Frequent joining of Bcl-2 to a JH6 gene in hepatitis C virus-associated t(14;18)

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.

Expert opinion on managing chronic HCV in patients with non-Hodgkin lymphoma and other extrahepatic malignancies

HCV is a carcinogen that is well established as a major risk factor for hepatocellular carcinoma. Evidence that HCV plays a role in the development of extrahepatic malignancies is less robust; however, epidemiological studies have consistently demonstrated an association between HCV infection and B-cell non-Hodgkin lymphoma (NHL). The strongest evidence for a link between HCV and tumourigenesis is the clear association between viral eradication, as indicated by achievement of sustained virological response, and remission of B-cell NHL. All-oral direct-acting antiviral-based therapies are effective in patients with HCV-associated NHL and well tolerated. For this reason, it is important that clinicians assess HCV-infected patients for HCV-associated extrahepatic malignancies so patients can receive timely diagnosis and treatment.

Hepatitis C virus infection is an independent prognostic factor in follicular lymphoma

Hepatitis C virus (HCV) is a single-stranded RNA virus that not only affects hepatocytes, by B cells as well. It is thought that HCV is involved in the onset of B-cell lymphoma. The clinicopathological characteristics of HCV-positive diffuse large B-cell lymphoma (DLBCL) and HCV-positive splenic marginal zone lymphoma (SMZL) are known, but there has been no report on HCV-positive follicular lymphoma (FL). In this study, the clinicopathological characteristics of HCV-positive FL were examined in 263 patients with FL who were classified into a HCV-positive group with HCV antibody and negative groups without one. The number of patients with HCV-positive FL and HCV-negative FL was 10 (3.8%) and 253 (96.2%), respectively. The patients with HCV-positive FL commonly had more than one region of lymphadenopathy, Ann Arbor stage III/IV, hemoglobin <120 g/l, elevated lactate dehydrogenase level, and high-risk categorization of Follicular Lymphoma International Prognostic Index (FLIPI) than in patients with HCV-negative FL. Overall survival and progression-free survival were poorer in patients with HCV-positive FL than in those with HCV-negative FL (p < 0.0001 and 0.006, respectively). Also, multivariate analysis revealed that positive HCV antibody was a poor prognostic factor of OS. In conclusion, HCV-positive FL has unique clinical features and may have a great impact on the overall survival of affected patients.

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.

Renal involvement in HCV-related vasculitis

Renal involvement has been frequently reported in the setting of hepatitis C virus (HCV) infection. The most common renal pathology associated with chronic HCV infection is type I membranoproliferative glomerulonephritis associated with type II mixed cryoglobulinemia, while membranoproliferative glomerulonephritis without cryoglobulinemia and membranous nephropathy were less frequently reported. Rarely, focal segmental glomerulosclerosis, fibrillary and immunotactoid glomerulopathies, and thrombotic microangiopathies were described during the course of HCV infection. In the present review, we have focused on renal involvement in HCV-related vasculitis.

Hepatitis viruses and non-Hodgkin’s lymphoma: A review

Non-Hodgkin’s lymphoma (NHL) is among the haematological malignancies with high prevalence worldwide, causing estimated 355 900 new cases and 191 400 deaths in 2008. High prevalence of NHL is documented in economically more developed areas while low prevalence is observed in less developed areas of the globe. A wide array of environmental factors have been reported to be either directly involved or in modifying the risk of NHL development. In addition to these factors, a number of infectious agents, chiefly viruses have also been implicated in the development of NHL. This article reviews the available literature to discuss the role of hepatitis viruses in NHL development, possible mechanisms of lymphomagenesis and also identify the areas in which further research is required to better understand this disease. A brief discussion on the clinical aspects such as classification, staging, treatment approaches have also been included in this article.

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.

Detection of the hepatitis C virus antigen in kidney tissue from infected patients with various glomerulonephritis

BACKGROUND

Several studies have postulated a causal link between hepatitis C virus (HCV) infection and renal diseases through the induction of cryoglobulinaemia. However, the detection of viral antigens within kidneys of HCV-infected patients has proved to be difficult. We studied a cohort of Chinese HCV-infected patients with various glomerulonephritis (GN) in an attempt to detect HCV antigens within their kidneys.

