Persistent expression of the full genome of hepatitis C virus in B cells induces spontaneous development of B-cell lymphomas in vivo. Blood. 2010;116:4926-4933. [PMID: 20733156 DOI: 10.1182/blood-2010-05-283358]

Shared genetic factors and causal association between chronic hepatitis C infection and diffuse large B cell lymphoma

BACKGROUND

Epidemiological research and systematic meta-analyses indicate a higher risk of B-cell lymphomas in patients with chronic hepatitis C virus (HCV) compared to non-infected individuals. However, the genetic links between HCV and these lymphomas remain under-researched.

METHODS

Mendelian randomization analysis was employed to explore the association between chronic hepatitis C (CHC) and B-cell lymphomas as well as chronic lymphocytic leukemia (CLL). Approximate Bayes Factor (ABF) localization analysis was conducted to find shared genetic variants that might connect CHC with B-cell lymphomas and chronic lymphocytic leukemia (CLL). Furthermore, The Variant Effect Predictor (VEP) was utilized to annotate the functional effects of the identified genetic variants.

RESULTS

Mendelian randomization revealed a significant association between CHC and increased diffuse large B cell lymphoma (DLBCL) risk (OR: 1.34; 95% CI: 1.01-1.78; P = 0.0397). Subsequent colocalization analysis pinpointed two noteworthy variants, rs17208853 (chr6:32408583) and rs482759 (chr6:32227240) between these two traits. The annotation of these variants through the VEP revealed their respective associations with the butyrophilin-like protein 2 (BTNL2) and notch receptor 4 (NOTCH4) genes, along with the long non-coding RNA (lncRNA) TSBP1-AS1.

CONCLUSION

This research provides a refined genetic understanding of the CHC-DLBCL connection, opening avenues for targeted therapeutic research and intervention.

Carcinogenic mechanisms of virus-associated lymphoma

The development of lymphoma is a complex multistep process that integrates numerous experimental findings and clinical data that have not yet yielded a definitive explanation. Studies of oncogenic viruses can help to deepen insight into the pathogenesis of lymphoma, and identifying associations between lymphoma and viruses that are established and unidentified should lead to cellular and pharmacologically targeted antiviral strategies for treating malignant lymphoma. This review focuses on the pathogenesis of lymphomas associated with hepatitis B and C, Epstein-Barr, and human immunodeficiency viruses as well as Kaposi sarcoma-associated herpesvirus to clarify the current status of basic information and recent advances in the development of virus-associated lymphomas.

High prevalence of past hepatitis B virus infection in diffuse large B cell lymphoma: a retrospective study from Italy

Studies from high endemic areas, mostly China, indicate that surface antigen positive (HBsAgpos) chronic hepatitis B virus (HBV) infection is associated with an increased risk of developing diffuse large B-cell lymphoma (DLBCL), whereas studies in low endemic areas have provided conflicting results. Past infection, serologically defined by negative HBsAg and positive anti-core antibody (HBsAgnegHBcAbpos), has also been suggested to increase the risk of B-cell non-Hodgkin's lymphoma (NHL) in high endemic areas. We retrospectively reviewed unselected clinical records of 253 patients with DLBCL (54% male, aged 60.3 ± 14.6 years at diagnosis) and 694 patients with different types of indolent B-cell NHL (46% male, aged 61.7 ± 12.8 years). Patients were seen at a single center in Italy between 2001 and 2022 and HBV serological status (HBsAg, HBsAb, HBcAb, HBeAg, HBeAb, and HBV DNA) was analyzed through enzyme-linked immunosorbent assays and molecular assays; patients infected with hepatitis C virus or human immunodeficiency virus were excluded. We used an unconditional multiple logistic regression model including as matching variables gender, age at diagnosis, immigrant status, and HBV serological status. Patients with DLBCL had, compared to indolent NHL, a higher prevalence of HBsAgpos active infection (odds ratio (OR) 2.8, 95% confidence interval (95% CI) 1.2-6.3, p = 0.014). Strikingly, patients with DLBCL had also a significantly higher prevalence of past infection (OR 2.4, 95% CI 1.5-4.0, p = 0.0006). Male gender was associated with increased risk of DLBCL independently of the HBV serological status. These findings suggest that both past and active HBV infection may increase the risk of DLBCL in a low endemic area. Our study needs confirmation by studies in areas or populations with different rates of chronic or past HBV infection.

Gut-derived Endotoxin-TLR4 Signaling Drives MYC-Ig Translocation to Promote Lymphoproliferation through c-JUN and STAT3 Activation

Synergism between obesity and virus infection promotes the development of B-cell lymphoma. In this study, we tested whether obesity-associated endotoxin release induced activation-induced cytidine deaminase (AID). TLR4 activation in turn caused c-JUN-dependent and STAT3-dependent translocations of MYC loci to suppress transactivation of CD95/FAS. We used viral nucleocapside Core transgenic (Tg) mice fed alcohol Western diet to determine whether oncogenesis arising from obesity and chronic virus infection occurred through TLR4-c-JUN-STAT3 pathways. Our results showed B cell-specific, c-Jun and/or Stat3 disruption reduced the incidence of splenomegaly in these mice. AID-dependent t(8;14) translocation was observed between the Ig promoter and MYC loci. Comparison with human B cells showed MYC-immunoglobulin (Ig) translocations after virus infection with lipopolysaccharide stimulation. Accordingly, human patients with lymphoma with virus infections and obesity showed a 40% incidence of MYC-Ig translocations. Thus, obesity and virus infection promote AID-mediated translocation between the Ig promoter and MYC through the TLR4-c-JUN axis, resulting in lymphoproliferation. Taken together, preventative treatment targeting either c-JUN and/or STAT3 may be effective strategies to prevent tumor development.

IMPLICATIONS

Obesity increases gut-derived endotoxin which induces Toll-like receptor-mediated MYC-Ig translocation via c-JUN-STAT3, leading to lymphoproliferation.

Altered Phenotype and Enhanced Antibody-Producing Ability of Peripheral B Cells in Mice with Cd19-Driven Cre Expression

Given the importance of B lymphocytes in inflammation and immune defense against pathogens, mice transgenic for Cre under the control of Cd19 promoter (Cd19^Cre/+ mice) have been widely used to specifically investigate the role of loxP-flanked genes in B cell development/function. However, impacts of expression/insertion of the Cre transgene on the phenotype and function of B cells have not been carefully studied. Here, we show that the number of marginal zone B and B1a cells was selectively reduced in Cd19^Cre/+ mice, while B cell development in the bone marrow and total numbers of peripheral B cells were comparable between Cd19^Cre/+ and wild type C57BL/6 mice. Notably, humoral responses to both T cell-dependent and independent antigens were significantly increased in Cd19^Cre/+ mice. We speculate that these differences are mainly attributable to reduced surface CD19 levels caused by integration of the Cre-expressing cassette that inactivates one Cd19 allele. Moreover, our literature survey showed that expression of Cd19^Cre/+ alone may affect the development/progression of inflammatory and anti-infectious responses. Thus, our results have important implications for the design and interpretation of results on gene functions specifically targeted in B cells in the Cd19^Cre/+ mouse strain, for instance, in the context of (auto) inflammatory/infectious diseases.

