characterized by increased programmed death receptor 1 expression and reduced ADCC activity at baseline. DAA treatment restored ADCC ability and reduced programmed death receptor 1 expression.

CONCLUSIONS

HCV profoundly affects the frequency, phenotype, and function of adaptive NK cells. DAA therapy restores a normal adaptive NK phenotype and enhances interferon-gamma production by this cell subset.

Peripheral blood correlates of virologic relapse after Sofosbuvir and Ribavirin treatment of Genotype-1 HCV infection

Background

Treatment of chronic hepatitis C virus infection with direct acting antiviral therapy results in viral elimination in over 90% of cases. The duration of treatment required to achieve cure differs between individuals and relapse can occur. We asked whether cellular and transcriptional profiling of peripheral blood collected during treatment could identify biomarkers predictive of treatment outcome.

Methods

We analyzed peripheral blood collected during treatment of genotype 1 HCV with 24 weeks of sofosbuvir and weight-based or low dose ribavirin in a trial in which 29% of patients relapsed. Changes in host immunity during treatment were assessed by flow cytometry and whole blood gene expression profiling. Differences in expression of immune-relevant transcripts based on treatment outcome were analyzed using the Nanostring Human Immunology V2 panel.

Results

Multiple cellular populations changed during treatment, but pre-treatment neutrophil counts were lower and natural post-treatment killer cell counts were higher in patients who relapsed. Pre-treatment expression of genes associated with interferon-signaling, T-cell dysfunction, and T-cell co-stimulation differed by treatment outcome. We identified a pre- and post-treatment gene expression signature with high predictive capacity for distinguishing treatment outcome, but neither signature was sufficiently robust to suggest viability for clinical use.

Conclusions

Patients who relapse after hepatitis C virus therapy differ immunologically from non-relapsers based on expression of transcripts related to interferon signaling and T-cell dysfunction, as well as by peripheral neutrophil and NK-cell concentrations. These data provide insight into the host immunologic basis of relapse after DAA therapy for HCV and suggests mechanisms which may be relevant for understanding outcomes with currently approved regimens.

Recurrence of Hepatocellular Carcinoma in Hepatitis C Virus (HCV) Liver Transplant Recipients Treated with Pretransplant Direct-Acting Antiviral (DAA) Therapy

Background

Direct-acting antivirals (DAAs) have revolutionized the treatment of hepatitis C virus (HCV). The impact of DAAs on recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) remains uncertain.

Objective

We aimed to evaluate the risk of HCC recurrence in LT recipients cleared of HCV with DAAs at the time of LT compared to a control group of LT recipients who were viremic at the time of LT.

Methods

The study was a single-center, retrospective cohort study of patients undergoing LT for HCV-related HCC from 2002 to 2017. We compared time to post-LT HCC recurrence in patients with a sustained virological response (SVR) from DAAs prior to LT (DAA group) to patients who were viremic at LT (HCV+ group) using Kaplan-Meier analysis. We performed a secondary analysis comparing post-LT HCC recurrence in the DAA group to LT recipients with SVR from interferon-based treatment prior to LT (IFN group).

Results

One hundred fifty-one patients underwent LT for HCC related to HCV: 34 patients in DAA group, 95 patients in HCV+ group, and 22 in IFN group. Kaplan-Meier estimates of being HCC free were 96.2, 96.2, and 78.8% at 6, 12, and 24 months in DAA group, respectively, and 100, 98.6, and 95.8% at 6, 12, and 24 months in the HCV+ group, respectively; p = 0.08. There was no difference observed for HCC recurrence between the DAA and IFN groups. In a multivariate Cox proportional hazards model, DAA use increased the risk of post-LT HCC recurrence (HR 5.2, 95% CI 0.9-29.81, p = 0.07).

Conclusions

A strong trend was observed on both Kaplan-Meier and multivariate analyses toward increased post-LT HCC recurrence in patients who achieved SVR prior to LT with DAAs compared to patients who were viremic at LT. Caution is required when considering pre-LT treatment of HCV with DAAs in patients with HCC.

Lymphocyte Landscape after Chronic Hepatitis C Virus (HCV) Cure: The New Normal

Chronic HCV (CHC) infection is the only chronic viral infection for which curative treatments have been discovered. These direct acting antiviral (DAA) agents target specific steps in the viral replication cycle with remarkable efficacy and result in sustained virologic response (SVR) or cure in high (>95%) proportions of patients. These treatments became available 6–7 years ago and it is estimated that their real impact on HCV related morbidity, including outcomes such as cirrhosis and hepatocellular carcinoma (HCC), will not be known for the next decade or so. The immune system of a chronically infected patient is severely dysregulated and questions remain regarding the immune system’s capacity in limiting liver pathology in a cured individual. Another important consequence of impaired immunity in patients cleared of HCV with DAA will be the inability to generate protective immunity against possible re-infection, necessitating retreatments or developing a prophylactic vaccine. Thus, the impact of viral clearance on restoring immune homeostasis is being investigated by many groups. Among the important questions that need to be answered are how much the immune system normalizes with cure, how long after viral clearance this recalibration occurs, what are the consequences of persisting immune defects for protection from re-infection in vulnerable populations, and does viral clearance reduce liver pathology and the risk of developing hepatocellular carcinoma in individuals cured with these agents. Here, we review the recent literature that describes the defects present in various lymphocyte populations in a CHC patient and their status after viral clearance using DAA treatments.

Reversal of Immunity After Clearance of Chronic HCV Infection-All Reset?

