Pietro Gatti

Pegylated interferon-α, ribavirin, and rituximab combined therapy of hepatitis C virus–related mixed cryoglobulinemia: a long-term study

This study illustrates the use and efficacy of a combination of pegylated interferon-alpha (Peg-IFN-alpha) and ribavirin (RBV), with or without rituximab (RTX), in hepatitis C virus (HCV)-related mixed cryoglobulinemia (MC). Twenty-two patients with HCV-related MC received Peg-IFN-alpha (2a: 180 mug or 2b: 1.5 mug/kg) weekly plus RBV (1000 or 1200 mg) daily for 48 weeks, and RTX (375 mg/m(2)) once a week for 1 month followed by two 5-monthly infusions (termed PIRR). Fifteen additional patients received Peg-IFN-alpha/RBV with the same modalities as the PIRR schedule. Complete response was achieved in 54.5% (12/22) and in 33.3% (5/15) of patients who received PIRR and Peg-IFN-alpha/RBV, respectively (P < .05). Clearance of HCV RNA and conversion of B-cell populations from oligoclonal to polyclonal in liver, bone marrow, and peripheral blood was maintained for up to 3 years in 10 of 12 (83.3%) and in 2 of 5 (40%) patients receiving PIRR and Peg-IFN-alpha/RBV, respectively (P < .01). Cryoproteins in 22.7% (5/22) of patients with PIRR and in 33.3% (5/15) with Peg-IFN-alpha/RBV persisted despite sustained HCV RNA clearance. No response occurred in remaining 5 patients of both groups. PIRR therapy is well tolerated and more effective than Peg-IFN-alpha/RBV combination in HCV-related MC. Its effect may last for more than 3 years.

Intrahepatic B cell clonal expansions and extrahepatic manifestations of chronic HCV infection

B cell repertoire in three biological compartments (liver, bone marrow and peripheral blood) of 30 unselected patients chronically infected with HCV has been characterized. Restriction of humoral immune response defined by enrichment of B cell clonal expansions occurred in the liver of 15 patients (50%), in the bone marrow and peripheral blood of 2 (6.7%) and 8 (26.7%) patients, respectively. An in situ hybridization technique was developed for the detection of dominant B cell clones in patients with monoclonal expansions. It was shown that morphologically distinct B cell expansion contributes to the formation of intraportal follicle‐like structures. Sequence analyses of CDRH3 gene segments revealed a wide range of variations. Clones derived from the same founder were demonstrated simultaneously in the three compartments explored. The occurrence of B cell clonal expansions profoundly influenced the clinical expression of HCV infection, since it was associated with extrahepatic manifestations. In sharp contrast, no extrahepatic signs or disease occurred in patients without evidence of intrahepatic B cell clonalities. These findings emphasize the profound B cell function derangement in at least half of HCV‐infected patients. Thus, the restriction of V gene usage has a direct impact on the clinical spectrum of HCV infection.

Non-enveloped HCV core protein as constitutive antigen of cold-precipitable immune complexes in type II mixed cryoglobulinaemia

Hepatitis C virus (HCV) infection has been detected in a large proportion of patients with mixed cryoglobulinaemia (MC). Circulating ‘free’ non‐enveloped HCV core protein has been demonstrated in HCV‐infected patients, and this suggests its possible involvement in the formation of cryoprecipitable immune complexes (ICs). Thirty‐two anti‐HCV, HCV RNA‐positive patients with type II MC were evaluated. Non‐enveloped HCV core protein, HCV RNA sequences, total IgM, rheumatoid factor (RF) activity, IgG and IgG subclasses, C3 and C4 fractions, C1q protein and C1q binding activity were assessed in both cryoprecipitates and supernatants. Non‐enveloped HCV core protein was demonstrated in 30 of 32 (93·7%) type II MC patients. After separation of cold‐precipitable material, the protein was removed completely from supernatant in 12 patients (40%), whereas it was enriched in the cryoprecipitates of the remaining 18. In addition, HCV RNA and IgM molecules with RF activity were concentrated selectively in the cryoprecipitates. Differential precipitation was found for both total IgG and IgG subclasses, as they were less represented in the cryoglobulins and no selective enrichment was noted. Immunological characterization of HCV core protein‐containing cryoprecipitating ICs after chromatographic fractionation showed that the IgM monoclonal component had RF activity, whereas anti‐HCV core reactivity was confined to the IgG fraction. C1q enrichment in addition to high avidity of ICs for C1q binding in the cryoprecipitates suggest that complement activation may occur through the C1q protein pathway. The present data demonstrate that non‐enveloped HCV core protein is a constitutive component of cryoprecipitable ICs in type II MC patients.