Impact of DAA-Based Regimens on HCV-Related Extra-Hepatic Damage: A Narrative Review

Two-third of patients with chronic hepatitis C show extrahepatic manifestations due to HCV infection of B lymphocytes, such as mixed cryoglobulinemia and non-Hodgkin B-cell lymphoma, or develop a chronic inflammatory status that may favor the development of adverse cardiovascular events, kidney diseases or metabolic abnormalities.DAAs treatments induce HCV eradication in 95% of treated patients, which also improves the clinical course of extrahepatic manifestations, but with some limitations. After HCV eradication a good compensation of T2DM has been observed, but doubts persist about the possibility of obtaining a stable reduction in fasting glucose and HbA1c levels.Chronic HCV infection is associated with low total and LDL cholesterol serum levels, which however increase significantly after HCV elimination, possibly due to the disruption of HCV/lipid metabolism interaction. Despite this adverse effect, HCV eradication exerts a favorable action on cardiovascular system, possibly by eliminating numerous other harmful effects exerted by HCV on this system.DAA treatment is also indicated for the treatment of patients with mixed cryoglobulinemia syndrome, since HCV eradication results in symptom reduction and, in particular, is effective in cryoglobulinemic vasculitis. Furthermore, HCV eradication exerts a favorable action on HCV-related lymphoproliferative disorders, with frequent remission or reduction of clinical manifestations.There is also evidence that HCV clearance may improve impaired renal functions, but same conflicting data persist on the effect of some DAAs on eGFR.

Tissue Engineering in Liver Regenerative Medicine: Insights into Novel Translational Technologies

Organ and tissue shortage are known as a crucially important public health problem as unfortunately a small percentage of patients receive transplants. In the context of emerging regenerative medicine, researchers are trying to regenerate and replace different organs and tissues such as the liver, heart, skin, and kidney. Liver tissue engineering (TE) enables us to reproduce and restore liver functions, fully or partially, which could be used in the treatment of acute or chronic liver disorders and/or generate an appropriate functional organ which can be transplanted or employed as an extracorporeal device. In this regard, a variety of techniques (e.g., fabrication technologies, cell-based technologies, microfluidic systems and, extracorporeal liver devices) could be applied in tissue engineering in liver regenerative medicine. Common TE techniques are based on allocating stem cell-derived hepatocyte-like cells or primary hepatocytes within a three-dimensional structure which leads to the improvement of their survival rate and functional phenotype. Taken together, new findings indicated that developing liver tissue engineering-based techniques could pave the way for better treatment of liver-related disorders. Herein, we summarized novel technologies used in liver regenerative medicine and their future applications in clinical settings.

Hepatitis virus B and C infections are associated with an increased risk of non-Hodgkin lymphoma: A nested case-control study using a national sample cohort

BACKGROUND

Hepatitis B virus (HBV) and hepatitis C virus (HCV) are suspected of being associated with non-Hodgkin lymphoma (NHL); however, persuasive data are lacking. Hence, a nested large-population case-control study was performed to investigate such associations in Koreans.

METHODS

Data were collected from 929 patients with NHL and 3716 healthy subjects, who were matched 1:4 for age, sex, income, and region of residence, from the Korean Health Insurance Review and Assessment Service-National Sample Cohort. The diagnoses of NHL and HBV/HCV infection were based on the International Classification of Diseases (version 10) codes. Conditional logistic regression models were used to assess odds ratios (ORs) for NHL with respect to HBV or HCV with adjustment for the Charlson comorbidity index.

RESULTS

HBV and HCV rates were higher in the NHL group (3.3% and 1.3%, respectively) than in the control group (0.9% and 0.3%, respectively; P < .001 for each). The adjusted OR of hepatitis infection in patients with NHL were 3.25 (95% confidence interval [CI] = 1.99-5.31) for HBV and 3.36 (95% CI = 1.51-7.46) for HCV (P < .001 for each). Subgroups categorized by age (<55 vs ≥55 years) or sex showed significantly higher adjusted ORs of HBV for NHL. Moreover, patients with NHL ≥ 55 years of age or those who were female showed significantly higher adjusted ORs of HCV; those <55 years or who were male also tended to have higher ORs of HCV.

CONCLUSION

Infection with either HBV or HCV is associated with NHL in Koreans.

Incidence and Mortality Trends and Risk Prediction Nomogram for Extranodal Diffuse Large B-Cell Lymphoma: An Analysis of the Surveillance, Epidemiology, and End Results Database

Background: DLBCL is the most commonly occurring type of non-Hodgkin's lymphoma, which may be found at various extranodal sites. But little is known about the particular trends of extranodal DLBCL. Methods: A total of 15,882 extranodal DLBCL patients were included in incidence analysis from the Surveillance, Epidemiology, and End Results (SEER) database (1973-2015). The joinpoint regression software was used to calculate the annual percent change (APC) in rates. Nomograms were established by R software to predict overall survival (OS). Results: The extranodal DLBCL incidence continued to rise at a rate of 1.6% (95% CI, 0.4-2.8, p < 0.001) per year over the study period, until it declined around 2003. The incidence-based mortality trend of extranodal DLBCL had a similar pattern, with a decrease happening around 1993. Five-year survival rates improved dramatically from the 1970s to 2010s (44.15 vs. 63.7%), and the most obvious increase occurred in DLBCL patients with primary site in the head/neck. The C-index showed a value for OS of 0.708, which validated the nomograms performed well and were able to forecast the prognosis of patients with extranodal DLBCL. The calibration curves showed satisfactory consistency between true values and predicted values for 1-, 5-, and 10-year overall survival, respectively. Conclusions: The incidence and incidence-based mortality of extranodal DLBCL had been increasing for decades, followed by a promising downward trend in recent years. These findings may help scientists identify disease-related risk factors and better manage the disease. The prediction signature cloud identifies high-risk patients who should receive effective therapies to prevent the fatal nature of this disease, and low-risk patients to reduce over-treatment.

[Hepatic tropism of hepatitis C virus infection]

Hepatitis C virus (HCV) infects over 170 million people worldwide and is a major cause of life-threatening liver diseases such as liver cirrhosis and hepatocellular carcinoma. In current research, we aimed to clarify the mechanism of hepatic tropism of HCV infection. Although non-hepatic cells could not permit replication of HCV RNA, exogenous expression of liver specific miRNA, miR-122 facilitated efficient replication of viral RNA through direct interaction with 5'UTR of viral genome, indicating that miR-122 is one of the key determinants for hepatic tropism of HCV infection. In spite of efficient replication of viral RNA, formation of infectious particles was not observed in non-hepatic cells exogenously expressing miR-122. We found that expression of apolipoprotein E (ApoE) facilitated the formation of infectious HCV particles in non-hepatic cells, indicating that not only miR-122 but also ApoE participate in tissue tropism of HCV infection. To understand the exact roles of miR-122 and apolipoproteins in hepatic tropism of HCV, we established miR-122 and ApoB/ApoE knockout (KO) Huh7 cells, respectively. Although slight increase of intracellular HCV RNA and infectious titers in the culture supernatants was observed, propagation of HCV was impaired in miR-122 KO Huh7 cells. After serial passages of HCV in miR-122 KO cells, we obtained an adaptive mutant that possessed G28A substitutions in the 5'UTR of the HCV genome and exhibited efficient translation and replication in both miR-122 KO Huh7 and non-hepatic cells without exogenous expression of miR-122. These results suggest that HCV mutants replicating in non-hepatic cells in an miR-122-independent manner participate in the induction of extrahepatic manifestations in chronic hepatitis C patients. Deficiency of both ApoB and ApoE strongly inhibited the formation of infectious HCV particles. Interestingly, expression not only of ApoE but also of ApoA or ApoC could rescue the production of infectious HCV particles in ApoB/ApoE KO cells, suggesting that exchangeable apolipoproteins redundantly participate in the formation of infectious HCV particles.

Heterogeneity and coexistence of oncogenic mechanisms involved in HCV-associated B-cell lymphomas

The association of HCV-infection with B-lymphomas is supported by the regression of most indolent/low-grade lymphomas following anti-viral therapy. Studies on direct and indirect oncogenic mechanisms have elucidated the pathogenesis of HCV-associated B-lymphoma subtypes. These include B-lymphocyte proliferation and sustained clonal expansion by HCV-envelope protein stimulation of B-cell receptors, and prolonged HCV-infected B-cell growth by overexpression of an anti-apoptotic BCL-2 oncogene caused by the increased frequency of t(14;18) chromosomal translocations in follicular lymphomas. HCV has been implicated in lymphomagenesis by a "hit-and-run" mechanism, inducing enhanced mutation rate in immunoglobulins and anti-oncogenes favoring immune escape, due to permanent genetic damage by double-strand DNA-breaks. More direct oncogenic mechanisms have been identified in cytokines and chemokines in relation to NS3 and Core expression, particularly in diffuse large B-cell lymphoma. By reviewing genetic alterations and disrupted signaling pathways, we intend to highlight how mutually non-contrasting mechanisms cooperate with environmental factors toward progression of HCV-lymphoma.