Chronic viral infections cause deterioration of our immune system. However, since persistent infections rarely can be eliminated, the reinvigoration capacity of an exhausted immune system has remained largely elusive. Chronic hepatitis C virus (HCV) infection can since some years be effectively cured with novel direct acting antiviral agents. Thus, it is now possible to study reversal of immunity in patients that are cured from a long-lasting chronic infection. We here highlight recent developments in the analysis of various immune cell populations during and after clearance of HCV infection. Surprisingly, whereas reinvigoration of certain immune traits clearly can be seen, many features of immune exhaustion persist over time after viral elimination. Thus, a long-term chronic insult might result in irreversible damage to our immune system. This will be important to consider in therapeutic vaccination efforts against chronic infection and in the development of immunotherapy based strategies against cancer.

Control of HCV Infection by Natural Killer Cells and Macrophages

Host defense against invading pathogens within the liver is dominated by innate immunity. Natural killer (NK) cells have been implicated at all stages of hepatitis C virus (HCV) infection, from providing innate protection to contributing to treatment-induced clearance. Decreased NK cell levels, altered NK cell subset distribution, activation marker expression, and functional polarization toward a cytolytic phenotype are hallmarks of chronic HCV infection. Interferon α (IFN-α) is a potent activator of NK cells; therefore, it is not surprising that NK cell activation has been identified as a key factor associated with sustained virological response (SVR) to IFN-α-based therapies. Understanding the role of NK cells, macrophages, and other innate immune cells post-SVR remains paramount for prevention of disease pathogenesis and progression. Novel strategies to treat liver disease may be aimed at targeting these cells.

Hepatitis C Virus (HCV) Eradication With Interferon-Free Direct-Acting Antiviral-Based Therapy Results in KLRG1+ HCV-Specific Memory Natural Killer Cells

Direct acting antiviral therapies rapidly clear chronic hepatitis C virus (HCV) infection and restore natural killer (NK) cell function. We investigated NK-cell memory formation following HCV clearance by examining NK-cell phenotype and responses from control and chronic HCV patients before and after therapy following sustained virologic response at 12 weeks post therapy (SVR12). NK-cell phenotype at SVR12 differed significantly from paired pretreatment samples, with an increase in maturation markers CD16, CD57, and KLRG1. HCV patients possessed stronger cytotoxic responses against HCV-infected cells as compared to healthy controls; a response that further increased following SVR12. The antigen-specific response was mediated by KLRG1+ NK cells, as demonstrated by increased degranulation and proliferation in response to HCV antigen only. Our data suggest that KLRG1+ HCV-specific memory NK cells develop following viral infection, providing insight into their role in HCV clearance and relevance with regard to vaccine design.

JSH Guidelines for the Management of Hepatitis C Virus Infection, 2019 Update; Protective Effect of Antiviral Therapy against Hepatocarcinogenesis

The Drafting Committee for Hepatitis Management Guidelines established by the Japan Society of Hepatology (JSH) drafted the first version of the clinical practice guidelines for the management of hepatitis C virus (HCV) infection in 2012. Since then, we have been publishing updates as new drugs for hepatitis C become available and new indications for existing drugs are added. The new approval of sofosbuvir/velpatasvir prompted us to publish the seventh version of the guidelines in Japanese in March 2019. We also published the first English-language version of the JSH guidelines in 2013 and English versions of updates made to the Japanese-language guidelines in 2014 and 2016. In 2020, the committee has decided to publish a new English version, covering general information about treatment for hepatitis C, drugs used, recommended treatments for chronic hepatitis and cirrhosis, and special populations, such as patients who have renal impairment, are on dialysis, or have developed recurrence of hepatitis C after liver transplantation. Furthermore, the committee has released a separate publication covering the protective effect of antiviral therapy against hepatocarcinogenesis.

Liver Stiffness Hinders Normalization of Systemic Inflammation and Endothelial Activation after Hepatitis C Virus (HCV) Eradication in HIV/HCV Coinfected Patients

Systemic inflammation, endothelial dysfunction and coagulopathy are of high clinical relevance in the management of people living with HIV (PLWH), and even more in patients coinfected with hepatitis C virus (HCV). It has been suggested a significant impact of HCV coinfection on these conditions. However, HCV can be eradicated in most patients with the new direct-acting antivirals (DAAs) therapy. We have analyzed the effect of HCV on systemic inflammation, endothelial activation and coagulopathy in PLWH and its evolution after HCV eradication with DAAs. Twenty-five HIV/HCV coinfected (HIV/HCV group), 25 HIV monoinfected (HIV group) and 20 healthy controls (HC) were included in the study. All patients were on ART and HIV suppressed. Levels of fourteen markers of systemic inflammation, endothelial activation and coagulopathy (IL-1ß, IL-6, IL-12p70, IL-8, TNFα, D-dimer, Eotaxin, IL-18, IP-10, monocyte chemotactic protein-1 (MCP-1), plasminogen activator inhibitor-1 (PAI-1), TNFα receptor 1 (TNFR1), vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1)) were measured on plasma at baseline and after DAAs-mediated HCV eradication. Non-parametric tests were used to establish inter/intra-group differences. At baseline, the HIV/HCV group showed increased levels of IL-18 (p = 0.028), IP-10 (p < 0.0001), VCAM-1 (p < 0.0001) and ICAM-1 (p = 0.045), compared to the HC and HIV groups, with the highest levels for IL18 and IP10 observed in HIV/HCV patients with increased liver stiffness (≥7.1 KPa). Eradication of HCV with DAAs-based therapy restored some but not all the evaluated parameters. VCAM-1 remained significantly increased compared to HC (p = 0.001), regardless of the level of basal liver stiffness in the HIV/HCV group, and IP-10 remained significantly increased only in the HIV/HCV group, with increased level of basal liver stiffness compared to the HC and to the HIV groups (p = 0.006 and p = 0.049, respectively). These data indicate that DAAs therapy in HIV/HCV co-infected patients and HCV eradication does not always lead to the normalization of systemic inflammation and endothelial dysfunction conditions, especially in cases with increased liver stiffness.

