Splenic lymphoma with villous lymphocytes, associated with type II cryoglobulinemia and HCV infection: a new entity?

Emerging role of infectious etiologies in the pathogenesis of marginal zone B-cell lymphomas

Extranodal marginal zone B-cell lymphomas of the mucosa-associated lymphoid tissue (MALT) arise from lymphoid populations that are induced by chronic inflammation in extranodal sites. The most frequently affected organ is the stomach, where MALT lymphoma is incontrovertibly associated with a chronic gastritis induced by a microbial pathogen, Helicobacter pylori. Gastric MALT lymphoma therefore represents a paradigm for evaluating inflammation-associated lymphomagenesis, which may lead to a deeper understanding of a possible etiologic association between other microorganisms and nongastric marginal zone lymphomas. Besides infectious etiology, chronic inflammation caused by autoimmune diseases, such as Sjögren syndrome or Hashimoto thyroiditis, can also carry a significant risk factor for the development of marginal zone lymphoma. In addition to the continuous antigenic drive, additional oncogenic events play a relevant role in lymphoma growth and progression to the point at which the lymphoproliferative process may eventually become independent of antigenic stimulation. Recent studies on MALT lymphomas have in fact demonstrated genetic alterations affecting the NF-κB) pathway, a major signaling pathway involved in many cancers. This review aims to present marginal zone lymphoma as an example of the close pathogenetic link between chronic inflammation and tumor development, with particular attention to the role of infectious agents and the integration of these observations into everyday clinical practice. See all articles in this CCR Focus section, "Paradigm Shifts in Lymphoma."

Hepatitis C Associated B-cell Non-Hodgkin Lymphoma: Clinical Features and the Role of Antiviral Therapy

The link between chronic hepatitis C virus (HCV) infection and a subset of B-cell non-Hodgkin lymphomas (B-NHL) is strongly supported by epidemiological studies. Evidence demonstrating complete regression of lymphoma after antiviral treatments suggests possible chronic antigenic stimulation for the origin of B-NHL and provides evidence for a virus-mediated lymphomagenesis. B-NHL is a heterogeneous group of lymphomas with varied clinical presentation and may be indolent or aggressive. The optimal management of HCV related B-NHL is not clear. Antiviral treatment may be sufficient for low-grade lymphomas, but chemotherapy is necessary in patients with high grade lymphomas. Interferon (IFN)-based antiviral treatment regimens for HCV infection are limited by poor tolerance and suboptimal antiviral response. Recently approved novel direct acting antiviral (DAA) drugs are highly effective and safe. This has opened a new era for the treatment of HCV related B-NHL alone or in conjunction with chemotherapy. Treatment of HCV associated B-NHL should be performed in an interdisciplinary approach in close consultation with hematologist and hepatologist. In this review, we summarize data regarding clinical features and epidemiology of B-NHL and discuss novel therapeutic approaches, including DAAs, that may prove to be effective in the treatment of HCV associated lymphomas.

Antiviral therapy is associated with a better survival in patients with hepatitis C virus and B-cell non-Hodgkin lymphomas, ANRS HC-13 lympho-C study

Hepatitis C virus (HCV) infection increases the risk of B-cell non-Hodgkin lymphomas (B-NHL). Antiviral treatment (AT) can induce hematological responses in patients with marginal zone lymphomas (MZL). The ANRS HC-13 Lympho-C study aimed at a better understanding of the impact of AT on HCV associated B-NHL. This multicentric study enrolled 116 HCV-positive patients with B-NHL between 2006 and 2012. Cytological and histological samples were collected for centralized review. At lymphoma diagnosis, median age was 61 years and gender ratio M/F was 1. Cytohistological distribution was marginal zone lymphoma (MZL) n = 45 (39%), diffuse large B-cell lymphoma (DLBCL) n = 45 (39%), and other types n = 26 (22%). MZL patients had more frequent detection of rheumatoid factor (68% vs. 35%; P = 0.001) and more frequently mixed cryoglobulinemia (74% vs. 44%; P = 0.021) than patients with DLBCL. Among patients receiving AT, a sustained virologic response was achieved in 23 of 38 (61%) patients with MZL and in 9 of 17 (53%) with DLBCL (P = 0.42). Three-year overall survival (OS) and progression-free survival were 78% 95%CI [63-88] and 64% [48-76], respectively, without difference between cytohistological groups. Outcome analysis showed a favorable association between OS and AT in all patients (P = 0.05) and in the subgroup of MZL patients only (P = 0.04). Our data support that AT improves the outcomes of HCV-associated NHLs. The impact of new AT regimen with protease inhibitor needs to be investigated in this setting. [clinicalTrials.gov Identification number NCT01545544]

