Hepatitis C virus persistence after spontaneous or treatment-induced resolution of hepatitis C

Differences in the patterns and outcomes of enhanced viral replication between hepatitis C virus and hepatitis B virus in patients with hepatocellular carcinoma during transarterial chemolipiodolization

Background/Aims

Enhanced replication of hepatitis C virus (HCV) is well described in the setting of moderate to severe immunosuppression. The aims of this retrospective study were to determine the incidence of enhanced HCV replication in hepatocellular carcinoma (HCC) patients undergoing transarterial chemolipiodolization (TACL) and to identify the factors associated with enhanced replication of HCV. The clinical pattern of enhanced HCV replication was compared with hepatitis B virus (HBV) reactivation during TACL.

Methods

This study enrolled 49 anti-HCV-seropositive patients who were diagnosed with HCC between January 2005 and December 2010 and who underwent TACL using epirubicin and/or cisplatin with consecutive HCV RNA copies checked. For comparison, 46 hepatitis B surface antigen¹-positive patients with HCC who were treated with TACL were also enrolled. The frequency, associated factors, and clinical outcomes of enhanced HCV replication were analyzed and compared with those of HBV reactivation during TACL.

Results

Enhanced replication of HCV occurred in 13 (26.5%) of the 49 anti-HCV-seropositive patients during TACL. Of these 13 patients, 4 developed hepatitis, but none of the subjects developed decompensation due to the hepatitis. No significant clinical factors for enhanced HCV replication during TACL were found. Compared with HBV reactivation, the frequency of hepatitis attributed to enhanced HCV replication was significantly lower than that for HBV reactivation (8.2% vs. 23.9%, P=0.036).

Conclusions

TACL can enhance HCV replication; however, the likelihood of hepatitis and decompensation stemming from enhanced HCV replication was lower than that for HBV reactivation in patients undergoing TACL.

Occult infection with hepatitis C virus: friend or foe?

Hepatitis C virus (HCV) infection is a global pandemic associated with a growing disease burden due to cirrhosis and the consequent morbidity and mortality. Transmission is largely via blood-to-blood contact. Following primary infection, a minority of individuals clear the infection predominantly via cellular immune mechanisms, whereas the majority become chronically infected. Recent data suggest that a third outcome may also be possible, termed 'occult' infection in which subjects who are known, or suspected to have previously been infected with HCV, no longer have viral RNA in their serum at levels detectable by sensitive commercial assays, but do have virus detected by ultra-sensitive techniques. Occult infection has also been detected in peripheral blood mononuclear cells, which may indicate an extra-hepatic reservoir of the virus. Although the clinical significance of occult infection remains unknown, most authors have raised concerns of recrudescent infection. Here we critically review the published literature, suggest further avenues of investigation and propose that occult infection may be beneficial to the host by maintaining immunological memory to protect against reinfection.

Lymphotropic hepatitis C virus has an interferon-resistant phenotype

Hepatitis C virus (HCV) infects and associates with B cells, leading to abnormal B-cell activation and development of lymphoproliferative and autoimmune disorders. This immune perturbation may in turn be associated with the resistance of HCV against the host immune system. The objective of this study was to analyse the effects of HCV infection of B cells on the efficacy of interferon (IFN)-based therapy. The study enrolled 102 patients with chronic hepatitis C who were treated with pegylated IFN plus ribavirin. HCV RNA titres in B cells were compared in patients with rapid viral responder (RVR) vs non-RVR, sustained viral responder (SVR) vs non-SVR and null viral responder (NVR) vs VR. The levels of HCV RNA in B cells were significantly higher in non-RVR, non-SVR and NVR groups. Association between the therapy outcome and the positive B-cell HCV RNA was also investigated in relation to other known viral and host factors. Multivariable analyses showed that the positive B-cell HCV RNA and the minor single-nucleotide polymorphism near the IL28B gene (rs8099917) were independent factors associated with NVR in patients infected with HCV genotype 1. When these two factors were combined, the sensitivity, specificity, positive and negative predictive values for NVR were 92.3%, 98.2%, 92.3% and 98.2%, respectively. Genotype 1 and the presence of one or no mutations in the IFN-sensitivity determining region were associated with higher levels of B-cell HCV RNA. B-cell-tropic HCV appears to have an IFN-resistant phenotype. B-cell HCV RNA positivity is a predictive factor for resistance to IFN-based therapy.

Presence of plus-strand HCV RNA in serum and PBMCs as an indicator for relapse and resistance to IFN therapy in patients infected by HCV

Aim: The aim of our study was to investigate the correlation between the presence of plus-/minus-strand HCV RNA in peripheral blood mononuclear cells (PBMCs) and serum following pegylated IFN/ribavirin therapy with response to therapy in HCV-infected patients. Methods: Forty-three HCV-infected patients who completed 48 weeks of IFN/ribavirin therapy, including 25 sustained virologic responders, 12 resistants and six relapsers, comprised the study population. Plus-/minus-strand HCV RNA was detected by reverse transcription PCR in serum and PBMCs. Results: The frequency of plus-strand HCV RNA was significantly higher in PBMC and serum samples of relapsers and resistants, and this might have important implications in clinical practice and patient management. There was no correlation between presence of plus- and minus-strand HCV RNA and genotypes, except the fact that most of the patients who had plus-strand HCV RNA in PBMCs (60%) and in serum (61.53%) belonged to genotype 1a. Conclusion: Presence of plus-strand HCV RNA in PBMCs and serum after termination of therapy is associated with viral relapse and resistance to IFN/ribavirin treatment in HCV-infected patients.

