Extrahepatic manifestations associated with Chronic Hepatitis C Virus Infection

Chronic hepatitis C virus (HCV) infection has been associated with both organ-specific and systemic autoimmune diseases, with cryoglobulinemia being the most frequent associated disease. Experimental, virologic, and clinical evidence have demon-strated a close association between HCV infection and some systemic autoimmune diseases, especially Sjögren's syndrome, but also rheumatoid arthritis and lupus. A higher prevalence of hematological processes has also been described in patients with HCV infection, including cytopenias and lymphoproliferative disorders (B-cell lymphoma). In addition, patients with chronic HCV infection have a higher frequency of other extrahepatic manifestations including endocrine, metabolic and cardiovascular disorders that may worse the prognosis of patients, along with neuropsychiatric manifestations and general symptoms that have a significant influence on the quality of life of the patient. Direct-acting antiviral therapies (DAAs) that have recently begun to be used are providing the opportunity to effectively cure chronic HCV infection and reduce the burden of both hepatic and extrahepatic complications

Pathophysiology of HCV-Related cryoglobulinemic vasculitis: molecular, immunological and clinical analysis

ABSTRACT INTRODUZIONE: L’infezione da virus dell’epatite C (HCV) rappresenta la principale causa di malattia cronica del fegato, che può evolvere in cirrosi e carcinoma epatocellulare (HCC). L’infezione cronica da HCV è inoltre caratterizzata dall’insorgenza di diverse manifestazioni extraepatiche, la più comune delle quali è la crioglobulinemia mista (MC). Si tratta di una vasculite mediata da immunocomplessi che coinvolge vasi sanguigni di piccolo calibro, caratterizzata da una proliferazione B-cellulare con possibile evoluzione in linfoma non-Hodgkin a cellule B. Il caratteristico tropismo dell’HCV per il tessuto linfoide è stato ampiamente dimostrato. La persistenza dell’HCV può rappresentare uno stimolo continuo per il sistema immunitario dell’ospite. Questo potrebbe sostenere proliferazioni oligo/monoclonali B-cellulari con l’espansione di un singolo clone dominante da cui deriva, ad esempio, la sintesi di IgM monoclonali con attività di fattore reumatoide nella crioglobulinemia mista. D’altro canto, la proliferazione linfocitaria può essere promossa in maniera diretta dall’infezione e dalla replicazione dell’HCV all’interno delle cellule B. Su queste basi, l’approccio terapeutico della MC HCV-associata è attualmente basato sulla terapia antivirale, in presenza o assenza di deplezione B-cellulare con rituximab. Tra i fattori dell’ospite che influenzano la risposta virologica ai regimi terapeutici antivirali basati sull’uso di interferone-α peghilato e ribavirina, i polimorfismi del gene dell’IL28B sono stati identificati mediante studi di associazione genomewide come fattori predittivi attendibili dell’esito della terapia antivirale. Lo scopo dello studio consiste nella valutazione della possibile associazione tra i polimorfismi del singolo nucleotide (SNPs) rs12979860/ rs8099917 a livello del gene IL28B e la risposta terapeutica in pazienti con MC HCV-correlata. È stata anche considerata la possibile associazione dei polimorfismi con le manifestazioni cliniche specifiche della MC nonché il loro possibile ruolo nella valutazione della risposta completa (intesa come virologica, molecolare ed immunologica) alla terapia. METODI: Sono stati reclutati 159 pazienti infetti da HCV con MC e 172 pazienti infetti da HCV senza MC, trattati con terapia antivirale basata su interferone-α peghilato e ribavirina. È stata effettuata la genotipizzazione degli SNPs rs12979860/ rs8099917 in tutti i pazienti. In 106 (66.6%) pazienti affetti da crioglobulinemia mista è stato determinato il profilo clonale delle cellule B circolanti. RISULTATI: Il genotipo T/T IL28B rs12979860 è risultato più frequente nei pazienti con MC piuttosto che nei pazienti senza MC (17% vs 8.1%, p=0.02). Il genotipo C/C è risultato associato con un maggior tasso di risposte complete alla terapia (52.6% vs 39.2%, p=0.13). È stata inoltre riscontrata una maggior frequenza di espansioni clonali B-cellulari in circolo (84.2% vs 55.9%, p=0.005), coinvolgimento renale (21% vs 2.9%, p=0.003) e linfomi non-Hodgkin a cellule B (17.5% vs 6.8%, p=0.048). L’analisi del polimorfismo rs8099917 ha fornito risultati sostanzialmente sovrapponibili. CONCLUSIONI: Nei pazienti HCV-positivi affetti da MC, il genotipo C/C rs12979860 del gene IL28B è caratterizzato biologicamente da una maggior frequenza di restrizione clonale nella risposta B-cellulare e clinicamente da un maggior rischio di nefropatia crioglobulinemica e neoplasie B-cellulari; è, inoltre, un fattore predittivo indipendente di risposta virologica sostenuta alla terapia antivirale. Nei pazienti con vasculite crioglobulinemica si è riscontrato una maggior prevalenza della variante T/T rs12979860 del gene IL28B. ABSTRACT INTRODUCTION: Hepatitis C virus (HCV) infection represents the leading cause of chronic liver damage evolving into cirrhosis and hepatocellular carcinoma (HCC). HCV chronic infection is also characterized by the emergence of several extrahepatic manifestations, the most common of which is represented by mixed cryoglobulinemia (MC). It is an immune complex-mediated vasculitis involving small vessels, characterized by an underlying B cell proliferation with potential evolution into B-cell non- Hodgkin lymphoma. The peculiar tropism of HCV for the lymphoid tissue has been clearly demonstrated. HCV persistence could represent a continuous stimulus to host immune system. It should lead to B cells oligo/monoclonal expansions with the emergence of a single dominant clone whose expression may be represented by monoclonal IgM RF production in MC. On the other hand, lymphocyte proliferation may be promoted by HCV direct infection and replication into B cells. On these bases the therapeutic approach of HCV-associated MC is currently based on antiviral therapy with or without B-cell depletion with rituximab. Among host factors influencing virological response to pegylated interferon- ibavirin-based antiviral therapeutic regimens, IL28B gene polymorphisms have been identified by genome wide association studies, as highly reliable predictors of the outcome after antiviral therapy. Aim of the study was to assess the possible association between IL28B single nucleotide polymorphism (SNPs) rs12979860/ rs8099917 and therapeutic response in patients with HCV-related MC. We also searched for their association with peculiar clinical manifestations of MC and the potential influence on the complete response (virological, molecular, and immunological) to the therapy. METHODS: Study cohort included 159 and 172 HCV infected patients with or without MC treated with pegylated interferon- -based antiviral therapy. We performed SNP rs12979860/ rs8099917 genotyping in all patients. In 106 (66.6%) patients with MC, the profile of circulating B cell clonalities was determined. RESULTS: The T/T IL-28B rs12979860 was more common in patients with MC than in those without (17% vs 8.1%, p = 0.02). C/C genotype was associated with a higher rate of complete response (52.6% vs 39.2%, p = 0.13). A higher frequency of expanded B cell clonalities in the circulation (84.2% vs 55.9%; p = 0.005), kidney involvement (21% vs 2.9%; p = 0.003), and B cell non-Hodgkin lymphoma (17.5% vs 6.8%; p = 0.048) were also observed. No additional results derived from the analysis of IL28B rs8099917 polymorphisms. CONCLUSIONS: In HCV-positive patients with MC, the IL-28B rs12979860 C/C genotype is distinguished biologically by a higher frequency of restriction of B cell response and clinically by a higher risk of cryoglobulinemic nephropathy and B cell malignancies, while acting as an independent predictor of a sustained virological response to antiviral therapy. In addition, we found that IL-28B rs12979860 T/T variant was more prevalent in patients with CV than in those without

