Role of microRNA profile modifications in hepatitis C virus-related mixed cryoglobulinemia

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.

Hepatitis C Virus (HCV)-Ribonucleic Acid (RNA) As a Biomarker for Lymphoid Malignancy with HCV Infection

The hepatitis C virus (HCV) is potentially associated with liver cancer, and advances in various drugs have led to progress in the treatment of hepatitis C and attempts to prevent its transition to liver cancer. Furthermore, reactivation of HCV has been observed in the treatment of lymphoma, during which the immortalization and proliferation of lymphocytes occur, which leads to the possibility of further stimulating cytokines and the like and possibly to the development of lymphoid malignancy. There are also cases in which the disappearance of lymphoid malignancy has been observed by treating HCV and suppressing HCV-Ribonucleic acid (RNA), as well as cases of recurrence with an increase in HCV-RNA. While HCV-associated lymphoma has a poor prognosis, improving the prognosis with Direct Acting Antivirals (DAA) has recently been reported. The reduction and eradication of HCV-RNA by means of DAA is thus important for the treatment of lymphoid malignancy associated with HCV infection, and HCV-RNA can presumably play a role as a biomarker. This review provides an overview of what is currently known about HCV-associated lymphoma, its epidemiology, the mechanisms underlying the progression to lymphoma, its treatment, the potential and limits of HCV-RNA as a therapeutic biomarker, and biomarkers that are expected now that DAA therapy has been developed.

Hepatitis C virus-related vasculitis

Cryoglobulinemic vasculitis (CryoVas) is a small-to-medium vessel systemic vasculitis caused by the deposition of mixed cryoglobulins and immune complexes. Clinical spectrum of CryoVas ranges from mild symptoms to vasculitis involving multiple organs that may progress to more life-threatening ilness. Hepatitis C virus (HCV) chronic infection is the most frequent condition to be assessed in patients with CryoVas. The mortality rate among patients with HCV-associated CryoVas is 3× that of the general population, with a 63% 10-year survival rate. The recent advent of interferon-free direct-acting antivirals (DAAs), which have the potential to induce sustained virological response rates greater than 95%, has dramatically changed the management of chronic HCV infection and HCV-related CryoVas. B-cell depleting strategies, mainly with rituximab, are the main therapeutic option in severe and refractory cases of HCV-associated CryoVas. Despite the progress in the last years on the management of chronic HCV infection, there are still unmet needs regarding therapeutic management of severe and refractory HCV-associated CryoVas.

Impact of direct acting antivirals on hepatitis c virus-related cryoglobulinemic syndrome

INTRODUCTION

Mixed cryoglobulinemia (MC) is a B-cell lymphoproliferative disorder largely attributable to HCV infection. MC clinical manifestations are determined by systemic vasculitis of low/medium sized vessels (mixed cryoglobulinemia syndrome or cryoglobulinemic vasculitis and CV) caused by the deposition of cryoglobulins in blood vessels.

EVIDENCE ACQUISITION

A systematic review was performed via the Medline and Scopus databases to evaluate studies concerning CV treatment with new direct antiviral agents (DAAs) and their effect on the syndrome.

EVIDENCE SYNTHESIS

The introduction of Interferon-free protocols has led to more evident positive effects than those observed in the treatment of C hepatitis/cirrhosis. In fact, IFN-free, DAA-based therapy minimised side effects permitting the treatment of previously contraindicated patients and led to a particularly high SVR rate and to a clinical/immunological response in the majority of patients, even if at different levels in different patients, from restitutio ad integrum to partial response. In view of the clearly positive evolution in CV management, the persistence of CV manifestations, in partial or non-responders continues to pose problems in the clinical approach to patients who represent a new condition that is still not completely known.

CONCLUSIONS

Results of DAAs-based therapy strongly confirm the use of anti-HCV therapy as the first-line therapeutic option in CV patients. However, growing evidence of a possible persistence or late relapse of CV suggests the need for longer/more accurate post-DAAs follow-ups as well as biomarkers that are capable of predicting the risk of clinical relapse/persistence to allow for the design of rational post-HCV eradication clinical flow-charts.

The Relevance of MicroRNAs in the Pathogenesis and Prognosis of HCV-Disease: The Emergent Role of miR-17-92 in Cryoglobulinemic Vasculitis

Hepatitis C virus (HCV) is a major public health problem. HCV is a hepatotropic and lymphotropic virus that leads to hepatocellular carcinoma (HCC) and lymphoproliferative disorders such as cryoglobulinemic vasculitis (CV) and non-Hodgkin's lymphoma (NHL). The molecular mechanisms by which HCV induces these diseases are not fully understood. MicroRNAs (miRNAs) are small non-coding molecules that negatively regulate post-transcriptional gene expression by decreasing their target gene expression. We will attempt to summarize the current knowledge on the role of miRNAs in the HCV life cycle, HCV-related HCC, and lymphoproliferative disorders, focusing on both the functional effects of their deregulation as well as on their putative role as biomarkers, based on association analyses. We will also provide original new data regarding the miR 17-92 cluster in chronically infected HCV patients with and without lymphoproliferative disorders who underwent antiviral therapy. All of the cluster members were significantly upregulated in CV patients compared to patients without CV and significantly decreased in those who achieved vasculitis clinical remission after viral eradication. To conclude, miRNAs play an important role in HCV infection and related oncogenic processes, but their molecular pathways are not completely clear. In some cases, they may be potential therapeutic targets or non-invasive biomarkers of tumor progression.