Dynamic Changes in Ex Vivo T-Cell Function After Viral Clearance in Chronic HCV Infection

BACKGROUND

Direct-acting antiviral (DAA) agents can successfully treat chronic hepatitis C virus (HCV) infection. However, the ex vivo HCV-specific T-cell function following viral clearance remains unknown.

METHODS

We investigated functional alterations and phenotypic changes in ex vivo HCV-specific CD8+ T cells with a longitudinal analysis of 41 patients with chronic HCV infection who were undergoing DAA treatment.

RESULTS

A patient subset exhibited a significantly increased T-cell response (mainly CD8+ T cells) at week 4 of treatment. However, this increased T-cell response diminished in later weeks. Relative to pretreatment levels, the ex vivo HCV-specific CD8+ T-cell frequency decreased at 12 weeks after the end of treatment, along with a decreased antigen-experienced CD8+ T-cell population. DAA treatment increased the proliferative capacity of HCV-specific CD8+ T cells, but this change was not correlated with ex vivo function. Patients experiencing viral breakthrough or relapse exhibited defective restoration of T-cell function.

CONCLUSION

Our present results indicated that DAA-mediated viral clearance only transiently restored ex vivo T-cell function, suggesting a need to enhance T-cell function in DAA-treated patients.

Risk of Hepatocellular Carcinoma after HCV Clearance by Direct-Acting Antivirals Treatment Predictive Factors and Role of Epigenetics

Direct-acting antivirals (DAAs) induce a rapid virologic response (SVR) in up to 99% of chronic hepatitis C patients. The role of SVR by DAAs on the incidence or recurrence of hepatocellular carcinoma (HCC) is still a matter of debate, although it is known that SVR does not eliminate the risk of HCC. In this review, we made an updated analysis of the literature data on the impact of SVR by DAAs on the risk of HCC as well as an assessment of risk factors and the role of epigenetics. Data showed that SVR has no impact on the occurrence of HCC in the short–medium term but reduces the risk of HCC in the medium–long term. A direct role of DAAs in the development of HCC has not been demonstrated, while the hypothesis of a reduction in immune surveillance in response to the rapid clearance of HCV and changes in the cytokine pattern influencing early carcinogenesis remains to be further elucidated. HCV induces epigenetic alterations such as modifications of the histone tail and DNA methylation, which are risk factors for HCC, and such changes are maintained after HCV clearance. Future epigenetic studies could lead to identify useful biomarkers and therapeutic targets. Cirrhosis has been identified as a risk factor for HCC, particularly if associated with high liver stiffness and α-fetoprotein values, diabetes and the male sex. Currently, considering the high number and health cost to follow subjects’ post-HCV clearance by DAAs, it is mandatory to identify those at high risk of HCC to optimize management.

Hepatocellular Carcinoma Mechanisms Associated with Chronic HCV Infection and the Impact of Direct-Acting Antiviral Treatment

Hepatitis C virus (HCV) infection is the major risk factor for liver cirrhosis and hepatocellular carcinoma (HCC). The mechanisms of HCC initiation, growth, and metastasis appear to be highly complex due to the decade-long interactions between the virus, immune system, and overlapping bystander effects of host metabolic liver disease. The lack of a readily accessible animal model system for HCV is a significant obstacle to understand the mechanisms of viral carcinogenesis. Traditionally, the primary prevention strategy of HCC has been to eliminate infection by antiviral therapy. The success of virus elimination by antiviral treatment is determined by the SVR when the HCV is no longer detectable in serum. Interferon-alpha (IFN-α) and its analogs, pegylated IFN-α (PEG-IFN-α) alone with ribavirin (RBV), have been the primary antiviral treatment of HCV for many years with a low cure rate. The cloning and sequencing of HCV have allowed the development of cell culture models, which accelerated antiviral drug discovery. It resulted in the selection of highly effective direct-acting antiviral (DAA)-based combination therapy that now offers incredible success in curing HCV infection in more than 95% of all patients, including those with cirrhosis. However, several emerging recent publications claim that patients who have liver cirrhosis at the time of DAAs treatment face the risk of HCC occurrence and recurrence after viral cure. This remains a substantial challenge while addressing the long-term benefit of antiviral medicine. The host-related mechanisms that drive the risk of HCC in the absence of the virus are unknown. This review describes the multifaceted mechanisms that create a tumorigenic environment during chronic HCV infection. In addition to the potential oncogenic programming that drives HCC after viral clearance by DAAs, the current status of a biomarker development for early prediction of cirrhosis regression and HCC detection post viral treatment is discussed. Since DAAs treatment does not provide full protection against reinfection or viral transmission to other individuals, the recent studies for a vaccine development are also reviewed.

Immunomodulation of the Natural Killer Cell Phenotype and Response during HCV Infection

Hepatitis C virus (HCV) infection develops into chronic hepatitis in over two-thirds of acute infections. While current treatments with direct-acting antivirals (DAAs) achieve HCV eradication in >95% of cases, no vaccine is available and re-infection can readily occur. Natural killer (NK) cells represent a key cellular component of the innate immune system, participating in early defence against infectious diseases, viruses, and cancers. When acute infection becomes chronic, however, NK cell function is altered. This has been well studied in the context of HCV, where changes in frequency and distribution of NK cell populations have been reported. While activating receptors are downregulated on NK cells in both acute and chronic infection, NK cell inhibiting receptors are upregulated in chronic HCV infection, leading to altered NK cell responsiveness. Furthermore, chronic activation of NK cells following HCV infection contributes to liver inflammation and disease progression through enhanced cytotoxicity. Consequently, the NK immune response is a double-edged sword that is a significant component of the innate immune antiviral response, but persistent activation can drive tissue damage during chronic infection. This review will summarise the role of NK cells in HCV infection, and the changes that occur during HCV therapy.