Hepatitis C Virus Infection and Mixed Cryoglobulinemia

Hepatitis C virus (HCV) chronic infection is recognized as the major cause of mixed cryoglobulinemia (MC). Its persistence represents a continuous stimulus for host immune system with production of circulating immune complexes (ICs), one-third of them with cryoprecipitate property. Several factors contribute to the biological activities of ICs, many of which are not completely known. Among them, complement factors play a crucial role in the cold-insoluble ICs-mediated vasculitis, involving primarily small blood vessels in different tissues including skin, kidney, peripheral, and central nervous system. Liver represents the major target of HCV infection with inflammatory infiltrates, resembling secondary lymphoid follicles. Cytokine like CXCL13 contribute to B-cell homing in intraportal lymphoid aggregates, in which B-cell clonal selection may arise. B-cell clonal expansion starts as an antigen-driven event and expands towards indolent and malignant B-cell proliferation. Occurrence of intrahepatic B-cell clonalities correlates with extrahepatic clinical manifestations of HCV infection. In this context, cryoglobulinemic patients should be considered a peculiar HCV-infected population that needs a clinical multidisciplinary approach and more articulated therapeutic measures

Molecular signatures of hepatitis C virus (HCV)-induced type II mixed cryoglobulinemia (MCII)

The role of hepatitis C virus (HCV) infection in the induction of type II mixed cryoglobulinemia (MCII) and the possible establishment of related lymphoproliferative disorders, such as B-cell non-Hodgkin lymphoma (B-NHL), is well ascertained. However, the molecular pathways involved and the factors predisposing to the development of these HCV-related extrahepatic complications deserve further consideration and clarification. To date, several host- and virus-related factors have been implicated in the progression to MCII, such as the virus-induced expansion of selected subsets of B-cell clones expressing discrete immunoglobulin variable (IgV) gene subfamilies, the involvement of complement factors and the specific role of some HCV proteins. In this review, we will analyze the host and viral factors taking part in the development of MCII in order to give a general outlook of the molecular mechanisms implicated