Hepatitis C virus persistence after sustained virological response to antiviral therapy in patients with or without past exposure to hepatitis B virus

Hepatitis C virus (HCV) and hepatitis B virus (HBV) frequently coinfect and persist long after clinical resolution. We assessed the incidence of low-level (occult) HCV infection (OCI) after sustained virological response (SVR) to standard anti-HCV therapy in individuals with or without past exposure to HBV to recognize whether HBV could influence the prevalence of OCI, HCV level and hepatic histology. Plasma and peripheral blood mononuclear cells (PBMC) were collected from 24 individuals at 6- to 12-month intervals for up to 72 months after SVR. Liver histology was available for nine patients. HCV and HBV genomes were detected with sensitivity <10 genome copies/mL. In individuals without HBV exposure (n = 15), comprehensive analyses of sequential plasma and PBMC samples revealed HCV RNA in all 15 cases (75% plasma and 61% PBMC). In the group with HBV exposure (n = 9), evidenced by circulating anti-HBc and/or HBV DNA detection by a highly sensitive assay, HCV RNA was identified in all cases (83% plasma and 59% PBMC), at levels similar to those in HBV nonexposed individuals. In both groups of patients, most liver biopsies included those reactive for viral genomes displayed low-grade inflammation (8 of 9) and fibrosis (7 of 9). Sequence polymorphisms at the 5`-UTR between PBMC and liver or plasma, as well as circulating HCV virion-like particles, were observed in patients with or without HBV exposure. In conclusion, the prevalence of OCI after SVR is comparable in individuals with or without past exposure to HBV. HCV loads and liver alterations in OCI appear to be unaffected by low-level HBV DNA carriage.

Hepatitis C virus infection of human T lymphocytes is mediated by CD5

Hepatitis C virus (HCV) is one of the main causes of chronic liver disease. Although infection of hepatocytes is mainly responsible for manifestations of hepatitis C, the virus also invades the immune system by a yet-to-be-identified mechanism. Using human T cell lines and primary T lymphocytes as targets and patient-derived HCV as inocula, we aimed to identify how HCV gains entry into these cells. HCV replication was determined by detection of the HCV RNA replicative (negative) strand and viral proteins, while specific antibodies, knocking down gene expression and making otherwise-resistant cells prone to HCV, were employed to identify a receptor molecule determining T lymphocyte permissiveness to HCV infection. The results revealed that T cell susceptibility to HCV requires CD5, a lymphocyte-specific glycoprotein belonging to the scavenger receptor cysteine-rich family. Blocking of T cell CD5 with antibody or silencing with specific short hairpin RNA (shRNA) decreased cell susceptibility to HCV, while increasing CD5 expression by mitogen stimulation had the opposite effect. Moreover, transfection of naturally CD5-deficient HEK-293 fibroblasts with CD5 facilitated infection of these otherwise HCV-resistant cells. In contrast to T cells, hepatocytes do not express CD5. The data revealed that CD5 is a molecule important for HCV entry into human T lymphocytes. This finding provides direct insight into the mechanism of HCV lymphotropism and defines a target for potential interventions against HCV propagating in this extrahepatic compartment.

Occult hepatitis C virus infection and its relevance in clinical practice

Hepatitis C virus (HCV) can persist in the liver, lymphoid (immune) cells, and serum of individuals long after an apparently complete therapy-induced or a spontaneous resolution of hepatitis C. This essential asymptomatic infection, called secondary occult HCV infection (OCI), usually occurs in anti-HCV antibody reactive individuals with normal liver function tests. This infection has been identified when the nucleic acid amplification assays of enhanced sensitivity were applied for the detection of HCV genome and its replication. In addition to the secondary OCI, a form of low-level HCV-RNA-positive infection of unknown etiology coinciding with moderately elevated serum liver enzymes and progressing in the absence of anti-HCV detectable by standard clinical assays has been reported. Because of its undefined origin, it can be termed cryptogenic OCI. In this review, the general characteristics of OCI, the ways of its detection and associated controversies, and the potential clinical implications of its existence will be concisely outlined.

Hepatitis C virus fails to activate NF-κB signaling in plasmacytoid dendritic cells

Plasmacytoid dendritic cells (pDCs) respond to viral infection by production of alpha interferon (IFN-α), proinflammatory cytokines, and cell differentiation. The elimination of hepatitis C virus (HCV) in more than 50% of chronically infected patients by treatment with IFN-α suggests that pDCs can play an important role in the control of HCV infection. pDCs exposed to HCV-infected hepatoma cells, in contrast to cell-free HCV virions, produce large amounts of IFN-α. To further investigate the molecular mechanism of HCV sensing, we studied whether exposure of pDCs to HCV-infected hepatoma cells activates, in parallel to interferon regulatory factor 7 (IRF7)-mediated production of IFN-α, nuclear factor kappa B (NF-κB)-dependent pDC responses, such as expression of the differentiation markers CD40, CCR7, CD86, and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and secretion of the proinflammatory cytokines TNF-α and interleukin 6 (IL-6). We demonstrate that exposure of pDCs to HCV-infected hepatoma cells surprisingly did not induce phosphorylation of NF-κB or cell surface expression of CD40, CCR7, CD86, or TRAIL or secretion of TNF-α and IL-6. In contrast, CpG-A and CpG-B induced production of TNF-α and IL-6 in pDCs exposed to the HCV-infected hepatoma cells, showing that cell-associated virus did not actively inhibit Toll-like receptor (TLR)-mediated NF-κB phosphorylation. Our results suggest that cell-associated HCV signals in pDCs via an endocytosis-dependent mechanism and IRF7 but not via the NF-κB pathway. In spite of IFN-α induction, cell-associated HCV does not induce a full functional response of pDCs. These findings contribute to the understanding of evasion of immune responses by HCV.

Long-term virological follow up of patients with occult hepatitis C virus infection

BACKGROUND

Patients with occult hepatitis C virus (HCV) infection (HCV-RNA in liver without detectable anti-HCV and serum HCV-RNA) may have viral RNA in peripheral blood mononuclear cells (PBMCs) and in serum after ultracentrifugation, and may present HCV-specific T-cell responses, but it is unknown whether these markers persist to be detectable over time.

AIM

To perform a prospective virological long-term follow up of patients with occult HCV.

METHODS

Viral markers were tested every 3-4 months during 55.7 ± 20.3 months in 37 patients with occult HCV who were under ursodeoxycholic acid treatment.

RESULTS

Viral RNA was detectable in PBMCs of 31 patients during the follow up. In 23 of them, viral RNA in PBMCs was detected intermittently and in the other eight patients HCV-RNA was positive in a single sample. After ultracentrifugation, serum HCV-RNA was detected in 33 patients, being the viraemia intermittently detectable in 28, whereas in the remaining five patients, serum HCV-RNA was positive only once. Only one patient tested always HCV-RNA negative in PBMCs and in ultracentrifuged serum during follow up. Specific Core, NS3, and/or NS4 T-cell responses were found in 31 of the patients. The patient who was always HCV-RNA negative in PBMCs and in ultracentrifuged serum had specific HCV-T-cell responses.