METHODS

Twenty-one patients with various GN were found to be serum HCV-antibody positive (seven serum HCV-RNA positive simultaneously), at the time of renal biopsy, from January 2005 to April 2008 in our hospital. A murine monoclonal antibody against the HCV-NS3 protein was employed to detect the HCV antigen using immunohistochemistry and immunogold labelling. Their clinical and pathological data were collected and further analysed.

RESULTS

The HCV-NS3 antigen was detected in six (6/21, 28.6%) HCV-antibody-positive patients by immunohistochemistry and four out of the six were serum HCV-RNA positive (4/7 in HCV-RNA positive, 57.1%). The HCV antigen mainly displayed a linear or granular deposition along glomerular capillary walls and/or mesangial region. Immunoelectron microscopy showed that the labelling of HCV-NS3 was localized mainly in electronic dense deposits. In the HCV-NS3 detectable patients, three patients were with membranoproliferative glomerulonephritis (MPGN), one with membranous nephropathy, one with IgA nephropathy and one with amyloid nephropathy. The age and urinary protein were significantly greater in HCV-NS3-positive patients than those in HCV-NS3 negative, while serum C3 level was significantly lower in the former group. No significant difference was found in serum ALT, albumin and creatinine level between the two groups.

CONCLUSION

HCV-NS3 antigens could be detected in kidney tissue of HCV-infected patients with various GN, but mainly in those with MPGN and HCV-RNA positive. HCV itself might be involved directly in the pathogenesis of HCV-associated GN.

The B lymphocyte stimulator receptor-ligand system in hepatitis C virus-induced B cell clonal disorders

OBJECTIVE

The study aim was to examine the B lymphocyte stimulator (BLyS) receptor-ligand system in hepatitis C virus (HCV)-induced B lymphocyte clonal disorders.

METHODS

94 patients with chronic HCV (including 35 with HCV+ mixed cryoglobulinaemia (MC)-vasculitis and nine with HCV+ B cell non-Hodgkin's lymphoma (B-NHL)) and 15 healthy volunteers were included.

RESULTS

A twofold serum BLyS increase was associated with HCV-induced MC-vasculitis, and a threefold increase with HCV-induced B-NHL, compared with patients that were HCV+, but without vasculitis, or healthy controls (p<0.05). Lower membrane BLyS expression in HCV-induced MC-vasculitis was observed. CD19+ BLyS binding and BLyS receptor 3 (BR3) staining showed a stepwise decrease with highest values in healthy controls and who were HCV+ without MC, and lowest in B-NHL (p<0.05, p<0.0001, respectively) with a further decrease in VH1-69+ clonal B cells. BLyS anti-apoptotic effects were maintained despite this decrease in BR3 staining. Complete clinical remission after antiviral treatment was associated with a decrease in serum BLyS, and an increase in BR3 staining. Rituximab treatment was associated with a fivefold increase in serum BLyS (p<0.001), mirroring the depletion of CD19+ cells. BR3 staining in repopulating B cells was significantly decreased (p<0.005).

CONCLUSIONS

The BLyS ligand-receptor activity is increased in HCV-induced B cell clonal disorders, indicating a possible role for treatment targeting the BLyS receptor-ligand system.

Extrahepatic manifestations of hepatitis C virus infection

Hepatitis C virus may cause hepatic and extrahepatic diseases. Extrahepatic manifestations range from disorders for which a significant association with viral infection is supported by epidemiologic and pathogenetic data, to anecdotal observations without clear proof of causality. This article describes the diagnosis and treatment of these diseases.