The miR-21 potential of serving as a biomarker for liver diseases in clinical practice

The role of miR-21 in the pathogenesis of various liver diseases, together with the possibility of detecting microRNA in the circulation, makes miR-21 a potential biomarker for noninvasive detection. In this review, we summarize the potential utility of extracellular miR-21 in the clinical management of hepatic disease patients and compared it with the current clinical practice. MiR-21 shows screening and prognostic value for liver cancer. In liver cirrhosis, miR-21 may serve as a biomarker for the differentiating diagnosis and prognosis. MiR-21 is also a potential biomarker for the severity of hepatitis. We elucidate the disease condition under which miR-21 testing can reach the expected performance. Though miR-21 is a key regulator of liver diseases, microRNAs coordinate with each other in the complex regulatory network. As a result, the performance of miR-21 is better when combined with other microRNAs or classical biomarkers under certain clinical circumstances.

miRNA-26b downregulation in peripheral blood mononuclear cells of patients with hepatitis C associated lymphomas is restored by successful interferon-free antiviral therapy

BACKGROUND

Patients with chronic HCV infection are at increased risk of developing B-cell non-Hodgkin lymphoma (B-NHL). Regression of HCV-associated B-NHL (HCV-NHL) can be achieved through HCV eradication using interferon (IFN). However, only about two-thirds of patients with sustained virological response (SVR) also had a consecutive lymphoma response. miRNA-26b is associated with HCV-NHL response to antiviral therapy. Recent data suggest that IFN-free direct-acting antiviral (DAA) regimens also have anti-lymphoma activity in this patient population.

METHODS

We report four patients with HCV-NHL who were treated with different IFN-free DAA regimens as oncological monotherapy in our centre between 2015 and 2016. We analysed the virological and lymphoproliferative disease response. Moreover, we analysed miRNA-26b expression in peripheral blood mononuclear cells at different time points during antiviral therapy for all included patients as well as for a total of 10 controls with (n=5) and without (n=5) chronic HCV infection.

RESULTS

All patients had marginal zone lymphoma subtype and received different DAA regimens for 12-24 weeks. All four patients achieved SVR, but only three patients also had lymphoma response (one complete response, two partial responses). One patient showed progression to a high-grade lymphoma subtype after SVR. miRNA-26b expression was generally decreased in patients with HCV-NHL. Moreover, miRNA-26b expression was restored in those HCV-NHL patients with lymphoma response after 6 months (P=0.009).

CONCLUSIONS

We have demonstrated that IFN-free DAA treatment of HCV can improve or even cure NHL. miRNA-26b-levels could be a potentially useful biomarker to predict lymphoma response in HCV-NHL patients.

Hepatitis B and C virus infection and risk of haematological malignancies

Hepatitis B virus (HBV) and hepatitis C virus (HCV) are classified as oncogenic human viruses. Chronic HBV and HCV infections are associated with higher risk of haematological malignancy development. Direct and indirect oncogenic mechanisms have been demonstrated for both HBV and HCV in several studies. HCV and overt/occult HBV infections in patients with oncohaematological disease constitute an impediment and a threat during immunosuppressive chemotherapy treatment. We review the HBV and HCV oncogenic mechanisms and the impact and the safety of antiviral treatment in patients with haematological malignancies.

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.

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.

[Chronic hepatitis C virus infection: An internist's opinion (Part 1)]

Hepatitis C virus (HCV) infection results in not only chronic hepatitis and subsequent complications as liver cirrhosis and hepatocellular carcinoma, but also in a significant number of other diseases, the so-called extrahepatic manifestations of chronic HCV infection. This is because of viral hepatotropicity and lymphotropicity. The most striking example of the course of chronic HCV infection, in which the infectious and inflammatory processes are concurrent with autoimmune disorders and carcinogenesis, is mixed cryoglobulinemia and B-cell non-Hodgkin's lymphoma. The pathogenesis of these diseases is based on the clonal expansion of B cells, which occurs under their prolonged stimulation with the virus or viral proteins. Part 1 of this review is devoted to the analysis of a correlation of chronic HCV infection with lymphoproliferative and autoimmune disorders, as well as its association with kidney injury.

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.

