On-treatment decrease of NKG2D correlates to early emergence of clinically evident hepatocellular carcinoma after interferon-free therapy for chronic hepatitis C

Risk of hepatocellular carcinoma after viral clearance achieved by DAA treatment

The advent of direct-acting antiviral (DAA) therapy has revolutionized hepatitis C virus (HCV) treatment, enabling most HCV-infected patients to achieve a sustained viral response (SVR) easily and safely in a short period. On the other hand, it is gradually being recognized that a significant proportion of patients are still at risk of developing de novo and recurrent hepatocellular carcinoma (HCC), even after HCV elimination, and therefore, elucidation of the risk of de novo and recurrent HCC, investigation of its molecular basis, and construction of accurate prediction models are emerging as new important clinical topics. In this review, we present recent advances regarding these issues.

Unmet needs in the post-direct-acting antivirals era: The risk and molecular mechanisms of hepatocellular carcinoma after hepatitis C virus eradication

Hepatitis C virus (HCV) infection is one of the major etiologies of hepatocellular carcinoma (HCC) with approximately 30% of HCC being due to HCV infection worldwide. HCV eradication by antivirals greatly reduces the risk of HCC; nevertheless, HCC remains to occur in chronic hepatitis C (CHC) patients who have achieved a sustained virological response (SVR). The proportion of post-SVR HCC among newly diagnosed HCC patients is increasing in the direct-acting antiviral (DAA) era and might be due to preexisting inflammatory and fibrotic liver backgrounds, immune dysregulation between host and virus interactions, as well as host epigenetic scars, genetic predispositions and alternations. By means of applying surrogate markers and adopting risk stratification, HCC surveillance should be consistently performed in high-risk populations. In this review, we discuss the possible molecular mechanism, risk factors, and HCC surveillance strategy for HCC development after HCV eradication in CHC patients.

Hepatitis C Virus-Related One-Year Hepatocellular Carcinoma Recurrence After Directly Acting Antivirals: A Randomized Controlled Trial

PURPOSE

Available data on hepatocellular carcinoma (HCC) recurrence after direct-acting antivirals (DAAs) treatment for hepatitis C virus (HCV) are conflicting. No randomized trials were done. This study aims to compare the 1-year HCC recurrence rates in patients who received DAAs after tumor ablation versus those who postponed HCV treatment for 1 year.

METHODS

Included patients were randomized after complete HCC ablation into two groups: a postponed DAAs group for whom DAAs initiation was postponed for 12 months and a DAAs group who were given sofosbuvir/velpatasvir. Patients were followed for 1 year.

RESULTS

Eighty-four HCV patients with a mean age of 56.35 ± 8.12 years were included; 78.57% of them were males. The number of lesions per patient ranged from 1 to 3 lesions, and the size of the largest lesion ranged from 1.5 to 5 cm. There were no statistically significant differences between both groups regarding baseline characteristics. In the DAAs group (43 patients), 11 patients had HCC recurrence, while 25 patients in the postponed DAAs group (41 patients) had HCC recurrence. Using Kaplan-Meier analysis, the 1-year recurrence-free survival (RFS) was significantly higher in the DAAs group (72.2% vs. 38%, P = 0.001). On multivariate analysis, both higher albumin levels (HR 0.147, 95% CI 0.066-0.329) and receiving DAAs (HR 0.358, 95% CI 0.176-0.730) 1 year after ablation were associated with significantly lower recurrence.

CONCLUSION

Direct-acting antiviral usage after complete hepatocellular carcinoma ablation significantly decreases the 1-year HCC recurrence rates, but the risk of recurrence is still not eliminated. The study registration number on clinicaltrials.gov : NCT04653818 (initial release on 28/11/2020).

Natural killer group 2D-major histocompatibility complex class I polypeptide-related sequence A activation enhances natural killer cell-mediated immunity against hepatocellular carcinoma: A review

The recent clinical introduction of immune checkpoint inhibitors has improved therapeutic outcomes in patients with advanced hepatocellular carcinoma. However, these therapies targeting CD8+ T lymphocytes have a response rate of approximately 30%. In addition to CD8+ T lymphocytes, natural killer (NK) cells represent promising therapeutic targets for hepatocellular carcinoma, because they comprise 30%-50% of all lymphocytes in the liver and contribute to antitumor immunity. A recent meta-analysis revealed that the percentage of infiltrating NK cells in hepatocellular carcinoma correlates with a better patient outcome. Similarly, our previous genome-wide association study on chronic viral hepatitis showed that a single-nucleotide polymorphism of major histocompatibility complex class I polypeptide-related sequence A (MICA), a ligand to the NK activating receptor, plays a critical role in hepatocarcinogenesis. In this review, we summarize the mechanisms underlying the regulation of MICA and NK group 2D expression in chronic hepatitis. Furthermore, we describe recent reports on MICA single-nucleotide polymorphism-driven hepatocarcinogenesis. The suppression of MICA shedding could represent a promising approach for immunosurveillance, as increased expression of membrane-bound MICA achieved through the use of a MICA shedding inhibitor also enhances NK cell-mediated cytotoxicity.

Therapeutic restoration of miR-126-3p as a multi-targeted strategy to modulate the liver tumor microenvironment

BACKGROUND

Impaired natural killer (NK) cell-mediated antitumor responses contribute to the growth of liver tumors. Expression of a disintegrin and metalloprotease 9 (ADAM9) increases shedding of membrane-bound major histocompatibility complex class I chain-related protein A and results in evasion from NK cell-mediated cytolysis. ADAM9 is also involved in angiogenesis and tumor progression and is a target of miR-126-3p, a tumor suppressor that is downregulated and alters tumor cell behavior in the liver and other cancers. We evaluated the restoration of miR-126-3p and modulation of the miR-126-3p/ADAM9 axis as a therapeutic approach to simultaneously enhance NK cell-mediated cytolysis while targeting both tumor cells and their microenvironment.

METHODS

Precursor miRNAs were loaded into milk-derived nanovesicles to generate therapeutic vesicles (therapeutic milk-derived nanovesicles) for the restoration of functional miR-126-3p in recipient cancer cells.

RESULTS

Administration of therapeutic milk-derived nanovesicles increased miR-126-3p expression and reduced ADAM9 expression in target cells and was associated with an increase in membrane-bound major histocompatibility complex class I chain-related protein A. This enhanced NK cell cytolysis in adherent tumor cells and in multicellular tumor spheroids while also impairing angiogenesis and modulating macrophage chemotaxis. Moreover, IV administration of therapeutic milk-derived nanovesicles with adoptive transfer of NK cells reduced tumor burden in orthotopic hepatocellular cancer xenografts in mice.