From hepatitis C virus infection to B-cell lymphoma

In addition to liver disorders, hepatitis C virus (HCV) is also associated with extrahepatic immune manifestations and B-cell non-Hodgkin lymphoma (NHL), especially marginal zone lymphoma, de novo or transformed diffuse large B-cell lymphoma and to a lesser extent, follicular lymphoma. Epidemiological data and clinical observations argue for an association between HCV and lymphoproliferative disorders. The causative role of HCV in NHL has been further supported by the response to antiviral therapy. Pathophysiological processes at stake leading from HCV infection to overt lymphoma still need to be further elucidated. Based on reported biological studies, several mechanisms of transformation seem however to emerge. A strong body of evidence supports the hypothesis of an indirect transformation mechanism by which sustained antigenic stimulation leads from oligoclonal to monoclonal expansion and sometimes to frank lymphoma, mostly of marginal zone subtype. By infecting lymphocytes, HCV could play a direct role in cellular transformation, particularly in de novo large B-cell lymphoma. Finally, HCV is associated with follicular lymphoma in a subset of patients. In this setting, it may be hypothesized that inflammatory cytokines stimulate proliferation and transformation of IgH-BCL2 clones that are increased during chronic HCV infection. Unraveling the pathogenesis of HCV-related B-cell lymphoproliferation is of prime importance to optimize therapeutic strategies, especially with the recent development of new direct-acting antiviral drugs.

Clinicopathological features of HCV-positive splenic diffuse large B cell lymphoma

The hepatitis C virus (HCV) is a single-stranded RNA virus which is thought to be involved in the onset of B cell lymphoma. HCV-positive diffuse large B cell lymphoma (DLBCL) has been reported to clinically manifest in extranodal lesions (e.g., in the liver, spleen, and stomach). Here, we investigated HCV-positive and -negative primary splenic DLBCL (p-spDLBCL) and non-primary splenic DLBCL (ordinary DLBCL). Furthermore, to examine HCV lymphomagenesis, RNA in situ hybridization (ISH), RT-PCR (reverse-transcription polymerase chain reaction), and NS3 immunostaining of HCV viral nonstructural proteins were performed. HCV-positive p-spDLBCL patients presented fewer B symptoms (asymptomatic) and better performance status, with elevated presence of splenic macronodular lesions and more germinal center B cell (GCB) sub-group cases than HCV-negative p-spDLBCL patients. However, HCV-positive ordinary DLBCL patients were found to have more non-GCB sub-group cases than HCV-negative ordinary DLBCL patients. HCV-positive DLBCL patients showed 20.6% (7/34) NS3 positivity, 16.7% (1/6) HCV-RNA in situ positivity, and 22.2% (2/9) detection of HCV-RNA in tumor tissue by RT-PCR. Splenic samples were found to have a higher frequency of HCV detection than lymph node samples, thus suggesting that HCV may be closely related to lymphomagenesis, especially in splenic lymphoma.

Considering hepatitis C virus infection as a systemic disease

Hepatitis C virus (HCV) infection has been demonstrated to result in several adverse hepatic outcomes and has been associated with a number of important extrahepatic manifestations. The scope of extrahepatic clinical possibilities includes systemic diseases such as vasculitis and lymphoproliferative disorders, cardiovascular disease, myalgia, arthritis, and sicca syndrome. These end-organ effects of HCV may dominate the clinical course beyond the hepatic complications and significantly worsen the long-term prognosis of infected patients. Until several years ago, the standard of care for the treatment of HCV infection had been interferon-alpha-based regimens, which not only had limited effectiveness in achieving a cure but were often poorly tolerated, especially in patients with kidney disease. In those HCV-infected patients with significant systemic manifestations, the interferon-based regimens were problematic given their association with a wide variety of toxicities. The development of highly effective direct-acting antiviral agents to treat HCV infection presented an opportunity to improve the HCV care cascade with the eradication of HCV in most infected patients and by reducing the burden of both hepatic and extrahepatic complications.

Bleeding from a Small-Intestinal Ulcer Associated with Chronic Hepatitis C

BACKGROUND Hepatitis C virus infection is probably the most common chronic viral infection and affects an estimated 180 million people worldwide. Extrahepatic manifestations are well recognized among patients with chronic HCV infection. CASE REPORT We report a case of melena occurring in a 69-year-old Japanese man who had been diagnosed with CHC and who was treated with antiviral therapy. CONCLUSIONS Finally, he was diagnosed with multiple small intestine ulcers in a short time. We herein report the case of HCV with rapidly developing small intestine ulcers.

From the pathogenesis to the cure of indolent B-cell lymphoproliferative disorders associated with hepatitis C virus infection: which role for direct-acting antivirals?

INTRODUCTION

Hepatitis C virus (HCV) causes monoclonal B cell lymphoproliferative disorders ranging from benign, such as in mixed cryoglobulinemia (MC), to indolent or aggressive lymphomas. MC and indolent lymphomas commonly regress when HCV is eradicated with interferon (IFN) therapy; however, sustained virologic response (SVR) to IFN is achieved only in ~50% of patients. The new all oral direct-acting antivirals (DAA), yielding nearly 100% SVR, promise a breakthrough in the treatment of HCV-associated lymphoproliferative disorders, but experience is still scanty. Areas covered: A literature search was performed to summarize current pathogenetic hypotheses in HCV-associated indolent lymphoproliferative disorders and to identify clinical trials focused on the use of antiviral therapy. Hematological outcomes of IFN-based and IFN-free DAA-based regimens were compared. Expert commentary: While MC appears to regress in most patients after DAA therapy, the still very limited experience with indolent lymphomas suggests that hematologic responses might be less than those observed with IFN. Furthermore, anecdotal observations of early progression to aggressive lymphoma after DAA are disquieting. Large studies are needed to determine the values and limits of DAA for treating HCV-associated indolent lymphomas and to identify subgroups at risk of non-response.

Clinicopathological analysis of primary splenic diffuse large B-cell lymphoma

Splenic infiltration is often seen in diffuse large B-cell lymphoma (DLBCL). However, primary splenic DLBCL is rare and studies on its clinicopathological features are limited. We assessed 66 cases of primary splenic DLBCL and 309 control DLBCL, not otherwise specified. Hepatitis C virus antibody prevalence, B symptoms, poor performance status and CD5 positivity differed significantly between the primary splenic DLBCL and control DLBCL groups. Primary splenic DLBCL cases were classified histopathologically into two groups [white pulp pattern (n = 46), red pulp pattern (n = 20)]. Survival analysis showed no difference in overall survival between the primary splenic DLBCL and the control group, but the former had a more favourable progression-free survival. In the examination of primary splenic DLBCL, the white pulp pattern was statistically associated with a lower performance status (2-4), and a lower CD5 positivity than the red pulp pattern. In the survival analysis, the red pulp pattern demonstrated poorer overall survival. Multivariate analysis of overall survival in primary splenic DLBCL cases identified CD5 positivity as an indicator of poor prognosis. Classifying primary splenic DLBCL into white and red pulp patterns was useful in terms of clinicopathological features and overall survival.