Hepatitis C Virus (HCV) Clearance After Treatment With Direct-Acting Antivirals in Human Immunodeficiency Virus (HIV)-HCV Coinfection Modulates Systemic Immune Activation and HIV Transcription on Antiretroviral Therapy

Background

Hepatitis C virus (HCV) coinfection among people with human immunodeficiency virus (HIV) might perturb immune function and HIV persistence. We aimed to evaluate the impact of HCV clearance with direct-acting antivirals (DAAs) on immune activation and HIV persistence in HIV/HCV-coinfected individuals on antiretroviral therapy (ART).

Methods

In a prospective observational study, ART-treated participants with HIV/HCV coinfection received sofosbuvir/daclatasvir ± ribavirin (n = 19). Blood samples were collected before DAA therapy, at the end of treatment, and 12 months after DAA termination (12MPT). T- and natural killer (NK)-cell phenotype, soluble plasma factors, cell-associated (CA)-HIV deoxyribonucleic acid (DNA) forms (total, integrated, 2LTR), CA-unspliced (US) and multiple-spliced ribonucleic acid (RNA), and plasma HIV RNA were evaluated.

Results

Hepatitis C virus clearance was associated with (1) a downmodulation of activation and exhaustion markers in CD4⁺, CD8⁺ T, and NK cells together with (2) decreased plasma levels of Interferon gamma-induced protein 10 (IP10), interleukin-8 (IL-8), soluble (s)CD163 and soluble intercellular adhesion molecule (sICAM). Cell-associated US HIV RNA was significantly higher at 12MPT compared to baseline, with no change in HIV DNA or plasma RNA.

Conclusions

Elimination of HCV in HIV/HCV-coinfected individuals alters immune function and the transcriptional activity of latently infected cells. This report provides insights into the effects of HCV coinfection in HIV persistence and regards coinfected subjects as a population in which HIV remission might prove to be more challenging.

Relation of Reduction of Antibodies against Hepatitis B Virus to Hepatocellular Carcinoma Recurrence in the Patients with Resolved Hepatitis B Virus Infection Following Direct-acting Antiviral Therapy for Hepatitis C Virus Infection

Background

A possible interaction of hepatitis viruses at cellular and molecular levels has been suggested. Eradication of hepatitis C virus (HCV) has been reported to induce activation of hepatitis B virus (HBV)-related liver diseases.

Materials and methods

The present study examined association of HBV markers with recurrence of hepatocellular carcinoma (HCC) in patients with resolved HCV infection by direct-acting antiviral (DAA) therapy. In a patient pool of 378 patients with sustained virologic response (SVR) by DAA, the antibody to the hepatitis B surface antigen (anti-HBs), the antibody to the hepatitis B core antigen (anti-HBc), and HBV-DNA levels were estimated before and at the end of DAA therapy. These patients were HBsAg negative. Eighty-nine patients had a history of curative treatment of HCC by resection or radiofrequency ablation. A Cox proportional hazards model was used to identify risk factors for HCC recurrence, including the change ratio of the antibody against HBV proteins.

Results

Although 188 patients had resolved HBV infection, no patient showed HBV reactivation, but anti-HBs and anti-HBc levels decreased significantly. No significant difference in the HCC recurrence rate was evident between patients with and without resolved HBV infection. Changes of immune responses to HBV proteins did not affect HCC recurrence after DAA therapy for HCV infection in this cohort.

Conclusion

The mechanisms underlying diverse roles of DAA-induced SVR of HCV on HBV kinetics need to be resolved in future.

How to cite this article

Joko K, Mashiba T, Ochi H, et al. Relation of Reduction of Antibodies against Hepatitis B Virus to Hepatocellular Carcinoma Recurrence in the Patients with Resolved Hepatitis B Virus Infection Following Direct-acting Antiviral Therapy for Hepatitis C Virus Infection. Euroasian J Hepato-Gastroenterol 2019;9(2):78–83.

Cirrhosis Hampers Early and Rapid Normalization of Natural Killer Cell Phenotype and Function in Hepatitis C Patients Undergoing Interferon-Free Therapy

Background: Chronic hepatitis C virus (HCV) infection impairs natural killer (NK) cell phenotype and function. Whether restoration of NK cells occurs after successful interferon (IFN)-free therapies remains a controversial issue. Aim: To analyze how HCV-related liver cirrhosis impacts changes in NK cells prior and post-IFN-free therapies. Methods: NK cell analysis by multicolor flow cytometry was performed in HCV-infected patients with (n = 17) and without (n = 14) cirrhosis at baseline, week 4 during therapy, and weeks 12 and 48 after the end of therapy (FU12 and FU48, respectively). Non-HCV cirrhotic patients (n = 12) and healthy individuals (n = 12) served as controls. Results: At baseline, HCV cirrhotic patients presented an altered distribution of NK subsets (CD56dim and CD56bright) with higher expression of NKp46, HLA-DR, NKp30, KIR2DL2/L3, NKG2A, and CD85j receptors compared to healthy controls. All frequencies normalized by FU48, except for CD85j+ cells. Likewise, substantial alterations were detected in NK cell function assessed by (i) signal transducer and activator of transcription 1 (STAT1) and phosphorylated levels of STAT1 and STAT4, (ii) degranulation (CD107a), (iii) cytotoxicity [tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)], and (iv) cytokine production [IFN-γ and tumor necrosis factor-α (TNF-α)]. Of note, NK cell function at FU48 remained partially impaired. In contrast, non-cirrhotics showed normal baseline frequencies of HLA-DR-, NKG2A-, and CD85j-expressing NK cells. Importantly, altered baseline frequencies of NK cell subsets and NKp46+ CD56dim cells, as well as NK cell function, were rapidly and completely restored. Conclusions: NK cell phenotype alterations persist after HCV eradication in cirrhotic patients, while their function is only partially restored, compromising immune restoration and immunosurveillance.