CONCLUSION

A directed RNA therapeutic approach can mitigate NK cell immune evasion, reduce angiogenesis, and alter the tumor cell phenotype through the restoration of miR-126-3p in liver tumor cells. The pleiotropic effects elicited by this multi-targeted approach to modulate the local tumor microenvironment support its use for the treatment of liver cancer.

HCV and HCC Tango-Deciphering the Intricate Dance of Disease: A Review Article

Hepatitis C virus (HCV) is a major cause of hepatocellular carcinoma (HCC) accounting for around one-third of all HCC cases. Prolonged inflammation in chronic hepatitis C (CHC), maintained through a variety of pro- and anti-inflammatory mediators, is one of the aspects of carcinogenesis, followed by mitochondrial dysfunction and oxidative stress. Immune response dysfunction including the innate and adaptive immunity also plays a role in the development, as well as in the recurrence of HCC after treatment. Some of the tumor suppressor genes inhibited by the HCV proteins are p53, p73, and retinoblastoma 1. Mutations in the telomerase reverse transcriptase promoter and the oncogene catenin beta 1 are two more important carcinogenic signaling pathways in HCC associated with HCV. Furthermore, in HCV-related HCC, numerous tumor suppressor and seven oncogenic genes are dysregulated by epigenetic changes. Epigenetic regulation of gene expression is considered as a lasting "epigenetic memory", suggesting that HCV-induced changes persist and are associated with liver carcinogenesis even after cure. Epigenetic changes and immune response dysfunction are recognized targets for potential therapy of HCC.

CD4/CD8 Ratio could be predictor of burden hepatocellular carcinoma in Egyptian chronic hepatitis C after combined sofosbuvir and daclatasvir therapy

Background

During the first years of the use of direct acting Hepatitis C antiviral drugs (DAAS), several studies reported a possible correlation between this new era of treatment and an increased risk of Hepatocellular carcinoma (HCC). Its development could possibly be favored by the changes in the immunological milieu and the different cellular behavior after eradication of HCV infection with them. For this reason, this study aimed to address the immunological effect of DAAS.

Subject & methods

Prospective paired -sample design, carried out on 90 naïve chronically infected HCV patients before and after receiving a combination therapy of sofosbuvir; at a dose of 400 mg once daily and daclatasvir; at a dose of 60 mg once daily for 12 weeks and follow up for one year. immunological tests including: total T cell count, T helper cell count, T cytotoxic cell count and natural killer cell count in peripheral blood through (CD3, CD3/CD4, CD3/CD8 and CD56 respectively) by Fluorochrome monoclonal antibodies labelled with specific dyes through Multiparameter, FACSCanto ™ II flow cytometer (Becton Dickinson, USA).

Result

Concerning the immunological changes, total T cells (CD3+), Natural killer cells showed non-significant decrease at end of therapy while significant decrease in T helper cells (CD3+CD4+) T cytotoxic cells (CD3+CD8+) compared to pre-treatment value. Long follow up revealed 26.6% developed focal HCC, in more addition, multivariate analysis show CD4/CD8 ratio could be predictor as well as sex for early development of HCC after combined DAAS therapy.

Conclusion

HCV treatment by DAAS produces significant decrease in T helper, T cytotoxic cells in CHC patients at the end of therapy. 26.6% developed focal HCC with independent CD4/CD8 predictor for burden malignancy. Further large extended population study is needed for clarify this concern.

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.

Innate-like bystander-activated CD38+ HLA-DR+ CD8+ T cells play a pathogenic role in patients with chronic hepatitis C

BACKGROUND AND AIMS

HCV-specific T cells are few and exhausted in patients with chronic hepatitis C (CHC). Whether these T cells are responsible for the liver damage and fibrosis is still debated. However, cluster of differentiation 38-positive (CD38⁺ ) human leukocyte antigen DR-positive (HLA-DR⁺ ) CD8⁺ T cells are regarded as bystander CD8⁺ T cells that cause liver injury in acute hepatitis. We propose that these innate CD8⁺ T cells play a pathogenic role in CHC.

METHODS

Lymphocytes from peripheral blood were obtained from 108 patients with CHC and 43 healthy subjects. Immunophenotyping, functional assays, T-cell receptor (TCR) repertoire, and cytotoxic assay of CD38⁺ HLA-DR⁺ CD8⁺ T cells were studied.

RESULTS

The percentage of CD38⁺ HLA-DR⁺ CD8⁺ T cells increased significantly in patients with CHC. These cells expressed higher levels of effector memory and proinflammatory chemokine molecules and showed higher interferon-γ production than CD38^- HLA-DR^- CD8 T cells. They were largely composed of non-HCV-specific CD8⁺ T cells as assessed by HLA-A2-restricted pentamers and next-generation sequencing analysis of the TCR repertoire. In addition, these CD38⁺ HLA-DR⁺ CD8⁺ T cells had strong cytotoxicity, which could be inhibited by anti-DNAX accessory molecule 1, anti-NKG2 family member D, and anti-natural killer NKp30 antibodies. Lastly, the percentage of CD38⁺ HLA-DR⁺ CD8⁺ T cells was significantly associated with liver injury and fibrosis and decreased significantly along with serum alanine aminotransferase normalization after successful direct-acting antiviral treatment.

CONCLUSIONS

The TCR-independent, cytokine-responsive bystander CD38⁺ HLA-DR⁺ CD8⁺ T cells are strongly cytotoxic and play a pathogenic role in patients with CHC.

Sofosbuvir induces gene expression for promoting cell proliferation and migration of hepatocellular carcinoma cells

Direct-acting antivirals (DAAs) have achieved a sustained virological response (SVR) rate of 95–99% in treating HCV. Several studies suggested that treatment with sofosbuvir (SOF), one type of DAAs, may be associated with increased risk of developing HCC. The aim of this study is to investigate the potential mechanisms of SOF on the development of HCC. OR-6 (harboring full-length genotype 1b HCV) and Huh 7.5.1 cells were used to examine the effects of SOF on cell proliferation and migration of HCC cells. SOF-upregulated genes in OR-6 cells were inspected using next generation sequencing (NGS)and the clinical significance of these candidate genes was analyzed using The Cancer Genome Atlas (TCGA) database. We found that SOF increased cell proliferation and cell migration in OR-6 and Huh 7.5.1 cells. Several SOF-upregulated genes screened from NGS were confirmed by real-time PCR in OR-6 cells. Among these genes, PHOSPHO2, KLHL23, TRIM39, TSNAX-DISC1 and RPP21 expression were significantly elevated in the tumor tissues compared with the non-tumor tissues of HCC according to TCGA database. High expression of PHOSPHO2 and RPP21 was associated with poor overall survival of HCC patients. Moreover, knockdown of PHOSPHO2-KLHL23, TSNAX-DISC1, TRIM39 and RPP21 diminished cell proliferation and migration increased by SOF in OR-6 and Huh 7.5.1 cells. In conclusion, SOF-upregulated genes promoted HCC cell proliferation and migration, which might be associated with the development of HCC.