Hepatitis C Virus Infection, Mixed Cryoglobulinemia, and Non-Hodgkin's Lymphoma: an Emerging Picture

Hepatitis C virus (HCV) is a single-stranded RNA agent which expresses its genetic informations in the form of a single, large polyprotein encoded by an open reading frame (ORF) that extends through most of its genomic RNA. Proteolytic cleavage of the ORF product is essential for the virogenesis and the production of viral progeny. HCV is responsible for chronic liver disease, cirrhosis and possibly hepatocellular carcinoma. Viral persistence is considered the greatest problem in the management of HCV infection. It may result from several mechanisms, two of which are established. In the first, the high rate of genetic variations during viral replication results in the production of mutants capable of escaping the immune attack. In the second, the virus infects cells of the immune system itself, which represent a privileged site that cannot be reached by virus-specific T cell response. Involvement of lymphoid cells in the early stages of HCV infection may provide insight into the pathobiologic patterns of extrahepatic dissemination (lymph nodes, major salivary glands, kidneys, blood vessels). Dissemination of HCV-infected lymphoid cells throughout the organism is likely to maintain a mobile and extensive reservoir of the virus. In this respect, extrahepatic sites may act as a source of continuous reinfection of hepatocytes. Studies of intrahepatic B lymphocytes indicate that they are infected with HCV, clonally expanded and activated to secrete IgM molecules with rheumatoid factor activity. This strongly suggests that HCV directly stimulates B cell expansion, which may result in an indolent stage of lymphoproliferation (i.e., mixed cryoglobulinemia) or in frank B cell non-Hodgkins lymphoma (NHL). The frequency of NHL, however, is much lower than that of HCV infection, suggesting that HCV alone is not able to induce tumors and that cellular events, in addition to the presence of virus and virus-encoded products, are necessary in order to obtain a malignant B cell phenotype. The demonstration of HCV productive infection in bone marrow-recruited and circulating pluripotent hematopoietic CD34+ stem cells indicates that HCV replication occurs in the early differentiation stages of hematopoietic progenitors. These are stable cell populations and are likely to represent the initial site of infection and a continuous source of virus production.

Role of the Receptor for the Globular Domain of C1q Protein in the Pathogenesis of Hepatitis C Virus-Related Cryoglobulin Vascular Damage

Mixed cryoglobulinemia (MC) is a lymphoproliferative disorder observed in ∼10 to 15% of hepatitis C virus (HCV)-infected patients. Circulating, nonenveloped HCV core protein, which has been detected in cryoprecipitable immune complexes, interacts with immunocytes through the receptor for the globular domain of C1q protein (gC1q-R). In this study, we have evaluated circulating gC1q-R levels in chronically HCV-infected patients, with and without MC. These levels were significantly higher in MC patients than in those without MC and in healthy controls and paralleled specific mRNA expression in PBL. Soluble gC1q-R circulates as a complexed form containing both C1q and HCV core proteins. Higher serum gC1q-R levels negatively correlated with circulating concentrations of the C4d fragment. The presence of sequestered C4d in the vascular bed of skin biopsies from MC patients was indicative of in situ complement activation. In vitro studies showed that release of soluble gC1q-R is regulated by HCV core-mediated inhibition of cell proliferation. Our results indicate that up-regulation of gC1q-R expression is a distinctive feature of MC, and that dysregulated shedding of C1q-R molecules contributes to vascular cryoglobulin-induced damage via the classic complement-mediated pathway.

Immunochemical and biomolecular studies of circulating immune complexes isolated from patients with acute and chronic hepatitis C virus infection

Circulating immune complexes (ICs) were isolated by affinity chromatography and sucrose density gradient fractionation during acute and chronic hepatitis C virus (HCV) infection. Immunochemical and biomolecular studies showed that they basically consist of the virus component, IgG with specific anti‐HCV activity and IgM bearing 17.109 epitope (IgM 17.109), an antigenic determinant common to rheumatoid factors (RFs) with WA cross‐idiotype (XId). An antigen‐specific IC assay was used to demonstrate IgG anti‐HCV/IgM 17.109 ICs (IgG‐IgM ICs) in five out of the five patients with acute and in 8 out of the 10 patients with chronic hepatitis C who mounted an IgG anti‐HCV immune response. They were not detected in patients with no IgG anti‐HCV response. IgG–IgM ICs appeared in step with IgG anti‐HCV seroconversion and remained detectable for a long period irrespective of clinical outcome, in that they were demonstrated over a 4‐year follow‐up of patients with chronic hepatitis C. Their presence was unrelated to the severity and progression of liver histology. Despite similar serum levels of IgM 17.109 XId, antigen‐specific IgG‐IgM ICs were not found in acute and chronic hepatitis B or in acute hepatitis A. Thus, these ICs appear to be uniquely associated with HCV infection, supporting the view that IgM 17.109 XId derive from an antigen‐driven response strictly related to the involved antigen. Even although they have no apparent effects on the progression of HCV‐related liver disease, their presence may help to explain the immunological abnormalities and extrahepatic disorders observed in HCV infection.

