Immunohistochemical detection of hcv in cirrhosis, dysplastic nodules, and hepatocellular carcinomas with parallel-tissue quantitative RT-PCR

Assessment of hepatitis c core antigen in epithelial salivary gland neoplasms (ex-vivo study)

BACKGROUND

Salivary gland neoplasms (SGNs) pose a challenge to both pathologists and clinicians. Despite research, the etiology of these neoplasms remains unclear. This study aimed to identify any potential association between the presence of hepatitis C virus (HCV) at the protein or gene level and epithelial salivary gland neoplasms.

METHODS

Formalin-fixed paraffin-embedded (FFPE) blocks of epithelial salivary gland neoplasms were retrieved from the archives of the Oral and Maxillofacial Pathology Department, Faculty of Dentistry, Cairo University within the 5-year period from 2016 to 2020. Immunohistochemistry was used to assess HCV core antigen, while reverse transcription polymerase chain reaction was employed for the evaluation of HCV RNA.

RESULTS

A total of 44 specimens were collected, 28 of which were benign neoplasms and 16 were malignant neoplasms. There was a statistically significant difference in HCV positivity between the two groups (P-value = 0.036). Benign tumors showed a statistically significant lower percentage of positive cases than malignant tumors. The localization of staining was also evaluated, revealing various patterns of HCV core antigen expression, including diffuse cytoplasmic, patchy cytoplasmic, nuclear, and a combination of nuclear and cytoplasmic expression. There was no statistically significant difference between the expression patterns in benign and malignant tumors (P-value = 0.616). Given that Pleomorphic Adenoma and Mucoepidermoid Carcinoma were the predominant tumor types in this study, four cases were selected for RNA detection. HCV RNA was detected in all cases using RT-PCR.

CONCLUSIONS

HCV core antigen is frequently detected in SGNs and is suggested to be a potential risk factor for the development of these neoplasms. Further studies are required to discover other biomarkers, their roles, and the pathways associated with HCV in SGNs.

Laboratory Profile of COVID-19 Patients with Hepatitis C-Related Liver Cirrhosis

Patients with cirrhosis are known to have multiple comorbidities and impaired organ system functioning due to alterations caused by chronic liver failure. In the past two years, since the COVID-19 pandemic started, several studies have described the affinity of SARS-CoV-2 with the liver and biliary cells. Considering hepatitis C as a significant independent factor for cirrhosis in Romania, this research was built on the premises that this certain group of patients is susceptible to alterations of their serum parameters that are yet to be described, which might be useful in the management of COVID-19 in these individuals. A retrospective cohort study was developed at a tertiary hospital for infectious disease in Romania, which included a total of 242 patients with hepatitis C cirrhosis across two years, out of which 46 patients were infected with SARS-CoV-2. Stratification by patient weight and COVID-19 status identified several important laboratory serum tests as predictors for acute-on-chronic liver failure and risk for intensive care unit admission. Thus, white blood cell count, lymphocyte count, ferritin, hypoglycemia, prothrombin time, and HCV viral load were independent risk factors for ACLF in patients with COVID-19. High PT, creatinine, BUN, and HCV viral load were the strongest predictors for ICU admission. Inflammatory markers and parameters of gas exchange were also observed as risk factors for ACLF and ICU admission, including procalcitonin, CRP, IL-6, and D-dimers. Our study questions and confirms the health impact of COVID-19 on patients with cirrhosis and whether their laboratory profile significantly changes due to SARS-CoV-2 infection.

Hepatitis C Virus Mimics Effects of Glypican-3 on CD81 and Promotes Development of Hepatocellular Carcinomas via Activation of Hippo Pathway in Hepatocytes