Association between direct-acting antiviral agents in hepatitis C virus treatment and hepatocellular carcinoma occurrence and recurrence: The endless debate

Since direct-acting antiviral agents (DAAs) have been introduced into hepatitis C virus treatment, the sustained viral response (SVR) rate has significantly increased to more than 95%. Scientific evidence supports the idea that SVR after interferon therapy has beneficial effects related to cirrhosis progression, resulting in a reduction in the incidence of hepatocellular carcinoma (HCC). However, a significant debate exists related to DAA impact on HCC development. We reviewed the current literature highlighting the controversial data related to DAA association with de novo HCC occurrence or recurrence and possible pathophysiology of HCC related to DAAs. After a review of the published literature, we believe that the current evidence does not confirm or repudiate a higher rate of de novo HCC occurrence or recurrence related to DAA therapy. More trials are needed to determine if there is an association between HCC occurrence or recurrence and DAA or if it is related to preexisting liver cirrhosis.

The interactions between major immune effector cells and Hepatocellular Carcinoma: A systematic review

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common liver neoplasm with high morbidity and mortality. Tumor immunotherapy might be promising adjuvant therapy for HCC after surgery. To better develop HCC immunotherapy, comprehensive understanding of cell-cell interactions between immune effector cells and HCC cells remains crucial.

AIM

To review the existing studies to summarize the cell-cell interactions between major immune effector cells and HCC cells providing new data for HCC immunotherapy.

METHODS

A systematic review was conducted by searching PubMed database covering all papers published in recent five years up to January 2020. The guidelines of the preferred reporting items for systematic reviews were firmly followed.

RESULTS

There are 9 studies researching the interactions between CD8⁺ T lymphocytes and HCC cells and 22 studies researching that between natural killer (NK) cells and HCC cells. Among the 9 studies, 6 studies reported that CD8⁺ T lymphocytes showed cytotoxicity towards HCC cells while 3 studies found CD8⁺ T lymphocytes were impaired by HCC cells. Among the 22 studies, 20 studies presented that NK cells could inhibit HCC cells. Two studies were found to report NK cell dysfunction in HCC.

CONCLUSION

Based on the systematic analysis, we concluded that CD8⁺ T lymphocytes and NK cells can inhibit HCC cells. While in turn, HCC cells can also result in the dysfunction of those effector cells through various mechanisms. Organoids and direct contact cell co-culture with primary HCC cells and TILs should be the most innovative way to investigate the interactions and develop novel immunotherapy.

Restoring NK cells functionality via cytokine activation enhances cetuximab-mediated NK-cell ADCC: A promising therapeutic tool for HCC patients

Natural Killer (NK) cells are considered the first line of defense against viral infections and tumors. Several factors affect NK cytotoxic activity rendering it dysfunctional and thereby impeding the ability to scavenge abnormal cells as a part of immune escaping mechanisms induced by different types of cancers. NK cells play a crucial role augmenting the activity of various types of anticancer mAb since dysfunctional NK cells are the main reason for the low response to these therapies. To this light, we examined the phenotypic characters of the circulating NK cells isolated from HCC patients compared to healthy controls. Then, dysfunctional NK cells, from HCC patients, were reactivated with cytokines cocktail and their cytotoxic activity with the anti-EGFR mAb "cetuximab" was investigated. This showed a downregulation of patients NK cells activating receptors (NKP30, NKP46, NKG2D and CD16) as well as CD56 and up-regulation of NKG2A inhibitory receptor. We also reported an increase in aberrant CD56^- NK cells subset in peripheral blood of HCC patients compared to healthy controls. Thus, confirming the dysfunctionality of peripheral NK cells isolated from HCC patients. Cytokines re-activation of those NK cells lead to upregulation of NK activating receptors and downregulation of inhibitory receptor. Moreover, the percentage of aberrant CD56^- NK cells subset was reduced. Here, we proved that advanced HCC patients have an increased percentage of more immature and noncytotoxic NK cell subsets in their peripheral blood, which might account for the low cytotoxicity noticed in those patients. A significant improvement in the cytotoxicity against HCC was noticed upon using reactivated NK cells combined with cetuximab. Therefore, this study highlights the potential recruitment of NK immune cells along with cetuximab to enhance cytotoxicity against HCC.

De novo hepatocellular carcinoma in cirrhotic hepatitis C virus: Are directly acting antivirals beneficial?

BACKGROUND AND AIM

Behavior of HCC that developed after DAAs therapy for HCV infection is still debated. In this study we aim to compare characteristics and pattern of de novo HCC in cirrhotic HCV patients who were treated and untreated with DAAs.

PATIENTS AND METHODS

This study included 160 cirrhotic HCV patients presented with de novo HCC during the period of December 2017 to December 2018. Patients were divided into two groups, group A included 80 patients who received DAAs and group B included 80 patients who were not exposed to DAAs. The characteristics of HCC in both groups were compared using BCLC Staging System.

RESULTS

The size of the largest lesion was 47mm±26 in group A and 41mm±27 in group B with statistically significant difference between both groups (p=0.03). No other significant differences existed regarding number, site, or total tumor size and most of the lesions were solid in both groups. Portal vein thrombosis and extrahepatic spread detected in 16 and 11 patients in group A, while in group B the number was 17 and 9 patients respectively (p=0.83 and 0.06). No significant differences between groups in type of intervention done, BCLC staging (p=0.4), or survival.

CONCLUSION

Although CHCV patients treated with DAAs had larger de novo HCC lesions than untreated patients, there was no difference in BCLC staging or in aggressive behavior between both groups.

HCC in the Era of Direct-Acting Antiviral Agents (DAAs): Surgical and Other Curative or Palliative Strategies in the Elderly

Hepatocellular carcinoma (HCC) accounts for 75-85% of primary liver malignancies, and elderlies have the highest incidence rates. Direct-acting antiviral agents (DAAs) have shown satisfying results in terms of HCV sustained viral response (SVR). However, data regarding HCC risk post-DAA-SVR is still conflicting. This study aims to consider HCC onset in moderate underlying liver disease. We conducted a retrospective study on 227 chronically infected patients (cHCV), treated with DAAs. Patients were divided into three groups: "de novo occurrent HCC", "recurrent HCC", and "without HCC". Fifty-six patients aged <65 years (yDAA) were studied separately. HCC patients aged ≥65 years (DAA-HCC) were compared to a historical group of 100 elderly HCC patients, treated with peginterferon (Peg-IFN) ± ribavirin antiviral agents, non-SVR (hHCC). The HCC prevalence in DAA patients was 32.75%: "de novo occurrent'' 18.13% and "recurrent'' 14.62%, despite 42.85% of them having no fibrosis to mild or moderate fibrosis (F0-F1-F2). yDAA showed 5.36% "de novo occurrent" HCC. Curative procedure rates were compared between DAA-HCC and hHCC at the first and at recurrent presentation (22 (39.29%) vs. 72 (72%); 17 (30.36%) vs. 70 (70%), respectively (p < 0.001)). No significant difference was found in 3-year OS (p = 0.6). However, in cause-specific mortality analysis, HCC-related death was higher in the DAA-treated group, whereas cirrhosis-related death was more common in the historical group (p = 0.0288), considering together the two causes of death. A more accurate patient stratification according to multifactorial and new diagnostic investigations identifying HCC risk might allow an improvement in management and access to curative therapies.