The roles of microRNA families in hepatic fibrosis

When hepatocytes are damaged severely, a variety of signaling pathways will be triggered by inflammatory factors and cytokines involving in the process of hepatic fibrosis. The microRNA (miRNA) family consists of several miRNAs which have the potential for synergistic regulation of these signaling pathways. However, it is poor to understand the roles of miRNA family as a whole in hepatic fibrosis. Increasing studies have suggested several miRNA families are related with activation of hepatic stellate cells and hepatic fibrosis through cooperatively regulating certain signaling pathways. During the process of hepatic fibrosis, miR-29 family primarily induces cell apoptosis by modulating phosphatidylinositol 3-kinase/AKT signaling pathway and regulates extracellular matrix accumulation. miR-34 family promotes the progression of hepatic fibrosis by inducing activation of hepatic stellate cells, while miR-378 family suppresses the process in Glis dependent manner. miR-15 family mainly promotes cell proliferation and induces apoptosis. The miR-199 family and miR-200 family are responsible for extracellular matrix deposition and the release of pro-fibrotic cytokines. These miRNA family members play pro-fibrotic or anti-fibrotic roles by targeting genes collectively or respectively which involve in hepatic fibrosis related signaling pathways and hepatic stellate cell activation. Thus, good understandings of molecular mechanisms which are based on miRNA families may provide new ideas for the molecular targeted therapy of hepatic fibrosis in the future.

Pathogenic mechanism of miR-21 in autoimmune lymphoid hyperplasia syndrome

miR-21 plays an important role in immune responses and inflammatory diseases, but the mechanism of action of miR-21 in autoimmune lymphoid hyperplasia syndrome still remains unclear. The aim of the present study was to assess the mechanism of miR-21 in autoimmune disease, particularly, the autoimmune lymphoid hyperplasia syndrome. The pathology and immunity-related phenotypes of miR-21 transgenic mice, and the lymphocyte subsets were analyzed. The related T cell subsets and germinal center B (GCB) cells generated at the germinal center were detected with flow cytometry. The target genes of miR-21 were evaluated with the luciferase reporter gene method. The homeostatic proliferation of the lymphocytes was detected with the EdU incorporation assay. Inflammatory infiltration occurred to the lung and liver of the transgenic mice at 8 weeks. The frequency of the regulatory helper T cells decreased slightly. Significantly increased double negative T cells were observed in the spleen of the transgenic mice (P<0.05). The immunoglobulins IgG1, IgG2a, IgG2b, and IgG3 in the serum of the transgenic mice aged 8 weeks were significantly higher than those in the wild-type mice aged 8 weeks (P<0.05). The percentages of the GCB cells in the peripheral lymphoid organs such as lymph nodes, mesenteric lymph nodes, PP and spleen in the transgenic mice aged 8–52 weeks increased significantly (P<0.05). The percentage (26.32%) of the newly-formed GCB cells derived from transgenic mice was significantly higher than that (3.87%) of the GCB cells derived from the wild-type mice. miR-21 played a role of negative feedback regulation by inhibiting the NF-κB signal pathway. The highly-expressed miR-21 B cells promoted homeostatic proliferation of the T cells. miR-21 can promote homeostatic proliferation of lymphocytes by inhibiting the NF-κB signal pathway.

Proof-of-concept study: profile of circulating microRNAs in Bovine serum harvested during acute and persistent FMDV infection

Background

Changes in the levels of circulating microRNAs (miRNAs) in the serum of humans and animals have been detected as a result of infection with a variety of viruses. However, to date, such a miRNA profiling study has not been conducted for foot-and-mouth disease virus (FMDV) infection.

Methods

The relative abundance of 169 miRNAs was measured in bovine serum collected at three different phases of FMDV infection in a proof-of-concept study using miRNA PCR array plates.

Results

Alterations in specific miRNA levels were detected in serum during acute, persistent, and convalescent phases of FMDV infection. Subclinical FMDV persistence produced a circulating miRNA profile distinct from cattle that had cleared infection. bta-miR-17-5p was highest expressed during acute infection, whereas bta-miR-31 was the highest during FMDV persistence. Interestingly, miR-1281was significantly down-regulated during both acute and persistent infection. Cattle that cleared infection resembled the baseline profile, adding support to applying serum miRNA profiling for identification of sub-clinically infected FMDV carriers. Significantly regulated miRNAs during acute or persistent infection were associated with cellular proliferation, apoptosis, modulation of the immune response, and lipid metabolism.

Conclusions

These findings suggest a role for non-coding regulatory RNAs in FMDV infection of cattle. Future studies will delineate the individual contributions of the reported miRNAs to FMDV replication, determine if this miRNA signature is applicable across all FMDV serotypes, and may facilitate development of novel diagnostic applications.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-017-0743-3) contains supplementary material, which is available to authorized users.