Plasma FABP4 is associated with liver disease recovery during treatment-induced clearance of chronic HCV infection

Direct-acting antivirals (DAAs) have dramatically improved the management of chronic hepatitis C (CHC). In this study, we investigated the effects of hepatitis C virus clearance on markers of systemic inflammation measured in plasma samples from CHC patients before, during and after DAA therapy. We identified a plasma soluble protein profile associated with CHC. Successful DAA therapy rapidly normalised the plasma inflammatory milieu, with the notable exception of soluble (s)CD163, a marker of macrophage activation, which remained elevated after viral clearance and segregated patients with high and low levels of cirrhosis. Patients who received DAA in combination with Ribavirin maintained elevated levels of CXCL10, consistent with an immune-stimulatory role of Ribavirin. As anticipated, DAA-treated patients experienced durable improvement in liver fibrosis measurements. Interestingly, pre-treatment levels of fatty acid-binding protein 4 (FABP4) were inversely associated with reduction of APRI and FIB-4 scores during treatment. Together, these results support the notion of a rapid restoration of many aspects of the inflammatory state in CHC patients in response to DAA therapy. Furthermore, the associations with sCD163 and FABP4 warrant further investigation into the role of macrophages in residual liver disease and fibrosis resolution after viral clearance.

The effects of nucleoside/nucleotide analogues on host immune cells: the baseline for future immune therapy for HBV?

HBV is a non-cytopathic virus and the progression of liver fibrosis is attributed to the host immune response. Complete suppression of viral replication using nucleotide or nucleoside analogues (NUCs) can prevent most complications related to chronic HBV infection. Unfortunately, antiviral treatment has to be administered lifelong to the majority of patients as HBV persists in the hepatocytes. However, although NUCs are very frequently administered in clinical practice, their effects on vital parts of the host immune response to HBV are not well established. In this review we summarize the currently available data gathered from longitudinal studies that investigated treatment-associated alterations of HBV-specific CD4⁺ and CD8⁺ T-cells, regulatory T-cells and natural killer (NK) cells. These observations are important, as they can guide the design of studies that investigate the efficacy of new immune therapeutic agents. Novel experimental compounds will likely be added to ongoing NUC treatment, which leads to a functional cure in only a small minority of patients.

Immunological Dynamics Associated with Direct-Acting Antiviral Therapies in Naive and Experimented HCV Chronic-Infected Patients

The therapeutic strategies used in the treatment of hepatitis C are essentially based on the combination of direct-acting antiviral agents (DAAs). This therapy has been shown to be very effective in relation to patient adherence to treatment and has shown high rates of sustained virological response (SVR). However, the immunological dynamics of patients infected with HCV is poorly understood. This fact led us to investigate the immune system of naive and experienced patients, who we followed before the therapy and three months after the end of treatment. In this study, 35 naive and experienced Brazilian patients with chronic hepatitis C and 50 healthy donors (HD group) were studied. The analysis of the soluble immunological biomarkers was performed using the flow cytometry methodology. The SVR rate was >90% among the 35 patients. Before treatment, correlations in the naive HCV group demonstrated a mix of inflammatory response occurring with moderate correlations between chemokines, inflammatory cytokines, and Th2 profile, with a strong regulation between IL-10 and IL-17A. On the other hand, experienced patients demonstrated a poor interaction between cytokines, chemokines, and cells with a strong correlation between IL-10, IL-6, CXCL-10, and CD8⁺ besides the interactions between IFN-γ and IL-4. Furthermore, naive and experienced patients seem to have a distinct soluble biomarker profile; therefore, a long-term follow-up is needed to evaluate patients treated with DAAs.

Risk of Hepatocellular Cancer Recurrence in Hepatitis C Virus+ Patients Treated with Direct-Acting Antiviral Agents

BACKGROUND

With advent of direct-acting antiviral agents (DAA), hepatitis C virus (HCV) treatment is dramatically increasing. Although few studies reported rates of hepatocellular carcinoma (HCC) recurrence following DAA treatment, there have been no studies that followed sufficient number of DAA-treated patients after successful HCC treatment to examine HCC recurrence.

METHODS

We conducted a cohort study of HCV+ patients who had successfully treated HCC before initiating DAAs. We conducted medical record reviews to confirm HCC diagnosis, treatment, and remission prior to DAA initiation, and subsequent HCC recurrence. We calculated HCC recurrence rate and examined the recurrent tumor characteristics. We used Cox proportional hazard model to identify factors associated with HCC recurrence.

RESULTS

We identified 264 HCV+ patients who received DAAs after an average of 30.9 (20.6) months following HCC treatment. HCC recurred in 26.1% patients during 23.3 (9.8) months follow-up, at a rate of 0.38 [0.30, 0.48] per 1000 person-month. Most (82.3%) recurrent HCC were early stage. Receiving non-curative treatment for HCC was associated with a higher risk of recurrence than curative treatment (HR_adj = 2.06, [1.24, 3.40]). The risk of HCC recurrence decreased with longer duration between HCC treatment completion and DAA initiation (HR_adj = 0.97, [0.95, 0.99] per additional month). Compared with patients who achieved sustained virological response (SVR), those without SVR had significantly increased risk of HCC recurrence (HR_adj = 4.17, [1.48, 11.75]).

CONCLUSIONS

We conclude that most HCV+ patients with HCC benefit from DAA treatment; however, timing of DAA initiation after HCC treatment should be carefully considered.