Crioglobulinemia: Relação entre hepatite C e glomerulonefrite

A Hepatite C é um problema de saúde mundial. Uma associação entre infecção pelo vírus da hepatite C (HCV) e crioglobulinemia mista com doença renal tem sido descrita, sendo a glomerulonefrite membranopoliferativa (GNMP) tipo I o acometimento renal mais comum. A GNMP é frequentemente associada com a crioglobulinemia mista tipo II. Esse relato de caso objetiva descrever fatores clínicos dos pacientes com crioglobulinemia mista, a qual é uma manifestação extra-hepática da infecção por HCV, assim como discutir a sua fisiopatologia e tratamento, baseado no relato de caso.Palavras-chave: Crioglobulinemia; hepatite C; hepatite C crônica, glomerulonefrite; glomerulonefrite membranoproliferativaA Hepatite C é um problema de saúde mundial. Uma associação entre infecção pelo vírus da hepatite C (HCV) e crioglobulinemia mista com doença renal tem sido descrita, sendo a glomerulonefrite membranopoliferativa (GNMP) tipo I o acometimento renal mais comum. A GNMP é frequentemente associada com a crioglobulinemia mista tipo II. Esse relato de caso objetiva descrever fatores clínicos dos pacientes com crioglobulinemia mista, a qual é uma manifestação extra-hepática da infecção por HCV, assim como discutir a sua fisiopatologia e tratamento, baseado no relato de caso.Palavras-chave: Crioglobulinemia; Hepatite C; Hepatite C crônica, Glomerulonefrite; Glomerulonefrite membranoproliferativa

Immune signatures in human PBMCs of idiotypic vaccine for HCV-related lymphoproliferative disorders

Hepatitis C virus (HCV) is one of the major risk factors for chronic hepatitis, which may progress to cirrhosis and hepatocellular carcinoma, as well as for type II mixed cryoglobulinemia (MC), which may further evolve into an overt B-cell non-Hodgkin's lymphoma (NHL)

Reversion of anergy signatures in clonal CD21low B cells of mixed cryoglobulinemia patients after clearance of HCV viremia with direct-acting antivirals

Introduction Type II Mixed cryoglobulinemia (MC) is an autoimmune and benign lymphoproliferative disorder caused by Hepatitis C virus (HCV) and characterized by the expansion of monoclonal CD27+ IgM+ B cells producing a rheumatoid factor often encoded by the VH1-69 and VK3-20 genes. These cells display peculiar phenotypic and functional features: in particular, they commonly express low levels of CD21 (CD21low B cells), an array of inhibitory and apoptosis-related genes and a distinctive pattern of homing receptors, fail to proliferate in response to the stimulation of BCR or of TLR9 and, similarly to murine B cells made anergic by continual antigenic stimulation, overexpress pERK and are prone to apoptosis. Usually MC regresses after eradication of HCV with interferon (IFN), whose immunomodulatory activity might contribute to this effect; the newly available direct-acting antivirals (DAAs) rapidly suppress HCV viremia in HCV+MC patients and lack the immunomodulatory properties of IFN. Aim To investigate phenotypic and functional changes in clonal B cells of MC patients with sustained virologic response to DAAs, untangling the effects of BCR disengagement in a human model of virus-driven anergy and exhaustion. Results In patients treated with DAA, B cell phenotype, constitutive and BCR-induced ERK signaling, spontaneous apoptosis and cell proliferation were analyzed before and after HCV eradication, using healthy donors as control. Immunophenotyping studies were performed with combinations of fluorochrome-labeled monoclonal antibodies, using the VH1-69-specific G6 mAb (which recognize an epitope of the VH1-69-encoded protein) to identify VH1-69+ B cells; spontaneous apoptosis was assessed by staining cells with annexin V and 7- aminoactinomycin D; the intracellular pERK content was measured by the BD PhosFlow system and represented as pERK-specific Mean Fluorescence Intensity (MFI); finally, cell proliferation was evaluated at day 5 of in vitro culture by the carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution assay. All these experiments have been done by flow cytometry. Phenotypic and functional analyses in untreated patients were in agreement with previous data showing an anergic status and an exhausted behavior of VH1-69+ CD21low B cells. After treatment with DAA, when all patients were negative for HCV RNA, it was observed a slow reduction of VH1-69+ CD21low B cells in peripheral blood; moreover, these cells showed a significantly reduced constitutive ERK phosphorylation and a significative decrease in spontaneous apoptosis after eradication of the virus. To investigate whether reduced lifespan was related to ERK signaling, MC B cells were treated with the MEK/ERK inhibitor U0126; no effect on spontaneous in vitro apoptosis was observed, suggesting that ERK signaling is not directly involved in the pro-apoptotic pathway of these cells. Despite phenotypic changes, clonal B cells failed to restore their capacity to proliferate in response to TLR9 stimulation. Conclusions Clonal B cells of HCV+MC display signatures of anergy induced by continual BCR occupancy and of exhaustion driven by chronic viral infection. Anergy features (pERK overexpression and accelerated apoptosis) rapidly revert after disengagement from HCV; phenotypic and functional features of exhaustion persist for several months. The rapid clearance of HCV viremia with DAAs offers a unique model for untangling the interplay of virus-driven anergy and exhaustion in human B cells