Domenico Sansonno

Summary: Immunoglobulin variable region heavy chain (IgVH) somatic gene diversification is instrumental in the transformation process that characterizes hepatitis C virus (HCV)-related B cell lymphoproliferative disorders. However, the extent to which activation-induced cytidine deaminase (AID), an enzyme essential for IgV gene somatic hypermutation (SHM), is active in cryoglobulinaemic vasculitis (CV) remains unclear. AID mRNA expression in the peripheral blood of 102 chronically hepatitis C virus (HCV)-infected patients (58 with and 44 without CV) and 26 healthy subjects was investigated using real-time reverse transcription–polymerase chain reaction (RT–PCR). The features of activation-induced cytidine deaminase (AID) protein and mRNA transcripts were explored in liver tissue biopsies and portal tracts isolated using laser capture microdissection. In chronically HCV-infected patients, AID mRNA expression was almost threefold higher in those with than in those without CV and sevenfold higher than in healthy subjects (median-fold: 6·68 versus 2·54, P = 0·03 and versus 0·95, P = 0·0003). AID transcript levels were significantly higher in polyclonal than in clonally restricted B cell preparations in either CV or non-CV patients (median-fold, 15·0 versus 2·70, P = 0·009 and 3·46 versus 1·58, P = 0·02, respectively). AID gene expression was found to be related negatively to age and virological parameters. AID protein was found in portal tracts containing inflammatory cells that, in several instances, expressed AID mRNA transcripts. Our data indicate that the aberrant expression of AID may reflect continuous B cell activation and sustained survival signals in HCV-related CV patients.

[This corrects the article DOI: 10.1371/journal.pone.0117420.].

Introduction: Hepatitis C virus (HCV) infection can be detected in virtually all patients with cryoglobulinemic vasculitis (CV). Among its many effects, the virus is able to stimulate the production of thymic stromal lymphopoietin (TSLP) by infected hepatocytes. In this study, we assessed the systemic levels and tissue distribution of TSLP in 60 chronically HCV-infected patients, 36 with and 24 without CV. Methods: Serum TSLP levels were measured by an enzyme-linked immunosorbent assay (ELISA) method. TSLP mRNA was assessed in patient samples by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). TSLP protein in liver and skin biopsy samples was revealed by indirect immunofluorescence. All other methods were carried out according to standardized procedures. Results: Serum TSLP levels were significantly higher in patients with than in those without CV and in healthy individuals. Higher TSLP levels paralleled specific mRNA expression and the up-regulation of TSLP protein in liver tissue. Compared with non-CV patients, higher TSLP levels in CV were accompanied by a higher frequency of circulating mono/oligoclonal B-cell expansions (8% vs. 92%, p < 0.0001) and a higher number of peripheral CD20⁺ B-cells (10.3% vs. 15.5% p = 0.04). In addition, TSLP mRNA expression in the liver of CV patients was lower than in their correspondent skin tissue and paralleled specific immune deposits of TSLP protein in keratinocytes. Conclusion: Overall, this study shows that TSLP secreted by hepatocytes and keratinocytes of HCV-infected patients with CV is involved in the pathogenesis of vasculitis and may possibly support the therapeutic use of TSLP-targeted monoclonal antibodies.

The variability in the association of host innate immune response to Hepatitis C virus (HCV) infection requires ruling out the possible role of host KIR and HLA genotypes in HCV-related disorders: therefore, we therefore explored the relationships between KIR/HLA genotypes and chronic HCV infection (CHC) as they relate to the risk of HCV-related hepatocarcinoma (HCC) or lymphoproliferative disease progression. We analyzed data from 396 HCV-positive patients with CHC (n = 125), HCC (118), and lymphoproliferative diseases (153), and 501 HCV-negative patients. All were HIV and HBV negative. KIR-SSO was used to determine the KIR typing. KIR2DL5 and KIR2DS4 variants were performed using PCR and GeneScan analysis. HLA/class-I genotyping was performed using PCR-sequence-based typing. The interaction between the KIR gene and ligand HLA molecules was investigated. Differences in frequencies were estimated using Fisher’s exact test, and Cochran-Armitage trend test. The non-random association of KIR alleles was estimated using the linkage disequilibrium test. We found an association of KIR2DS2/KIR2DL2 genes, with the HCV-related lymphoproliferative disorders. Furthermore, individuals with a HLA-Bw6 KIR3DL1+ combination of genes showed higher risk of developing lymphoma than cryoglobulinemia. KIR2DS3 gene was found to be the principal gene associated with chronic HCV infection, while a reduction of HLA-Bw4 + KIR3DS1+ was associated with an increased risk of developing HCC. Our data highlight a role of the innate-system in developing HCV-related disorders and specifically KIR2DS3 and KIR2D genes demonstrated an ability to direct HCV disease progression, and mainly towards lymphoproliferative disorders. Moreover the determination of KIR3D/HLA combination of genes direct the HCV progression towards a lymphoma rather than an hepatic disease. In this contest IFN-α therapy, a standard therapy for HCV-infection and lymphoproliferative diseases, known to be able to transiently enhance the cytotoxicity of NK-cells support the role of NK cells to counterstain HCV-related and lymphoproliferative diseases.