Hepatitis C virus and lymphoma

Hepatitis C virus (HCV) is well known for its aetiological role in chronic non-A, non-B viral hepatitis, liver cirrhosis and hepatocellular carcinoma; in addition, the virus has also been implicated in a number of extra-hepatic "autoimmune" disease manifestations. A causative association between HCV and non-Hodgkin lymphoma (NHL) was postulated relatively recently and has been the subject of intense investigation, as well as some debate. On the strength of epidemiological data, emerging biological investigations and clinical observations, HCV appears to be involved in the pathogenesis of at least a proportion of patients with NHL. Morphologically, HCV-associated lymphomas represent a variety of histological subtypes including marginal zone lymphoma (splenic, nodal and extranodal), small lymphocytic lymphoma/chronic lymphocytic leukaemia, lymphoplasmacytic lymphoma and diffuse large B-cell lymphoma. Remarkably, some HCV-associated NHL appears to be highly responsive to antiviral therapy, providing some clinical evidence for this relationship, as well as the prospect for novel therapeutic intervention.

Hepatitis C virus core protein enhances B lymphocyte proliferation

HCV chronic infection leads to liver diseases and also to a wide range of extrahepatic disorders including benign, but pre-lymphomatous forms (mixed cryoglobulinemia) to frank hematological neoplasia (non-Hodgkin's lymphoma). Recent data showed the involvement of p53 superfamily members in the pathogenesis of different lymphatic malignancies. In fact, tymomas and a subset of non-Hodgkin's lymphomas (NHLs) express high levels of p63. Thus, we analyzed whether alterations in p53 superfamily gene expression are observable in B lymphocytes isolated from HCV-infected patients with and without lymphoproliferative disorders. We showed, by real-time PCR, a significant induction of DNp63 mRNAs in B lymphocytes obtained from HCV-positive low grade non-Hodgkin's lymphoma patients. Since our current understanding of HCV proteins emphasizes the ability of the HCV core protein to deregulate the expression and activity of p53-related proteins, we established different B lymphocyte cell lines (Wil2-ns, Daudi and Ramos) stably expressing HCV core protein, in order to investigate the possible involvement of the viral protein in the upregulation of DNp63 in B lymphocytes. The analysis of p63 family transcripts showed no transcriptional changes for the p63 TA isoforms, whereas an increase (>5 times) of DNp63 mRNA occurred. In all cell lines, this abnormal expression was associated with a significant increase of cell proliferation that was specifically inhibited by silencing DNp63 mRNA. These findings suggest a pathogenetic role of the HCV core in HCV-related lymphomagenesis, through the induction of DNp63's pro-proliferative effects.

Hepatitis C virus-related lymphoproliferative disorders: An overview

Hepatitis C virus (HCV) is a global health problem affecting 3% of the world's population (about 180 million) and a cause of both hepatic and extrahepatic diseases. B-cell lymphoproliferative disorders, whose prototype is mixed cryoglobulinemia, represent the most closely related as well as the most investigated HCV-related extrahepatic disorder. The association between extrahepatic (lymphoma) as well as hepatic malignancies (hepatocellular carcinoma) has justified the inclusion of HCV among human cancer viruses. HCV-associated manifestations also include porphyria cutanea tarda, lichen planus, nephropathies, thyreopathies, sicca syndrome, idiopathic pulmonary fibrosis, diabetes, chronic polyarthritis, sexual dysfunctions, cardiopathy/atherosclerosis, and psychopathological disorders. A pathogenetic link between HCV virus and some lymphoproliferative disorders was confirmed by their responsiveness to antiviral therapy, which is now considered the first choice treatment. The aim of the present paper is to provide an overview of extrahepatic manifestations of HCV infection with particular attention to B-cell lymphoproliferative disorders. Available pathogenetic hypotheses and suggestions about the most appropriate, currently available, therapeutic approaches will also be discussed.

Extrahepatic manifestations of Hepatitis C Virus infection: a general overview and guidelines for a clinical approach

