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

Mixed cryoglobulinemia (MC), is a HCV-related, clinically benign, lymphoproliferative disorder (LPD) that may evolve into a non Hodgkin's lymphoma (NHL). Significant associations were found between two single nucleotide polymorphisms near NOTCH4 (rs2071286) and the HLA class II (rs9461776) genes and HCV-related MC syndrome (MCS). We analyzed NOTCH4 rs2071286 and HLA-II rs9461776 in 3 HCV-related LPD groups (asymptomatic MC, MCS, NHL) with HCV infection without lymphoproliferative disorders. We found a positive relationship between NOTCH4 rs207186 T minor allele frequency (MAF) and patients with HCV-related LPDs at risk of NHL (Chi-square test for trend = 14.84 p = 0.0001), in accordance with an over-dominant model in the NHL group (CT vs CC + TT, OR=1.88, 95% CI 1.24-2.83, p = 0.0026). Regarding HLA II rs9461776, G MAF increased in patients with HCV-related LPDs at risk of NHL (Chi-square test for trend = 8.40 p = 0.0038), in accordance with a recessive genotypic model in the NHL group (G/G vs A/A + A/G, OR = 11.07, 95% CI 2.37-51.64, p = 0.0022). Both NOTCH4 rs2071286 and HLA-II rs9461776 were present on chromosome 6 and showed D' and r values of linkage disequilibrium (LD) of about 0.5 values, thereby suggesting there is no extensive LD in the HCV+ population. This data shows that the previously demonstrated association between NOTCH4 rs2071286 and HLA-II rs9461776 polymorphisms and HCV-related MCS could be extended to overall patients with HCV-related LPDs. The significant relationship between rs2071286 and rs9461776 MAF and the increased risk for NHL, suggests their use as non-invasive markers to categorize patients at risk of lymphoma.

IgG3 subclass: A possible trigger of mixed cryoglobulin cascade in hepatitis C virus chronic infection.

HCV is a hepatotropic and lymphotropic virus and is the most frequent cause of "benign" mono-oligoclonal B-lymphocyte proliferation, observed in mixed cryoglobulinemia (MC). The study aims to investigate the presence, prevalence and characteristics of the subclasses of cryoglobulins in HCV-patients to look for a relationship with MC. Fifty HCV-infected patients with cryoglobulins were enrolled. IgG subclasses were characterized in cryoprecipitate, and serum IgG and IgM Rheumatoid Factor (RF) were determined. Patients were stratified into two subgroups according to the presence of IgG3 subclass. Differences were observed in supernatant IgM, IgG3-positive and IgG3-negative patients with a higher IgM concentration in the IgG3-negative cohort (p=0.03). Higher IgM-RF was detected in the IgG3-negative group (p=0.01). IgG3-positive group showed higher IgG-RF compared to the IgG3-negative group (p<0.0001). IgG3-negative/monoclonal-IgM patients had higher cryocrit compared to IgG3-negative/polyclonal-IgM patients (p<0.01). C4 levels were higher in the polyclonal-IgM group compared to monoclonal-IgM group (p<0.01). We speculate that cryoglobulins are part of a progressive clonal selection process in which, B-cells are stimulated to produce oligoclonal IgG3 with RF activity. The persistence of the antigenic stimulus elicits the production of polyclonal IgM-RF and subsequently the formation of oligoclonal IgG/polyclonal IgM containing cryoglobulins. In the last stage, a monoclonal IgM-RF clone is formed which may coexist with a monoclonal IgG3-RF clone.

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.

Prospective study of guideline-tailored therapy with direct-acting antivirals for hepatitis C virus-associated mixed cryoglobulinemia.

Hepatitis C virus (HCV)-associated mixed cryoglobulinemia (MC) vasculitis commonly regresses upon virus eradication, but conventional therapy with pegylated interferon and ribavirin yields approximately 40% sustained virologic responses (SVR). We prospectively evaluated the efficacy and safety of sofosbuvir-based direct-acting antiviral therapy, individually tailored according to the latest guidelines, in a cohort of 44 consecutive patients with HCV-associated MC. In two patients MC had evolved into an indolent lymphoma with monoclonal B-cell lymphocytosis. All patients had negative HCV viremia at week 12 (SVR12) and at week 24 (SVR24) posttreatment, at which time all had a clinical response of vasculitis. The mean (±standard deviation) Birmingham Vasculitis Activity Score decreased from 5.41 (±3.53) at baseline to 2.35 (±2.25) (P < 0.001) at week 4 on treatment to 1.39 (±1.48) (P < 0.001) at SVR12 and to 1.27 (±1.68) (P < 0.001) at SVR24. The mean cryocrit value fell from 7.2 (±15.4)% at baseline to 2.9 (±7.4)% (P < 0.01) at SVR12 and to 1.8 (±5.1)% (P < 0.001) at SVR24. Intriguingly, in the 2 patients with MC and lymphoma there was a partial clinical response of vasculitis and ∼50% decrease of cryocrit, although none experienced a significant decrease of monoclonal B-cell lymphocytosis. Adverse events occurred in 59% of patients and were generally mild, with the exception of 1 patient with ribavirin-related anemia requiring blood transfusion. CONCLUSION: Interferon-free, guideline-tailored therapy with direct-acting antivirals is highly effective and safe for HCV-associated MC patients; the overall 100% rate of clinical response of vasculitis, on an intention-to-treat basis, opens the perspective for curing the large majority of these so far difficult-to-treat patients. (Hepatology 2016;64:1473-1482).