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 virus-associated B-cell non-Hodgkin lymphomas

Epidemiological studies have demonstrated an increased risk of developing B-cell lymphomas in patients with chronic hepatitis C virus (HCV) infection. However, the strength of the association shows great geographic discrepancies, with higher relative risk in countries with high HCV prevalence. It remains unclear whether additional environmental and genetic factors are involved or if the international variability is simply a consequence of the variable infection prevalence. Therefore, a causal relationship remains controversial. Other confounding factors may affect the comparability of the different studies, including the method of HCV assessment, the selection of normal controls, the lymphoma classification used, and the year of publication. The most convincing proof is the observation, mainly limited to some indolent subtypes, of B-cell lymphoma regressions after HCV eradication with IFN and ribavirin. However, the molecular mechanisms of the HCV-induced lymphomagenesis are mainly hypothetical. According to the model considered to be most plausible, lymphoma growth is a consequence of the continuous antigenic stimulation of the B-cell immunologic response induced by the chronic viral infection. This review summarizes the current epidemiological and biological evidence of a role of HCV in lymphomagenesis, describing the putative mechanisms for a causative relationship. The clinical characteristics and management difficulties of the HCV-associated lymphomas are also discussed. HCV treatment with IFN cannot be given safely in concomitance with cytotoxic lymphoma treatment because of hematological and liver toxicity. However, novel and better tolerated antiviral regimens are under development and will hopefully make the treatment of both lymphoma and hepatitis easier in the future.

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.

The NOTCH pathway is recurrently mutated in diffuse large B-cell lymphoma associated with hepatitis C virus infection

Hepatitis C virus has been found to be associated with B-cell non-Hodgkin lymphomas, mostly marginal zone lymphomas and diffuse large B-cell lymphoma. Deregulation of signaling pathways involved in normal marginal zone development (NOTCH pathway, NF-κB, and BCR signaling) has been demonstrated in splenic marginal zone lymphoma. We studied mutations of NOTCH pathway signaling in 46 patients with hepatitis C virus-positive diffuse large B-cell lymphoma and in 64 patients with diffuse large B-cell lymphoma unrelated to HCV. NOTCH2 mutations were detected in 9 of 46 (20%) hepatitis C virus-positive patients, and NOTCH1 mutations in 2 of 46 (4%). By contrast, only one of 64 HCV-negative patients had a NOTCH1 or NOTCH2 mutation. The frequency of the NOTCH pathway lesions was significantly higher in hepatitis C virus-positive patients (P=0.002). The 5-year overall survival was 27% (95%CI: 5%-56%) for hepatitis C virus-positive diffuse large B-cell lymphoma patients carrying a NOTCH pathway mutation versus 62% (95%CI: 42%-77%) for those without these genetic lesions. By univariate analysis, age over 60 years, NOTCH2 mutation, and any mutation of the NOTCH pathway (NOTCH2, NOTCH1, SPEN) were associated with shorter overall survival. Mutation of the NOTCH pathway retained an independent significance (P=0.029). In conclusion, a subset of patients with hepatitis C virus-positive diffuse large B-cell lymphoma displays a molecular signature of splenic marginal zone and has a worse clinical outcome.

Non-Hodgkin lymphoma and hepatitis C: where we are and what next?

The association between hepatitis C virus and certain B-cell non-Hodgkin lymphomas, such as marginal zone lymphomas, is supported by epidemiological studies. The exact pathogenetic mechanism is still unknown but both chronic antigenic stimulation and viral lymphotropism may contribute to the evolution of the malignant clone. Furthermore, the hematologic response following hepatitis C antiviral treatment suggests that the virus may have an etiologic role. Interferon and ribavirin based treatment proved to be successful in small case series of hepatitis C virus associated splenic lymphoma with villous lymphocytes, therefore, it is suggested that antiviral treatment could be an alternative to chemo-immunotherapy. In the near future new more potent direct acting antivirals will make interferon free treatments possible. It is still an open question whether these new short-course regimens are also effective in the treatment of associated lymphomas and what is the importance of the lymphoid reservoir in eliminating HCV.