Notch4 and mhc class II polymorphisms are associated with hcv-related benign and malignant lymphoproliferative diseases

Mixed cryoglobulinemia (MC), is a HCV-related, clinically benign, lymphoproliferative disorder (LPD) that may evolve into a non Hodgkin's lymphoma (NHL). Significant associations were found between two single nucleotide polymorphisms near NOTCH4 (rs2071286) and the HLA class II (rs9461776) genes and HCV-related MC syndrome (MCS). We analyzed NOTCH4 rs2071286 and HLA-II rs9461776 in 3 HCV-related LPD groups (asymptomatic MC, MCS, NHL) with HCV infection without lymphoproliferative disorders.

We found a positive relationship between NOTCH4 rs207186 T minor allele frequency (MAF) and patients with HCV-related LPDs at risk of NHL (Chi-square test for trend = 14.84 p = 0.0001), in accordance with an over-dominant model in the NHL group (CT vs CC + TT, OR=1.88, 95% CI 1.24–2.83, p = 0.0026).

Regarding HLA II rs9461776, G MAF increased in patients with HCV-related LPDs at risk of NHL (Chi-square test for trend = 8.40 p = 0.0038), in accordance with a recessive genotypic model in the NHL group (G/G vs A/A + A/G, OR = 11.07, 95% CI 2.37–51.64, p = 0.0022).

Both NOTCH4 rs2071286 and HLA-II rs9461776 were present on chromosome 6 and showed D’ and r values of linkage disequilibrium (LD) of about 0.5 values, thereby suggesting there is no extensive LD in the HCV+ population.

This data shows that the previously demonstrated association between NOTCH4 rs2071286 and HLA-II rs9461776 polymorphisms and HCV-related MCS could be extended to overall patients with HCV-related LPDs. The significant relationship between rs2071286 and rs9461776 MAF and the increased risk for NHL, suggests their use as non-invasive markers to categorize patients at risk of lymphoma.

Selective inhibitor of Wnt/β-catenin/CBP signaling ameliorates hepatitis C virus-induced liver fibrosis in mouse model

Chronic hepatitis C virus (HCV) infection is one of the major causes of serious liver diseases, including liver cirrhosis. There are no anti-fibrotic drugs with efficacy against liver cirrhosis. Wnt/β-catenin signaling has been implicated in the pathogenesis of a variety of tissue fibrosis. In the present study, we investigated the effects of a β-catenin/CBP (cyclic AMP response element binding protein) inhibitor on liver fibrosis. The anti-fibrotic activity of PRI-724, a selective inhibitor of β-catenin/CBP, was assessed in HCV GT1b transgenic mice at 18 months after HCV genome expression. PRI-724 was injected intraperitoneally or subcutaneously in these mice for 6 weeks. PRI-724 reduced liver fibrosis, which was indicated by silver stain, Sirius Red staining, and hepatic hydroxyproline levels, in HCV mice while attenuating αSMA induction. PRI-724 led to increased levels of matrix metalloproteinase (MMP)-8 mRNA in the liver, along with elevated levels of intrahepatic neutrophils and macrophages/monocytes. The induced intrahepatic neutrophils and macrophages/monocytes were identified as the source of MMP-8. In conclusion, PRI-724 ameliorated HCV-induced liver fibrosis in mice. We hypothesize that inhibition of hepatic stellate cells activation and induction of fibrolytic cells expressing MMP-8 contribute to the anti-fibrotic effects of PRI-724. PRI-724 is a drug candidate which possesses anti-fibrotic effect.

Hepatitis C virus - Associated marginal zone lymphoma

The link between hepatitis C virus (HCV) infection and the development of B-cell non-Hodgkin lymphoma is now well established and based on a number of epidemiological studies. It is further supported by the observation of lymphoma regression after HCV eradication by antiviral treatment. The far most frequent entities are marginal zone lymphoma (MZL) and diffuse large B-cell lymphoma (DLBCL). MZL usually emerge on a background of mixed cryoglobulinemia, a low-grade lymphoproliferation, and often transform into DLBCL, thereby following a multistep oncogenesis process. The role of HCV in lymphomagenesis is not yet fully understood but several mechanisms have been proposed including (i) chronic external stimulation through the B-cell receptor and other surface receptors, and (ii) direct transformation by intracellular viral proteins, the former being probably predominant in MZL. Regression of HCV-associated MZL can be achieved with antiviral therapy and the novel generation of direct-acting antiviral agents appears highly effective and safe for the treatment of these lymphoma.

Global epidemiology and burden of HCV infection and HCV-related disease

Chronic HCV infection is a global health problem that affects >184 million people worldwide. HCV is associated with several hepatic and extrahepatic disorders, including several malignancies. The burden of HCV-related disorders is influenced by the number of new and existing cases, number of existing cases and the natural history of the infection. The natural history of HCV is affected by several demographic, virological, clinical and lifestyle factors. Major variations exist in the burden of HCV among different populations and geographical regions, as well as over time. With the advent of new and efficacious antiviral treatments, it is important to learn the determinants of HCV burden to design appropriate strategies for detection, prognostication and treatment. Furthermore, with the expected growth of patients cured of HCV, it is essential to learn about the possible change in natural history and burden of disease in these patients. In this Review, we will discuss the global epidemiology and burden of HCV and its complications, as well as the natural history and clinical course of chronic and cured HCV infection.

Hepatitis C virus has a genetically determined lymphotropism through co-receptor B7.2

B-cell infection by hepatitis C virus (HCV) has been a controversial topic. To examine whether HCV has a genetically determined lymphotropism through a co-receptor specific for the infection by lymphotropic HCV, we established an infectious clone and chimeric virus of hepatotropic and lymphotropic HCV strains derived from an HCV-positive B-cell lymphoma. The viral envelope and 5'-UTR sequences of the lymphotropic HCV strain were responsible for the lymphotropism. Silencing of the virus sensor, RIGI, or overexpression of microRNA-122 promoted persistent viral replication in B cells. By cDNA library screening, we identified an immune cell-specific, co-stimulatory receptor B7.2 (CD86) as a co-receptor of lymphotropic HCV. Infection of B cells by HCV inhibited the recall reaction to antigen stimulation. Together, a co-receptor B7.2 enabled lymphotropic HCV to infect memory B cells, leading to inhibition of memory B-cell function and persistent HCV infection in HCV-infected hosts.

Lymphoma: current status of clinical and preclinical imaging with radiolabeled antibodies

Lymphoma is a complex disease that arises from cells of the immune system with an intricate pathology. While lymphoma may be classified as Hodgkin or non-Hodgkin, each type of tumor is genetically and phenotypically different and highly invasive tissue biopsies are the only method to investigate these differences. Noninvasive imaging strategies, such as immunoPET, can provide a vital insight into disease staging, monitoring treatment response in patients, and dose planning in radioimmunotherapy. ImmunoPET imaging with radiolabeled antibody-based tracers may also assist physicians in optimizing treatment strategies and enhancing patient stratification. Currently, there are two common biomarkers for molecular imaging of lymphoma, CD20 and CD30, both of which have been considered for investigation in preclinical imaging studies. In this review, we examine the current status of both preclinical and clinical imaging of lymphoma using radiolabeled antibodies. Additionally, we briefly investigate the role of radiolabeled antibodies in lymphoma therapy. As radiolabeled antibodies play critical roles in both imaging and therapy of lymphoma, the development of novel antibodies and the discovery of new biomarkers may greatly affect lymphoma imaging and therapy in the future.

