Virological and Clinical Response to Interferon-Free Regimens in Patients with HCV-Related Mixed Cryoglobulinemia: Preliminary Results of a Prospective Pilot Study.

Mixed Cryoglobulinemia (MC) is the most frequent extrahepatic manifestation of Hepatitis C virus (HCV) infection. MC is an autoimmune /B-cell lymphoproliferative disorder characterized by circulating immune-complexes, named cryoglobulins. MC patients exhibit symptoms due to a systemic vasculitis of small/medium size vessels (mixed cryoglobulinemia syndrome, MCS) in a percentage going from 5 to 30%. The first-line therapeutic option in MCS patients is the etiologic treatment and, in the past fifteen years, antiviral therapy with Pegylated-Interferon (Peg-IFN) plus Ribavirin (RBV) represented the standard of care. Lately, the arrival of direct acting antivirals (DAAs) significantly modified the cure of HCV infection, consenting the use of IFN-free regimens. Here we report a review of the literature about the role of antiviral treatment, following its evolution, in treating HCVrelated MC. Furthermore, we report the results, after 8 weeks of treatment, of a preliminary pilot prospective study, counting 17 patients with HCV-related MC with or without MCS, treated with new generation DAAs in IFN-free regimens. After 8 weeks of DAA administration, all the subjects were HCV RNA negative. Moreover, in 6/17 (35%) patients cryoglobulins disappeared and, on the whole, in all patients a decrease of the cryocrit values was observed (p<0.05). Furthermore, three MCS-HCV patients (30%) resulted to be complete clinical responders and 5 subjects (50%) partial clinical responders. Therefore, IFN-free anti-HCV treatment appears to be safe and effective in MC patients from virological and clinical points of view, thus supporting the importance of HCV eradication in leading MC remission.

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.

Efficacy of low-dose rituximab for the treatment of mixed cryoglobulinemia vasculitis: Phase II clinical trial and systematic review.

OBJECTIVE: To evaluate whether rituximab at a low dose of 250 mg/m(2) × 2 may be as effective as at higher dosages, most commonly 375 mg/m(2)×4, used in previous studies on the treatment of patients with refractory mixed cryoglobulinemia (MC) vasculitis associated with hepatitis C virus (HCV) infection. METHODS: We conducted a phase 2, single-arm two-stage trial (EUDRACT n. 2008-000086-38) of low-dose rituximab in 52 patients with HCV-associated MC who were ineligible/intolerant or non-responder to antiviral therapy. The primary outcomes were response of vasculitis evaluated by the Birmingham Vasculitis Activity Score (BVAS) at months 3, 6 and 12, rate of relapses and time to relapse, and rate of adverse events. Our data were compared with those reported in 19 published studies selected among 291 reviewed in a literature search. RESULTS: The cumulative response rate (complete and partial) at month 3 was 81% in our patients, and 86% in 208 patients from studies using high-dose rituximab. The relapse rate and median time to relapse were, respectively, 41% and 6 months in our study, and 32% and 7 months in high-dose studies. Treatment-related adverse events were 11.5% in our study and 19.9% in high-dose studies. None of these differences was statistically significant. CONCLUSION: Rituximab at a low dosage of 250 mg/m(2) × 2 is as effective as at higher dosages for treating MC vasculitis. This low-dose regimen may improve the cost/benefit profile of rituximab therapy for MC.

Hepatitis C virus syndrome: A constellation of organ- and non-organ specific autoimmune disorders, B-cell non-Hodgkin's lymphoma, and cancer.