Interrupted crosstalk between natural killer cells and anti-epidermal growth factor receptor: a possible role in hepatocellular carcinoma treatment failure

Hepatocellular carcinoma (HCC) is a major health problem worldwide. Most patients are diagnosed for the first time at late stages; this leads to a very poor prognosis. It is challenging to discover strategies for treatment at these advanced stages. Recently, monoclonal antibodies (mAbs) targeting specific cellular signaling pathways in HCC have been developed. Unfortunately, they still have a low survival rate, and some of them failed clinically to produce effective responses even if they showed very good results against HCC in preclinical studies. This review focuses on and discusses the possible causes for the failure of mAbs, precisely anti-Epidermal Growth Factor Receptor (EGFR) mAb and the crosstalk between this mAb and patients' NK cells.

Tertiary Prevention of HCC in Chronic Hepatitis B or C Infected Patients

Simple Summary

Hepatocellular carcinoma (HCC) recurrence is the major obstacle concerning patients’ survival. Tertiary prevention by antiviral therapies could reduce HCC recurrence rate in both chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infected patients. In chronic hepatitis B (CHB) patients, nucleos(t)ide analogues (Nuc) provide a more effective HCC tertiary prevention effect than an interferon (IFN)-based regimen. In chronic hepatitis C (CHC) patients, the tertiary prevention effect by direct acting antiviral agents (DAAs) was reported non-inferior to that by IFN-based therapy. Chronic hepatitis C patients left untreated had the worst survival benefit as well as shorted recurrence-free interval than those treated by either type of antiviral regimen. Although the risk of HCC recurrence could only be decreased but not diminished by antiviral therapies due to host and microenvironmental factors beyond virus infection, antiviral therapy helps to preserve and improve liver function which makes multi-modality anticancer treatment feasible to improve survival.

Abstract

Hepatocellular carcinoma (HCC) ranks as a leading cause of common cancer and cancer-related death. The major etiology of HCC is due to chronic hepatitis virus including HBV and HCV infections. Scheduled HCC surveillance in high risk populations improves the early detection rate and the feasibility of curative treatment. However, high HCC recurrence rate still accounts for the poor prognosis of HCC patients. In this article, we critically review the pathogenesis of viral hepatitis-related hepatocellular carcinoma and the evidence of tertiary prevention efficacy by current available antiviral treatment, and discuss the knowledge gap in viral hepatitis-related HCC tertiary prevention.

Hepatocellular carcinoma recurrence after directly acting antivirals for chronic hepatitis C: a 2-year follow-up study

AIM OF THE STUDY

Data regarding hepatocellular carcinoma (HCC) recurrence after directly acting antivirals for hepatitis C are contradictory. Our aim was to study the HCC recurrence in patients who received directly acting antivirals after tumor ablation.

MATERIAL AND METHODS

This retrospective study included all Child-Pugh A and B patients with hepatitis C related < 5 cm single or up to 3 HCC without any vascular or extrahepatic involvement whose lesions were managed using microwave or radiofrequency ablation at the Internal Medicine Department of Alexandria Faculty of Medicine, in the period from 1 January 2016 to 31 December 2016, and then received directly acting antivirals.

RESULTS

Data from 52 patients were analyzed. Throughout the 2 years from ablation, 42.3% of patients experienced tumor recurrence (22 out of 52 patients). In addition, two subjects died and 4 subjects were lost to follow-up before any tumor recurrence.

CONCLUSIONS

Although our study included both modified Child-Pugh A and B patients and included lesions up to 5 cm treated using thermal ablation, the 2-year HCC recurrence rate was similar to that previously reported after surgical resection or radiofrequency ablation of lesions up to 3 cm in Child-Pugh A patients before development of directly acting antivirals.

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.

lnc-HOTAIR predicts hepatocellular carcinoma in chronic hepatitis C genotype 4 following direct-acting antivirals therapy

Emerging hepatocellular carcinoma (HCC) has been sequentially reported in chronic hepatitis C virus (HCV) treated with direct-acting antivirals (DAAs). Homeobox transcript antisense RNA (HOTAIR), an oncogene, has been reported to be associated with cancer. We investigated the predictive value of lnc-HOTAIR for HCC surveillance in chronic HCV patients following DAAs therapy. The expression levels of lnc-HOTAIR and ATG-7 genes were measured in 220 with chronic HCV, following a DAAs based therapy for 12 weeks, the patients were followed-up for attentive surveillance of HCC for 12 months after starting DAAs. In terms of lnc-HOTAIR, patients with HCC and high viral load had significantly higher median expression levels of HOTAIR of (68 vs. 24; p = .001) and (94 vs. 52; p = .001), respectively. Moreover, the median expression level of ATG-7 was higher in those who developed HCC (114 vs. 51; p = .001). The expression of lnc-HOTAIR and ATG-7 are significant predictors of the development of HCC in HCV-4 infected patients treated with DAAs, with a cut-off value of 37 and 86, respectively. The increased expression levels of lnc-HOTAIR more than 68 in HCC patients following DAAs were correlated with poorer disease outcomes compared to those with lower expression levels; however, ATG-7 expression levels more than 114 were correlated with worse overall survival but not the progression-free one. We suggest that high expression levels of lnc-HOTAIR could serve as a risk assessment biomarker for HCC before and during DAAs course therapy in Chronic HCV-4 patients, and should be rigorously taken into consideration before DAAs.