Human Cathelicidin Compensates for the Role of Apolipoproteins in Hepatitis C Virus Infectious Particle Formation

Exchangeable apolipoproteins (ApoA, -C, and -E) have been shown to redundantly participate in the formation of infectious hepatitis C virus (HCV) particles during the assembly process, although their precise role in the viral life cycle is not well understood. Recently, it was shown that the exogenous expression of only short sequences containing amphipathic α-helices from various apolipoproteins is sufficient to restore the formation of infectious HCV particles in ApoB and ApoE double-gene-knockout Huh7 (BE-KO) cells. In this study, through the expression of a small library of human secretory proteins containing amphipathic α-helix structures, we identified the human cathelicidin antimicrobial peptide (CAMP), the only known member of the cathelicidin family of antimicrobial peptides (AMPs) in humans and expressed mainly in bone marrow and leukocytes. We showed that CAMP is able to rescue HCV infectious particle formation in BE-KO cells. In addition, we revealed that the LL-37 domain in CAMP containing amphipathic α-helices is crucial for the compensation of infectivity in BE-KO cells, and the expression of CAMP in nonhepatic 293T cells expressing claudin 1 and microRNA miR-122 confers complete propagation of HCV. These results suggest the possibility of extrahepatic propagation of HCV in cells with low-level or no expression of apolipoproteins but expressing secretory proteins containing amphipathic α-helices such as CAMP.

IMPORTANCE

Various exchangeable apolipoproteins play a pivotal role in the formation of infectious HCV during the assembly of viral particles, and amphipathic α-helix motifs in the apolipoproteins have been shown to be a key factor. To the best of our knowledge, we have identified for the first time the human cathelicidin CAMP as a cellular protein that can compensate for the role of apolipoproteins in the life cycle of HCV. We have also identified the domain in CAMP that contains amphipathic α-helices crucial for compensation and show that the expression of CAMP in nonhepatic cells expressing claudin 1 and miR-122 confers complete propagation of HCV. We speculate that low levels of HCV propagation might be possible in extrahepatic tissues expressing secretory proteins containing amphipathic α-helices without the expression of apolipoproteins.

New insights into HCV-related rheumatologic disorders: A review

Hepatitis C virus (HCV) infected patients are known to be exposed to major liver complications i.e. cirrhosis and hepatocellular carcinoma. In addition, many extrahepatic manifestations including rheumatologic disorders have been reported in up to two-third of HCV infected patients. These manifestations include frank auto-immune and rheumatic diseases (such as arthralgia, myalgia, arthritis, sicca syndrome and vasculitis) which may dominate the course of infection. Until recently, the standard of care of HCV has been the use of interferon-alpha based regimens, which not only had limited effectiveness in HCV cure but were poorly tolerated. In patients with rheumatic diseases interferon-based regimens may be problematic given their association with a wide variety of autoimmune toxicities. Recent therapeutic advances with new direct anti-HCV therapies (interferon-free) which are more effective and better tolerated, make screening for this comorbidity in patients with rheumatic disorders more important than ever. This review aimed to outline main HCV extrahepatic with a special focus on rheumatologic manifestations.

Extrahepatic manifestations of chronic hepatitis C virus infection

During hepatitis C virus (HCV) chronic infection, extrahepatic manifestations are frequent and polymorphous. This article reports on a large cohort of patients with HCV-related autoimmune or lymphoproliferative disorders, from mixed cryoglobulinemia vasculitis to frank lymphomas. The relationship between HCV infection and such immune-related diseases has been formally demonstrated by epidemiological, clinical, immunological and pathological data, and results of therapeutic trials. More recently, other nonliver-related HCV disorders have been reported, including cardiovascular (i.e. stroke, ischemic heart disease), renal, metabolic and central nervous system diseases. For these manifestations, most evidence comes from large epidemiological studies; there is a need for mechanistic studies and therapeutic trials for confirmation. Beyond the risk of developing liver complications, that is, cirrhosis and liver cancer, patients with HCV infection have an increased risk of morbidity and mortality related to nonliver diseases. HCV chronic infection should be analyzed as a systemic disease in which extrahepatic consequences increase the weight of its pathological burden. The need for effective viral eradication measures is underlined.

M2 Macrophages Play Critical Roles in Progression of Inflammatory Liver Disease in Hepatitis C Virus Transgenic Mice

Macrophages in liver tissue are widely defined as important inflammatory cells in chronic viral hepatitis due to their proinflammatory activity. We reported previously that interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) play significant roles in causing chronic hepatitis in hepatitis C virus (HCV) transgenic mice (S. Sekiguchi et al., PLoS One 7:e51656, 2012, http://dx.doi.org/10.1371/journal.pone.0051656). In addition, we showed that recombinant vaccinia viruses expressing an HCV nonstructural protein (rVV-N25) could protect against the progression of chronic hepatitis by suppression of macrophage activation. Here, we focus on the role of macrophages in liver disease progression in HCV transgenic mice and examine characteristic features of macrophages following rVV-N25 treatment. The number of CD11b(+) F4/80(+) CD11c(-) CD206(+) (M2) macrophages in the liver of HCV transgenic mice was notably increased compared to that of age-matched control mice. These M2 macrophages in the liver produced elevated levels of IL-6 and TNF-α. rVV-N25 infection suppressed the number and activation of M2 macrophages in liver tissue. These results suggested that inflammatory cytokines produced by M2-like macrophages contribute to the induction of chronic liver inflammation in HCV transgenic mice. Moreover, the therapeutic effect of rVV-N25 might be induced by the suppression of the number and activation of hepatic macrophages.

IMPORTANCE

HCV causes persistent infections that can lead to chronic liver diseases, liver fibrosis, and hepatocellular carcinoma; the search for an HCV curative is the focus of ongoing research. Recently, effective anti-HCV drugs have been developed; however, vaccine development still is required for the prevention and therapy of infection by this virus. We demonstrate here that M2 macrophages are important for the pathogenesis of HCV-caused liver diseases and additionally show that M2 macrophages contribute to the therapeutic mechanism observed following rVV-N25 treatment.

Hepatitis C virus upregulates B-cell receptor signaling: a novel mechanism for HCV-associated B-cell lymphoproliferative disorders

B-cell receptor (BCR) signaling is essential for the development of B cells and has a critical role in B-cell neoplasia. Increasing evidence indicates an association between chronic hepatitis C virus (HCV) infection and B-cell lymphoma, however, the mechanisms by which HCV causes B-cell lymphoproliferative disorder are still unclear. Herein, we demonstrate the expression of HCV viral proteins in B cells of HCV-infected patients and show that HCV upregulates BCR signaling in human primary B cells. HCV nonstructural protein NS3/4A interacts with CHK2 and downregulates its activity, modulating HuR posttranscriptional regulation of a network of target mRNAs associated with B-cell lymphoproliferative disorders. Interestingly, the BCR signaling pathway was found to have the largest number of transcripts with increased association with HuR and was upregulated by NS3/4A. Our study reveals a previously unidentified role of NS3/4A in regulation of host BCR signaling during HCV infection, contributing to a better understanding of the molecular mechanisms underlying HCV-associated B-cell lymphoproliferative disorders.

Virus-driven autoimmunity and lymphoproliferation: the example of HCV infection

HCV chronic infection is characterized by possible development of both hepatic and extrahepatic manifestations. The infection by this both hepatotropic and lymphotropic virus is responsible for polyoligoclonal B-lymphocyte expansion, leading to several immune-mediated disorders. Mixed cryoglobulinemia syndrome that in some cases may evolve to frank B-cell non-Hodgkin's lymphoma is the prototype of HCV-driven autoimmune and lymphoproliferative disorders. The HCV oncogenic potential has been suggested by several clinicoepidemiological and laboratory studies; it includes hepatocellular carcinoma, B-cell non-Hodgkin's lymphoma and papillary thyroid cancer. The definition HCV syndrome refers to the complex of HCV-driven diseases; these latter are characterized by heterogeneous geographical distribution, suggesting a role of other important genetic and/or environmental cofactors. The natural history of HCV syndrome is the result of a multifactorial and multistep pathogenetic process, which may evolve from mild manifestations to systemic autoimmune disorders, and less frequently to malignant neoplasias. The present updated review analyzes the clinical and pathogenetic aspects of the main HCV-associated diseases.