Antiviral treatment in patients with indolent B-cell lymphomas associated with HCV infection: a study of the Fondazione Italiana Linfomi

BACKGROUND

Tumor regression after antiviral therapy (AT) is in favor of an etiological role of hepatitis C virus (HCV) in non-Hodgkin's B-cell lymphomas (NHL).

PATIENTS AND METHODS

We carried out a cohort study of 704 consecutive HIV-negative, HCV-positive patients with indolent NHL diagnosed and treated from 1993 to 2009 in 39 centers of the Fondazione Italiana Linfomi; 134 patients were managed with AT for lymphoma control.

RESULTS

For entire cohort, 5-year overall survival (OS) was 78% [95% confidence interval (CI): 74%-82%] and 5-year progression-free survival (PFS) was 48% (95% CI: 44%-53%). In multivariate analysis, the use of AT during the patients' life had positive impact on OS. Forty-four of the 100 patients treated with first-line AT achieved a complete remission (CR) and 33 a partial response (PR). HCV-RNA clearance was achieved in 80 patients and was related to lymphoma response. At a median follow-up of 3.6 years, 5-year PFS was 63% (95% CI: 50%-73%). CR + PR rate was 85% with AT as second-line treatment.

CONCLUSION

AT produces HCV-RNA clearance and consequent tumor regression in most patients with HCV-related indolent NHL. AT used at any time is associated with improved OS. Consequently, AT can be considered an option for patients with indolent lymphomas who do not need immediate cytoreductive treatment.

CD21(-/low) marginal zone B cells highly express Fc receptor-like 5 protein and are killed by anti-Fc receptor-like 5 immunotoxins in hepatitis C virus-associated mixed cryoglobulinemia vasculitis

OBJECTIVE

Hepatitis C virus (HCV) is associated with B cell lymphoproliferative disorders, including mixed cryoglobulinemia (MC) vasculitis and B cell non-Hodgkin's lymphoma. The expansion of clonal and autoreactive rheumatoid factor-bearing CD21(-/low) marginal zone (MZ) B cells was demonstrated in patients with HCV-associated MC vasculitis. Fc receptor-like (FCRL) proteins comprise a family of immunoregulatory proteins preferentially expressed on B lineage cells. The goal of this study was to investigate the expression of FCRL proteins 1-5 on B cells from patients with HCV-associated MC vasculitis.

METHODS

Expression of FCRL proteins 1-5 was assessed by flow cytometry on B cells from 15 HCV-infected patients with type II MC (7 of whom had B cell non-Hodgkin's lymphoma), 20 HCV-infected patients without MC, and 20 healthy donors. To evaluate FCRL-5 as an immunotherapy target in HCV-associated MC vasculitis, 2 anti-FCRL-5 recombinant immunotoxins were produced using anti-FCRL-5 monoclonal antibodies and Pseudomonas exotoxin.

RESULTS

Expression of FCRLs 2, 3, and 5 was markedly increased while expression of FCRL-1 was decreased on clonal CD21(-/low) MZ B cells, as compared with other B cell subsets, from HCV-infected patients and healthy donors. However, there was no difference in the pattern of FCRL expression between HCV-MC patients with lymphoma and those without lymphoma. The anti-FCRL-5 immunotoxins showed specific cytotoxicity against FCRL-5-expressing clonal CD21(-/low) MZ B cells isolated from HCV-infected patients as well as FCRL-5-transfected cell lines. No cytotoxicity against T cells or conventional B cells was observed.

CONCLUSION

These findings suggest that FCRL-5-targeting therapies could be a specific treatment for HCV-associated MC vasculitis and other FCRL-5-positive autoimmune B cell disorders.

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.

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 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.

Expansion of autoreactive unresponsive CD21-/low B cells in Sjögren's syndrome-associated lymphoproliferation

OBJECTIVE

Primary Sjögren's syndrome (SS) is an autoimmune disease associated with a high risk of developing non-Hodgkin's lymphoma. This study was undertaken to determine the nature of B cells driving lymphoproliferation in primary SS.

METHODS

B cell subsets and function were analyzed in peripheral blood from 66 adult patients with primary SS (including 14 patients with B cell lymphoproliferative disease [LPD]) and 30 healthy donors, using flow cytometry, calcium mobilization, and gene array analysis. The reactivity of recombinant antibodies isolated from single B cells from patients with primary SS and LPD was tested using an enzyme-linked immunosorbent assay.