CONCLUSIONS

Occult HCV infection persists over time with fluctuating viraemia levels that induce and maintain specific T-cell responses against viral proteins.

Occult HCV or delayed viral clearance from lymphocytes of Chronic HCV genotype 3 patients after interferon therapy

Background

A recently discovered occult HCV entity reported by various investigators seems to be highly controversial. Especially, the clinical significance of these findings remains uncertain. For optimal outcome of antiviral therapy, investigation of occult HCV needs a broad-based probe in order to investigate the results of viral therapy and its host/viral interaction. The current study was aimed at determining the prevalence of occult HCV in peripheral blood lymphocytes of predominantly genotype 3 HCV-infected patients after completion of antiviral therapy and to investigate long term outcomes in the presence or absence of PBMC positivity.

Method

A total of 151 chronic, antiHCV and serum RNA-positive patients were enrolled in the study. Patients with a complete virological response at the end of treatment were screened for the presence of viral RNA in their PBMCs and were followed for up to one year for the presence of serum and PBMC viral genomic RNA.

Results

Out of 151 patients, 104 (70%) responded to the prescribed interferon treatment and showed viral-clearance from serum. These were screened for the presence of genomic RNA in their PBMCs. Sixteen samples were PBMC-positive for viral RNA at the end of treatment (EOT). All these patients had also cleared the virus from peripheral blood cells after the 6-12 month follow-up study.

Conclusion

True occult hepatitis C virus does not exist in our cohort. Residual viremia at the EOT stage merely reflects a difference in viral kinetics in various compartments that remains a target of immune response even after the end of antiviral therapy and is eventually cleared out at the sustained viral response (SVR).

Viral RNA but no evidence of replication can be detected in the peripheral blood mononuclear cells of hepatitis E virus-infected patients

Hepatitis E virus (HEV) infection is an important cause of acute viral hepatitis in several developing countries but has recently been shown to cause chronic hepatitis in immunosuppressed persons. Other hepatotropic viruses that cause chronic infection have been shown to infect peripheral blood mononuclear cells (PBMCs) and to persist in those cells. We therefore decided to look for evidence of replication of HEV in PBMCs obtained from patients with acute hepatitis E, using strand-specific assays for positive and negative HEV RNA. Of the 44 patients with acute hepatitis E during an outbreak in India, including 27 with detectable IgM anti-HEV and 19 with detectable serum HEV RNA, 11 had detectable HEV RNA in their PBMCs. However, of the six PBMC specimens with strong HEV RNA signal, none had detectable negative-strand HEV RNA, a marker of viral replication. These findings indicate the presence of HEV RNA but the absence of its replication in PBMCs from patients with acute hepatitis E.

Immunopathogenesis of HIV/hepatitis C virus coinfection

As a result of shared infection routes, approximately 25% of individuals infected with HIV in North America are also infected with hepatitis C virus (HCV). In the setting of HIV coinfection, the course of HCV disease is more aggressive, resulting in higher HCV viral loads and a more rapid progression of liver pathology. With the success of HAART, HCV-related end-stage liver disease has become a leading cause of morbidity and mortality in HIV/HCV-coinfected patients. In this article, we will discuss recent studies examining the immune response during HIV and HCV coinfection, focusing on alterations or dysfunctions in virus-specific T-cell responses that may play a role in the immunopathogenesis of HIV/HCV coinfection. Summarizing the impact of HIV coinfection on HCV-specific T-cell immunity and highlighting some of the proposed mechanisms of T-cell dysfunction in HIV/HCV-coinfected individuals may uncover information that could lead to new treatment strategies for these patients experiencing accelerated liver disease and generally poorer outcomes than their HCV-monoinfected counterparts.

[Occult hepatitis C virus infection]

Occult hepatitis C virus (HCV) infection is characterized by the detection of HCV-RNA in liver in the absence of anti-HCV and serum HCV-RNA determined by conventional techniques. The development of a new enzyme immunoassay for the detection of antibodies against a conserved epitope in the HCV core protein, together with the detection of HCV-RNA in peripheral blood mononuclear cells and in serum after concentrating the viral particles by ultracentrifugation, allow diagnosis of more than 90% of patients with occult HCV without the need to perform a liver biopsy. Histological damage in occult HCV infection ranges from minimal changes to liver cirrhosis and hepatocellular carcinoma, although in general this disease is less severe than classical chronic hepatitis C. A significant prevalence of occult HCV infection has been identified in risk groups such as hemodialysis patients and the family members of patients with occult hepatitis C. This occult HCV infection can also be found in subjects without clinical or biochemical evidence of liver disease.

Sustained virologic response to antiviral therapy for chronic hepatitis C virus infection: a cure and so much more

Sustained virologic response (SVR) is defined as aviremia 24 weeks after completion of antiviral therapy for chronic hepatitis C virus (HCV) infection. In analyses of SVR durability, the incidence of late relapse is extremely low (<1%). Histologic regression of both necroinflammation and fibrosis has been demonstrated in paired liver biopsy samples in SVR-achieving patients. More noteworthy is the sustained responder's favorable prognosis even with baseline cirrhosis; despite mostly retrospective analyses, relative to nonresponders or to those untreated, patients with SVR have significantly fewer liver-related complications, less hepatocellular carcinoma, and fewer liver-related deaths. Although HCV is associated with insulin resistance, successful eradication of HCV appears to reduce the risk of impaired fasting glucose and diabetes development. In summary, chronic HCV infection is curable with SVR attainment, and with cure comes improved liver histology and more favorable clinical outcomes, in comparison with patients who do not achieve the same therapeutic milestone.

Human cell types important for hepatitis C virus replication in vivo and in vitro: old assertions and current evidence

Hepatitis C Virus (HCV) is a single stranded RNA virus which produces negative strand RNA as a replicative intermediate. We analyzed 75 RT-PCR studies that tested for negative strand HCV RNA in liver and other human tissues. 85% of the studies that investigated extrahepatic replication of HCV found one or more samples positive for replicative RNA. Studies using in situ hybridization, immunofluorescence, immunohistochemistry, and quasispecies analysis also demonstrated the presence of replicating HCV in various extrahepatic human tissues, and provide evidence that HCV replicates in macrophages, B cells, T cells, and other extrahepatic tissues. We also analyzed both short term and long term in vitro systems used to culture HCV. These systems vary in their purposes and methods, but long term culturing of HCV in B cells, T cells, and other cell types has been used to analyze replication. It is therefore now possible to study HIV-HCV co-infections and HCV replication in vitro.