Most patients with HCV-associated lymphoma present with mild liver disease: a call to revise antiviral treatment prioritization

BACKGROUND & AIMS

Hepatitis C virus (HCV) is associated with development of B-cell non-Hodgkin lymphoma (HCV-NHL). Antiviral therapy (AVT) is prioritized in HCV-infected patients with significant fibrosis/cirrhosis. It is unknown whether current recommendations based on liver parameters cover the risk of HCV-NHL development. We aimed to evaluate the liver disease stages of patients with HCV-NHL.

METHODS

Hepatitis C virus-NHL patients seen at MD Anderson Cancer Center between 2008 and 2014 were evaluated for underlying liver disease within a year of HCV-NHL diagnosis by non-invasive fibrosis markers, radiology or liver biopsy. Included patients were observed retrospectively (2008-2012) or prospectively (2012-2014).

RESULTS

Eighty nine patients with HCV-NHL were evaluated. Most patients had genotype 1 (62%) infection, had diffuse large B cell lymphomas (62%), and detectable HCV RNA (90%) at NHL diagnosis. Notably, advanced liver disease (Metavir stage ≥ 3) was present in only 18% of the patients at the time of HCV-NHL diagnosis. All 53 patients with chronic HCV infection documented before lymphoma diagnosis were seen by HCV-treating physicians. Providers did not recommend AVT in almost one half of cases (44%), mostly because of the lack of advanced liver disease at HCV diagnosis (38%).

CONCLUSIONS

Most patients with HCV-NHL have mild liver disease at cancer diagnosis. Our findings suggest the need for early initiation of AVT in infected patients to eradicate HCV infection and its extra-hepatic manifestations. Treatment prioritization and cost must be weighed against the potential benefits of preventing NHL.

Extrahepatic manifestations of chronic hepatitis C virus infection

Hepatitis C virus (HCV) infected patients are known to be at risk of developing liver complications i.e. cirrhosis and liver cancer. However, the risks of morbidity and mortality are underestimated because they do not take into account non-liver consequences of chronic hepatitis C virus infection. Numerous extrahepatic manifestations have been reported in up to 74% of patients, from perceived to disabling conditions. The majority of data concern hepatitis C virus-related autoimmune and/or lymphoproliferative disorders, from mixed cryoglobulinaemia vasculitis to frank lymphomas. More recently, other hepatitis C virus-associated disorders have been reported including cardiovascular, renal, metabolic, and central nervous system diseases. This review aims to outline most of the extrahepatic manifestations that are currently being investigated, including some of autoimmune and/or lymphoproliferative nature, and others in which the role of immune mechanisms appears less clear. Beyond the liver, hepatitis C virus chronic infection should be analyzed as a multifaceted systemic disease leading to heavy direct and indirect costs. The accurate consideration of extrahepatic consequences of such a systemic infection significantly increases the weight of its pathological burden. The need for effective viral eradication measures is underlined.

Hepatitis C infection and lymphoproliferative disease: Accidental comorbidities?

Chronic hepatitis C virus (HCV) infection has been associated with liver cancer and cirrhosis, autoimmune disorders such as thyroiditis and mixed cryoglobulinema, and alterations in immune function and chronic inflammation, both implicated in B cell lymphoproliferative diseases that may progress to non-Hodgkin lymphoma (NHL). HCV bound to B cell surface receptors can induce lymphoproliferation, leading to DNA mutations and/or lower antigen response thresholds. These findings and epidemiological reports suggest an association between HCV infection and NHL. We performed a systematic review of the literature to clarify this potential relationship. We searched the English-language literature utilizing Medline, Embase, Paper First, Web of Science, Google Scholar, and the Cochrane Database of Systematic Reviews, with search terms broadly defined to capture discussions of HCV and its relationship with NHL and/or lymphoproliferative diseases. References were screened to further identify relevant studies and literature in the basic sciences. A total of 62 reports discussing the relationship between HCV, NHL, and lymphoproliferative diseases were identified. Epidemiological studies suggest that at least a portion of NHL may be etiologically attributable to HCV, particularly in areas with high HCV prevalence. Studies that showed a lack of association between HCV infection and lymphoma may have been influenced by small sample size, short follow-up periods, and database limitations. The association appears strongest with the B-cell lymphomas relative to other lymphoproliferative diseases. Mechanisms by which chronic HCV infection promotes lymphoproliferative disease remains unclear. Lymphomagenesis is a multifactorial process involving genetic, environmental, and infectious factors. HCV most probably have a role in the lymphomagenesis but further study to clarify the association and underlying mechanisms is warranted.

Hepatitis C virus and lymphoma

Hepatitis C virus (HCV) is a hepatotrophic and lymphotrophic virus and is a global health problem. Cirrhosis and hepatocellular cancer are the most common complications of HCV. Association between HCV and B cell non-Hodgkin lymphomas (B-NHL) has been shown in epidemiological studies in the last 20 years. High prevalence of HCV infection among patients with NHL has been reported in the early 1990s by Ferri in Italy and this association has been confirmed in later studies. Geographically, HCV related NHL is highly variable and chronic rather than cleared HCV infection is required for lymphomagenesis. Although anti-HCV antibody test is the most commonly used technique in epidemiological studies, HCV-RNA is more useful test to detect the association between HCV and NHL. The optimal management of HCV related NHL is not clear. However, anti-viral treatment may be sufficient for cases with low grade and/or asymptomatic lymphomas, while immuno-chemotherapy is necessary, in spite of probable hepatic toxicity, in cases with high grade lymphomas.

Hepatitis C virus and diffuse large B-cell lymphoma: Pathogenesis, behavior and treatment

A significant association between hepatitis C virus (HCV) infection and B-cell lymphoma has been reported by epidemiological studies, most of them describing a strong relationship between indolent lymphomas and HCV. Furthermore, the curative potential of antiviral therapy on HCV related indolent lymphomas supports a specific role for the virus in lymphomagenesis. These observations are reinforced by numerous laboratory experiments that led to several hypothetical models of B-cell transformation by HCV. Diffuse large B-cell lymphoma (DLBCL), the most common lymphoma subtype in the western countries, has been associated to HCV infection despite its aggressive nature. This association seems particularly prominent in some geographical areas. Clinical presentation of HCV-associated DLBCL has consistently been reported to differ from the HCV-negative counterpart. Nevertheless, histopathology, tolerance to standard-of-care chemo-immunotherapy (R-CHOP or CHOP-like regimens) and final outcome of HCV-positive DLBCL patients is still matter of debate. Addition of rituximab has been described to enhance viral replication but the probability of severe hepatic complications remains low, with some exceptions (i.e., hepatitis B virus or immune immunodeficiency virus co-infected patients, presence of grade > 2 transaminases elevation, cirrhosis or hepatocarcinoma). HCV viral load in this setting is not necessarily directly associated with liver damage. Overall, treatment of HCV associated DLBCL should be performed in an interdisciplinary approach with hepatologists and hematologists with close monitoring of liver function. Available reports reveal that the final outcome of HCV-positive DLBCL that receive standard immunochemotherapy is not inferior to their HCV-negative counterpart. This review summarizes data on epidemiology, pathogenesis and therapeutic approach on HCV-associated DLBCL. Several issues that are matter of debate like clinical management of patients with transaminase elevation, criteria for discontinuing or starting immuno-chemotherapy, as well as the exact role of monoclonal antibodies will be analyzed.

B-cell-intrinsic hepatitis C virus expression leads to B-cell-lymphomagenesis and induction of NF-κB signalling

Hepatitis C virus (HCV) infection leads to the development of hepatic diseases, as well as extrahepatic disorders such as B-cell non-Hodgkin's lymphoma (B-NHL). To reveal the molecular signalling pathways responsible for HCV-associated B-NHL development, we utilised transgenic (Tg) mice that express the full-length HCV genome specifically in B cells and develop non-Hodgkin type B-cell lymphomas (BCLs). The gene expression profiles in B cells from BCL-developing HCV-Tg mice, from BCL-non-developing HCV-Tg mice, and from BCL-non-developing HCV-negative mice were analysed by genome-wide microarray. In BCLs from HCV-Tg mice, the expression of various genes was modified, and for some genes, expression was influenced by the gender of the animals. Markedly modified genes such as Fos, C3, LTβR, A20, NF-κB and miR-26b in BCLs were further characterised using specific assays. We propose that activation of both canonical and alternative NF-κB signalling pathways and down-regulation of miR-26b contribute to the development of HCV-associated B-NHL.