Glypican (GPC)-3 is overexpressed in hepatocellular carcinomas (HCCs). GPC3 binds to CD81. Forced expression of CD81 in a GPC3-expressing HCC cell line caused activation of Hippo, a decrease in ezrin phosphorylation, and a decrease in yes-associated protein (YAP). CD81 is also associated with hepatitis C virus (HCV) entry into hepatocytes. Activation of CD81 by agonistic antibody causes activation of tyrosine-protein kinase SYK (SYK) and phosphorylation of ezrin, a regulator of the Hippo pathway. In cultures of normal hepatocytes, CD81 agonistic antibody led to enhanced phosphorylation of ezrin and an increase in nuclear YAP. HCV E2 protein mimicked GPC3 and led to enhanced Hippo activity and decreased YAP in cultured normal human hepatocytes. HCC tissue microarray revealed a lack of expression of CD81 in most HCCs, rendering them insusceptible to HCV infection. Activation of CD81 by agonistic antibody suppressed the Hippo pathway and increased nuclear YAP. HCV mimicked GPC3, causing Hippo activation and a decrease in YAP. HCV is thus likely to enhance hepatic neoplasia by acting as a promoter of growth of early CD81-negative neoplastic hepatocytes, which are resistant to HCV infection, and thus have a proliferative advantage to clonally expand as they participate in compensatory regeneration for the required maintenance of 100% of liver weight (hepatostat).

Fibrosis in Chronic Hepatitis C: Correlation between Immunohistochemically-Assessed Virus Load with Steatosis and Cellular Iron Content

AIM

We aimed study impact of hepatocytic viral load, steatosis, and iron load on fibrosis in chronic hepatitis C and role of VEGF and VEGFR overexpression in cirrhotic cases in evolving HCC.

MATERIAL AND METHODS

Total of 120 cases were included from TBRI and Beaujon Hospital as chronic hepatitis C (CHC), post-hepatitis C cirrhosis, and HCC. Cases of CHC were stained for Sirius red, Prussian blue and immunohistochemically (IHC) for HCV-NS3/NS4. HCC were stained IHC for VEGF and by FISH.

RESULTS

Stage of fibrosis was significantly correlated with inflammation in CHC (P < 0.01). Noticed iron load did not correlate with fibrosis. Steatosis was associated with higher inflammation and fibrosis. The cellular viral load did not correlate with inflammation, steatosis or fibrosis. VEGF by IHC was significantly higher in cases of HCC when compared to cirrhotic group (P < 0.001). Amplification of VEGFR2 was confirmed in 40% of cases of HCC. Scoring of VEGF by IHC was the good indicator of VEGFR2 amplification by FISH (P < 0.005).

CONCLUSION

Grade of inflammation is the factor affecting fibrosis in CHC. The degree of liver damage is not related to cellular viral load or iron load. Steatosis is associated with higher inflammation and fibrosis. VEGF by IHC is correlated with overexpression of VEGFR2 by FISH.

Hepatitis C virus infection is blocked by HMGB1 released from virus-infected cells

High-mobility group box 1 (HMGB1), an abundant nuclear protein that triggers host immune responses, is an endogenous danger signal involved in the pathogenesis of various infectious agents. However, its role in hepatitis C virus (HCV) infection is not known. Here, we show that HMGB1 protein is translocated from the nucleus to cytoplasm and subsequently is released into the extracellular milieu by HCV infection. Secreted HMGB1 triggers antiviral responses and blocks HCV infection, a mechanism that may limit HCV propagation in HCV patients. Secreted HMGB1 also may have a role in liver cirrhosis, which is a common comorbidity in HCV patients. Further investigations into the roles of HMGB1 in the diseases caused by HCV infection will shed light on and potentially help prevent these serious and prevalent HCV-related diseases.

Real-time quantitative assay for routine testing of HCV RNA in formalin-fixed, paraffin-embedded liver samples

The assessment of hepatitis C virus (HCV) RNA in liver tissues is clinically relevant in cases where histology, liver function tests, and HCV serology are not sufficient for a definitive diagnosis of HCV-related hepatitis. We analyzed 215 formalin-fixed, paraffin-embedded liver needle biopsies from patients infected with HCV genotypes 1b and 2. HCV RNA extracted from paraffin sections were quantified by means of a TaqMan real-time reverse transcription-polymerase chain reaction method. The quantification of HCV RNA in liver tissue was correlated with the amount of HCV detected by immunohistochemistry (IHC) on paired frozen biopsies, the HCV RNA load in the serum, and the main serum tests of liver function and cholestasis. HCV RNA was detected by real-time reverse transcription-polymerase chain reaction in 169 liver biopsies (78.6%) with a mean value of 13.59+/-37.25 IU/ng. Tissue HCV RNA levels strongly correlated with the IHC results (P<0.001, Spearman test), HCV serum load (P<0.001), aspartate aminotransferase (P=0.001), gamma-glutamyl transpeptidase (P=0.012), and aspartate aminotransferase/alanine aminotransferase ratio (P=0.029). HCV RNA was amplified in up to 7-year-old archival tissue samples. Real-time HCV RNA quantification on archival liver tissue may be clinically relevant in case of "occult" HCV infection or for the diagnosis of patients with known HCV infection and hepatic dysfunction but seronegative for HCV RNA. The assessment of the levels of HCV RNA in the liver might also be important for monitoring the effectiveness of antiviral therapy and the progression of disease in patients with chronic HCV hepatitis.