The clinical course of chronic hepatitis C virus (HCV) infection is characterized by possible development of both liver and extrahepatic disorders. The tropism of HCV for the lymphoid tissue is responsible for several immune-mediated disorders; a poly-oligoclonal B-lymphocyte expansion, commonly observed in a high proportion of patients with HCV infection, are responsible for the production of different autoantibodies and immune-complexes, such as mixed cryoglobulins. These serological alterations may characterize a variety of autoimmune or neoplastic diseases. Cryoglobulinemic vasculitis due to small-vessel deposition of circulating mixed cryoglobulins is the prototype of HCV-driven immune-mediated and lymphoproliferative disorders; interestingly, in some cases the disease may evolve to frank malignant lymphoma. In addition, HCV shows an oncogenic potential as suggested by several clinico-epidemiological and laboratory studies; in addition to hepatocellular carcinoma that represents the most frequent HCV-related malignancy, a causative role of HCV has been largely demonstrated in a significant percentage of patients with isolated B-cells non-Hodgkin's lymphomas. The same virus may be also involved in the pathogenesis of papillary thyroid cancer, a rare neoplastic condition that may complicate HCV-related thyroid involvement. Patients with HCV infection are frequently asymptomatic or may develop only hepatic alteration, while a limited but clinically relevant number can develop one or more autoimmune and/or neoplastic disorders. Given the large variability of their prevalence among patients' populations from different countries, it is possible to hypothesize a potential role of other co-factors, i.e., genetic and/or environmental, in the pathogenesis of HCV-related extra-hepatic diseases.

Combined treatment with antiviral therapy and rituximab in patients with mixed cryoglobulinemia: review of the literature and report of a case using direct antiviral agents-based antihepatitis C virus therapy.

Mixed cryoglobulinemia (MC) is an autoimmune/B-cell lymphoproliferative disorder associated with Hepatitis C Virus (HCV) infection, manifesting as a systemic vasculitis. In the last decade, antiviral treatment (AT) with pegylated interferon (Peg-IFN) plus ribavirin (RBV) was considered the first therapeutic option for HCV-MC. In MC patients ineligible or not responsive to antivirals, the anti-CD20 monoclonal antibody rituximab (RTX) is effective. A combined AT plus RTX was also suggested. Since the introduction of direct acting antivirals (DAAs), few data were published about MC and no data about a combined schedule. Here, we report a complete remission of MC after a sustained virological response following a combined RTX/Peg-IFN+RBV+DAA (boceprevir) treatment and review the literature about the combined RTX/AT.

Assessment of free light chains in HCV-positive patients with mixed cryoglobulinaemia vasculitis undergoing rituximab treatment.

BACKGROUND & AIMS: Mixed cryoglobulinaemia (MC) is an HCV-related lymphoproliferative disorder characterized by the presence of circulating immune complexes called cryoglobulins. Treatment with anti-CD20 monoclonal antibody rituximab is proved to be very useful, especially in patients ineligible to interferon-based antiviral therapy. Recently, free light chain (FLC) κ/λ ratio and FLC patterns were associated with MC. The aim of this study was to evaluate changes in FLC-κ, FCL-λ, FLC ratio following rituximab treatment in patients with HCV-related MC and to correlate FLC-κ, FCL-λ and FLC ratio values with therapy response. PATIENTS AND METHODS: We retrospectively enrolled 46 patients with HCV infection (26 females, 20 males), including 10 patients without signs/symptoms of MC-related vasculitis, 36 with MC vasculitis. Clinical and biological data were recorded at baseline and 6 months after RTX treatment. Nephelometric measurement of serum FLCs was taken. RESULTS: The mean serum FLC-κ level and FLC ratio were significantly higher in patients with MC, compared to HCV patients without MC and to blood donors. An abnormal FLC ratio at baseline correlated with the presence of cryoglobulins, C4 consumption, higher RF level and higher vasculitis rate. To evaluate the predictive value of FLCs, patients with MC were divided into two groups according to RTX therapy outcome (responders and no/partial responders). Abnormal baseline FLC ratio was significantly associated with no/partial response. CONCLUSIONS: RTX treatment in HCV-related MC induces a reduction in FLC-κ and RF levels. Moreover, pretreatment FLC ratio, which can be easily assessed by a routine test, may be useful to predict response to this expensive treatment for patients with HCV-related MC ineligible to IFN-based therapy.

Evaluation of the prognostic value of liver stiffness in patients with hepatitis C virus treated with triple or dual antiviral therapy: A prospective pilot study.