Elimination of hepatitis C virus has limited impact on the functional and mitochondrial impairment of HCV-specific CD8+ T cell responses

BACKGROUND & AIMS

Hepatitis C virus (HCV)-specific CD8+ T cells are functionally impaired in chronic hepatitis C. Even though HCV can now be rapidly and sustainably cleared from chronically infected patients, the repercussions of HCV clearance on virus-specific CD8+ T cells remain elusive. Here, we aimed to investigate if HCV clearance by direct-acting antivirals (DAAs) could restore the functionality of exhausted HCV-specific CD8+ T cell responses.

METHODS

HCV-specific CD8+ T cells in peripheral blood were obtained from 40 patients with chronic HCV infection, during and 6 months following IFN-free DAA therapy. These cells were analyzed for comprehensive phenotypes, proliferation, cytokine production, mitochondrial fitness and response to immune-checkpoint blockade.

RESULTS

We show that, unlike activation markers that decreased, surface expression of multiple co-regulatory receptors on exhausted HCV-specific CD8+ T cells remained unaltered after clearance of HCV. Likewise, cytokine production by HCV-specific CD8+ T cells remained impaired following HCV clearance. The proliferative capacity of HCV multimer-specific CD8+ T cells was not restored in the majority of patients. Enhanced in vitro proliferative expansion of HCV-specific CD8+ T cells during HCV clearance was more likely in women, patients with low liver stiffness and low alanine aminotransferase levels in our cohort. Interestingly, HCV-specific CD8+ T cells that did not proliferate following HCV clearance could preferentially re-invigorate their proliferative capacity upon in vitro immune-checkpoint inhibition. Moreover, altered mitochondrial dysfunction exhibited by exhausted HCV-specific CD8+ T cells could not be normalized after HCV clearance.

CONCLUSION

Taken together, our data implies that exhausted HCV-specific CD8+ T cells remain functionally and metabolically impaired at multiple levels following HCV clearance in most patients with chronic hepatitis C. Our results might have implications in cases of re-infection with HCV and for HCV vaccine development.

LAY SUMMARY

Direct-acting antiviral therapy results in cure of hepatitis C virus (HCV) in almost all treated patients. However, the impacts of HCV cure on immune responses remain controversial. Whether immune responses to HCV recover is important in cases of re-exposure, or for the resolution of extrahepatic manifestations. The main finding of our study was that HCV-specific T cells remain functionally impaired despite HCV clearance. This finding could explain the fact that HCV cure does not lead to protective immunity and that re-infections have frequently been observed.

Residual hepatitis C virus in peripheral blood mononuclear cell as a risk factor for hepatocellular carcinoma after achieving a sustained virological response: a dogma or fiction

BACKGROUND

Clinical worsening after achieving a sustained virological response (SVR) needs to be clarified and explained. Persistence of hepatitis C virus (HCV) core antigen interacts with the host proteins to interfere with signaling pathways and increases the susceptibility to hepatic carcinogenesis.

OBJECTIVE

This study aimed to investigate the risk factors that increase the progression of liver disease and hepatocellular carcinoma in a subgroup of HCV patients who achieved a SVR.

PATIENTS AND METHODS

Eighty-nine HCV patients with hepatic decompensation were selected 8.2 ± 1.8 months after achieving SVR24. HCV core antigen and HCV RNA were detected in peripheral blood mononuclear cells. Matched control (n = 100) and training (n = 200) groups were recruited.

RESULTS

Eighty-five patients showed a progression of Child-Turcotte-Pugh and model for end-stage liver disease scores, with positive RNA in peripheral blood mononuclear cell (357.4 ± 42.1 IU/million cell) and positive hepatitis C virus core antigen (n = 73); four patients were excluded. Susceptibility to decompensation and hepatocellular carcinoma after direct-acting antiviral drugs increased with age [odds ratio (OD) = 1.87], and was associated with male sex (OD = 1.65), diabetes (OD = 3.68), thrombocytopenia (OD = 2.44), pretreatment Alfa-fetoprotein (OD = 3.41), and occult HCV (OD = 4.1).

CONCLUSION

Clinical deterioration after SVR could be explained by occult HCV mainly in older male patients with diabetes and thrombocytopenia.

The role of anti-HBs in hepatitis B reactivation during direct-acting antiviral therapy for chronic hepatitis C

BACKGROUND

Hepatitis B reactivation in patients with resolved HBV can occur during hepatitis C treatment with direct-acting antivirals, but only a few cases have been described. It is not clear which patients are at risk for HBV reactivation and how to manage them.

METHODS

Three patients (all hepatitis B surface antigen [HBsAg]-negative, antibody to hepatitis B core [anti-HBc] positive and HBV DNA negative) experienced a late HBV reactivation 12 weeks post-treatment but were able to control their viraemia. HCV RNA, HBV DNA, anti-HBc and anti-HBs were measured in these patients and in 37 HBsAg-negative, anti-HBc positive, HBV DNA negative control patients during direct-acting antiviral therapy for chronic hepatitis C.

RESULTS

Baseline anti-HBs do not differ between patients with and without HBV reactivation. Patients with HBV reactivation, however, significantly increased their anti-HBs at time of reactivation, while patients without HBV reactivation show stable anti-HBs during therapy (P=0.007).

CONCLUSIONS

Anti-HBs might be an important marker to delineate patients at risk for clinically significant HBV reactivation.