RESULTS

We observed an expansion of an unusual CD21-/low B cell population that correlated with lymphoproliferation in patients with primary SS. A majority of CD21-/low B cells from patients with primary SS expressed autoreactive antibodies, which recognized nuclear and cytoplasmic structures. These B cells belonged to the memory compartment, since their Ig genes were mutated. They were unable to induce calcium flux, become activated, or proliferate in response to B cell receptor and/or CD40 triggering, suggesting that these autoreactive B cells may be anergic. However, CD21-/low B cells from patients with primary SS remained responsive to Toll-like receptor (TLR) stimulation. Molecules specifically expressed in CD21-/low B cells that are likely to induce their unresponsive stage were detected in gene array analyses.

CONCLUSION

Patients with primary SS who display high frequencies of autoreactive and unresponsive CD21-/low B cells are susceptible to developing lymphoproliferation. These cells remain in peripheral blood controlled by functional anergy instead of being eliminated, and chronic antigenic stimulation through TLR stimulation may create a favorable environment for breaking tolerance and activating these cells.

Marginal zone lymphoma: old, new, targeted, and epigenetic therapies

Marginal zone lymphoma (MZL) is an indolent B-cell lymphoma arising from marginal zone B-cells present in lymph nodes and extranodal tissues. MZL comprises 5-17% of all non-Hodgkin's lymphomas in adults. The World Health Organization categorizes MZL into three distinct types based on their site of impact: (1) splenic marginal zone lymphoma (SMZL); (2) nodal marginal zone lymphoma (NMZL); (3) extranodal mucosa-associated lymphoid tissue (MALT) lymphoma, which can be subdivided into gastric and nongastric. The subgroups of MZL share some common features but are different in their biology and behavior. Owing to the rarity of MZL there are few randomized trials available comparing various treatment options and therefore treatment is controversial, lacking standard guidelines. Treatment should be patient tailored and can range from a 'watchful waiting' approach for asymptomatic patients without cytopenias to surgery or localized radiation therapy. Rituximab in combination with chemotherapy has resulted in longer failure-free survival than chemotherapy alone in patients with SMZL. Helicobacter pylori positive gastric MALT shows a good response rate to triple antibiotic therapy. Newer therapies such as bendamustine, everolimus, lenalidomide, vorinostat and phosphoinositide 3-kinase inhibitors are in clinical trials for patients with relapsed or refractory MZL and have shown promising results. We are presently conducting clinical trials testing the efficacy of the epigenetic activity of cladribine as a hypomethylating agent in combination with the histone deacetylase inhibitor (HDACi) vorinostat and rituximab in patients with MZL. Further studies with the newer agents should be done both in newly diagnosed or relapsed/refractory MZL to streamline the care and to avoid the use of toxic chemotherapies as initial treatment.

Indolent B-cell lymphomas associated with HCV infection: clinical and virological features and role of antiviral therapy

The association between hepatitis C virus (HCV) infection and B-cell non-Hodgkin's lymphomas (NHL) has been demonstrated by epidemiological studies, in particular in highly endemic geographical areas such as Italy, Japan, and southern parts of United States. In these countries, together with diffuse large B-cell lymphomas, marginal zone lymphomas are the histotypes most frequently associated with HCV infection; in Italy around 20–30% cases of marginal zone lymphomas are HCV positive. Recently, antiviral treatment with interferon with or without ribavirin has been proved to be effective in the treatment of HCV-positive patients affected by indolent lymphoma, prevalently of marginal zone origin. An increasing number of experiences confirmed the validity of this approach in marginal zone lymphomas and in other indolent NHL subtypes like lymphoplasmacytic lymphoma. Across different studies, overall response rate was approximately 75%. Hematological responses resulted significantly associated with the eradication of the virus. This is the strongest evidence of a causative link between HCV and lymphomas. The aim of this paper is to illustrate the relationship between HCV infection and different subtypes of indolent B-cell lymphomas and to systematically summarize the data from the therapeutic studies that reported the use of antiviral treatment as hematological therapy in patients with HCV-associated indolent lymphomas.

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.