Liver cancer-derived hepatitis C virus core proteins shift TGF-beta responses from tumor suppression to epithelial-mesenchymal transition

Background

Chronic hepatitis C virus (HCV) infection and associated liver cirrhosis represent a major risk factor for hepatocellular carcinoma (HCC) development. TGF-β is an important driver of liver fibrogenesis and cancer; however, its actual impact in human cancer progression is still poorly known. The aim of this study was to investigate the role of HCC-derived HCV core natural variants on cancer progression through their impact on TGF-β signaling.

Principal Findings

We provide evidence that HCC-derived core protein expression in primary human or mouse hepatocyte alleviates TGF-β responses in terms or growth inhibition or apoptosis. Instead, in these hepatocytes TGF-β was still able to induce an epithelial to mesenchymal transition (EMT), a process that contributes to the promotion of cell invasion and metastasis. Moreover, we demonstrate that different thresholds of Smad3 activation dictate the TGF-β responses in hepatic cells and that HCV core protein, by decreasing Smad3 activation, may switch TGF-β growth inhibitory effects to tumor promoting responses.

Conclusion/Significance

Our data illustrate the capacity of hepatocytes to develop EMT and plasticity under TGF-β, emphasize the role of HCV core protein in the dynamic of these effects and provide evidence for a paradigm whereby a viral protein implicated in oncogenesis is capable to shift TGF-β responses from cytostatic effects to EMT development.

Acute expression of hepatitis C core protein in adult mouse liver: Mitochondrial stress and apoptosis

OBJECTIVE

In infection with hepatitis C virus (HCV), spontaneous clearance of the virus occurs in 30-40% of cases. By contrast, in chronic infection, this is rare. The basis for viral clearance in acute disease is unknown. Whereas cellular immune responses have been studied in detail, few data exist on the role of viral structural proteins, such as the core protein. The purpose of this study was to investigate the effects of core produced de novo within adult mouse hepatocytes by using a new transgenic mouse line in which expression of HCV core is regulated by tetracycline (tet-off).

MATERIAL AND METHODS

In this work, transgenic mice with conditional HCV core were created, to study the acute expression of HCV core protein in the context of the mature liver. The subcellular distribution of the core, hepatocellular oxidative stress and apoptosis were monitored.

RESULTS

Core protein is readily detectable and strongly associated with cytoplasmic lipid vesicles, endoplasmic reticulum and mitochondria. Mitochondrial oxidative stress was evidenced by a reduction in thioredoxin-2 (trx2). Concurrently, caspase-3 activity and TUNEL increased and, over time, the level of core protein in the liver declined.

CONCLUSIONS

Mice that are conditionally transgenic for HCV core protein, which is readily detected and morphologically associated with steatosis in individual hepatocytes, were developed. Acute expression of core protein causes mitochondrial stress, as demonstrated by a reduction in trx2 and in the apoptosis of core-positive hepatocytes. We speculate that these events could be involved in the clearance of virus during acute hepatitis C, by both reducing the burden of virus in the liver and effectively priming the immune response.