Tumor microenvironment in primary liver tumors: A challenging role of natural killer cells

In the last years, several studies have been focused on elucidate the role of tumor microenvironment (TME) in cancer development and progression. Within TME, cells from adaptive and innate immune system are one of the main abundant components. The dynamic interactions between immune and cancer cells lead to the activation of complex molecular mechanisms that sustain tumor growth. This important cross-talk has been elucidate for several kind of tumors and occurs also in patients with liver cancer, such as hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). Liver is well-known to be an important immunological organ with unique microenvironment. Here, in normal conditions, the rich immune-infiltrating cells cooperate with non-parenchymal cells, such as liver sinusoidal endothelial cells and Kupffer cells, favoring self-tolerance against gut antigens. The presence of underling liver immunosuppressive microenvironment highlights the importance to dissect the interaction between HCC and iCCA cells with immune infiltrating cells, in order to understand how this cross-talk promotes tumor growth. Deeper attention is, in fact, focused on immune-based therapy for these tumors, as promising approach to counteract the intrinsic anti-tumor activity of this microenvironment. In this review, we will examine the key pathways underlying TME cell-cell communications, with deeper focus on the role of natural killer cells in primary liver tumors, such as HCC and iCCA, as new opportunities for immune-based therapeutic strategies.

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.

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.

Direct-acting antiviral treatment downregulates immune checkpoint inhibitor expression in patients with chronic hepatitis C

Chronic hepatitis C (CHC) infection is associated with increased TIM-3, PD-1 immune checkpoint receptors expression that inhibits adaptive T cells and increases NK cell cytotoxicity against T helper cells, both resulting T cell exhaustion. Elimination of the virus with direct-acting antivirals (DAAs) may modify host immune response via altering these immune checkpoint receptors’ expression. We conducted a prospective study to analyze changes in TIM-3, PD-1 and their ligands galectin-9, PD-L1 expression by peripheral blood T cell subpopulations, NK cell subpopulations, and monocytes by multicolor flow cytometry in 14 CHC patients successfully treated with 12 weeks of dasabuvir, ombitasvir, and paritaprevir/ritonavir plus ribavirin. Blood samples were collected before, at the end of treatment, and 12 and 24 weeks later. Sustained virological response (SVR) was associated with increased percentage of peripheral blood CD3+ T and CD8+ cytotoxic T lymphocytes and decreased percentage of NKbright cells. After DAA treatment, decreased TIM-3 expression by CD4+ T cells, by NKbright, and by NKT cells was found. Expression of immune checkpoint molecules’ ligand PD-L1 by NK cells and by regulatory T cells and galectin-9 by NK cells and monocytes also decreased significantly at SVR. Our data suggest that DAA treatment not only inhibits viral replication but may alter host adaptive and innate immune responses. A decrease in immune checkpoint molecules and their ligands expression both on adaptive and on innate immune cells may contribute to the recovery of exhausted adaptive immune responses and to sustained virological response.

Hepatitis C Antiviral Therapy In Patients With Successfully Treated Hepatocellular Carcinoma: Dancing With Wolves

Hepatitis C virus (HCV) infection is known to be one of the leading causes of hepatocellular carcinoma (HCC) all over the world. Previously, multiple studies have confirmed a decreased rate of HCC occurrence or recurrence in the cases of hepatitis C associated cirrhosis after treatment with interferon, in comparison to the untreated cases, even in the absence of clearance of HCV. Treatment programs with direct-acting antivirals (DAAs) as a new method for HCV treatment and cure in 2014, with higher safety and efficacy, were considered as an important step in the treatment of patients with history of HCC, improving their overall prognosis. Recently, reports coming from various European centers claimed that the risk of HCC increased following DAAs therapy, especially in cases with previous HCC. Moreover, other studies revealed that the recurrence of HCC after DAAs treatment was more aggressive. Even though others were not able to conclude the same results, the role of DAA therapy in recurrence of HCC in patients with previous HCC after sustained virological response (SVR) achievement remains questionable. This review explored the existing literature and discussed opinions on the possibility of increasing recurrence of HCC following DAA therapy, possible mechanisms, predictors of HCC recurrence post DAAs, and whether those patients should be treated or not.

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Risk of hepatocellular carcinoma development after hepatitis C virus eradicated by direct-acting antivirals: Fact or fiction?

Although interferon (IFN)-based therapy has been shown to reduce hepatocellular carcinoma (HCC) development once patients with chronic hepatitis C virus (HCV) infection achieve sustained virologic response (SVR), IFN-based therapy is limited by its multiple adverse effects, non-oral administration, and unsatisfactory SVR rate. In recent years, IFN-free all-oral direct-acting antivirals (DAAs) have replaced IFN-based therapy as the standard of care for HCV infection worldwide because of the higher SVR rate and lower incidence of adverse effects. By using currently approved DAA regimens, HCV can be eradicated in more than 95% of infected hosts, regardless of their disease severity. Since 2016, the risk of de novo occurrence or recurrence of HCC in hepatitis C patients receiving DAAs has been debatable because of a report addressing an unexpected high early tumor recurrence rate. To solve this important, interesting, yet controversial issue, we thus reviewed the latest and most relevant articles on this subject and proposed recommendations to manage such patients for healthcare providers.

APASL HCV guidelines of virus-eradicated patients by DAA on how to monitor HCC occurrence and HBV reactivation

In the direct-acting antiviral (DAA) era for hepatitis C virus (HCV) infection, sustained virological response (SVR) is very high, but close attention must be paid to the possible occurrence of hepatocellular carcinoma (HCC) and reactivation of hepatitis B virus (HBV) in patients with co-infection who achieved SVR in short term. HCC occurrence was more often observed in patients with previous HCC history. We found occurrence of HCC in 178 (29.6%) of 602 patients with previous HCC history (15.4 months mean follow-up post-DAA initiation) but, in contrast, in only 604 (1.3%) of 45,870 patients without previous HCC history (18.2 months mean follow-up). Thus, in these guidelines, we recommend the following: in patients with previous HCC history, surveillance at 4-month intervals for HCC by ultrasonography (US) and tumor markers should be performed. In patients without previous HCC history, surveillance at 6- to 12-month intervals for HCC including US is recommended until the long-term DAA treatment effects, especially for the resolution of liver fibrosis, are confirmed. This guideline also includes recommendations on how to follow-up patients who have been infected with both HCV and HBV. When HCV was eradicated in these HBsAg-positive patients or patients with previous HBV infection (anti-HBc and/or anti-HBs-positive), it was shown that HBV reactivation or HBV DNA reappearance was observed in 67 (41.4%) of 162 or 12 (0.9%) of 1317, respectively. For these co-infected patients, careful attention should be paid to HBV reactivation for 24 weeks post-treatment.

Sustained virologic response to direct-acting antiviral therapy in patients with chronic hepatitis C and hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND & AIMS

The effect of hepatocellular carcinoma (HCC) on the response to interferon-free direct-acting antiviral (DAA) therapy in patients with chronic hepatitis C (CHC) infection remains unclear. Using a systematic review and meta-analysis approach, we aimed to investigate the effect of DAA therapy on sustained virologic response (SVR) among patients with CHC and either active, inactive or no HCC.

METHODS

PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials were searched from 1/1/2013 to 9/24/2018. The pooled SVR rates were computed using DerSimonian-Laird random-effects models.