Objective. The aim of this study was to validate the classification criteria for cryoglobulinaemic vasculitis (CV). Methods. Twenty-three centres were involved. New patients with CV (group A) and controls, i.e. subjects with serum cryoglobulins but lacking CV based on the gold standard of clinical judgment (group B) and subjects without cryoglobulins but with clinical features that can be observed in the course of CV (group C), were studied. Positivity of serum cryoglobulins was necessary for CV classification. Sensitivity and specificity of the criteria were calculated by comparing group A vs group B. The group A vs group C comparison was done to demonstrate the possible diagnostic utility of the criteria. Results. The study included 268 patients in group A, 182 controls in group B and 193 controls in group C (small vessel vasculitis, 51.8%). The questionnaire (at least 2/3 positive answers) showed 89.0% sensitivity and 93.4% specificity; the clinical item (at least 3/4 clinical involvement) showed 75.7% sensitivity and 89.0% specificity and the laboratory item (at least 2/3 laboratory data) showed 80.2% sensitivity and 62.4% specificity. The sensitivity and specificity of the classification criteria (at least 2/3 positive items) were 89.9% and 93.5%, respectively. The comparison of group A with group C demonstrated the clinical utility of the criteria in differentiating CV from CV mimickers. Conclusion. Classification criteria for CV were validated in a second, large, international study confirming good sensitivity and specificity in a complex systemic disease.

Introduction: In hepatitis C virus (HCV)-related mixed cryoglobulinemia (MCG), the nonenveloped HCV core protein (HCV-Cp) is a constituent of the characteristic cold-precipitating immune complexes (ICs). A possible correlation between HCV-Cp, virologic, laboratory, and clinical parameters in both untreated MCG patients and those undergoing specific treatment was explored. Methods: HCV-Cp was quantified by a fully automated immune assay. Correlations between HCV-Cp and HCV RNA, cryocrit, and virus genotype (gt) were investigated in 102 chronically HCV-infected MCG patients. Results: HCV-Cp concentrations strongly correlated with HCV RNA levels in baseline samples. An average ratio of 1,425 IU and 12,850 IU HCV RNA per picogram HCV-Cp was estimated in HCV gt-1 and gt-2 patients, respectively. This equation allowed us to estimate that, on average, HCV-Cp was associated with the viral genome in only 3.4% of the former and in 35% of the latter group of patients. The direct relation between HCV-Cp and the cryocrit level suggests that the protein directly influences the amount of cryoprecipitate. Although the therapy with rituximab (RTX) as a single agent resulted in the enhancement of HCV-Cp levels, in patients treated with RTX in combination with a specific antiviral therapy (pegylated interferon-α plus ribavirin), the prompt and effective clearance of HCV-Cp was documented. Conclusions: Our data provide evidence that HCV-Cp has a direct effect on the cold-precipitation process in a virus genotype-dependence in HCV-related MCG patients.

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.

Objective.: Single-nucleotide polymorphisms (SNP) in the interleukin 28B (IL-28B) gene region are strongly predictive of the response of infected patients to antiviral therapy for hepatitis C virus (HCV). We sought to determine the prevalence of SNP IL-28B rs12979860 C/C and non-C/C (C/T plus T/T) genotypes in HCV-related cryoglobulinemic vasculitis (CV), as compared with HCV-positive patients without CV. We also searched for their association with peculiar clinical manifestations of CV and potential influence on the complete response (virological, molecular, and immunological) to the therapy. Methods.: The study cohort comprised 159 and 172 HCV-infected patients with and without CV, respectively, prospectively followed starting from 1990. SNP rs12979860 genotyping was performed by Taq-Man allelic discrimination. In 106 patients (66.6%) with CV, the profile of circulating B cell clonalities was determined as well. All patients with CV were treated with pegylated interferon-α/ribavirin-based antiviral therapy. Results.: The T/T IL-28B genotype was more common in patients with CV than in those without (17% vs 8.1%, p = 0.02). In patients with CV, compared with non-C/C variants, the IL-28B C/C genotype was associated with a higher rate of complete response (52.6% vs 39.2%, p = 0.13), whereas a treatment response of 61.4% was demonstrated when solely virological response was considered (p = 0.008). 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. Conclusion.: In HCV-positive patients with CV, the IL-28B 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 T/T variant was more prevalent in patients with CV than in those without.

Cryoglobulins are present in about a quarter of patients with hepatitis C; in some, cryoglobulinemia can become symptomatic or even life-threatening. This review summarizes evolving therapy for the disorder, including new therapeutic options that are becoming available.