Spontaneous loss of hepatitis C virus RNA from serum is associated with genotype 1 and younger age at exposure

A variety of factors have been associated with spontaneous loss of hepatitis C virus (HCV)-RNA from serum, including infecting HCV type, although results are conflicting. This study aimed to investigate further whether infecting HCV type was linked to spontaneous loss of HCV-RNA. Serum samples from 321 untreated HCV antibody positive patients presenting at the Hepatology clinic at Addenbrooke's Hospital, Cambridge between 2004 and 2007 were tested. These individuals were classified either as HCV antibody and HCV-RNA positive (viremic, n = 219) or HCV antibody positive and repeatedly HCV-RNA negative (non-viremic, n = 102). Infecting HCV type was identified by genotyping (viremic) or serotyping (non-viremic). Binomial regression analysis investigated the independent effect of HCV type on spontaneous loss of HCV-RNA from serum by comparing the two groups. Ninety-one percent of patients were found to be either genotype 1 or genotype 3. The prevalence of type 1 infection was greater among non-viremic (64.5%) than viremic individuals (45%). After controlling for the effects of potential confounding factors, multivariable analyses showed that individuals with type 1 infections were more likely to be non-viremic than genotype 3 infections (RR = 2.07; 95% CI: 1.25, 3.43; P = 0.005). Individuals infected at an older age were also less likely to become HCV-RNA negative spontaneously (RR = 0.42 comparing those infected at ≥20 years of age against those infected at <20 years of age, 95% CI: 0.25, 0.72; P = 0.002). In conclusion, the results suggest that HCV genotype 1 infections are more likely than genotype 3 infections to become spontaneously non-viremic, as are infections acquired at younger age.

Sporadic reappearance of minute amounts of hepatitis C virus RNA after successful therapy stimulates cellular immune responses

BACKGROUND & AIMS

Several studies have reported hepatitis C virus (HCV) RNA sequences in the circulation after treatment-induced or spontaneous recovery. We investigated whether the HCV RNA represents persistence of HCV infection or reinfection.

METHODS

We studied 117 patients who recovered from HCV infection (98 following therapy and 19 spontaneously). A reverse-transcription polymerase chain reaction assay was used to detect the 5'-untranslated region of HCV. T-cell responses were studied by enzyme-linked immunospot for interferon-γ.

RESULTS

Plasma samples from 15% of treatment-recovered patients and no spontaneously recovered patient tested positive for HCV RNA. Lymphocytes from 3 patients who responded to therapy and 1 who recovered spontaneously tested positive. The frequency of HCV RNA detection in plasma correlated inversely with the time after the end of treatment. Post-treatment HCV 5'-untranslated region sequences matched pretreatment sequences in 85% of cases. T-cell responses were significantly greater at time points with detectable trace amounts of HCV RNA than at time points without detectable HCV RNA (P = .035) and were primarily against nonstructural HCV antigens. The immune hierarchy was preserved over 5 years in patients whose post-treatment HCV RNA sequences matched pretreatment sequences, indicating HCV RNA persistence. An altered immune hierarchy with dominant immune responses, shifting from nonstructural to structural antigens, was observed in a single patient whose post-treatment HCV genotype differed from that of the pretreatment genotype, indicating HCV reinfection.

CONCLUSIONS

Trace amounts of HCV RNA of pretreatment sequence persisted and reappeared sporadically in the circulation within 8 years after recovery from hepatitis C but not thereafter, indicating that patients are cured of HCV infection. Reappearance of HCV RNA induced HCV-specific T-cell responses.

A sustained virologic response is durable in patients with chronic hepatitis C treated with peginterferon alfa-2a and ribavirin

BACKGROUND & AIMS

A sustained virologic response (SVR) to therapy for hepatitis C virus (HCV) infection is defined as the inability to detect HCV RNA 24 weeks after completion of treatment. Although small studies have reported that the SVR is durable and lasts for long periods, it has not been conclusively shown.

METHODS

The durability of treatment responses was examined in patients originally enrolled in one of 9 randomized multicenter trials (n = 1343). The study included patients who received pegylated interferon (peginterferon) alfa-2a alone (n = 166) or in combination with ribavirin (n = 1077, including 79 patients with normal alanine aminotransferase levels and 100 patients who were coinfected with human immunodeficiency virus and HCV) and whose serum samples were negative for HCV RNA (<50 IU/mL) at their final assessment. Patients were assessed annually, from the date of last treatment, for a mean of 3.9 years (range, 0.8-7.1 years).

RESULTS

Most patients (99.1%) who achieved an SVR had undetectable levels of HCV RNA in serum samples throughout the follow-up period. Serum samples from 0.9% of the patients contained HCV RNA a mean of 1.8 years (range, 1.1-2.9 years) after treatment ended. It is not clear if these patients were reinfected or experienced a relapse.

CONCLUSIONS

In a large cohort of patients monitored for the durability of an SVR, the SVR was maintained for almost 4 years after treatment with peginterferon alfa-2a alone or in combination with ribavirin. In patients with chronic hepatitis C infection, the SVR is durable and these patients should be considered as cured.

Expression of NOD2 in a rat model of acute pancreatitis

OBJECTIVES

To observe the expression of nucleotide-binding oligomerization domain 2 (NOD2) in rats with acute pancreatitis (AP).

METHODS

Sprague-Dawley rats were randomly divided into sham operation (SO) groups and AP groups. Acute pancreatitis was induced with retrograde infusion of sodium taurocholate into the biliopancreatic duct. They were then killed at 3, 6, 12, 24, and 48 hours after induction of AP. Blood biochemical indicators were detected with automatic biochemistry analyzer. Nuclear factor-κB (NF-κB) was measured by immunohistochemistry. The NOD2 was detected by real-time quantitative polymerase chain reaction and Western blot. Tumor necrosis factor-α (TNF-α) was determined by enzyme-linked immunosorbent assay.