RESULTS

We included 49 studies from 15 countries, comprised of 3,341 patients with HCC and 35,701 without HCC. Overall, the pooled SVR was lower in patients with HCC than in those without HCC (89.6%, 95% CI 86.8-92.1%, I² = 79.1% vs. 93.3%, 95% CI 91.9-94.7%, I² = 95.0%, p = 0.0012), translating to a 4.8% (95% CI 0.2-7.4%) SVR reduction by meta-regression analysis. The largest SVR reduction (18.8%) occurred in patients with active/residual HCC vs. inactive/ablated HCC (SVR 73.1% vs. 92.6%, p = 0.002). Meanwhile, patients with HCC who received a prior liver transplant had higher SVR rates than those who did not (p <0.001). Regarding specific DAA regimens, patients with HCC treated with ledipasvir/sofosbuvir had lower SVR rates than patients without HCC (92.6%, n = 884 vs. 97.8%, n = 13,141, p = 0.026), but heterogeneity was high (I² = 84.7%, p <0.001). The SVR rate was similar in patients with/without HCC who were treated with ombitasvir/paritaprevir/ritonavir ± dasabuvir (n = 101) (97.2% vs. 94.8%, p = 0.79), or daclatasvir/asunaprevir (91.7% vs. 89.8%, p = 0.66).

CONCLUSION

Overall, SVR rates were lower in patients with HCC, especially with active HCC, compared to those without HCC, though heterogeneity was high. Continued efforts are needed to aggressively screen, diagnose, and treat HCC to ensure higher CHC cure rates.

LAY SUMMARY

There are now medications (direct-acting antivirals or "DAAs") that can "cure" hepatitis C virus, but patients with hepatitis C and liver cancer may be less likely to achieve cure than those without liver cancer. However, patients with liver cancer are also more likely to have advanced liver disease and risk factors that can decrease cure rates, so better controlled studies are needed to confirm these findings.

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.

Impact of treating chronic hepatitis C infection with direct-acting antivirals on the risk of hepatocellular carcinoma: The debate continues - A mini-review

Hepatitis C virus clearance is expected in more than 95% of patients treated with direct-acting antivirals (DAAs). However, an extensive debate about the impact of DAAs on the development of hepatocellular carcinoma (HCC) is currently ongoing. This review aimed to explore currently available evidence about the relationship between DAAs and HCC development. The American studies and some European studies clearly showed no relation, while the Japanese and Egyptian studies and the other European studies showed an increased risk of developing HCC after DAA exposure. These conflicting results may be due to geographical and ethnic variations and differences in the design and inclusion criteria among the studies. After reviewing the data from these different studies, it seems that some patients are at increased risk of developing HCC after DAA exposure. Identifying those at increased risk is very important for the management of HCC in light of the potentially major consequences of HCC for the patients' quality of life and the subsequent major burden imposed on healthcare resources.

Hepatocellular Carcinoma Recurrence in HCV Patients Treated with Direct Antiviral Agents

The risk of hepatocellular carcinoma recurrence is universal regardless of the treatment modality applied, and secondary prevention is still an unmet issue even though the elimination of hepatitis C (HCV) with direct antiviral agents (DAAs) was expected to be one of the new options. Unfortunately, the impact of DAAs on hepatocellular carcinoma (HCC) development (de novo and recurrence) is still controversial. Since the first publication on the subject in 2016, almost all groups worldwide have carried out research in this field with hundreds of publications now available. This revision is focused on the impact of DAAs on HCC recurrence and aims to discuss the potential underlying mechanisms and host factors pointing out the time association phenomenon between DAA treatment and HCC recurrence. Moreover, we comment on the methodological issues that could affect the different interpretations of the published results. In conclusion, this is an area of research with potential in the understanding of the impact of factors not previously considered, and may also help change hepatocarcinogenesis tenets, such as the belief that the elimination of HCV should be used as a second prevention treatment.

Recurrence rate of hepatocellular carcinoma in patients with treated hepatocellular carcinoma and hepatitis C virus-associated cirrhosis after ombitasvir/paritaprevir/ritonavir+dasabuvir+ribavirin therapy

Introduction

Recent studies have suggested a higher recurrence rate of hepatocellular carcinoma (HCC) in patients with a history of HCC and hepatitis C virus (HCV)-associated cirrhosis treated with direct-acting antiviral (DAA) agents.

Material and methods

We conducted a prospective analysis of 24 patients with HCV-associated cirrhosis and treated HCC who received ombitasvir/paritaprevir/ritonavir+dasabuvir+ribavirin for 12 weeks. Prior therapies for HCC included resection (9/24 patients), radiofrequency ablation (RFA) (7/24) and trans-arterial chemoembolization (TACE) (8/24). All patients were eligible for treatment if they had no HCC recurrence 6 months after their last procedure. A control group was defined. All patients were followed every 6 months, with dynamic computed tomography and/or magnetic resonance imaging.

Results

The sustained virological response rate per protocol was 21/24 (87.5%). The study group included 14 (59%) males, median age 64 years (51-77), 50% with associated non-alcoholic steatohepatitis and 24% with Child-Pugh A6 points. HCC recurrence rate/100 patient-years was lower in the DAA-HCC group versus control: 5.5 versus 24.6% patient-years for the resection+RFA group (p = 0.044), respectively, and 18.6 versus 72.7% patient-years for TACE group (p = 0.002). Survival without recurrence was higher in the resection+RFA group (45 compared to 18 months (p < 0.001)) and also in the TACE group (44 compared to 11.5 months (p = 0.002)).

Conclusions

DAA therapy significantly reduced the recurrence rate of HCC and improved survival without recurrence in patients with treated HCV-associated HCC.

Hepatocellular carcinoma after direct-acting antivirals: an unresolved problem. Review of five cases

Aim of the study

To present the problem of hepatocellular carcinoma (HCC) occurring in patients treated with direct-acting antiviral (DAA) agents and to draw attention to the fact that HCC may develop even after successful therapy and in patients who were not previously diagnosed with it.

Material and methods

The inclusion criterion was confirmation of successful DAA treatment prior to HCC among hepatitis C virus (HCV)-infected patients with liver cirrhosis. The analysed group consisted of 5 patients.

Results

In three patients the emergence of hepatocellular carcinoma was very rapid. They developed sudden decompensation of liver function with its symptoms – ascites, oedema, coagulation dysfunction. Furthermore, they had liver encephalopathy and renal failure. One of the patients had cancer cell thrombosis. Two patients’ status was stable, but they were disqualified from liver surgery due to large size of the focal lesions and their plurality.

Conclusions

DAAs, despite their high effectiveness in HCV treatment, still bear the risk of developing HCC. Patients after the therapy should remain under medical control for the early detection and treatment of the presumptive cancer.