Cryoglobulin Test and Cryoglobulinemia Hepatitis C-Virus Related

Cryoglobulins are immunoglobulins that precipitate in serum at temperatures below 37°C and resolubilize upon warming. The clinical syndrome of cryoglobulinemia usually includes purpura, weakness, and arthralgia, but the underlying disease may also contribute other symptoms. Blood samples for cryoglobulin are collected, transported, clotted and spun at 37°C, before the precipitate is allowed to form when serum is stored at 4°C in a Wintrobe tube for at least seven days. The most critical and confounding factor affecting the cryoglobulin test is when the preanalytical phase is not fully completed at 37°C. The easiest way to quantify cryoglobulins is the cryocrit estimate. However, this approach has low accuracy and sensitivity. Furthermore, the precipitate should be resolubilized by warming to confirm that it is truly formed of cryoglobulins. The characterization of cryoglobulins requires the precipitate is several times washed, before performing immunofixation, a technique by which cryoglobulins can be classified depending on the characteristics of the detected immunoglobulins. These features imply a pathogenic role of these molecules which are consequently associated with a wide range of symptoms and manifestations. According to the Brouet classification, Cryoglobulins are grouped into three types by the immunochemical properties of immunoglobulins in the cryoprecipitate. The aim of this paper is to review the major aspects of cryoglobulinemia and the laboratory techniques used to detect and characterize cryoglobulins, taking into consideration the presence and consequences of cryoglobulinemia in Hepatitis C Virus (HCV) infection.

The impact of chronic hepatitis C infection on cholesterol metabolism in PBMCs is associated with microRNA-146a expression

Chronic hepatitis C (CHC) infection is known to induce important changes in host cholesterol metabolism. MicroRNAs (miRNAs) regulate the expression of many genes and, in consequence, control various processes, including human metabolism and response to viral infection. Recently, the alteration of the immune-associated miR-146a, which is abundantly present in peripheral blood mononuclear cells (PBMCs), was found in some viral infections. The study aimed to analyse the influence of hepatitis C virus (HCV) infection on miR-146a expression in PBMCs in vivo and in vitro, as well as to assess the possible impact of miR-146a alteration on the intracellular cholesterol level in PBMCs. Blood samples collected from 42 healthy donors and 72 CHC patients were the source of materials. HCV RNA, intracellular cholesterol level and miR-146a expression were determined in PBMCs, as well as HCV genotype and interferon (IFN)α concentration in sera. The influence of miR-146a inhibition on cholesterol expression in PBMCs was analysed in vitro after transient cell transfections with mirVana™ anti-miR-146a Inhibitor. Our data demonstrated an alteration of miR-146a and intracellular cholesterol expression in PBMCs and of IFNα concentration in sera of genotype 1, HCV-infected patients compared to the healthy donors. Also, in cultured PBMCs, miR-146a expression and intracellular cholesterol level were significantly decreased in CHC patients compared to the healthy donors. In vitro blockage of miR-146a expression in PBMCs of CHC patients greatly impaired intracellular cholesterol expression. In these conditions, miR-146a expression was positively correlated with the intracellular cholesterol level. These results suggest that genotype 1 HCV infection may alter miR-146a expression in PBMCs and, consequently, contribute to the observed dysregulation of cholesterol synthesis.

HCV-induced miR146a controls SOCS1/STAT3 and cytokine expression in monocytes to promote regulatory T-cell development

Host innate and adaptive immune responses must be tightly regulated by an intricate balance between positive and negative signals to ensure their appropriate onset and termination while fighting pathogens and avoiding autoimmunity; persistent pathogens may usurp these regulatory machineries to dampen host immune responses for their persistence in vivo. Here, we demonstrate that miR146a is up-regulated in monocytes from hepatitis C virus (HCV)-infected individuals compared to control subjects. Interestingly, miR146a expression in monocytes without HCV infection increased, whereas its level in monocytes with HCV infection decreased, following Toll-like receptor (TLR) stimulation. This miR146a induction by HCV infection and differential response to TLR stimulation were recapitulated in vitro in monocytes co-cultured with hepatocytes with or without HCV infection. Importantly, inhibition of miR146a in monocytes from HCV-infected patients led to a decrease in IL-23, IL-10 and TGF-β expressions through the induction of suppressor of cytokine signalling 1 (SOCS1) and the inhibition of signal transducer and activator transcription 3 (STAT3), and this subsequently resulted in a decrease in regulatory T cells (Tregs) accumulated during HCV infection. These results suggest that miR146a may regulate SOCS1/STAT3 and cytokine signalling in monocytes, directing T-cell differentiation and balancing immune clearance and immune injury during chronic viral infection.