Autoimmunity and lymphoproliferation markers in naïve HCV-RNA positive patients without clinical evidences of autoimmune/lymphoproliferative disorders.

BACKGROUND: HCV can lead to both chronic liver disease and B-cell lymphoproliferative disorders. A strong association exists between HCV and mixed cryoglobulinaemia (MC). METHODS: Anti-nuclear antibodies (ANA), rheumatoid factor Ig-G (RF-IgG), free light chain κ and λ (FLC-κ, FLC-λ) levels and κ/λ ratio were evaluated in 50/420 subjects unexpectedly resulted anti-HCV positive after routine screenings for non-hepathological procedures. RESULTS: Three/fifty patients had HCV-RNA undetectable in the serum and were excluded from the analysis. Thirty-nine/fifty patients had laboratory evidence of circulating cryoglobulins without liver disease and MC-related symptoms. Among them, 17 resulted ANA-positive. The mean cryocrit was higher in ANA-positive patients, while no other demographic/clinical differences were observed between the groups. Significantly higher levels of RF-IgG were observed in ANA-positive vs ANA-negative patients. κ and λ FLC were higher in ANA-positive patients. A ROC analysis, based on ANA-positivity vs ANA-negativity, confirmed a high sensitivity and specificity of RF-IgG test. CONCLUSIONS: Published data concerning MC come mostly from symptomatic vasculitis. We analyzed HCV-patients without MC symptoms, founding cryoglobulins in the majority of them. The increased levels of FR-IgG and FLC in CGs-ANA-positive patients, suggest these test could be used to identify a state of silent autoimmune and/or lymphoproliferative condition before the transition to a frank disease in naïve HCV-patients without symptoms of extrahepatic manifestations.

HCV-related liver and lymphoproliferative diseases: association with polymorphisms of IL28B and TLR2.

To explore the relationship between innate immunity and hepatitis C Virus (HCV) in determining the risk of cirrhosis (CIR), hepatocellular carcinoma (HCC), mixed cryoglobulinemia syndrome (MCS) and non-Hodgkin lymphoma (NHL), we investigated the impact of the toll-like receptor-2 (TLR2) and interleukin-28B (IL28B) genetic variants. TLR2 -174 del variant was associated with TLR2 expression and with specific downstream molecules that drive the expression of different interleukins; rs12979860 Il28B was important in response to interferon-treatment and in spontaneous clearance of HCV. The risk for liver and lymphoproliferative diseases in HCV progression was clarified by stratifying 862 HCV-positive patients into groups based on liver (CIR, HCC) and lymphoproliferative HCV-related diseases (MCS, NHL) and compared with chronic HCV (CHC) infection. Analysis of TLR2-IL28B haplotypes showed an association of wild type haplotype with the lymphoproliferative diseases (OR 1.77, p = 0.029) and a slight increase in HCV viral load (HR 1.38, p = 0.054). Wild type haplotype (TLR2 ins/ins- IL28B C/C) was also found associated with older age in patients with an hepatic diseases (in CIR and in HCC p = 0.038 and p = 0.020, respectively) supporting an effect of innate immunity in the liver disease progression. TLR2 and IL28B polymorphisms in combination showed a role in the control of HCV viral load and different HCV disease progression.

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.

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.

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.

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.

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.

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.

Interferon lambda 3 rs12979860 polymorphism in patients with haemophilia and HCV infection: a predictor of spontaneous viral clearance and sustained virological response.

Chronic hepatitis C is the main cause of morbidity and mortality in adult haemophilic patients who received non-virally inactivated plasma-derived clotting factor concentrates. Overall, spontaneous viral clearance rate is 10-25% and the only approach that can halt disease progression is hepatitis C virus (HCV) eradication by means of antiviral therapy. In non-haemophilic patients a single nucleotide polymorphism located upstream the gene of interferon lambda 3 (IFNλ3) has been associated with both spontaneous viral clearance and sustained virological response after antiviral treatment. The aim of this study was to assess whether the rs12979860 polymorphism was a predictor of spontaneous viral clearance and of sustained virological response after antiviral therapy in a large cohort of haemophilic patients with HCV infection. The rs12979860 polymorphism, defined as CC genotype or T allele, was tested in a cohort of 342 haemophilic patients and evaluated as predictor of spontaneous clearance or response to antiviral therapy. By multivariate regression analysis the IFNλ3 CC genotype was an independent predictor of spontaneous viral clearance (odds ratio: 3.7, 95% confidence interval: 2.0-6.8). Sustained virological response rates were doubled in patients with the CC genotype than in those with the T allele (78% vs 44%; p<0.001), especially in patients with HCV type 1 (67% vs 32%; p<0.001) and higher sustained response rates were observed in patients with the CC genotype who did not achieve rapid virological response (61% vs 30% in T allele patients; p=0.006).

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.

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.

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.