Tissue hepatitis C virus RNA quantification and protein expression help identify early hepatitis C virus recurrence after liver transplantation

We compared tissue hepatitis C virus (HCV) RNA polymerase chain reaction quantification and HCV immunohistochemistry (IHC) to histology in biopsy tissues in order to differentiate between acute rejection and HCV hepatitis recurrence early after orthotopic liver transplantation (OLT). We analyzed the first biopsy performed because of alteration of serum aminotransferases in 65 consecutive OLT patients with HCV genotype 1b. In the histological analysis, we quantified the portal tracts, Councilman bodies, Councilman body/portal tract (CP) ratio, steatosis, and Knodell and Ishak scores. The 52 patients (80%) with histological HCV recurrence [recurrence-positive (Rec+)] were separated from the 6 (9%) with acute rejection and the 7 (11%) with undetermined pathological features [recurrence-negative (Rec-)]. HCV RNA strongly correlated with HCV IHC, regardless of the histological diagnosis (P < 0.001). Both HCV RNA and HCV IHC were significantly associated with CP ratio (P = 0.041 and P = 0.008). No statistical correlation was found between HCV RNA, HCV IHC, and the other histopathologic features or the hepatitis scores. HCV RNA, HCV IHC, and CP ratio were the only variables able to discriminate between Rec+ and Rec- patients (Mann-Whitney test P < 0.001, P < 0.001, P = 0.014). In conclusion, a combined evaluation of histology, tissue HCV RNA, and HCV IHC significantly discriminated between OLT patients with or without HCV recurrence.

Distinct hepatitis C virus core and F protein quasispecies in tumoral and nontumoral hepatocytes isolated via microdissection

Hepatitis C virus (HCV) genetic variability may be involved in liver carcinogenesis. We investigated HCV core and corresponding putative F protein genetic variability in hepatocellular carcinoma (HCC) and cirrhotic nodules. Hepatocyte clusters from 7 patients with HCC and HCV1b-related cirrhosis were isolated via microdissection of HCC tissues and 2 nontumoral cirrhotic nodules. The HCV core complementary DNA was cloned and sequenced from each liver compartment and from the serum of 2 patients. Nucleotide diversity and synonymous and nonsynonymous substitutions were analyzed within and between compartments via phylogenetic analysis and Mantel's test. Liver HCV RNA accumulation was lower in HCC. Increased quasispecies diversity and complexity was observed with HCC in 6 of 7 patients. Mantel's test demonstrated marked compartmentalization of quasispecies between HCC and cirrhotic nodules in all 7 patients and also between the 2 nontumoral nodules in 5 of them. Synonymous-nonsynonymous substitution analysis indicated low selection against tumoral core quasispecies in all patients and a more selective pressure against F protein quasispecies in all compartments. In the 2 subjects analyzed, HCC and nontumoral hepatocyte quasispecies were only minor or undetected in serum.

CONCLUSION

In tumoral hepatocytes, low-replicating hepatitis C quasispecies are compartmentalized and more diversified and are subjected to low selective pressure. Our study supports the importance of core genetic variability in hepatocellular carcinogenesis.

Expression studies of the core+1 protein of the hepatitis C virus 1a in mammalian cells. The influence of the core protein and proteasomes on the intracellular levels of core+1

Recent studies have suggested the existence of a novel protein of hepatitis C virus (HCV) encoded by an ORF overlapping the core gene in the +1 frame (core+1 ORF). Two alternative translation mechanisms have been proposed for expression of the core+1 ORF of HCV-1a in cultured cells; a frameshift mechanism within codons 8-11, yielding a protein known as core+1/F, and/or translation initiation from internal codons in the core+1 ORF, yielding a shorter protein known as core+1/S. To date, the main evidence for the expression of this protein in vivo has been the specific humoral and cellular immune responses against the protein in HCV-infected patients, inasmuch as its detection in biopsies or the HCV infectious system remains elusive. In this study, we characterized the expression properties of the HCV-1a core+1 protein in mammalian cells in order to identify conditions that facilitate its detection. We showed that core+1/S is a very unstable protein, and that expression of the core protein in addition to proteosome activity can downregulate its intracellular levels. Also, we showed that in the Huh-7/T7 cytoplasmic expression system the core+1 ORF from the HCV-1 isolate supports the synthesis of both the core+1/S and core+1/F proteins. Finally, immunofluorescence and subcellular fractionation analyses indicated that core+1/S and core+1/F are cytoplasmic proteins with partial endoplasmic reticulum distribution in interphase cells, whereas in dividing cells they also localize to the microtubules of the mitotic spindle.