AIM: To evaluate the association between liver stiffness (LS) prior to the initiation of dual/triple therapy and viral response. METHODS: LS was measured in all patients before treatment was administered. The therapeutic approach was based on hepatic, virological, and immunological evaluations and considered the fact that patients with severe fibrosis (F3) or compensated cirrhosis (F4) in Child-Pugh class A are the primary candidates for triple therapy. In total, 65 hepatitis C virus (HCV) patients were treated with Peg-interferon/ribavirin (Peg-IFN/RBV); 24 patients were classified as genotypes 1/4 (36.92%), and 41 patients were classified as genotypes 2/3 (63.08%) (dual therapy). In addition, 20 HCV treatment-experienced genotype 1 patients were treated with PegIFN-RBV and boceprevir (triple therapy). Wilcoxon rank-sum tests were used to compare the groups. RESULTS: LS significantly differed between dual therapy and triple therapy (P = 0.002). The mean LS value before dual therapy treatment was 8.61 ± 5.79 kPa and was significantly different between patients achieving a sustained virologic response (SVR) 24 weeks after therapy and those who did not (7.23 ± 5.18 kPa vs 11.72 ± 5.99 kPa, respectively, P = 0.0003). The relative risk of non-response to therapy was 4.45 (95%CI: 2.32-8.55). The attributable risk of non-response to therapy was 49%. The mean LS value before triple therapy treatment was 13.29 ± 8.57 kPa and was significantly different between patients achieving and not achieving SVR24 (9.41 ± 5.05 vs 19.11 ± 9.74, respectively; P = 0.008). The relative risk of non-response to therapy was 5.57% (95%CI: 1.50-20.65). The attributable risk of non-response to therapy (70%) was increased compared with dual therapy patients. Pre-treatment stiffness > 12 kPa was significantly associated with non-SVR (P < 0.025) in both groups. CONCLUSION: Pre-treatment liver stiffness may be useful for predicting the response to treatment in patients treated with either dual or triple anti-HCV therapy.

Long-term effect of HCV eradication in patients with mixed cryoglobulinemia: a prospective, controlled, open-label, cohort study.

UNLABELLED: Limited data are available about the efficacy of antiviral treatment in hepatitis C virus (HCV)-associated mixed cryoglobulinemia (MC), especially concerning the long-term effects of HCV eradication. The aim of this study was to evaluate the influence of MC on the virological response and the long-term effects of viral eradication on MC. We prospectively enrolled 424 HCV(+) patients belonging to the following groups: MC syndrome (MCS)-HCV (121 patients with symptomatic MC), MC-HCV (132 patients with asymptomatic MC), and HCV (158 patients without MC). Pegylated interferon plus ribavirin treatment was administered according to standard protocols. Posttreatment follow-up ranged from 35 to 124 months (mean 92.5 months). A significant difference was observed in the rate of sustained virological response between the HCV group and both the MC-HCV (P = 0.009) and MC-HCV+MCS-HCV (P = 0.014) groups. Multivariate logistic regression analysis identified cryoglobulinemia as an independent prognostic factor of nonresponse. The clinical-immunological response in MCS-HCV correlated with the virological one. All patients with sustained virological response also experienced a sustained clinical response, either complete or partial. In the majority of sustained virological response patients all MCS symptoms persistently disappeared (36 patients, 57%); in only two (3%) did definite MCS persist. All virological nonresponders were also clinical nonresponders, in spite of a transient improvement in some cases. No evolution to lymphoma was observed. For the first time we have evaluated both the effects of interferon-based therapy on HCV patients with and without MC and with and without symptoms, as well as the long-term effects of viral eradication on MC. CONCLUSION: MC is a negative prognostic factor of virological response. Clearance of HCV led to persistent resolution or improvement of MCS, strongly suggesting the need for a next generation of highly effective antiviral drugs.

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.

Triple antiviral therapy in hepatitis C virus infection with or without mixed cryoglobulinaemia: a prospective, controlled pilot study.