Morphologic features of extrahepatic manifestations of hepatitis C virus infection

Cirrhosis and hepatocellular carcinoma are the prototypic complications of chronic hepatitis C virus infection in the liver. However, hepatitis C virus also affects a variety of other organs that may lead to significant morbidity and mortality. Extrahepatic manifestations of hepatitis C infection include a multitude of disease processes affecting the small vessels, skin, kidneys, salivary gland, eyes, thyroid, and immunologic system. The majority of these conditions are thought to be immune mediated. The most documented of these entities is mixed cryoglobulinemia. Morphologically, immune complex depositions can be identified in small vessels and glomerular capillary walls, leading to leukoclastic vasculitis in the skin and membranoproliferative glomerulonephritis in the kidney. Other HCV-associated entities include porphyria cutanea tarda, lichen planus, necrolytic acral erythema, membranous glomerulonephritis, diabetic nephropathy, B-cell non-Hodgkin lymphomas, insulin resistance, sialadenitis, sicca syndrome, and autoimmune thyroiditis. This paper highlights the histomorphologic features of these processes, which are typically characterized by chronic inflammation, immune complex deposition, and immunoproliferative disease in the affected organ.

HCV and lymphoproliferation

Hepatitis C virus (HCV) infection is a serious public health problem because of its worldwide diffusion and sequelae. It is not only a hepatotropic but also a lymphotropic agent and is responsible not only for liver injury--potentially evolving to cirrhosis and hepatocellular carcinoma--but also for a series of sometimes severely disabling extrahepatic diseases and, in particular, B-cell lymphoproliferative disorders. These latter range from benign, but prelymphomatous conditions, like mixed cryoglobulinemia, to frank lymphomas. Analogously with Helicobacter pylori related lymphomagenesis, the study of the effects of viral eradication confirmed the etiopathogenetic role of HCV and showed it is an ideal model for better understanding of the molecular mechanisms involved. Concerning these latter, several hypotheses have been proposed over the past two decades which are not mutually exclusive. These hypotheses have variously emphasized the important role played by sustained stimulation of the immune system by HCV, infection of the lymphatic cells, viral proteins, chromosomal aberrations, cytokines, or microRNA molecules. In this paper we describe the main hypotheses that have been proposed with the corresponding principal supporting data.

Hepatitis C and non-Hodgkin lymphoma: the clinical perspective

Hepatitis C virus (HCV) is a commonly transmitted infection that has both hepatic and extrahepatic repercussions. These range from the inflammatory to the oncologic with an undisputed link to hepatitis, liver cirrhosis, and hepatocellular carcinoma. Its role in the development of B cell non-Hodgkin lymphoma (B-NHL) is becoming better understood, leading to opportunities for research, therapy, and even prevention. Research in the field has progressed significantly over the last decade, with the number of patients diagnosed with HCV and B-NHL rising incrementally. It is therefore becoming crucial to fully understand the pathobiologic link of HCV in B cell lymphomagenesis and its optimal management in the oncologic setting.

Manifestations of chronic hepatitis C virus infection beyond the liver

In addition to its effects in the liver, chronic hepatitis C virus (HCV) infection can have serious consequences for other organ systems. Extrahepatic manifestations include mixed cryoglobulinemia (MC) vasculitis, lymphoproliferative disorders, renal disease, insulin resistance, type 2 diabetes, sicca syndrome, rheumatoid arthritis-like polyarthritis, and autoantibody production; reductions in quality of life involve fatigue, depression, and cognitive impairment. MC vasculitis, certain types of lymphoma, insulin resistance, and cognitive function appear to respond to anti-HCV therapy. However, treatments for HCV and other biopsychosocial factors can reduce quality of life and complicate management. HCV treatment has a high overall cost that increases when extrahepatic manifestations are considered. HCV appears to have a role in the pathogenesis of MC vasculitis, certain types of lymphoma, and insulin resistance. Clinicians who treat patients with HCV infections should be aware of potential extrahepatic manifestations and how these can impact and alter management of their patients.

Anti-PL7 antisynthetase syndrome under interferon therapy

A 62-year-old woman with a past history of chronic hepatitis C virus infection presented an atypical predominantly painful polymyositis following a flu-like syndrome, persisting despite the withdrawal of PEG-interferon alpha-2b therapy. Clinical assessment, then immunological, electrophysiological and iconographic investigations including myositis antibodies, electromyography, pulmonary functions assessment and thoracic CT-scan found respectively "mechanic hands", arthralgia, presence of antisynthetase anti-PL7 antibody, typical myographic features of hip and shoulder girdles involvement, pulmonary fibrosis and restrictive syndrome features. A deltoid muscle biopsy revealed an unclassified myositis getting closer to anti-J0-1 and connective tissue disease associated myositis featuring: some components of polymyositis, dermatomyositis, and the following peculiar pathological aspects: noncaseous granulomatous infiltrate, endomysial microangiopathy and vascular and sarcolemic deposition of complement membrane attack complex. The diagnosis of interferon induced anti-PL7 antisynthetase syndrome with microangiopathic and granulomatous overlap myositis was retained. A treatment associating intravenous immunoglobulin and moderate tapered oral corticosteroids allowed a complete long-term resolution of myositis and a clear improvement of pulmonary involvement. This case points out the wide range of interferon alpha-associated disorders and call for a precise and detailed immunopathological analysis of myositis, instead of the usual vague classification as idiopathic polymyositis or dermatomyositis about antisynthetase syndrome.