Hepatitis C virus infection and chronic kidney disease: Time for reappraisal

Hepatitis C virus (HCV) infection is associated with tremendous morbidity and mortality due to liver complications. HCV infection is also associated with many extrahepatic manifestations including cardiovascular diseases, glucose metabolism impairment, cryoglobulinemia vasculitis, B cell non-Hodgkin lymphoma and chronic kidney disease (CKD). Many studies have shown a strong association between HCV and CKD, by reporting (i) an increased prevalence of HCV infection in patients on haemodialysis, (ii) an increased incidence of CKD and proteinuria in HCV-infected patients, and (iii) the development of membranoproliferative glomerulonephritis secondary to HCV-induced cryoglobulinemia vasculitis. HCV seropositivity is found to be associated with an increased relative risk for all-cause and cardiovascular mortality in the dialysis population. HCV seropositivity is linked to lower patient and graft survival after kidney transplantation. Such poor HCV-associated prognosis should have encouraged clinicians to treat HCV in CKD patients. However, due to frequent side effects and the poor efficacy of interferon-based treatments, very few HCV dialysis patients have received HCV medications until now. The emergence of new direct acting, interferon-free antiviral treatment, leading to HCV cure in most cases with a satisfactory safety profile, will shortly modify the management of HCV infection in CKD patients. In patients with a glomerular filtration rate (GFR) >30ml/min, the choice of DAA is not restricted. In those with a GFR <30 and >15ml/min, only paritaprevir/ritonavir/ombitasvir/dasabuvir or a grazoprevir plus elbasvir regimen are approved. In patients with end stage renal disease (GFR <15ml/min or dialysis), current data only allows for the use of a grazoprevir plus elbasvir combination. No doubt these data will be modified in the future with the advent of new studies including larger cohorts of HCV patients with renal impairment.

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.

Hepatitis C Therapy in Renal Patients: Who, How, When?

Renal patients are overexposed to hepatitis C virus (HCV) infection. Hepatitis C virus infection may induce renal disease, i.e., cryoglobulinemic membrano-proliferative glomerulopathy and non-cryoglobulinemic nephropathy. Hepatitis C virus impacts general outcomes in chronic kidney disease, dialysis or transplanted patients. Hepatitis C virus infection is now about to be only part of their medical history thanks to new direct acting antiviral drugs exhibiting as much as over 95% of sustained virological response. All HCV-infected patients potentially can receive the treatment. Control of the virus is associated with better outcomes in all cases, whatever the severity of the hepatic or renal disease. This article focuses on HCV-induced renal diseases, the reciprocal impact of HCV infection on the renal outcome and renal status in liver disease, use of new direct-acting antiviral drugs with dosage adaptations and the most recent safety data.

The anti-lymphoma activity of antiviral therapy in HCV-associated B-cell non-Hodgkin lymphomas: a meta-analysis

Many epidemiological studies provide solid evidence for an association of chronic hepatitis C virus (HCV) infection with B-cell non-Hodgkin's lymphoma (B-NHL). However, 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). We conducted a literature search to identify studies that included patients with HCV-associated B-NHL (HCV-NHL) who received AVT, with the intention to treat lymphoma and viral disease at the same time. The primary end point was the correlation of sustained virological response (SVR) under AVT with lymphoma response. Secondary end points were overall lymphoma response rates and HCV-NHL response in correlation with lymphoma subtypes. We included 20 studies that evaluated the efficacy of AVT in HCV-NHL (n = 254 patients). Overall lymphoma response rate through AVT was 73% [95%>confidence interval, (CI) 67-78%]. Throughout studies there was a strong association between SVR and lymphoma response (83% response rate, 95%>CI, 76-88%) compared to a failure in achieving SVR (53% response rate, 95%>CI, 39-67%, P = 0.0002). There was a trend towards favourable response for AVT in HCV-associated marginal zone lymphomas (response rate 81%, 95%>CI, 74-87%) compared to nonmarginal zone origin (response rate 71%, 95%>CI, 61-79%, P = 0.07). In conclusion, in the current meta-analysis, the overall response rate of HCV-NHL under AVT justifies the recommendation for AVT as first-line treatment in patients who do not need immediate conventional treatment. The strong correlation of SVR and lymphoma regression supports the hypothesis of a causal relationship of HCV and lymphomagenesis.

The expanding spectrum of HCV-related cryoglobulinemic vasculitis: a narrative review

Cryoglobulinemic vasculitis (CV) is a small-to-medium-vessel vasculitis that appears in 10-15 % of patients chronically infected with hepatitis C virus (HCV). The classic symptom triad of CV, purpura/asthenia/arthralgia, is accompanied by clinical features that include glomerulonephritis, neuropathy, interstitial pneumonitis, and cardiomyopathy, ranging in their severity from mild to life threatening. The risk of developing non-Hodgkin lymphoma is also higher. The cumulative 10-year survival rate of CV patients is significantly lower than in the age- and sex-matched general population, with death typically caused by nephropathy, malignancies, liver involvement, and severe infections. Unfailing serological stigmata include both a cryoglobulin IgM fraction with rheumatoid factor activity and decreased complement C4 levels. On peripheral B cells, the expression of the CD81 B cell receptor is reduced while that of the CD19 receptor is increased. A monoclonal B cell lymphocytosis develops in almost one-third of patients. HCV-related proteins (but not HCV-RNA genomic sequences) can be detected on biopsy samples by immunofluorescence and immunohistochemistry and involve the vessel lumen, vessel walls, and the perivascular spaces of the skin, kidney, and peripheral nerves, supporting the pathogenetic role of HCV in the onset of a widespread microvasculitis. Based on the demonstration of HCV infection in the large majority of CV patients, a therapeutic regimen consisting of once-weekly pegylated interferon-α and the daily administration of ribavirin results in a sustained virologic response in ~50 % of patients. In those with refractory and relapsing disease, addition of the anti-CD20 monoclonal antibody rituximab has significantly increased the overall response rates. The extension to CV of latest-generation direct-acting antivirals, strikingly successful in non-CV HCV-positive patients, has yielded high complete response rates according to the few studies published thus far.