Direct effects of hepatitis C virus on the lymphoid cells

It has been reported that the direct binding of hepatitis C virus (HCV) and/or the replication of HCV in the extrahepatic organs and, especially, lymphoid cells, might affect the pathogenesis of extrahepatic diseases with HCV infection. More than one decade ago, several reports described the existence of HCV-RNA in peripheral blood mononuclear cells. Moreover, many reports describing the existence of HCV in B lymphocytes and B cell lymphoma have been published. In addition to B lymphocytes, it was reported that HCV replication could be detected in T lymphocytes and T cell lines. Among the extrahepatic diseases with HCV infection, mixed cryoglobulinemia-related diseases and autoimmune-related diseases are important for understanding the immunopathogensis of HCV persistent infection. Moreover, HCV persistent infection can cause malignant lymphoma. The biological significance of lymphotropic HCV has not yet become clear. However, several candidates have been considered for a long time. One is that lymphotropic HCV is an HCV reservoir that might contribute to the recurrence of HCV infection and difficult-to-treat disease status. The other important issue is the carcinogenesis of the lymphoid cells and disturbances of the immune responses. Therefore, the extrahepatic diseases might be induced by direct interaction between HCV and lymphoid cells. In this article, we summarize various studies showing the direct effect of HCV on lymphoid cells and discuss the biological significance of lymphotropic HCV.

Outcome prediction of diffuse large B-cell lymphomas associated with hepatitis C virus infection: a study on behalf of the Fondazione Italiana Linfomi

A specific prognostication score for hepatitis C virus-positive diffuse large B-cell lymphomas is not available. For this purpose, the Fondazione Italiana Linfomi (FIL, Italian Lymphoma Foundation) carried out a multicenter retrospective study on a large consecutive series of patients with hepatitis C virus-associated diffuse large B-cell lymphoma to evaluate the prognostic impact of clinical and virological features and to develop a specific prognostic score for this subset of patients. All prognostic evaluations were performed on 535 patients treated with an anthracycline-based induction regimen (with rituximab in 255 cases). Severe hepatotoxicity was observed in 14% of patients. The use of rituximab was not associated with increased rate of severe hepatotoxicity. Three-year overall survival and progression-free survival were 71% and 55%, respectively. At multivariate analysis, ECOG performance status of 2 or over, serum albumin below 3.5 g/dL and HCV-RNA viral load over 1000 KIU/mL retained prognostic significance. We combined these 3 factors in a new "HCV Prognostic Score" able to discriminate 3 risk categories with different overall and progression-free survival (low=0; intermediate=1; high-risk ≥2 factors; P<0.001). This score retained prognostic value in the subgroups of patients treated with and without rituximab (P<0.001). The new score performed better than the International Prognostic Index at multivariate analysis and Harrel C-statistic. With the use of three readily available factors (performance status, albumin level and HCV-RNA viral load), the new "HCV Prognostic Score" is able to identify 3 risk categories with different survival, and may be a useful tool to predict the outcome of hepatitis C virus-associated diffuse large B-cell lymphomas.

Serum biomarker signature identifies patients with B-cell non-Hodgkin lymphoma associated with cryoglobulinemia vasculitis in chronic HCV infection

BACKGROUND

Hepatitis C virus (HCV) is associated with B-cell disorders, including mixed cryoglobulinemia (MC) and B-cell non-Hodgkin lymphoma (B-NHL). We hypothesized that combination of serum biomarkers could be used to identify B-NHL in HCV patients.

METHODS

We measured in 155 HCV infected patients, with and without MC and/or B-NHL, serum levels of eight markers previously described to be increased in patients with B-NHL, i.e. sCD22, sCD27, sIL-2Rα, sCD137, free-light chains of Ig (ratio κ/λ), heavy chains of Ig (ratio IgMκ/IgMλ), gammaglobulins and C4. We used a multiparametric analysis to determine a signature that identifies patients with overt B-NHL.

RESULTS

Serum levels were significantly different between patients without MC, patients with asymptomatic MC, patients with MC vasculitis and those with MC vasculitis and B-NHL for all biomarkers except for sCD137. Using multiparametric analysis, we identified a signature involving sCD27, sIL-2Rα, gammaglobulins and C4 levels associated with the presence of overt B-NHL in HCV-infected patients. This signature had a sensitivity of 100%, a specificity of 90%, and positive and negative predictive values of 97 and 100%, respectively for discriminating patients with overt B-NHL and those without B-NHL.

CONCLUSION

Our data indicate that serum biomarker signature allows identifying HCV-infected patients presenting with overt B-NHL.

Hepatitis C-associated B-cell non-Hodgkin lymphomas. Epidemiology, molecular signature and clinical management

There is ample epidemiologic evidence for an association of chronic hepatitis C virus (HCV) infection with B-cell non-Hodgkin lymphoma (B-NHL). B-NHL subtypes most frequently associated with HCV are marginal zone lymphoma and diffuse large B-cell lymphoma. The most convincing evidence for a causal relationship between HCV infection and lymphoma development is the observation of B-NHL regression after HCV eradication by antiviral therapy (AVT). In fact, for indolent HCV-associated B-NHL, first-line AVT instead of standard immune-chemotherapy might be considered. Molecular mechanisms of HCV-NHL development are still poorly understood. Three general theories have emerged to understand the HCV-induced lymphomagenesis: (1) continuous external stimulation of lymphocyte receptors by viral antigens and consecutive proliferation; (2) HCV replication in B cells with oncogenic effect mediated by intracellular viral proteins; (3) permanent B-cell damage, e.g., mutation of tumor suppressor genes, caused by a transiently intracellular virus ("hit and run" theory). This review systematically summarizes the data on epidemiology, interventional studies, and molecular mechanisms of HCV-associated B-NHL.

Differential expression of candidate virus receptors in human T lymphocytes prone or resistant to infection with patient-derived hepatitis C virus

Accumulated evidence implies that hepatitis C virus (HCV) infects not only the liver but also the immune system. A lymphocyte-specific CD5 molecule was recently identified as essential for infection of T cells with native, patient-derived HCV. To assess whether the proposed hepatocyte receptors may also contribute to HCV lymphotropism, expression of scavenger receptor-class B type 1 (SR-B1), claudin-1 (CLDN-1), claudin-6 (CLDN-6), occludin (OCLN), CD5 and CD81 was examined by real-time RT-PCR and the respective proteins quantified by immunoblotting in HCV-prone and resistant T cell lines, peripheral blood mononuclear cells (PBMC), primary T cells and their subsets, and compared to hepatoma Huh7.5 and HepG2 cells. SR-B1 protein was found in T and hepatoma cell lines but not in PBMC or primary T lymphocytes, CLDN-1 in HCV-resistant PM1 T cell line and hepatoma cells only, while CLDN-6 equally in the cells investigated. OCLN protein occurred in HCV-susceptible Molt4 and Jurkat T cells and its traces in primary T cells, but not in PBMC. CD5 was displayed by HCV-prone T cell lines, primary T cells and PBMC, but not by non-susceptible T and hepatoma cell lines, while CD81 in all cell types except HepG2. Knocking-down OCLN in virus-prone T cell line inhibited HCV infection, while de novo infection downregulated OCLN and CD81, and upregulated CD5 without modifying SR-B1 expression. Overall, while no association between SR-B1, CLDN-1 or CLDN-6 and the susceptibility to HCV was found, CD5 and CD81 expression coincided with virus lymphotropism and that of OCLN with permissiveness of T cell lines but unlikely primary T cells. This study narrowed the range of factors potentially utilized by HCV to infect T lymphocytes amongst those uncovered using laboratory HCV and Huh7.5 cells. Together with the demonstrated role for CD5 in HCV lymphotropism, the findings indicate that virus utilizes different molecules to enter hepatocytes and lymphocytes.