Stereotyped patterns of B-cell receptor in splenic marginal zone lymphoma

Antigen stimulation may be important for splenic marginal zone lymphoma pathogenesis. To address this hypothesis, the occurrence of stereotyped B-cell receptors was investigated in 133 SMZL (26 HCV+) compared with 4,414 HCDR3 sequences from public databases. Sixteen SMZL (12%) showed stereotyped BCR; 7 of 86 (8%) SMZL sequences retrieved from public databases also belonged to stereotyped HCDR3 subsets. Three categories of subsets were identified: i) "SMZL-specific subsets" (n=5), composed only of 12 SMZL (9 HCV-from our series); ii) "Non-Hodgkin's lymphoma-like subsets" (n=5), comprising 5 SMZL (4 from our series) clustering with other indolent lymphomas; iii) "CLL-like subsets" (n=6), comprising 6 SMZL (3 from our series) that belonged to known CLL subsets (n=4) or clustered with public CLL sequences. Immunoglobulin 3D modeling of 3 subsets revealed similarities in antigen binding regions not limited to HCDR3. Overall, data suggest that the pathogenesis of splenic marginal zone lymphoma may involve also HCV-unrelated epitopes or an antigenic trigger common to other indolent lymphomas.

Rituximab plus Peg-interferon-alpha/ribavirin compared with Peg-interferon-alpha/ribavirin in hepatitis C-related mixed cryoglobulinemia

Treatment of hepatitis C (HCV)-mixed cryoglobulinemia (MC) may target either the viral trigger (HCV) or the downstream B-cell clonal expansion. Prospective cohort study of 38 HCV-MC patients who received a combination of rituximab (375 mg/m(2)) once a week for 1 month followed by Peg-interferon-alpha (Peg-IFN-alpha; 2a, 180 microg or 2b, 1.5 microg/kg) weekly plus ribavirin (600-1200 mg) daily for 48 weeks were compared with 55 HCV-MC patients treated by Peg-IFN-alpha/ribavirin with the same modalities. In the whole population of HCV-MC patients (n = 93), a complete clinical response was achieved in 73.1% (68 of 93), cryoglobulin clearance in 52.7% (49 of 93), and a sustained virologic response in 59.1% (55 of 93). Compared with Peg-IFN-alpha/ribavirin, rituximab plus Peg-IFN-alpha/ribavirin-treated patients had a shorter time to clinical remission (5.4 +/- 4 vs 8.4 +/- 4.7 months, P = .004), better renal response rates (80.9% vs 40% of complete response, P = .040), and higher rates of cryoglobulin clearance (68.4% vs 43.6%, P = .001) and clonal VH1-69(+) B-cell suppression (P < .01). Treatment was well tolerated with 11% of discontinuation resulting from antiviral therapy and no worsening of HCV RNA under rituximab. Our findings indicate that rituximab combined with Peg-IFN-alpha/ribavirin is well tolerated and more effective than Peg-IFN-alpha/ribavirin in HCV-MC.

Hepatitis C virus infection and lymphoma

Apart from its well known role as an etiological agent for non-A and non-B viral hepatitis, there is growing evidence that hepatitis C virus is associated to B-cell non-Hodgkin lymphoma. The association between HCV and lymphoproliferative disorders has been recently postulated based on epidemiological data, biological studies and clinical observations. Although various subtypes of lymphomas appear to be associated to HCV, diffuse large B-cell lymphoma, small lymphocytic lymphoma/chronic lymphocytic leukemia and marginal zone lymphoma appeared to be particularly represented among HCV-positive patients. The causative role of HCV in those disorders has been further supported by the response to antiviral therapy. Despite a better understanding of pathophysiological processes at stake leading from HCV infection to overt lymphoma, many issues still need to be further elucidated. Although HCV has been demonstrated to directly infect peripheral blood mononuclear cells both in vitro and, in some cases, in vivo, a strong body of evidence rather supports the hypothesis of an indirect transformation mechanism by which sustained antigenic stimulation leads from oligoclonal to monoclonal expansion and sometimes to lymphoma, probably through secondary oncogenic events. Here, we review epidemiological and biological studies, as well as clinical data on antiviral therapy, linking HCV-infection to B-cell non-Hodgkin lymphoma.