Fibrosis is worse in HIV-HCV patients with low-level immunodepression referred for HCV treatment than in HCV-matched patients

Hepatitis C virus (HCV) infection is frequent in human immunodeficiency virus (HIV)-infected patients. It is known to have an aggressive course in significantly immunosuppressed patients, and cirrhosis C has become one of the main causes of mortality in HIV-HCV coinfected patients since the improvement of antiretroviral therapy. The reasons for this severe fibrotic evolution are unclear. This prospective study compared chronic HCV lesions, liver immunocompetent cells, fibrosis and liver HCV loads in 2 cohorts of naive patients referred for HCV treatment: 33 HIV-HCV coinfected patients with CD4 >250/microL and 33 HCV-infected patients matched for the main risk factors of fibrosis. Fibrosis, particularly perisinusoidal fibrosis, was more marked in the coinfected patients. This occurred in the absence of a significant difference in disease activity. The number of CD3+ cells in the liver was higher in the HIV-HCV patients than in the HCV patients. Conversely, the number of liver CD4+ cells was lower in HIV-HCV patients than in HCV patients. The numbers of CD8+ and CD68+ cells were similar in the 2 groups. Finally, liver HCV load, assessed by immunostaining and reverse-transcription polymerase chain reaction, was similar in the 2 groups. We conclude that in the population of HIV-HCV coinfected patients with low-level immunosuppression referred for HCV treatment, fibrosis is worse than in HCV patients and the proportion of CD4+ lymphocytes among CD3+ cells is markedly decreased in the liver, whereas intrahepatic viral load is similar. Our data confirm the need to treat such patients against HCV, and suggest that HIV infection could favor fibrosis via the modulation of the intrahepatic immune response.

A recombinant adenovirus encoding hepatitis C virus core and E1 proteins protects mice against cytokine-induced liver damage

Hepatitis C virus (HCV) infection has a strong tendency to evolve to chronicity despite up-regulation of proapoptotic cytokines in the inflamed liver. The mechanisms responsible for persistent viral replication in this inflammatory environment are obscure. It is conceivable that viral replication would be facilitated if the infected hepatocytes are rendered resistant to cytokine-induced cytotoxicity. In this study, we investigated if an adenovirus encoding HCV core and E1 (RAdCE1) could reduce liver cell injury in different in vivo models of cytokine-mediated hepatotoxicity in mice. We show that RAdCE1 markedly attenuates hepatocellular apoptosis and the increase in serum transaminase levels after concanavalin A (con A) challenge. This protective effect is accompanied by an inhibition of nuclear translocation of nuclear factor kappaB (NF-kappaB); reduced expression of inducible nitric oxide synthase (iNOS); decreased hepatic messenger RNA levels of chemokines macrophage inflammatory protein 2 (MIP-2), monocyte chemoattractant protein 1 (MCP-1), and interferon-inducible protein 10 (IP-10); and abrogation of liver leukocyte infiltration. RAdCE1 also causes a reduction in serum transaminase levels and inhibits hepatocellular apoptosis in mice given tumor necrosis factor (TNF)-alpha plus D-galactosamine. In conclusion, HCV structural antigens can protect liver cells against the proapoptotic effects of proinflammatory cytokines. The antiapoptotic status of infected liver cells may represent a mechanism favoring viral persistence. Our findings also suggest that, in chronic hepatitis C, the burden of hepatocellular damage mainly affects noninfected liver cells.

The core protein of hepatitis C virus is imported into the nucleus by transport receptor Kap123p but inhibits Kap121p-dependent nuclear import of yeast AP1-like transcription factor in yeast cells

The core protein of hepatitis C virus (HCV) is a major component of the viral nucleocapsid. The HCV core protein includes nuclear localization signal-like sequences and has various effects on cellular metabolism, playing roles, for example, in the regulation of transcription, apoptosis, and transformation. To examine the possibility of an effect of the core protein on nucleocytoplasmic transport, we used the yeast Saccharomyces cerevisiae as a model system. The core protein (p23) is processed to p21 and is localized in both the cytoplasm and nucleus in yeast cells, similar to that observed in mammalian cells in several cases. The nuclear import of the core protein requires the activity of small GTPase Ran/Gsp1p and is mediated by Kap123p in yeast cells. When the core protein was expressed in yeast cells, the import of the yeast AP1-like transcription factor Yap1p into the nucleus was inhibited. Experiments in vitro involving Kap121p, also known as Pse1p, a receptor for the nuclear import of Yap1p, indicated that the amount of Yap1p bound to Kap121p was reduced in the presence of core protein. These results suggest that the HCV core protein affects cellular metabolism by disturbing transport of proteins to the nucleus.