[miR-122 participates in the cell tropism of hepatitis C virus]

Hepatitis C virus (HCV) exhibits a narrow host range and a specific tissue tropism. Studies on HCV life cycle have been progressed by the developments of in vitro replication and infection systems and an HCV laboratory strain (HCVcc) capable of propagating in human hepatoma cell line, Huh7 cells. Mice expressing four human entry receptor candidates for HCV permit entry of HCVcc, therefore tissue tropism of HCV was believed to be rely on the expression of the entry receptors. However, HCV infection is often associated with extra-hepatic manifestations and the determinants for cell tropism of HCV remain elusive. Recently, we have shown that several nonhepatic cell lines permit HCV-RNA replication through an expression of a liver-specific microRNA, miR-122, upon infection with HCVcc, while no infectious particle was produced. In the nonhepatic cells, only small numbers of lipid droplets and low levels of VLDL-associated proteins were observed in compared with Huh7 cells, suggesting that expression of miR-122 and functional lipid metabolism participates in the replication and assembly of HCVcc, respectively In this review, we would like to discuss about involvement of miR-122 and functional lipid metabolism in the determination of HCV cell tropism.

Animal models of chronic liver diseases

Chronic liver diseases are frequent and potentially life threatening for humans. The underlying etiologies are diverse, ranging from viral infections, autoimmune disorders, and intoxications (including alcohol abuse) to imbalanced diets. Although at early stages of disease the liver regenerates in the absence of the insult, advanced stages cannot be healed and may require organ transplantation. A better understanding of underlying mechanisms is mandatory for the design of new drugs to be used in clinic. Therefore, rodent models are being developed to mimic human liver disease. However, no model to date can completely recapitulate the "corresponding" human disorder. Limiting factors are the time frame required in humans to establish a certain liver disease and the fact that rodents possess a distinct immune system compared with humans and have different metabolic rates affecting liver homeostasis. These features account for the difficulties in developing adequate rodent models for studying disease progression and for testing new pharmaceuticals to be translated into the clinic. Nevertheless, traditional and new promising animal models that mimic certain attributes of chronic liver diseases are established and being used to deepen our understanding in the underlying mechanisms of distinct liver diseases. This review aims at providing a comprehensive overview of recent advances in animal models recapitulating different features and etiologies of human liver diseases.

Assessing long-term treatment efficacy in chronic hepatitis B and C: between evidence and common sense

Chronic infection with the hepatitis B and C virus represents a major health problem worldwide, as it is estimated that roughly 400 and 200 million people respectively, are infected by each virus. By definition, any antiviral therapy that claims to be effective should have as its ultimate efficacy end point an improvement in patients' survival, or at least a reduction in the development rates of liver-related complications. However, this is extremely complicated to prove as the natural course of both viral diseases is extremely slow, requiring decades to evolve in cirrhosis and even more years to lead to liver complications. For this reason, clinicians and health authorities have relied on so called surrogate end points to assess the efficacy of any therapeutic intervention for viral hepatitis. Obviously, this allows for standardization in study designs that ultimately translates into an accelerated time frame for therapeutic drugs as well as healthcare innovations to enter the viral hepatitis clinical practice. However, it also calls for demonstration that surrogate end points in the treatment of patients with chronic hepatitis B or C are good and reliable markers of long-term efficacy.

The hepatitis C virus infection as a systemic disease

Hepatitis C Virus (HCV) is a major health problem, infecting about 3 % of people worldwide and leading to liver as well as extrahepatic diseases. This justifies the definition of HCV infection as a systemic disease. Based on available data, the link between the virus and some of these extrahepatic disorders is certain, whereas for some others needs further confirmation. HCV-related lymphoproliferative disorders, ranging from benign, but pre-lymphomatous conditions, like mixed cryoglobulinemia, to frank lymphomas, represent the extrahepatic manifestations most closely related to HCV. The primary involvement of the liver and lymphatic system corresponds to the double viral tropism, being HCV able to infect both hepatic and lymphatic cells. Other HCV-associated disorders include renal, endocrine, dermatological, cardiovascular, rheumatologic and central nervous system diseases. On the whole, the HCV disease appears a very important, mainly hidden, public health problem leading to heavy direct and indirect costs. The possibility that HCV may be eradicated following antiviral therapy is important for both the therapeutic and preventive points of view, making the HCV disease an ideal model for pathogenetic studies.

Molecular signature in HCV-positive lymphomas

Hepatitis C virus (HCV) is a positive, single-stranded RNA virus, which has been associated to different subtypes of B-cell non-Hodgkin lymphoma (B-NHL). Cumulative evidence suggests an HCV-related antigen driven process in the B-NHL development. The underlying molecular signature associated to HCV-related B-NHL has to date remained obscure. In this review, we discuss the recent developments in this field with a special mention to different sets of genes whose expression is associated with BCR coupled to Blys signaling which in turn was found to be linked to B-cell maturation stages and NF-κb transcription factor. Even if recent progress on HCV-B-NHL signature has been made, the precise relationship between HCV and lymphoma development and phenotype signature remain to be clarified.

Hepatitis C virus infection in the immunocompromised host: a complex scenario with variable clinical impact

The relationship between Hepatitis C Virus (HCV) infection and immunosuppression is complex and multifaceted. Although HCV-related hepatocytolysis is classically interpreted as secondary to the attack by cytotoxic T lymphocytes against infected cells, the liver disease is usually exacerbated and more rapidly evolutive in immunosuppressed patients. This generally occurs during the immunosuppression state, and not at the reconstitution of the host response after immunosuppressive therapy discontinuation. The field of immunosuppression and HCV infection is complicated both by the different outcome observed in different situations and/or by contrasting data obtained in the same conditions, with several still unanswered questions, such as the opportunity to modify treatment schedules in the setting of post-transplant follow-up. The complexity of this field is further complicated by the intrinsic tendency of HCV infection in itself to lead to disorders of the immune system. This review will briefly outline the current knowledge about the pathogenesis of both hepatic and extrahepatic HCV-related disorders and the principal available data concerning HCV infection in a condition of impairment of the immune system. Attention will be especially focused on some conditions - liver or kidney transplantation, the use of biologic drugs and cancer chemotherapy - for which more abundant and interesting data exist.

Hepatitis C virus entry: role of host and viral factors

Hepatitis C virus (HCV) has been considered to be a significant risk factor in developing liver associated diseases including hepatocellular carcinoma all over the world. HCV is an enveloped positive strand virus comprising a complex between genomic RNA and viral envelope glycoproteins (E1 and E2), which are anchored within host derived double-layered lipid membrane surrounding the nucleocapsid composed of several copies of core protein. HCV cell entry is the first step in infection and viral replication into host cells mainly hepatocytes. HCV cell entry is a complex process involving both the viral (envelope glycoproteins E1/E2) and host factors (cellular receptors and associated factors i.e. CD81, SR-BI, LDL-R, CLDN1, Occludin, DC-SIGN, L-SIGN and Glycosaminoglycans). Besides these the expression of certain other conditions such as polarization and EWI-2 expression inhibits the viral cell entry. Exploring the mechanism of HCV entry will help to better understand the viral life cycle and possible therapeutic targets against HCV infection including viral and host factors involved in this process. New strategies such as RNAi represents a new option for targeting the host or viral factors for prevention and therapeutic against HCV infection. In the current review we try to summarize the current knowledge about mechanism and interaction of cellular and viral factors involved in HCV cell entry and its implication as therapeutic target to inhibit HCV infection.