Hepatitis C viral infection increases the risk of lymphoid-neoplasms: A population-based cohort study

Chronic hepatitis C viral (HCV) infection has been associated with non-Hodgkin's lymphoma (NHL); however, the results are inconsistent among regions with different HCV prevalence rates. The temporal relationship, risk estimates, and association between HCV and lymphoid-neoplasms remain unclear. This study investigated the temporal relationship between HCV infection and lymphoid-neoplasms using a nationwide population-based cohort. Patients with chronic HCV infection were retrieved from the Taiwan National Health Insurance Research Database during 2001-2005 and designated as the HCV cohort. Those with prior malignancies or coinfected with hepatitis B or human immunodeficiency virus were excluded. The age, sex, and comorbidities, including rheumatological disorders and diabetes, were matched by propensity scores to another non-HCV cohort. Both cohorts were followed longitudinally until 2009 for a new diagnosis of any lymphoid-neoplasms or NHL. A total of 11,679 HCV and 46,716 non-HCV patients were included and followed for 8 years. The incidence rates of any lymphoid-neoplasms and NHL were significantly greater in the HCV cohort than the non-HCV cohort (48.4 versus 22.1, and 37.0 versus 17.5 per 100,000 person-years, respectively, both P < 0.001), even after we excluded lymphoid-neoplasms developed within the first year of follow-up. Cox proportional hazards regression analysis (after adjustment for age, sex, numbers of annual medical visits during follow-up, and comorbidities) indicated that HCV infection was associated with an increased risk of either any lymphoid-neoplasms (hazard ratio = 2.30, 95% confidence interval 1.55-3.43, P < 0.0001) or NHL (hazard ratio = 2.00, 95% confidence interval 1.27-3.16, P = 0.003).

CONCLUSION

After adjustment for confounders and biases, chronic HCV infection is temporally associated with a two-fold increased risk of lymphoid-neoplasms, especially NHL, in Asian patients; additional large studies are needed to explore whether HCV eradication can reduce the incidence of lymphoid-neoplasms.

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.

Deregulation of microRNA expression in peripheral blood mononuclear cells from patients with HCV-related malignancies

BACKGROUND AND AIM

Hepatocellular carcinoma is one of the major causes of death due to cancer worldwide, and its association with hepatitis C virus infection has been definitively established. Hepatitis C virus is also involved in the pathogenesis of non-Hodgkin's lymphoma. This is the only virus infecting humans that is able to induce two different malignancies. We analyzed the expression levels of a panel of microRNA in peripheral blood mononuclear cells of patients with hepatitis C virus-related malignancies in order to find a disease-associated deregulation and identify specific biomarkers.

METHODS

We tested peripheral blood mononuclear cells isolated from patients with hepatocellular carcinoma, non-Hodgkin's lymphoma, hepatitis C virus without malignancies and healthy subjects for a panel of microRNA selected on the basis of previous studies. MicroRNA expression was evaluated by real-time PCR.

RESULTS

Our results showed an upregulation of miRNA-21 and downregulation of miRNA-26b in hepatocellular carcinoma and non-Hodgkin's lymphoma patients compared to controls (p < 0.001). Deregulation of miRNA-16 and miRNA-155 was limited to lymphoma patients.

CONCLUSIONS

This study shows that some microRNAs are differently expressed in peripheral blood mononuclear cells from hepatitis C virus patients who develop hepatocellular carcinoma or lymphoma, while others share a common behavior. Thus, analysis of the expression of microRNAs could be a noninvasive marker of hepatitis C virus-related carcinogenesis. This analysis could be a suitable tool for identifying the existence of a malignancy and also discriminating between these two hepatitis C virus-related cancers.

MicroRNA expression in hepatitis C virus-related malignancies: A brief review

Not only is chronic hepatitis C virus (HCV) infection a major public health problem, but also it can cause hepatocellular carcinoma and, more rarely, non-Hodgkin’s lymphoma. These characteristics mean that HCV is the only virus infecting humans that is able to cause two different cancers. The fine pathogenetic and molecular mechanisms by which HCV induces these two malignancies are not completely clear. In the last decade, it has been shown that microRNAs (miRNAs), a class of 21-23-nucleotide molecules modulating post-transcriptional gene expression, make an important contribution to the pathogenesis of several cancers and are also considered highly promising biomarkers. Here, we briefly describe the current knowledge about microRNAs’ involvement in HCV-related molecular oncogenesis. We decided to focus our attention on studies fully conducted on ex vivo samples with this specific etiology, and on cultured cell lines partially or completely expressing the HCV genome. Some of the results reported in this review are controversial, possibly because of methodological issues, differences in sampling size and features, and ethnicity of patients. What is certain is that miRNAs play a remarkable role in regulating gene expression during oncogenetic processes and in viral infection. A clear understanding of their effects is fundamental to elucidating the mechanisms underlying virus-induced malignancies.