Identification of naïve HCV-1 patients with chronic hepatitis who may benefit from dual therapy with peg-interferon and ribavirin

BACKGROUND & AIMS The pool of HCV genotype 1 patients likely to be cured by peg-interferon and ribavirin remains to be quantified. METHODS In 1045 patients treated with peg-interferon and ribavirin, two therapeutic strategies were confronted: the first one evaluated only baseline variables associated with sustained virological response (SVR), and the second one included the rapid virologic response (RVR) in addition to baseline predictors. An 80% SVR rate was the threshold to retain a strategy as clinically relevant. RESULTS Overall, 414 patients (39.6%) attained SVR. In the first strategy, the hierarchy of features independently associated with SVR was IL28B CC genotype (OR 5.082; CI 3.637-7.101), low (<400,000 IU) viremia (OR 2.907; CI 2.111-4.004), F0-F2 fibrosis (OR 1.631; CI 1.122-2.372) and type 2 diabetes (OR 0.528; CI 0.286-0.972). In the alternative strategy, SVR was associated with RVR (OR 6.273; CI 4.274-9.208), IL28B CC genotype (OR 3.306; CI 2.301-4.751), low viremia (OR 2.175; CI 1.542-3.070), and F0-F2 fibrosis (OR 1.506; CI 1.012-2.242). Combining the favorable baseline variables, the rates of SVR ranged from 42.4% to 83.3%, but only 66 patients (6.3%, overall) with all predictors could be anticipated to reach the >80% SVR threshold. Only 26.6% of no-RVR patients attained SVR. Among the 255 RVR patients, the likelihood of SVR was 61.8% in those with unfavorable predictors, 80% in the presence of a single predictor, and 100% when both predictors were present. By using this model, 200 patients (19.1%) were predicted to have an 80% chance of being cured with dual therapy. CONCLUSIONS A consistent subset of naïve HCV-1 patients, identified by some baseline characteristics and RVR, may benefit from dual treatment with peg-interferon and ribavirin.

B-cell depletion in the treatment of mixed cryoglobulinemia

A controlled study has been carried out to assess the efficacy of rituximab (RTX), a chimeric antibody that binds to the B-cell surface antigen CD20, in twenty patients with mixed cryoglobulinemia (MC) and HCV-positive chronic active liver disease, resistant to interferon-alpha (IFN-alpha) therapy. They received an intravenous infusion of 375 mg/m(2) RTX once a week for 4 consecutive weeks. Infusion of RTX had a good safety profile, and no severe side-effects were reported. Sixteen patients (80%) had a complete response (CR), characterized by rapid improvement of clinical signs (disappearance of purpura, weakness, arthralgias and improvement of peripheral neuropathy), and decreased cryocrit. CR was associated with a significant reduction in rheumatoid factor (RF) activity and anti-HCV antibody titers. Decline of IgG anti-HCV titers in the cryoprecipitates was usually associated with a favorable response (r= 0.81; p <0.005). No differences in the dynamics of B-cell depletion and recovery were found between responders and non-responders. Molecular monitoring of the B-cell response revealed disappearance/deletion of peripheral clones in the responders and great stability in the non-responders. RTX had a deep impact on hepatitis C viremia: HCV RNA increased to approximately twice the baseline level in the responders, whereas it remained much the same in the non-responders. Twelve out of 16 responders (75%) remained in remission throughout the follow-up. The results indicate that RTX has clinical and biological activity in HCV-positive MC patients. However, in view of the increased viremia in the responders, additional modes of application and combination of RTX with other agents need to be investigated.

Bone metastases in hepatocellular carcinoma: an emerging issue

The nature and the characteristics of bone metastases (BMs) in hepatocellular carcinoma (HCC) have not been fully explored in literature, presumably because HCC skeletal involvement was rarely diagnosed until a few years ago. Recently, the prognosis and the management of HCC clinical progression have been improved thanks to novel imaging techniques and multidisciplinary treatment approaches. As in other osteotropic cancers, both angiogenesis and the epithelial-to-mesenchymal transition play a crucial role in skeletal colonization, with the cooperation of additional factors including vascular endothelial growth factor, transforming growth factor beta, platelet-derived growth factor, insulin-like growth factors I and II, bone morphogenetic proteins, secretory protein clusterin, and others. BMs from HCC are often characterized by soft-tissue expansion with an abundant vascular component and elevated tumor burden. As the majority of metastatic bone lesions from HCC are osteolytic, they are detectable by computerized tomography only at a late stage and not usually visualized by traditional bone scintigraphy. For this reason, new imaging tools are currently being investigated, such as dual tracer positron emission computerized tomography. HCC is frequently complicated by liver failure, resulting in a lower tolerance to opioids used for pain control, but radiotherapy and other local-regional treatments are useful in the treatment of BMs from HCC.

Variation in genes encoding for interferon λ‐3 and λ‐4 in the prediction of HCV‐1 treatment‐induced viral clearance

In patients with chronic HCV‐1 infection, recent evidences indicate that determination of a dinucleotide polymorphism (ss469415590, ΔG/TT) of a new gene, designated IFN λ‐4, might be more accurate than the 12979860CC type of the IL28B locus in predicting sustained virological response (SVR) following peg‐interferon and ribavirin. In addition, combined genotyping of different SNPs of the IL28B locus was shown to help dissect patients most prone to SVR among those with rs12979860CT.