BACKGROUND: Mixed cryoglobulinaemia is strongly related to hepatitis C virus infection. Treatment with peg-interferon and ribavirin has been indicated as first-line therapy for mild/moderate hepatitis C virus-related mixed cryoglobulinaemia. AIM: To evaluate the safety and efficacy of triple boceprevir-based antiviral therapy in patients with or without mixed cryoglobulinaemia previously treated with peg-interferon and ribavirin, and with advanced liver disease. METHODS: Thirty-five hepatitis C virus-positive patients (17 with asymptomatic mixed cryoglobulinaemia, 5 with symptomatic mixed cryoglobulinaemia, and 11 without mixed cryoglobulinaemia) were treated with triple boceprevir-based antiviral therapy. RESULTS: In 19/22 cryoglobulinaemic subjects (86%), the addition of boceprevir induced cryocrit disappearance. Cryocrit behaviour was related to virological response, with improvement of symptoms upon undetectable viraemia and reappearance after virological breakthrough. The rate of sustained virological response was lower in cryoglobulinaemic patients than in patients without mixed cryoglobulinaemia (23.8% vs 70% respectively, p=0.01). CONCLUSION: Boceprevir-based therapy was safe and effective in cryoglobulinaemic patients. The correlation between direct inhibition of hepatitis C virus replication and clinical improvement in mixed cryoglobulinaemic patients is definitive proof of the key pathogenetic role played by viral replication. Further studies are needed to confirm and clarify the reduced virological response in patients with mixed cryoglobulinaemia.

Impact of immunogenetic IL28B polymorphism on natural outcome of HCV infection.

With the aim of investigating whether interleukin 28B gene (IL28B) rs1297860 polymorphism is associated with different hepatitis C (HCV) infection statuses, we compared IL28B allelic distribution in an Italian case series of 1050 patients with chronic infection and different outcomes, 47 individuals who spontaneously cleared HCV, and 178 blood donors. Furthermore, we compared IL28B variants among 3882 Caucasian patients with chronic infection, 397 with spontaneous clearance, and 1366 blood donors reported in PubMed. Overall data confirmed a relation between IL28B C allele and HCV spontaneous clearance. Furthermore, we found that IL28B T allele had a weak relation with chronic HCV progression to hepatocellular carcinoma. Study findings are in accordance with the hepatocellular carcinogenic model where IL28B TT genotype, by promoting a persistent chronic hepatitis which leads to both hepatocyte injury and chronic inflammation, could facilitate HCC development. Conversely, patients with lymphoproliferative disorders had not any significantly different IL28B rs1297860 allelic distribution than those with chronic HCV, but, like all chronic HCV-related diseases, they showed a lower CC frequency than patients who spontaneously cleared HCV. Study results confirmed the model of persistent HCV infection as a risk factor for the pathogenesis of both liver and lymphoproliferative disorders.

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

Hepatitis C virus infection is closely related to lymphoproliferative disorders (LPDs), including mixed cryoglobulinemia (MC) and some lymphomas. Modification of the expression of specific microRNAs (miRNAs) has been associated with different autoimmune diseases and/or LPDs. No data exist about the modifications in miRNA expression in HCV-associated LPDs. The aim of this study was to analyze the expression levels of a panel of miRNAs previously associated with autoimmune/LPDs in a large population of HCV patients with and without MC or non-Hodgkin's lymphoma (NHL), to identify potential markers of evolution of HCV infection. PBMC expression of miR-Let-7d, miR-16, miR-21, miR-26b, miR-146a and miR-155 was evaluated by real-time PCR in 167 HCV patients (75 with MC [MC-HCV], 11 with HCV-associated NHL [NHL-HCV], 81 without LPD [HCV]) and in 35 healthy subjects (HS). A significant increase in miR-21 (p<0.001), miR-16 (p<0.01) and miR-155 (p<0.01) expression was detected in PBMCs from only NHL patients whereas a significant decrease in miR-26b was detected in both MC and NHL subjects (p<0.01) when compared to HS and HCV groups. A restoration of miR-26b levels was observed in the post-treatment PBMCs of 35 HCV-MC patients experiencing complete virological and clinical response following antiviral therapy. This study, for the first time, shows that specific microRNAs in PBMC from HCV patients who developed MC and/or NHL are modulated differently. The specific, reversible downregulation of miR-26b strongly suggests the key role it plays in the pathogenesis of HCV-related LPDs and its usefulness as a biomarker of the evolution of HCV infection to these disorders.