Increased miR-16 expression induced by hepatitis C virus infection promotes liver fibrosis through downregulation of hepatocyte growth factor and Smad7

Hepatitis C virus (HCV) is involved in the initiation and progression of liver fibrosis by regulating genes encoding host proteins. However, the underlying mechanism of HCV-induced liver fibrosis is still to be determined. Reverse transcription polymerase chain reaction (RT-PCR) and western blot were performed to investigate the effect of HCV infection on the expression of the cellular microRNA miR-16 and its target genes encoding hepatocyte growth factor (HGF) and Smad7 in patients infected with HCV and in a liver cell line, QSG-7701, transfected with Ad-HCV, a recombinant adenovirus construct for expression of the HCV core protein. Regulation of HGF and Smad7 expression by miR-16 was assessed using luciferase reporter construct assays and miR-16 mimic transfection. Interferon-α (IFN-α) was used to verify the alteration of gene expression induced by HCV in QSG-7701 cells. Here, we found that miR-16 levels were increased in patients with HCV infection and were correlated with HGF and Smad7 expression levels in patients with HCV infection. Furthermore, HGF and Smad7 were predicted by bioinformatics analysis to be targets of miR-16. Upregulation of miR-16 and decreased HGF and Smad7 expression were still shown in QSG-7701 cells infected with Ad-HCV. Additionally, interferon-α (IFN-α) could reverse the changes in gene expression induced by HCV infection. These results suggest that the upregulation of miR-16 expression induced by HCV infection is a novel mechanism that contributes to downregulation of HGF and Smad7 in the development of liver fibrosis.

B cell non-Hodgkin's lymphoma in chronic hepatitis C virus patients: An interesting relationship

BACKGROUND

An association exists between hepatitis C virus (HCV) infection and non-Hodgkin's lymphoma (NHL), but a causal relationship is not fully established. HCV is a lymphotropic virus that represents a major etiologic agent of mixed cryoglobulinemia (MC) type II which is characterized by a low-grade B cell clonal lymphoproliferative disorder that usually progresses to a more aggressive malignant lymphoma. This study assessed the role of cryoglobulin and B lymphocyte stimulator (BLys) in the pathogenesis of NHL in chronic HCV patients.

METHODS

Sixty HCV patients, 30 free of B cell NHL (group I) and 30 with B cell NHL (group II), and 30 healthy controls (group III) were studied. Qualitative cryoglobulin assessment and a quantitative assay for BLys were done.

RESULTS

In group II, BLyS positivity rate was 1.5-fold higher than of group I (p ≤ 0.01). A positive association was found between positivity rate of MC and the level of BLyS (p ≤ 0.01).

CONCLUSION

High BLyS levels were associated with HCV-associated lymphoproliferative disorder coupled with positive MC.

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.

Complex interactions between microRNAs and hepatitis B/C viruses

MicroRNAs (miRNAs) are a class of small noncoding RNAs that post-transcriptionally regulate the expression of many target genes via mRNA degradation or translation inhibition. Many studies have shown that miRNAs are involved in the modulation of gene expression and replication of hepatitis B virus (HBV) and hepatitis C virus (HCV) and play a pivotal role in host-virus interactions. Increasing evidence also demonstrates that viral infection leads to alteration of the miRNA expression profile in hepatic tissues or circulation. The deregulated miRNAs participate in hepatocellular carcinoma (HCC) initiation and progression by functioning as oncogenes or tumor suppressor genes by targeting various genes involved in cancer-related signaling pathways. The distinct expression pattern of miRNAs may be a useful marker for the diagnosis and prognosis of virus-related diseases considering the limitation of currently used biomarkers. Moreover, the role of deregulated miRNA in host-virus interactions and HCC development suggested that miRNAs may serve as therapeutic targets or as tools. In this review, we summarize the recent findings about the deregulation and the role of miRNAs during HBV/HCV infection and HCC development, and we discuss the possible mechanism of action of miRNAs in the pathogenesis of virus-related diseases. Furthermore, we discuss the potential of using miRNAs as markers for diagnosis and prognosis as well as therapeutic targets and drugs.

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.