Intrahepatic HCV RNA loads in 37 HIV-HCV co-infected patients with controlled HIV infection

Serum and intrahepatic hepatitis C virus (HCV) RNA were measured in 37 HIV-HCV co-infected patients with controlled human immunodeficiency virus (HIV) infection and correlated with clinical, biological, and histological parameters. Thirty-seven interferon-naive patients underwent liver biopsy. HCV-induced activity (A) and fibrosis (F) were evaluated with METAVIR score. The 37 patients included had HIV plasma loads < 10,000 copies/ml, CD4(+) count > 250/microl. All the patients but two were receiving antiretroviral treatment. Liver tissue and sera were used for measurement of HCV RNA by the Cobas Amplicor HCV Monitor. All patients had serum and liver HCV RNA, and both levels were correlated (r = 0.47; P = 0.003). Intrahepatic HCV load did not depend on age, sex, duration of HCV infection, CD4(+), HCV genotype, or fibrosis. AST levels correlated with intrahepatic HCV load (r = 0.52; P = 0.001). Patients with METAVIR A1/A2 had significantly lower levels of liver HCV-RNA than were found in patients with METAVIR A3 (P = 0.026). Highly active antiretroviral therapy (HAART) including protease inhibitors(PI)-treated patients had significantly lower intrahepatic HCV load (P = 0.04). A weak but significant correlation between serum and liver HCV RNA was found. The amount of hepatic HCV RNA was correlated with AST levels, histological activity, but not with HCV genotype or fibrosis. The immune improvement associated with PI regimens could help reduce HCV load, supporting a protective effect of PI-induced immune restoration.

Diagnostic issues in liver transplantation pathology

Liver biopsy is used to determine the pathogenesis of liver dysfunction after liver transplantation. One or more causative factors may be identified on biopsy. The pathologist must be familiar with the histopathology of acute rejection to differentiate it from other potential complications, including biliary obstruction, intercurrent cytomegalovirus hepatitis, or recurrent disease. Consensus documents from the Banff international panel provide useful guidelines for the appropriate grading of acute and chronic rejection.

Hepatobiliary pathology

Technologic advances using cDNA microarray hybridization, liver diseases characterized by mitochondrial DNA depletion, and new work characterizing bile salt transport problems in familial intrahepatic cholestasis syndromes were some of the major highlights of this past year. Analysis of normal livers by cDNA microarrays disclosed 2418 unique gene transcripts encoding a host of cellular structural and functional proteins. This technique was also applied to hepatocellular carcinoma, where enhanced expression of a number of genes involved in antiapoptosis and cell transformation may shed additional light on the process of hepatocarcinogenesis. Mitochondrial DNA depletion seen in Navajo neurohepatopathy and in respiratory chain disorders of infancy was associated with cholestasis and cirrhosis in the former and microvesicular steatosis and oncocytic transformation (mitochondrial hyperplasia) in the latter. Pathologists who routinely examine liver biopsies after liver or bone marrow transplantation should be aware of unusual biopsy features that mimic other diseases, such as the autoimmune hepatitis-like syndrome that may follow liver transplantation and chronic graft-versus-host disease that clinically and pathologically resembles acute hepatitis.

Impact of protease inhibitors on intrahepatic hepatitis C virus viral load

During chronic hepatitis C, hepatitis C virus (HCV) load in plasma was shown to be higher in HIV-co-infected than in immunocompetent patients [1]. The reason for this increased HCV replication is not known. It may be as a result of HIV-induced immune deficiency [2], although some authors did not find any correlation with the CD4 cell count [3]. A direct interaction between HCV and HIV was also hypothesized [4]. Protease inhibitors (PI) used in highly active antiretroviral therapy (HAART) have no HCV reduction effect during the first months of treatment [5-8]. However, a decrease in HCV plasma load was recently described in patients treated with HAART for a year [9,10]. We therefore investigated the potential impact of HAART on intrahepatic HCV load.