RESULTS

Compared with the SO group, the level of messenger RNA and protein of NOD2 in pancreatic tissue and peritoneal white blood cells (PWBCs) in the AP groups significantly declined (P < 0.05). The messenger RNA level of NOD2 in the AP groups was correlated positively with amylase (P < 0.05) and negatively with TNF-α (P < 0.05); TNF-α significantly decreased in the AP groups, whereas NF-κB significantly increased (P < 0.05).

CONCLUSIONS

The NOD2 may play an important role in the up-regulation and activation of NF-κB during inflammation reactions in AP.

Relapse of hepatitis C in a pegylated-interferon-alpha-2b plus ribavirin-treated sustained virological responder

A 41-year-old woman with chronic hepatitis C was treated with pegylated-interferon (PEG-IFN)-alpha-2b plus ribavirin for 24 weeks. She had hepatitis C virus (HCV) genotype 2a (1600 KIU/mL), and her liver histology showed mild inflammation and fibrosis. Four weeks after the start of the therapy, she achieved a rapid virological response (RVR) and then a sustained virological response (SVR). Serum alanine aminotransferase (ALT) levels remained within normal ranges and HCV RNA continued to be negative. However, ALT levels flared with the re-emergence of HCV RNA in the serum 1.5 years after discontinuation of therapy. HCV RNA obtained from sera before therapy and after relapse shared a 98.6% homology with the E2 region, and phylogenetic analyses indicated that they were the same HCV strain. These results eliminated the possibility of a re-infection and strongly indicated a late relapse of the disease. Therefore, follow-up is necessary for chronic hepatitis C patients after SVR, even if they respond well to therapy, including RVR.

Distribution of different hepatitis C virus genotypes in patients with hepatitis C virus infection

AIM: To investigate the presence of mixed infection and discrepancy between hepatitis C virus (HCV) genotypes in plasma, peripheral blood mononuclear cells (PBMCs), and liver biopsy specimens.

METHODS: From September 2008 up to April 2009, 133 patients with chronic hepatitis C referred to Firouzgar Hospital for initiation of an antiviral therapy were recruited in the study. Five milliliters of peripheral blood was collected from each patient and liver biopsy was performed in those who gave consent or had indications. HCV genotyping was done using INNO-LiPA™ HCV II in serum, PBMCs, and liver biopsy specimens and then confirmed by sequencing of 5’-UTR fragments.

RESULTS: The mean age of patients was 30.3 ± 17.1 years. Multiple transfusion was seen in 124 (93.2%) of patients. Multiple HCV genotypes were found in 3 (2.3%) of 133 plasma samples, 9 (6.8%) of 133 PBMC samples, and 8 (18.2%) of 44 liver biopsy specimens. It is notable that the different genotypes found in PBMCs were not the same as those found in plasma and liver biopsy specimens.

CONCLUSION: Our study shows that a significant proportion of patients with chronic hepatitis C are affected by multiple HCV genotypes which may not be detectable only in serum of patients.

Occult hepatitis C virus infection: what does it mean?

Occult hepatitis C virus infection (OCI) is a recently identified entity of which the existence became evident when nucleic acid amplification assays of enhanced sensitivity were introduced for the detection of hepatitis C virus (HCV) genome and its replication. This form of HCV infection has been found to persist in the presence of antibodies against HCV and normal levels of liver enzymes for years after spontaneous or antiviral therapy-induced resolution of hepatitis C and, therefore, can be termed as secondary OCI. HCV RNA in OCI circulate at fluctuating levels normally not exceeding 200 genome copies per millilitre of serum or plasma, while low levels of virus genome and its replicative intermediate RNA-negative strand are detectable in the liver and, importantly, immune cells, which provide an opportunity to detect active virus replication without the need for acquiring a liver biopsy. In addition to secondary OCI, a form of OCI accompanied by persistently moderately elevated serum liver enzymes in the absence of antibodies to HCV, which can be termed as cryptogenic OCI, has also been described. The current understanding of the nature and characteristics of OCI, methods and pitfalls of its detection, as well as the documented and expected pathological consequences of OCI will be summarized in this review.

Sustained virological response to pegylated interferon and ribavirin is maintained during long-term follow-up of chronic hepatitis C patients

BACKGROUND

There are few data in the literature regarding the long-term virological follow-up of chronic hepatitis C patients who obtain sustained virological response (SVR) to pegylated interferon (PEG-IFN) and ribavirin therapy.

AIM

To assess the durability of SVR to PEG-IFN and ribavirin therapy during long-term follow-up of chronic hepatitis C patients.

METHODS

We evaluated a cohort of 231 chronic hepatitis C patients who had at least 48 weeks of follow-up after SVR to PEG-IFN and ribavirin treatment. Median duration of follow-up after SVR was 164 weeks, and exceeded 5 years in 30% of the cohort. Patients underwent consistent clinical, biochemical and virological evaluations every 6 months during follow-up.

RESULTS

Sustained virological response was maintained in 211 patients (91%) while HCV-RNA became positive in two patients (<1%) within 1 year after SVR, and in 18 patients (8%) serum HCV-RNA was transiently positive in at least one follow-up evaluation. Clinical outcome was not significantly different between patients with persistently negative and transiently positive serum HCV-RNA.

CONCLUSIONS

Sustained virological response to PEG-IFN and ribavirin is maintained in 99% of patients during long-term follow-up. Late virological relapse occurred within 1 year after SVR and, from a clinical perspective, patients can be considered cured of infection after this period.

Characterization of the cellular immune response in hepatitis C virus infection

Hepatitis C virus (HCV), a hepatotropic RNA virus, is a major causative agent of chronic hepatitis, liver cirrhosis, and hepatocellular carcinomas. The host immune responses, especially cellular immune responses, play an important role in viral clearance, liver injury, and persistent HCV infection. A thorough characterization of the HCV cellular immune responses is important for understanding the interplays between host immune system and viral components, as well as for developing effective therapeutic and prophylactic HCV vaccines. Recent advances that provide better understanding the cell immune responses in HCV infection are summarized in this article.

Clinicopathological study on hepatitis C virus-associated glomerulonephritis without hepatitis C virus in the blood

PURPOSE

Patients with hepatitis C virus (HCV)-associated glomerulonephritis in whom HCV RNA was not detected in the blood have been reported. We attempted to uncover the differences between HCV RNA-negative and HCV RNA-positive cases.