Hepatitis C virus-associated hepatocellular carcinoma after sustained virologic response

The introduction of a direct-acting antiviral (DAA) for patients with hepatitis C virus (HCV) infection, could lead to higher sustained virologic response (SVR) rates with fewer adverse events, and it could shorten the treatment duration relative to the interferon era. Although most recent clinical studies have demonstrated that the occurrence rates of hepatocellular carcinoma (HCC) are decreased by SVR with both interferon-based and interferon-free-regimens, there are several reports about the unexpected observation of high rates of early tumor occurrence and recurrence in patients with HCV-related HCC undergoing interferon-free therapy despite SVR. Several mechanisms of HCC occurrence and rapid immunological changes, including cytokines and chemokines during and after DAA treatment, have also been reported. We focused on the possibilities that HCC occurs or recurs during and after DAA treatment, based on the reported clinical and basic studies. Further studies and observations will be needed to determine the short-term and long-term effects on hepatocarcinogenesis caused by the eradication of HCV with DAAs. New serum biomarkers and a follow-up system for HCV-patients with SVR should be established.

Molecular Mechanisms Involved in HCC Recurrence after Direct-Acting Antiviral Therapy

Chronic hepatitis C is associated with a high risk of developing hepatocellular carcinoma (HCC) because of a direct effect of the Hepatitis C Virus (HCV) proteins and an indirect oncogenic effect of chronic inflammation and impaired immune response. The treatment of chronic hepatitis C markedly reduces all-cause mortality; in fact, interferon-based treatment has shown a reduction of HCC incidence of more than 70%. The recent introduction of the highly effective direct-acting antivirals (DAAs) has completely changed the scenario of chronic hepatitis C (CHC) with rates of HCV cure over 90%. However, an unexpectedly high incidence of HCC recurrence was observed in patients after DAA treatment (27% versus 0.4–2% in patients who received interferon treatment). The mechanism that underlies the high rate of tumor relapse is currently unknown and is one of the main issues in hepatology. We reviewed the possible mechanisms involved in HCC recurrence after DAA treatment.

Natural Killer Cell Dysfunction in Hepatocellular Carcinoma: Pathogenesis and Clinical Implications

Hepatocellular carcinoma (HCC) is currently the third leading cause of malignancy-related mortalities worldwide. Natural killer (NK) cells are involved in the critical role of first line immunological defense against cancer development. Defects in NK cell functions are recognized as important mechanisms for immune evasion of tumor cells. NK cell function appears to be attenuated in HCC, and many previous reports suggested that NK cells play a critical role in controlling HCC, suggesting that boosting the activity of dysfunctional NK cells can enhance tumor cell killing. However, the detailed mechanisms of NK cell dysfunction in tumor microenvironment of HCC remain largely unknown. A better understanding of the mechanisms of NK cell dysfunction in HCC will help in the NK cell-mediated eradication of cancer cells and prolong patient survival. In this review, we describe the various mechanisms underlying human NK cell dysfunction in HCC. Further, we summarize current advances in the approaches to enhance endogenous NK cell function and in adoptive NK cell therapies, to cure this difficult-to-treat cancer.

Modulation of the Immune System in Chronic Hepatitis C and During Antiviral Interferon-Free Therapy

The treatment of patients with chronic hepatitis C virus (HCV) infection has changed tremendously over the past 2 years, with an increasing variety of all-oral direct-acting antiviral (DAA) treatment regimens available for different HCV genotypes and distinct clinical settings. These treatments have significantly improved safety in patients with advanced liver disease compared with interferon (IFN)-based regimens. HCV modifies the human immune system to escape immunosurveillance via several mechanisms. One of the basic mechanisms of HCV is the ability to “switch” the immune response by reducing the activity of cells responsible for the elimination of virus-infected cells. IFN-free DAA treatment regimens provide a unique opportunity to assess the effect of HCV elimination on the immune system. Abrupt changes in the immune system can in some cases be responsible for two alarming processes: viral reactivation in patients with chronic hepatitis B and recurrence of hepatocellular carcinoma in patients with previous successful cancer treatment.

Hepatocellular carcinoma after direct-acting antiviral drug treatment in patients with hepatitis C virus

Background and Aim

Given the use of direct‐acting antivirals (DAAs) to treat hepatitis C virus (HCV), their effects on hepatocarcinogenesis should be determined.

Methods

This study enrolled 349 patients with HCV who underwent DAA treatment at our hospital between 2014 and 2018. Their median age was 65 years, and 184 were male; 301 cases were of HCV serotype 1, and 48 were of serotype 2. The DAA treatment was daclatasvir/asunaprevir in 107 cases, sofosbuvir (SOF)/ledipasvir in 147 cases, ritonavir‐boosted ombitasvir/paritaprevir in 28 cases, elbasvir/grazoprevir in 19 cases, and SOF/ribavirin in 48 cases. The patients’ histories included hepatocellular carcinoma (HCC) in 45 cases, liver transplant (LT) in 10 cases, and kidney transplant (KT) in 17 cases.

Results

Sustained virological responses occurred in 335 cases (96%). DAA treatment was initiated a median of 16.3 months after HCC treatment. After DAA treatment, 15 cases (33%) had recurrence of HCC after a median of 11.6 months, and 3 cases (1%) developed de novo HCC. Six LT patients and one KT patient had HCC; however, no HCC was observed after DAA. The incidence of HCC was significantly higher in patients with multiple HCC treatments in the Cox hazard model (hazard ratio 1.664, 95% confidence interval 1.134–2.441, P < 0.01). Surgical resection or LT reduced the risk of HCC.

Conclusions

DAA did not increase the rate of HCC, even in immunosuppressed patients. However, careful follow‐up for HCC recurrence is required in previously treated cases.

Recovery of natural killer cells is mainly in post-treatment period in chronic hepatitis C patients treated with sofosbuvir plus ledipasvir

AIM

To investigate how natural killer (NK) cells are affected in the elimination of hepatitis C virus (HCV) by sofosbuvir/ledipasvir, two highly effective direct-acting antivirals (DAAs).

METHODS

Thirteen treatment-naïve and treatment-experienced chronic hepatitis C (CHC) patients were treated with sofosbuvir/ledipasvir, and NK cells were detected at baseline, weeks 2, 4, 8 and 12 during therapy, and week post of treatment (Pt)-12 and 24 after the end of therapy by multicolor flow cytometry and compared with those from 13 healthy controls.

RESULTS

All patients achieved sustained virological response. There was a significant decline in CD56bright NK cell frequencies at week 8 (P = 0.002) and week 12 (P = 0.003), which were altered to the level comparable to healthy controls at week Pt-12, but no difference was observed in the frequency of CD56dim NK cells. Compared with healthy controls, the expression levels of NKG2A, NKp30 and CD94 on NK cells from CHC patients at baseline were higher. NKG2A, NKp30 and CD94 started to recover at week 12 and reached the levels similar to those of healthy controls at week Pt-12 or Pt-24. Before treatment, patients have higher interferon (IFN)-γ and perforin levels than healthy controls, and IFN-γ started to recover at week 8 and reached the normalized level at week Pt-12.