Subcutaneous 'lipoma-like' B-cell lymphoma associated with HCV infection: a new presentation of primary extranodal marginal zone B-cell lymphoma of MALT

BACKGROUND

Hepatitis C virus (HCV) infection has been linked to lymphoproliferative disorders. Marginal zone B-cell lymphoma (MZL) represents one of the most frequent lymphoma subtypes associated with HCV infection. We describe an unusual subset of HCV-associated MZL characterized by subcutaneous presentation.

MATERIALS AND METHODS

A series of 12 HCV-positive patients presenting with subcutaneous nodules that revealed lymphoma infiltration at biopsy. Molecular analysis of immunoglobulin heavy chain (IGH) gene rearrangement and FISH investigations for t(11;18)(q21;q21) and t(14;18)(q32;q21) were carried out in nine patients.

RESULTS

The 12 patients (median age 69.5 years), all with positive HCV serology, presented with single or multiple subcutaneous nodules resembling lipomas. Histologically the lesions showed lymphoid infiltrates, consistent with extranodal MZL of mucosa-associated lymphoid tissue (MALT). Functional IGH gene rearrangements were identified in nine tested patients, with somatic mutations in 82%, indicating a histogenesis from germinal center-experienced B cells. The t(11;18) was found in two of nine cases. Staging did not show any other lymphoma localization. In two patients, a response was achieved with antiviral treatment. Extracutaneous spread to MALT sites occurred in a case.

CONCLUSIONS

Our observations expand the spectrum of HCV-associated lymphomas to include a subset of extranodal MZL characterized by a novel primary 'lipoma-like' subcutaneous presentation and indolent clinical course.

[Splenic marginal zone B cell lymphomas]

Splenic marginal zone B cell lymphomas (SMZBCL) are rare, organotypic, lymphoid neoplasms with distinct clinicopathological features. At initial presentation, the spleen, bone marrow and peripheral blood are usually involved, while generalized lymphadenopathy is only rarely observed. Molecularly, somatic hypermutation of IgVH genes can be detected in roughly half of the cases, and deletions in 7q are present in 45% of tumors. Approximately 10%-15% of SMZBCL do occur in the setting of chronic hepatitis C. This association underlines the importance of antigenic stimulation in the proliferation of the tumor cells in HCV-associated SMBCL, if not also in their classical counterparts. More recently, gene profiling studies using cDNA microarrays revealed a homogeneous expression profile in SMZBCL, thus further confirming the notion of a distinct tumor entity. The clinical course is indolent in the majority of cases; however, some patients follow a more aggressive clinical course, usually associated with some particular molecular features in these tumors, such as unmutated IgVH genes and 7q deletions.

Epidemiology, pathology and treatment of non-follicular indolent lymphomas

Non-follicular indolent subtypes of non-Hodgkin lymphoma (NHL), which include chronic lymphocytic leukemia, small lymphocytic lymphoma (SLL) and marginal zone lymphomas (MZL), are a diverse group of disorders with different presenting features, behaviour patterns and treatment outcomes. Current knowledge of these subtypes is largely based on retrospective analyses. A precise diagnosis can be difficult to achieve, and specific diagnostic criteria are needed to more precisely define some of the rarer indolent tumors, such as nodal and splenic MZLs. Although some subtypes of NHL have a prolonged indolent course, with a good prognosis (e.g. SLL), others (e.g. nodal and splenic MZLs) can rapidly evolve into more aggressive subtypes. In asymptomatic patients, treatment may be deferred until the disease progresses and the patient becomes symptomatic. Universally accepted therapeutic guidelines do not exist, however, and carefully designed, prospective clinical studies are needed to further assess optimal therapeutic approaches for these indolent NHLs.