METHODS

The clinical and pathological findings for 5 patients with HCV-associated glomerulonephritis without HCV in the blood were compared with those for 23 patients with HCV RNA-positive HCV-associated glomerulonephritis.

RESULTS

The HCV RNA-negative cases were characterized by advanced age, female dominance, no cryoglobulinemia and no glomerular deposition of IgG compared with the HCV RNA-positive cases, although no differences were observed in amount of urinary protein, frequency of nephrotic syndrome, serum levels of total protein, creatinine level, presence of hypocomplementemia and rheumatoid factor. The prognosis was similar for both groups.

CONCLUSION

These cases point to the need for further study of the pathogenesis of this disease.

No evidence of occult hepatitis C virus (HCV) infection in serum of HCV antibody-positive HCV RNA-negative kidney-transplant patients

Persistence of hepatitis C virus (HCV) in patients who cleared HCV is still debated. Occult HCV infection is described as the presence of detectable HCV RNA in liver or peripheral blood mononuclear cells (PBMCs) of patients with undetectable plasma HCV-RNA by conventional PCR assays. We have assessed the persistence of HCV in 26 kidney-transplant patients, followed up for 10.5 years (range 2-16), after HCV elimination while on hemodialysis. If HCV really did persist, arising out of the loss of immune control caused by institution of the regimen of immunosuppressive drugs after kidney transplantation, HCV reactivation would have taken place. Their immunosuppression relied on calcineurin inhibitors (100%), and/or steroids (62%), and/or antimetabolites (94%). An induction therapy, given to 22 patients, relied on rabbit antithymocyte globulin (59%) or anti-IL2-receptor blockers (32%). All patients had undetectable HCV RNA as ascertained by several conventional tests. At the last follow-up, no residual HCV RNA was detected in the five liver biopsies, the 26 plasma, and in the 37 nonstimulated and 24 stimulated PBMCs tested with an ultrasensitive RT-PCR assay (detection limit, 2 IU/ml). No biochemical or virologic relapse was seen during follow-up. The absence of HCV relapse in formerly HCV-infected immunocompromised patients suggests the complete eradication of HCV after its elimination while on dialysis.

Occult HCV infection: an unexpected finding in a population unselected for hepatic disease

Background

Occult Hepatitis C virus (HCV) infection is a new pathological entity characterized by presence of liver disease and absence or very low levels of detectable HCV-RNA in serum. Abnormal values of liver enzymes and presence of replicative HCV-RNA in peripheral blood mononuclear cells are also observed. Aim of the study was to evaluate occult HCV occurrence in a population unselected for hepatic disease.

Methodology/Principal Findings

We chose from previous epidemiological studies three series of subjects (n = 276, age range 40–65 years) unselected for hepatic disease. These subjects were tested for the presence of HCV antibodies and HCV-RNA in plasma and in the peripheral blood mononuclear cells (PBMCs) by using commercial systems. All subjects tested negative for HCV antibodies and plasma HCV-RNA and showed normal levels of liver enzymes; 9/276 patients (3.3%) were positive for HCV-RNA in PBMCs, identifying a subset of subjects with potential occult HCV infection. We could determine the HCV type for 8 of the 9 patients finding type 1a (3 patients), type 1b (2 patients), and type 2a (3 patients).

Conclusions

The results of this study show evidence that occult HCV infection may occur in a population unselected for hepatic disease. A potential risk of HCV infection spread by subjects harbouring occult HCV infection should be considered. Design of prospective studies focusing on the frequency of infection in the general population and on the clinical evolution of occult HCV infection will be needed to verify this unexpected finding.

Hepatitis C virus RNA localization in human carotid plaques

BACKGROUND

Hepatitis C virus (HCV) infection has certain characteristics that enable it to play an important role in atherosclerosis. Some studies report its association with an increased risk of carotid artery plaque.

OBJECTIVES

The aim of this study was to evaluate the presence of HCV genomic sequences and replicative intermediates in plaque tissues.

STUDY DESIGN

A cohort of consecutive, prospectively recruited patients with HCV infection and chronic ischemic heart disease from the Cardiology, Vascular Surgery and Hepatology Units of a University Hospital in Florence, Italy, were studied.

RESULTS

Positive-strand HCV RNA was detected in seven carotid plaque tissues from anti-HCV-positive patients and was not detected in the nine carotid plaque tissues obtained from anti-HCV-negative patients. In three patients, HCV RNA was found in carotid plaque and not in serum. HCV replicative intermediates were detected in three plaque samples. Direct sequencing of HCV RNA from the plaque and serum showed HCV genotypes 2 (five cases) and 1 (two cases).

CONCLUSIONS

The novel finding of HCV RNA sequences in plaque tissue strongly suggests an active local infection. This in turn makes it conceivable that the virus may exert local action in carotid atherosclerosis.

Hepatitis C virus and peripheral blood mononuclear cell reservoirs Patricia Baré

The existence of hepatitis C virus (HCV) infection in extrahepatic sites has been widely demonstrated. Since peripheral blood mononuclear cells have been the most investigated, compelling evidence of an association with HCV has been shown. Different studies have revealed that HCV RNA can persist and replicate in immune cells but the relevance of its presence and persistence over time is still unknown. As the contribution of this extrahepatic reservoir could have several clinical implications in viral transmission, treatment response and disease pathogenesis, future studies are required to improve our knowledge of the extrahepatic manifestations of HCV and its possible consequences.

Presence of HCV-RNA after ultracentrifugation of serum samples during the follow-up of chronic hepatitis C patients with a sustained virological response may predict reactivation of hepatitis C virus infection

BACKGROUND

Concentration of viral particles by ultracentrifugation of serum prior to PCR allows detection of hepatitis C virus (HCV) RNA in patients with undetectable viral RNA by conventional PCR assays.

AIM

To analyse if HCV-RNA is detected after serum ultracentrifugation in chronic hepatitis C patients with a sustained virological response to antiviral therapy (defined as serum HCV-RNA negativity by conventional assays 6 months after the end of therapy).

METHODS

HCV-RNA was tested using real-time PCR in ultracentrifuged sera collected during the post-treatment follow-up (mean: 42 +/- 27 months) in 57 sustained virological responders (SVR).