Relevance of miR-21 in HIV and non-HIV-related lymphomas

The critical role of microRNAs (miRNAs) in cell differentiation, homeostasis and cancer development has been extensively discussed in recent publications. The microRNAs with RISC enzyme complex allow it to find its complementary sequence, which is usually located in the 3'-untranslated region (UTR) of the target messenger RNA (mRNA). This is followed by inhibition of protein translation or promotion, resulting in degradation of the target gene. miR-21 has been mapped at chromosome 17q23.2, where it overlaps with the protein coding gene vacuole membrane protein 1 (VMP1), a human homologue of rat vacuole membrane protein. Recent evidence indicates that miR-21 plays a vital role in tumour cell proliferation, apoptosis and invasion. The inhibition of miR-21 may induce cell cycle arrest and increased chemosensitivity to anticancer agents, providing evidence that miR-21 functions as an oncogene in human cancer. Increased expression levels of miR-21 were observed in tumours arising from diverse tissue types. This also includes tumours of haematological origin, such as chronic lymphatic leukaemia, diffuse large B cell lymphomas (DLBCLs), acute myeloid leukaemia and Hodgkin lymphomas. Recently, it has been shown that high levels of B cell activation were induced by miR-21 in circulating B cells and are seen in HIV-infected individual. Notably, miR-21 is overexpressed in activated B cells, suggesting its assistance in maintaining B cell hyperactivation, which plays a pivotal role in HIV-infected cells. Therefore, miR-21 can be considered as a powerful biomarker in HIV-related lymphomas. The number of studies related to the role of miR-21 in HIV-related lymphomas is sparse; therefore, this mini review highlights the recent publications related to clinical impact and significance of miR-21, specifically in HIV- and non-HIV-related lymphomas.

MicroRNA and hepatitis C virus--challenges in investigation and translation: a review of the literature

Investigations into the role of microRNA (miRNA) in hepatitis C virus (HCV) infection, disease pathogenesis and host immune and treatment response have potential to produce innovations in diagnosis, prognosis and therapy. However, investigational challenges remain in generating clinically useful and reproducible results. We review the literature with a primary emphasis on methods and technologies used to construct our current understanding of miRNA and HCV disease. A second emphasis is to understand potential clinical research applications and provide clarification of previous study results. Many miRNA have key roles in viral and immunopathogenesis of HCV infection across multiple tissue compartments. Controversy exists among published studies regarding relative measurements, temporal changes and biological significance of specific miRNA and HCV infection. To reconcile diverging data, additional research into optimal sample processing, in vitro models, techniques for microarray differential expression of miRNAs, practices for sample result normalization, and effect of HCV genotype variation on expression are all necessary. Microarray and miRNA isolation techniques should be selected based on ability to generate reproducible results in the sample type of interest. More direct comparisons of efficacy and reliability of various multiplex microarrays and an improved consensus around miRNA normalization and quantitation are necessary so that data can be compared across studies.

Hepatitis C virus and microRNAs: miRed in a host of possibilities

It is well-established that the host microRNA (miRNA) milieu has a significant influence on the etiology of disease. In the context of viruses, such as hepatitis C virus (HCV), microRNAs have been shown to influence viral life cycles both directly, through interactions with the viral genome, and indirectly, through regulation of critical virus-associated host pathways. Several miRNA profiling studies have demonstrated that HCV infection aberrantly regulates a significant number of human miRNA. However, the biological relevance of these modulations remains poorly understood. In this review, we summarize recent research that has shed light on the pro-viral and anti-viral roles of HCV-induced changes in human miRNA expression and their significance in the development of HCV related sequelae and response to therapy.

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.

Hepatitis C virus-related mixed cryoglobulinemia: Is genetics to blame?

Mixed cryoglobulinemia (MC) is the extrahepatic manifestation most strictly correlated with hepatitis C virus (HCV) infection; it is a benign autoimmune and lymphoproliferative disorder that evolves to lymphoma in 5%-10% of cases. MC is reputed to be a multistep and multifactorial process whose pathogenicity is still poorly understood. It is still unknown why only some chronically infected HCV patients develop MC and only some of these exhibit systemic symptoms (MC syndrome). Several studies have investigated the pathogenetic basis of MC and the most recent ones suggest that the virus is able to trigger such a disorder only in the presence of genetic factors that are still unknown. Here, we try to clarify the complex relationship between HCV-related MC and the host’s genetic background. The data that we report are heterogeneous and sometimes even conflicting. Therefore, large, multicenter studies are clearly needed. The identification of a characteristic genetic signature of cryoglobulinemic patients would be an important step toward a personalized approach in their clinical care. The new wide-ranging genomics technologies will hopefully help to resolve these complex issues.

RNA viruses and microRNAs: challenging discoveries for the 21st century

RNA viruses represent the predominant cause of many clinically relevant viral diseases in humans. Among several evolutionary advantages acquired by RNA viruses, the ability to usurp host cellular machinery and evade antiviral immune responses is imperative. During the past decade, RNA interference mechanisms, especially microRNA (miRNA)-mediated regulation of cellular protein expression, have revolutionized our understanding of host-viral interactions. Although it is well established that several DNA viruses express miRNAs that play crucial roles in their pathogenesis, expression of miRNAs by RNA viruses remains controversial. However, modulation of the miRNA machinery by RNA viruses may confer multiple benefits for enhanced viral replication and survival in host cells. In this review, we discuss the current literature on RNA viruses that may encode miRNAs and the varied advantages of engineering RNA viruses to express miRNAs as potential vectors for gene therapy. In addition, we review how different families of RNA viruses can alter miRNA machinery for productive replication, evasion of antiviral immune responses, and prolonged survival. We underscore the need to further explore the complex interactions of RNA viruses with host miRNAs to augment our understanding of host-virus interplay.