Direct-Acting Antiviral Treatment of HCV Infection Does Not Resolve the Dysfunction of Circulating CD8+ T-Cells in Advanced Liver Disease

Chronic hepatitis C virus (HCV) infection disrupts immune functions, including that of cytotoxic CD8⁺ T-cells which are important mediators of immune response. While HCV cure aims to eliminate long term sequelae of infection, whether direct-acting antiviral (DAA) treatment results in immune reconstitution remains unclear. We and others have reported generalized CD8⁺ T-cell dysfunction in chronic HCV infection and our research suggests that the degree of liver damage is a factor in this process. Our recent research indicates that liver fibrosis is not readily reversed after DAA-mediated clearance of chronic HCV infection. We therefore examined the function of circulating CD8⁺ T-cell subsets in chronic HCV infection in the context of liver fibrosis severity, determined by ultrasound elastography and Metavir F-score system. We observed progressive shifts in CD8⁺ T-cell subset distribution in HCV-infected individuals with advanced liver fibrosis (F4) compared to minimal fibrosis (F0-1) or uninfected controls, and this remained unchanged after viral cure. Impaired CD8⁺ T-cell function was observed as a reduced proportion of CD107⁺ and perforin⁺ late effector memory cells in HCV⁺(F4) and HCV⁺(F0-1) individuals, respectively. In HCV⁺(F4) individuals, nearly all CD8⁺ T-cell subsets had an elevated proportion of perforin⁺ cells while naïve cells had increased proportions of IFN-γ⁺ and CD107⁺ cells. These exaggerated CD8⁺ T-cell activities were not resolved when evaluated 24 weeks after completion of DAA therapy and HCV clearance. This was further supported by sustained, high levels of cell proliferation and cytolytic activity. Furthermore, DAA therapy had no effect on elevated concentrations of systemic inflammatory cytokines and decreased levels of inhibitory TGF-β in the plasma of HCV⁺(F4) individuals, suggesting HCV infection and advanced liver disease result in a long-lasting immune activating microenvironment. These data demonstrate that in chronic HCV infection, liver fibrosis severity is associated with generalized hyperfunctional CD8⁺ T-cells, particularly with perforin production and cytotoxicity, and this persists after viral clearance. Whether DAA therapy will eliminate other related long-term sequelae in HCV⁺(F4) individuals remains an important research question.

Immune dissociation during acute hepatitis E infection

OBJECTIVE

We report the immune response during a case of acute HEV response in a patient with an acute hepatitis E virus (HEV) genotype 3 infection in the Netherlands.

METHODS

Cytokine evaluation was performed via multiplex cytokine array for 65 immune markers in plasma during the different phases of hepatitis.

RESULTS

The patient initially presented with features typical of acute viral hepatitis, with detectable HEV RNA in blood. This evolved into a cholestatic disease following peripheral clearance of the virus, leading to the demise of the patient. Real time PCR revealed the presence of HEV in liver tissue, suggestive of active intrahepatic infection despite clearance in blood. During the phase of detectable HEV RNA in serum, there was a surge in T-cell-related immune mediators, as well as interferon alpha and interferon gamma-induced protein 10 (IP-10), characteristic of a viral infection. After clearance of the virus in the blood and development of cholestatic hepatitis, several inflammatory markers subsided, followed by an increase in immune factors related to anti-inflammatory activity, as well as monocyte/macrophage-related markers, likely due to the intrahepatic presence of the virus.

CONCLUSIONS

This report describes the dissociation of intra- and extra-hepatic immune responses during acute HEV infection. As shedding of the virus became solely intrahepatic, an immune profile reflective of the activity of hepatic resident cells was observed.

Effect of sofosbuvir plus daclatasvir for treatment of chronic hepatitis C on patients with psoriasis

AIM

Until recently, clinicians caring for patients with psoriasis who were infected with hepatitis C virus (HCV) were concerned that treating one condition could exacerbate the other. We evaluated the outcome of treatment with direct-acting antiviral agents (DAAs) on patients with psoriasis having chronic hepatitis C (CHC) infection.

PATIENTS AND METHODS

This was an observational prospective cross-sectional study. It included CHC-naive patients with plaque psoriasis. All patients received sofosbuvir plus daclatasvir once daily for 12 weeks for treatment of CHC. Psoriasis area severity index (PASI) scores and the dermatology quality-of-life index were evaluated at the start of treatment with DAAs and then at 12 and 24 weeks after the end of HCV treatment. The primary end point was sustained virological response 12 weeks after treatment (SVR12).

RESULTS

A total of 34 CHC-naive patients were enrolled in this study. Most of them were of male sex (76.5%), and most of them had severe psoriasis, as the mean PASI score was 32. The primary and secondary end points (SVR12 and SVR24) for our patients were 100%. Regarding PASI and dermatology quality-of-life index scores, there was a highly significant difference before start of treatment and after treatment at 12 and 24 weeks. The most common adverse events are fatigue and headache.

CONCLUSION

Sofosbuvir plus daclatasvir is effective in the eradication of HCV and improvement of symptoms in patients with psoriasis having CHC infection. Future large series studies are needed to evaluate this promising effect of DAAs.

2018 Korean Liver Cancer Association-National Cancer Center Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer globally and the fourth most common cancer in men in Korea, where the prevalence of chronic hepatitis B infection is high in middle-aged and elderly patients. These practice guidelines will provide useful and constructive advice for the clinical management of patients with HCC. A total of 44 experts in hepatology, oncology, surgery, radiology, and radiation oncology in the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2014 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions.