Hepatitis C virus infection induced vasculitis

Cryoglobulinemia are immune complexes that may induce systemic cryoglobulinemic vasculitis, a small-vessel vasculitis involving the skin, the joints, the peripheral nerve system, and the kidneys. During the last 15 years, progresses have been done after the discovery of the hepatitis C virus, the main cause of cryoglobulins. Main factors associated with cryoglobulin production are female gender, alcohol intake above 50 g/day, extensive liver fibrosis, and steatosis. Symptomatic cryoglobulins (i.e., vasculitis) are associated with older age, longer duration of infection, and main characteristics of cryoglobulin (type II, IgM kappa, high serum levels). The physiopathology is complex, and it involves humoral immunity, B- and T-cellular immunity but not the virus itself. Peg-Interféron alpha Ribavirine combination leads to a virological and clinical response of the vasculitis in about 70% of patients. In nonresponders, recent open series suggested the efficacy of Rituximab with a good response in up to 80% of patients but a relapse in 42% after 7 months after the last infusion. For future prospects and projects, new therapeutic strategies include a combination of best antiviral treatment with Peg-Interferon plus Ribavirin and Rituximab. Multicenter controlled trials are mandatory.

Overview of lymphoma diagnosis and management

The malignant lymphomas, including both Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL), represent a diverse group of diseases that arise from a clonal proliferation of lymphocytes. Each of the more than 30 unique types of lymphoma is a disease with a distinct natural history. This biologic heterogeneity gives rise to marked differences among the lymphomas with respect to epidemiology, pathologic characteristics, clinical presentation, and optimal management. This article emphasizes the principles of diagnosis, including appropriate pathologic evaluation and staging considerations, and focuses on the clinical presentation, staging, and optimal management strategies for the most common types of lymphoma.

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 infection, mixed cryoglobulinemia and BLyS upregulation: targeting the infectious trigger, the autoimmune response, or both?

Mixed cryoglobulinemia syndrome (MCsn) is a systemic vasculitis prevalently mediated by immune complexes, i.e., mixed cryoglobulins, and characterized by non-neoplastic B-cell lymphoproliferation favouring the progression into frank B-cell non-Hodgkin lymphoma (NHL) in 5-10% of patients. The hepatitis C virus (HCV) infection is the etiologic agent in the large majority of MCsn cases and chronic antigenic stimulation by HCV is considered a key mechanism sustaining the proliferation of the RF-secreting B-cell clones. Besides chronic antigenic stimulation, cytokines and growth factors may also play a key role in sustaining B-cell overactivation. B-lymphocyte stimulator (BlyS) was recently described as a critical survival factor for B cells, promoting their activation and maturation. Abnormal production of BLyS alters immune tolerance by allowing the survival of autoreactive B cells, thus triggering autoimmune disorders. BLyS inhibits B-cell apoptosis, and B-cell apoptosis is implicated in the pathogenesis of MCsn, as well as of other autoimmune diseases. Both antiviral therapy and B- cell depletive therapy in MCsn may influence BlyS expression. Antiviral therapy, monotherapy against biologic targets downstream viral infection, or the combination of the two, should be optimized in the single patient and stage of the disease, based on disease pathobiology, efficacy and safety issues.

Treatment of hepatitis C-associated mixed cryoglobulinemia vasculitis

PURPOSE OF REVIEW

Hepatitis C virus infection is the main cause of mixed cryoglobulinemia vasculitis. The disease expression of mixed cryoglobulinemia vasculitis is variable, ranging from mild clinical symptoms (purpura, arthralgia) to fulminant life-threatening complications (glomerulonephritis, widespread vasculitis). Treatment of hepatitis C virus-mixed cryoglobulinemia vasculitis may target either the viral trigger (hepatitis C virus) or the downstream B-cell arm of autoimmunity. This review focuses on recent advances in our understanding of the treatment of hepatitis C virus-mixed cryoglobulinemia vasculitis.

RECENT FINDINGS

Aggressive antiviral therapy with Peg-IFNalpha and ribavirin should be considered as induction therapy for hepatitis C virus-mixed cryoglobulinemia vasculitis with mild to moderate disease severity and activity. In patients presenting with severe disease, an induction phase of immunosuppression is often necessary while awaiting the generally slow response to antiviral treatments. Combination therapy with rituximab and Peg-IFNalpha plus ribavirin appears logical as it may target both the viral trigger (hepatitis C virus) and cryoglobulin-producing B-cells.

SUMMARY

Antiviral therapy and rituximab are the main therapeutic options in hepatitis C virus-mixed cryoglobulinemia vasculitis. Further studies are needed to better define the therapeutic strategy.