RESULTS

After serum ultracentrifugation, HCV-RNA was detected on at least one occasion during the follow-up in 29/57 (51%) SVR. Thirteen (23%) of these 57 SVR suffered a reactivation 18 +/- 8 months after the end of therapy (reappearance of serum HCV-RNA detectable by conventional assays). Among reactivated patients, 11/13 (85%) had HCV-RNA in ultracentrifuged serum samples (detectable 10 +/- 5 months before reactivation), while HCV-RNA was positive after ultracentrifugation in 18/44 (41%) long-term SVR (P = 0.01). Persistence of detectable HCV-RNA after serum ultracentrifugation was associated with reactivation (P = 0.001).

CONCLUSIONS

Serum ultracentrifugation prior to PCR allows detection of HCV-RNA in SVR and its persistence may predict late reactivation.

Hepatitis C virus quasispecies in plasma and peripheral blood mononuclear cells of treatment naïve chronically infected patients

Peripheral blood mononuclear cells (PBMCs) from 45 treatment naïve, HIV-negative, chronically hepatitis C virus (HCV)-infected patients were analyzed for the presence of HCV RNA. Viral RNA was detected in 73% of the studied patients. Single-strand conformation polymorphism assays and sequence analysis of the HCV 5'untranslated regions amplified from RNA recovered from both Plasma and PBMCs suggested virus compartmentalization in 57.6% of patients studied. In summary, our study presents evidence that HCV RNA can be found in PBMCs of treatment naïve chronically infected patients that are not immunocompromised or co-infected with the human immunodeficiency virus.

Chronic hepatitis C and persistent occult hepatitis C virus infection are characterized by distinct immune cell cytokine expression profiles

Hepatitis C virus (HCV) replicates in immune cells in both chronic hepatitis C (CHC) and occult HCV infection, but the extent of virus replication in this compartment in these opposing infection forms varies greatly. It was unknown whether this could be linked to HCV genotype or to differences in host gene expression shaping the immune response, and whether HCV replication in immune cells is sensitive to endogenous antiviral cytokines. In this study, we uncovered that significantly greater HCV load in peripheral blood mononuclear cells (PBMC), but not in plasma, coincided with HCV genotypes 2 and 3 in CHC, but with genotype 1 in residual occult infection after clinical resolution of hepatitis C. Moreover, PBMC from individuals with occult infection transcribed significantly greater levels of IFN-alpha, IFN-gamma and TNF-alpha, but less interleukin (IL)-10 than those from CHC. In CHC, PBMC with low HCV load expressed significantly more IFN-gamma but less IL-12 than did cells with high virus content. In occult infection, HCV RNA detection in PBMC was associated with much lower IFN-alpha and IL-12 expression. Further, HCV replication in T lymphocytes could be completely eliminated by activation of endogenous IFN-gamma in CHC, but of IFN-alpha in occult infection. In conclusion, CHC and persistent occult HCV infection are characterized by clearly different profiles of antiviral cytokine response in circulating immune cells which are also different from those of healthy individuals. Higher expression of IL-10, combined with lower transcription of IFN-alpha, IFN-gamma and TNF-alpha, is associated with a more robust HCV replication in immune cells.

[Durability of a sustained virologic response in combination therapy with interferon/peginterferon and ribavirin for chronic hepatitis C]

BACKGROUNDS/AIMS

The ultimate goal of antiviral therapy using interferon/pegylated interferon combined with ribavirin in chronic C-viral hepatitis is to achieve a sustained virologic response (SVR). Several studies have shown that the reappearance rate of hepatitis C virus (HCV) RNA in serum after the achievement of an SVR is less than 1%; the durability of an SVR in Korean patients is not known. The aim of this study was to determine the durability of the virologic response in chronic hepatitis C patients with an SVR to antiviral therapy.

METHODS

A total of 156 patients who were treated successfully with interferon/peginterferon and ribavirin were evaluated retrospectively. Patients received either subcutaneous conventional interferon alpha 3x10(6) units three times a week or subcutaneous pegylated interferon (alpha-2a: 180 microgram, alpha-2b: 80-100 microgram) once a week in combination with ribavirin at 600-1,200 mg daily (depending on body weight). Patients with HCV genotype 1 were treated for 48 weeks, whereas those with non-genotype 1 were treated for 24 weeks.

RESULTS

Eighty-two patients underwent treatment with conventional interferon and ribavirin, whereas 74 patients were treated with pegylated interferon and ribavirin. An SVR was achieved in 73 patients (73/156, 46.8%). HCV RNA reappeared in eight patients (8/73, 11.0%; detected by qualitative PCR), including one patient with persistent viremia (1/73, 1.4%).

CONCLUSIONS

Reappearance of HCV RNA after earlier achievement of an SVR might appear more frequently than previously reported. Close follow-up of these patients is recommended and the implication of temporary viremia should be determined in the future.

Mevalonate pathway modulation is associated with hepatitis C virus RNA presence in peripheral blood mononuclear cells

Peripheral blood mononuclear cells (PBMC) constitute the main extrahepatic reservoir of hepatitis C virus (HCV). Lipid metabolism of host seems to play important role in HCV infection. The relationship between HCV presence in PBMC and the expression of mevalonate pathway has not been elucidated. The aim of this study was to investigate the association between mevalonate pathway and HCV RNA presence in PBMC after anti-HCV treatment. 67 serum and corresponding PBMC samples were collected from patients at the end of interferon alpha and ribavirin treatment. Serum total cholesterol, HDL-C and LDL-C fractions, triglycerides, as well as intracellular cholesterol and expression level of HMG-CoA reductase, geranylgeranyl pyrophosphate synthase in PBMC were measured and matched for the HCV RNA presence or absence in sera/PBMC. HCV RNA elimination from sera and PBMC was associated with higher serum cholesterol (118.5mg/dL) and LDL-C (66.42mg/dL) levels, compared to the group, where HCV RNA was detected only in PBMC (100.94 and 53.22mg/dL) or the group, where HCV RNA was found in both sera and PBMC (86.79 and 43.79mg/dL) after treatment. Increased expression of geranylgeranyl pyrophosphate synthase was found in the majority of PBMC samples that harbored HCV RNA after elimination of HCV RNA from sera. The expression of mevalonate pathway after antiviral treatment seems to be modulated depending on HCV RNA status in peripheral blood mononuclear cells.