Direct antiviral agents upregulate natural killer cell potential activity in chronic hepatitis C patients

Direct antiviral agents (DAAs) can eliminate hepatitis C virus rapidly and make chronic hepatitis C (CHC) curable. The changes in the innate immune system during treatment with DAAs are still in dispute. To investigate how the functions of natural killer (NK) cells change during and after treatment with DAAs in each NK cell subset. Thirteen CHC patients were treated with sofosbuvir/ledipasvir, and the expression levels of NKp46 and NKG2A were tested via flow cytometry at baseline, at 2, 4, 8 and 12 weeks during the therapy and 12 and 24 weeks after the end of treatment; expression levels were compared between CHC patients and 13 healthy controls. A redirected killing assay was used to detect the cytotoxicity of NK cells. After coculturing NK cells with JFH-Huh7 cells for 72 h, HCV RNA was tested to analyze the inhibition ability of NK cells. All patients achieved sustained virologic response. The expression of the activating receptor NKp46 was decreased first at week 8 during therapy with DAAs and then increased and normalized to levels in healthy controls after treatment with DAAs. The expression of the inhibitory receptor NKG2A was decreased during and after treatment with DAAs. Each NK cell subset has a similar changing trend during and after treatment with DAAs, although some differences can be found earlier and later. The ratio of NKp46 and NKG2A was upregulated after treatment with DAAs. CD56^bright NK cells have less amplitude in the frequency ratio changes after treatment with DAAs. The coculture results showed that both the specific lysis and the inhibition of HCV replication were significantly upregulated after treatment with DAAs. DAA treatments can affect patients' NK cell function. After DAA treatments, the expression of functional markers is downregulated, but the potential activity of NK cells is upregulated. The function of NK cells is normalized to levels in healthy controls. CD56^bright NK cells play an important role in this process.

Hepatitis C virus leaves an epigenetic signature post cure of infection by direct-acting antivirals

The increasing worldwide prevalence of Hepatocellular carcinoma (HCC), characterized by resistance to conventional chemotherapy, poor prognosis and eventually mortality, place it as a prime target for new modes of prevention and treatment. Hepatitis C Virus (HCV) is the predominant risk factor for HCC in the US and Europe. Multiple epidemiological studies showed that sustained virological responses (SVR) following treatment with the powerful direct acting antivirals (DAAs), which have replaced interferon-based regimes, do not eliminate tumor development. We aimed to identify an HCV-specific pathogenic mechanism that persists post SVR following DAAs treatment. We demonstrate that HCV infection induces genome-wide epigenetic changes by performing chromatin immunoprecipitation followed by next-generation sequencing (ChIP-seq) for histone post-translational modifications that are epigenetic markers for active and repressed chromatin. The changes in histone modifications correlate with reprogramed host gene expression and alter signaling pathways known to be associated with HCV life cycle and HCC. These epigenetic alterations require the presence of HCV RNA or/and expression of the viral proteins in the cells. Importantly, the epigenetic changes induced following infection persist as an "epigenetic signature" after virus eradication by DAAs treatment, as detected using in vitro HCV infection models. These observations led to the identification of an 8 gene signature that is associated with HCC development and demonstrate persistent epigenetic alterations in HCV infected and post SVR liver biopsy samples. The epigenetic signature was reverted in vitro by drugs that inhibit epigenetic modifying enzyme and by the EGFR inhibitor, Erlotinib. This epigenetic "scarring" of the genome, persisting following HCV eradication, suggest a novel mechanism for the persistent pathogenesis of HCV after its eradication by DAAs. Our study offers new avenues for prevention of the persistent oncogenic effects of chronic hepatitis infections using specific drugs to revert the epigenetic changes to the genome.

Occurrence of hepatocellular carcinoma after direct-acting antiviral therapy for hepatitis C virus infection: literature review and risk analysis

INTRODUCTION

Concerns were raised about a high occurrence of hepatocellular carcinoma (HCC) after successful treatment of chronic hepatitis C (CHC) by direct-acting antivirals (DAAs).

AREAS COVERED

The authors summarize the clinical studies reporting the occurrence rate and risk factors of HCC after DAAs in CHC.

EXPERT OPINION

The recent introduction of all-oral DAAs has substantially changed the scenario of CHC, achieving a sustained virological response (SVR) in >90% of cases. Earlier concerns raised about an increasing incidence of HCC post-DAAs were flawed by large heterogeneity of patients, the limited number of well-designed prospective studies (only nine, up to date) and the inclusion of a large number of patients with advanced liver disease, previously excluded from interferon-based studies. Current data on DAAs have shown a lower risk of HCC development; however, they were unable to identify patients at greater risk for HCC occurrence after SVR. Surveillance strategy, likely lifelong, is mandatory in these patients according to general expert opinion.

Observed Changes in Natural Killer and T cell Phenotypes with Evaluation of Immune Outcome in a Longitudinal Cohort Following Sofosbuvir-Based Therapy for Chronic Hepatitis C Infection

Background

Chronic hepatitis C virus (HCV) infection diminishes immune function through cell exhaustion and repertoire alteration. Direct acting antiviral (DAA)-based therapy can restore immune cell subset function and reduce exhaustion states. However, the extent of immune modulation following DAA-based therapy and the role that clinical and demographic factors play remain unknown.

Methods

We examined natural killer (NK) cell, CD4⁺, and CD8⁺ T cell subsets along with activation and exhaustion phenotypes across an observational study of sofosbuvir-based treatment for chronic HCV infection. Additionally, we examined the ability of clinical variables and duration of infection to predict 12 weeks of sustained virologic response (SVR12) immune marker outcomes.

Results

We show that sofosbuvir-based therapy restores NK cell subset distributions and reduces chronic activation by SVR12. Likewise, T cell subsets, including HCV-specific CD8⁺ T cells, show reductions in chronic exhaustion markers by SVR12. Immunosuppressive CD4⁺ regulatory T cells decrease at 4-weeks treatment and SVR12. We observe the magnitude and direction of change in immune marker values from pretreatment to SVR12 varies greatly among participants. Although we observed associations between the estimated date of infection, HCV diagnosis date, and extent of immune marker outcome at SVR12, our regression analyses did not indicate any factors as strong SVR12 outcome predictors.

Conclusion

Our study lends further evidence of immune changes following sofosbuvir-based therapy. Further investigation beyond SVR12 and into factors that may predict posttreatment outcome is warranted.