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.

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.

A phase II, single-arm multicenter study of low-dose rituximab for refractory mixed cryoglobulinemia secondary to hepatitis C virus infection.

Eradication of hepatitis C virus (HCV) by antiviral therapy is the treatment of choice for mixed cryoglobulinemia secondary to this infection, but many patients fail to achieve sustained viral responses and need second-line treatments. Several studies have demonstrated that the infusion of the anti-CD20 monoclonal antibody rituximab is highly effective for refractory mixed cryoglobulinemia, with a clinical response in approximately 80% of patients, although the relapse rate is high. Virtually all published studies employed a rituximab dosage of 375mg/m(2) given four times, a schedule used for treating non-Hodgkin's lymphomas. Based on a prior pilot study, we designed a phase II single-arm two-stage study (EUDRACT n. 2008-000086-38) to evaluate the efficacy of a lower dosage of rituximab, 250mg/m(2) given twice, for refractory mixed cryoglobulinemia. We present here the preliminary results in the first 27 patients enrolled. The overall response rate in 24 evaluable patients was 79%, and the mean time to relapse was 6.5months, similar to the 6.7months reported in studies with high-dose rituximab. Side effects were comparable to those seen in patients treated with high-dose. Increase of HCV viral load, reported in some high-dose studies, was not observed in our patients. Low-dose rituximab may provide a more cost/effective and possibly safer alternative for treating refractory HCV-associated mixed cryoglobulinemia.

Genetic determinants in hepatitis C virus-associated mixed cryoglobulinemia: role of polymorphic variants of BAFF promoter and Fcγ receptors.

OBJECTIVE: Mixed cryoglobulinemia (MC) is a hepatitis C virus (HCV)-related immune complex disorder. Only some HCV-infected patients develop MC, which suggests that the genetic background of the host plays a key role. This study was undertaken to evaluate the contribution of host genetic factors in the pathogenesis of HCV-associated MC (HCV-MC) by analyzing allelic variants of low-affinity Fcγ receptor (FcγR) genes and BAFF promoter. METHODS: FcγR polymorphisms (FCGR2A 131 R/H, FCGR2B 232 I/T, FCGR3A 176 V/F, and FCGR3B NA1/NA2) and BAFF promoter polymorphism -871 C/T were analyzed in 102 patients with HCV-MC and 108 patients with HCV without MC, using polymerase chain reaction-based techniques. RESULTS: A higher prevalence of -871 T/T homozygosity (31% versus 16%; P = 0.001) and a greater frequency of T alleles of the BAFF promoter (80% versus 57%; P = 0.004) were found in the HCV-MC group than in the HCV group. A significant increase in serum BAFF concentration was significantly associated with the higher frequency of the T allele in HCV-MC (mean ± SD 4.12 ± 1.29 versus 2.09 ± 0.81 ng/ml; P < 0.0005). The distribution of the FcγR genotypes was not significantly different. In the 21 HCV-MC patients treated with rituximab, the response was strictly related to F allele homozygosity (significantly reduced in 5 of 5 patients with the FCGR3A F/F genotype versus 4 of 16 with V/V or V/F; P < 0.0005). CONCLUSION: These results indicate the importance of host genetic background in the development of HCV-MC, suggesting that mechanisms enhancing Ig production and B cell survival may play a relevant role. Genetic FcγR variants seem to be crucial to the effectiveness of rituximab therapy.

HBV and HCV chronic infection: autoimmune manifestations and lymphoproliferation.

Hepatitis B (HBV) and C (HCV) viruses differ both in viral structure and in natural history of chronic infection. However, they seem to share, although to a different extent, some characteristics, like the possibility to infect not only hepatic but also lymphatic cells and to associate with some hepatic and/or extrahepatic disorders of an autoimmune and/or lymphoproliferative nature. These characteristics have been more widely studied in the case of chronic HCV infection, where they are more evident, but they have been described also in the case of HBV infection.