CONCLUSION

NK cells of CHC patients can be affected by DAAs, and phenotypes and function of NK cells recover not at early stage but mainly after the end of sofosbuvir/ledipasvir treatment.

Hepatocellular carcinoma after direct-acting antiviral therapy for chronic HCV infection: Is it a real risk?

The newer oral treatments for chronic hepatitis C virus infection are one of the greatest revolutions in modern medicine. These drugs promise to eradicate the infection, showing high cure rates even in difficult to treat populations with very few side effects. Nevertheless, some cases of recurrence and de novo hepatocellular carcinoma after treatment with these drugs have been reported. We describe two cases of patients treated with direct-acting antiviral agents that developed hepatocarcinoma during follow-up post-treatment.

Direct-acting antivirals and hepatocellular carcinoma in chronic hepatitis C: A few lights and many shadows

With the introduction of direct-acting antiviral agents (DAA), the rate of sustained virological response (SVR) in the treatment of hepatitis C virus (HCV) has radically improved to over 95%. Robust scientific evidence supports a beneficial role of SVR after interferon therapy in the progression of cirrhosis, resulting in a decreased incidence of hepatocellular carcinoma (HCC). However, a debate on the impact of DAAs on the development of HCC is ongoing. This review aimed to analyse the scientific literature regarding the risk of HCC in terms of its recurrence and occurrence after the use of DAAs to eradicate HCV infection. Among 11 studies examining HCC occurrence, the de novo incidence rate ranged from 0 to 7.4% (maximum follow-up: 18 mo). Among 18 studies regarding HCC recurrence, the rate ranged from 0 to 54.4% (maximum “not well-defined” follow-up: 32 mo). This review highlights the major difficulties in interpreting data and reconciling the results of the included studies. These difficulties include heterogeneous cohorts, potential misclassifications of HCC prior to DAA therapy, the absence of an adequate control group, short follow-up times and different kinds of follow-up. Moreover, no clinical feature-based scoring system accounts for the molecular characteristics and pathobiology of the tumours. Nonetheless, this review does not suggest that there is a higher rate of de novo HCC occurrence or recurrence after DAA therapy in patients with previous HCV infection.

Hepatocellular carcinoma: Prospects for natural killer cell immunotherapy

Liver disease is a growing cause of death in the United Kingdom and the incidence of hepatocellular carcinoma (HCC) is rising (http://www.cancerresearchuk.org/). The combination of an immunosuppressive environment within the liver and suboptimal host anti-tumour immune responses may account for the poor survival outcome of HCC. Understanding how tumours evade immune recognition coupled with new insights into the unique immunological environment within the liver will be critical to developing liver-specific immunotherapies.

The benefits of hepatitis C virus cure: Every rose has thorns

To examine mid-term benefits on hepatic complications, extrahepatic clinical syndromes and quality of life associated with HCV cure; to review the few safety issues linked to oral direct-acting antivirals (DAAs); and to discuss the potential population benefits of reducing the burden of HCV infection. DAAs cure HCV infection in more than 95% of patients. The halting of liver inflammation and fibrosis progression translates into both hepatic and extrahepatic benefits and reduces the need for liver transplantation. A reduction in the frequency of extrahepatic manifestations such as mixed cryoglobulinaemia and vasculitis and improvements in quality of life and fatigue have also been described. A few safety issues linked to DAAs such as the potential recurrence of aggressive HCC, the flares of hepatitis B virus in patients with overt or occult HBV infection are been discussed. Curing HCV infection also has a high potential to reduce the burden of HCV infection at the population level. With widespread scaling up of HCV treatment, several modeling studies suggest that major reductions in HCV prevalence and incidence are possible, and that elimination of viral hepatitis is an achievable target by 2030.

Impact of direct acting antivirals on occurrence and recurrence of hepatocellular carcinoma: Biologically plausible or an epiphenomenon?

Hepatocellular carcinoma (HCC) is a major cause of morbidity and mortality worldwide. Chronic hepatitis C virus infection (HCV) is the most common cause of HCC in many European countries, Japan and Pakistan. Introduction of the new direct acting antivirals (DAAs) has revolutionized the management of HCV worldwide, with high rates of sustained virologic response in patients who could not have tolerated the previous interferon based treatments. However, recently there have been reports raising caution about the long term effects of DAAs, particularly a possible increased risk of HCC. Therefore this review explores the current molecular studies as well as clinical data that investigate the impact of DAAs on occurrence and recurrence of HCC.

Post-infection viral superinfection technology could treat HBV and HCV patients with unmet needs

Background

Viral hepatitis deaths from acute infection, cirrhosis, and liver cancer have risen from the tenth to the seventh leading cause of death worldwide between 1990 and 2013. Even in the oral direct acting antiviral (DAA) agent era there are still large numbers of patients with unmet needs. Medications approved for treatment of chronic hepatitis B virus (HBV) infection do not eradicate HBV often requiring treatment for life associated with risks of adverse reactions, drug resistance, nonadherence, and increased cost. Although DAAs increased virologic cure rates well over 90% in all hepatitis C virus (HCV) genotypes, HCV infection still cannot be cured in a small but significant minority of patients. While most of the medical issues of HCV treatment have been solved, the current costs of DAAs are prohibitive.

Results

The post-infection viral superinfection treatment (SIT) platform technology has been clinically proven to be safe and effective to resolve acute and persistent viral infections in 42 HBV and HCV patients (20 HBV, 22 HCV), and in 4 decompensated patients (2 HBV, 2 HCV). SIT employs a non-pathogenic avian double stranded RNA (dsRNA) virus, a potent activator of antiviral gene responses. Unexpectedly, SIT is active against unrelated DNA (HBV) and RNA (HCV) viruses. SIT does not require lifelong therapy, which is a major advantage considering present HBV treatments. The new viral drug candidate (R903/78) is homogeneously produced by reverse genetics in Vero cells. R903/78 has exceptional pH and temperature stability and also excellent long-term stability; therefore, it can be orally administered, stored and shipped without freezing. Since R903/78 is easy to stockpile, the post-infection SIT could also alleviate the logistic hurdles of surge capacity in vaccine production during viral pandemics.

Conclusion

To help large number of HBV and HCV patients with unmet needs, broad-spectrum antiviral drugs effective against whole classes of viruses are urgently needed. The innovative SIT technological platform will be a great additional armament to conquer viral hepatitis, which is still a major cause of death and disability worldwide.