Hepatitis C Virus is associated with a wide series of extrahepatic manifestations. Based on available data the link between the virus and some of these extrahepatic diseases is only suggested and needs further confirmation. Hepatitis C Virus-related lymphoproliferative disorders, whose prototype is mixed cryoglobulinaemia, represent the most closely related extrahepatic manifestations of Hepatitis C Virus. Other Hepatitis C Virus-associated disorders include nephropathies, thyreopathies, sicca syndrome, idiopathic pulmonary fibrosis, porphyria cutanea tarda, lichen planus, diabetes, chronic polyarthritis, cardiopathy and atherosclerosis. A pathogenetic link between Hepatitis C Virus and some extrahepatic manifestations was confirmed by their responsiveness to antiviral therapy, which is now deemed the first therapeutic option to consider. By contrast, there are diseases where treatment with interferon was ineffective or dangerous. The aim of the present paper is to outline the most recent evidence concerning extrahepatic disorders that are possibly associated with Hepatitis C Virus infection. Special emphasis will be given to discussion of the most appropriate clinical approaches to be adopted in order to diagnose, treat (possibly prevent) and follow-up extrahepathic diseases in patients with Hepatitis C Virus infection.

HCV-associated B cell clonalities in the liver do not carry the t(14;18) chromosomal translocation

Infection with HCV can be associated with B-cell non-Hodgkin lymphoma. Polymerase chain reaction (PCR) amplification assays for Bcl-2/IgH rearrangement were performed on nucleic acids extracted from portal tract inflammatory infiltrates, isolated with laser capture microdissection (LCM), from liver biopsy sections of 16 hepatitis C virus (HCV)-infected patients with and without extrahepatic B cell-related disorders. Results were compared with total DNA extracted from core liver biopsy specimens and from peripheral blood mononuclear cells (PBMCs). We failed to demonstrate specific Bcl-2/IgH amplicons either in liver tissue or in PBMCs in all patients of the current series. Multiple PCR assays for variable diversity joining (VDJ) IgH gene rearrangements were also performed in the liver compartment. Selective amplification compatible with mono or oligoclonal B cell clonotypes was demonstrated in 80% (6/8) and 25% (2/8) of patients with and without clinical evidence of B-cell disorders. V(H)1 and V(H)3 were the most represented V(H) families. In situ expression of Bcl-2 protein was carried out by immunohistochemistry on liver biopsy sections. Bcl-2 protein was detected in 2 (12.5%) patients who did not associate extrahepatic disorders. In conclusion, current data support the concept that production of IgH gene rearrangements is not associated with Bcl-2/IgH chromosomal translocation in hepatic compartment. Liver overexpression of Bcl-2 protein may occur in at least a minor proportion of HCV-infected patients.

Splenic large B-cell lymphoma in patients with hepatitis C virus infection

Hepatitis virus infection, especially type C (hepatitis C virus [HCV]), has been suggested to be one of the important pathogenetic factors for low- and high-grade B-cell lymphoma, including splenic marginal zone lymphoma (SMZL), in southern Europe. Here, we analyzed the incidences of HCV and hepatitis B virus (HBV) infections, and the clinicopathologic features in 29 cases of splenic diffuse large B-cell lymphoma (DLBCL), 10 SMZL, 3 splenic mantle cell lymphoma, 1 hairy cell leukemia, 13 B-chronic lymphocytic leukemia, and 12 hepatosplenic T-cell and natural killer cell lymphoma. Fifteen (51.7%) splenic DLBCL cases were HCV antibody-positive, and another 6 (20.7%) had the HBsAg. The incidence of each was significantly (P < .01) higher than those of HCV (9.3%) and HBV (1.9%) infections in 54 node-based DLBCL cases. Four examined HCV-positive DLBCL cases showed no type II cryoglobulinemia. HCV RNA was detected in fresh tumor tissues from 6 of 7 examined DLBCL cases, and HBV DNA was present in another 2, as evaluated by real-time polymerase chain reaction. Immunohistologically, tumor cells in 5 of 7 examined DLBCL cases showed intracytoplasmic reactions for HCV NS3 and E2 proteins and the viral receptor CD81. Of 6 cases, 2 showed an intranuclear reaction for the HBV surface protein. By Southern blot analysis, no rearrangement of the Bcl2 gene was detected in the tumor tissue of 7 HCV-positive DLBCL cases. For the other types of malignant lymphoma, 1 case each of SMZL (10%) and hepatosplenic T-cell and natural killer cell lymphoma (8.3%) showed HCV infection. In conclusion, persistent human hepatitis virus infections, especially HCV, may play an important role in the tumorigenesis of splenic DLBCL in Japan.