Development and validation of a duplex quantitative real-time RT-PCR assay for simultaneous detection and quantitation of foot-and-mouth disease viral positive-stranded RNAs and negative-stranded RNAs

A simplified, cost-effective, two-step duplex quantitative real-time RT-PCR assay was shown to detect and quantify foot-and-mouth disease virus positive-stranded RNAs and negative-stranded RNAs simultaneously for improved investigation of the state of virus infection and replication. The primers and Taqman probes were selected from the coding regions of 2B gene and 3D gene respectively, which have the least variations among serotypes. Cells infected acutely, tissue samples and single cell samples were used for evaluation of the assay. At the early stages of virus infection in vitro, the replication level reached a peak at 9h.p.i. and the negative strands were detectable until 3h.p.i. The kinetics of ratios of positive strands to negative strands (+RNA/-RNA) in vivo in the liver, kidney and spleen were similar, which demonstrated that the replication dynamics were similar in the three organs. 55 single cell samples out of 187 were positive by both positive strands qPCR and negative strands qPCR, the ratios (+RNA/-RNA) ranged from 15.6 to 1463.4 which showed considerable difference among single cell samples, indicating that active viral replication differs greatly in single cells. A duplex quantitative real-time RT-PCR was validated as effective and reliable.

Hepatitis C virus and alcohol

This review will focus on the prevalence of hepatitis c virus (HCV) infection in alcoholics with and without liver disease. Evidence will be presented to demonstrate that ethanol and chronic HCV infection synergistically accelerate liver injury. Some of the major postulated mechanisms responsible for disease progression include high rates of apoptosis, lipid peroxidation, and generation of free radicals and reactive oxygen species with reduced antioxidant capacity of the liver. Acquisition and persistence of HCV infection may be due to the adverse effects of ethanol on humoral and cellular immune responses to HCV. Dendritic cells (DC) appear to be one of the major targets for ethanol's action and DC dysfunction impairs the ability of the host to generate viral specific cluster of differentiation 4 (CD4+) and cluster of differentiation 8 (CD8+) immune responses. There is a relationship between increased alcohol intake and decreased response to interferon (IFN) therapy, which may be reversed by abstinence. Clinical studies are needed to optimize treatment responses in alcoholic patients with chronic HCV infection.

Hepatitis C virus persisting after clinically apparent sustained virological response to antiviral therapy retains infectivity in vitro

Hepatitis C virus (HCV) can persist in the liver, lymphoid cells, and serum of individuals with apparently complete spontaneous or therapy-induced resolution of hepatitis C and can replicate in vivo and in vitro in human T cells. The current study was aimed at assessing the infectivity of HCV persisting at very low levels using the previously established HCV infection system in human T cells. Naive lymphoid cells were exposed to plasma and/or supernatants from cultured peripheral blood mononuclear cells from nine individuals with apparent sustained virological response after completion of antiviral therapy. Exposed cells were analyzed for HCV RNA-positive and HCV RNA-negative strands and, in selected cases, for HCV nonstructural protein 5a (NS5a), the appearance of HCV variants, and the release of virions by immunoelectron microscopy (IEM). The results showed that 11 of the 12 established cultures became HCV RNA-positive strand-reactive, whereas 4 also expressed the virus replicative strand. NS5a protein was detected in the de novo infected cells, and clonal sequencing revealed HCV variants not found in inocula. IEM demonstrated enveloped HCV particles in plasma used as inocula and in culture supernatant from T cells exposed to that plasma. Overall, HCV carried in three of the nine individuals studied elicited productive infection in vitro.

CONCLUSION

HCV persisting at very low levels long after therapy-induced resolution of chronic hepatitis C can remain infectious. The retained biological competence of the virus might have implications with respect to the mechanisms of its persistence and the epidemiology of HCV infection.

Hepatitis C virus (HCV) employs multiple strategies to subvert the host innate antiviral response

Hepatitis C virus (HCV) is a serious global health problem which accounts for approximately 40% of chronic liver diseases worldwide. HCV frequently establishes a persistent infection, although it is recognized and targeted by innate immunity as well as cellular and humoral immune mechanisms. This suggests that HCV has developed powerful strategies to escape elimination by innate and adaptive immunity. HCV-induced liver injury is thought to be mainly immune-mediated rather than due to direct cytopathic effects of the virus. Hence, therapeutic strategies should target those mechanisms favoring viral persistence since unspecific enhancement of host antiviral immunity may theoretically also promote liver injury. The present review summarizes our current understanding of how the hepatitis C virus interferes with the innate antiviral host-response to establish persistent infection.

Sustained virological response is associated with clearance of hepatitis C virus RNA and a decrease in hepatitis C virus antibody

BACKGROUND/AIM

Viral eradication in chronic hepatitis C patients with sustained virological response (SVR) after interferon (IFN) therapy remains controversial.

METHODS

During a long-term follow-up study, 157 patients with SVR to IFN-alpha-2b-based therapy were investigated with a transcription-mediated amplification (TMA) assay in serum. The hepatitis C virus (HCV) antibody was assessed by measuring the optical density (OD) (Axsym HCV v3.0) and the semiquantitative titres (RIBA HCV v3.0) of the HCV antibodies directed against the core, NS3, NS4 and NS5 proteins. A control group included 23 untreated patients with persistently normal serum alanine aminotransferase and detectable serum HCV-RNA.

RESULTS

The median duration of follow-up was 4.0 (0-10) years. Serum HCV-RNA remained undetectable in all patients. The mean HCV antibody OD were 93 +/- 19 and 45 +/- 21 before therapy and in the last available serum sample respectively (P=0.001). There was a marked decrease in the HCV antibodies directed against the NS3, NS4 and NS5 proteins (P=0.001), while the core protein titre remained strongly positive. The 23 control patients were followed for a median of 5 (2-14) years. The mean HCV antibody OD were 65 +/- 14 and 64 +/- 19 in the first and the last measurements, respectively (NS), and HCV antibody titres for structural and non-structural proteins remained unchanged.

CONCLUSION

This long-term study evaluating 157 patients demonstrated that SVR assessed by TMA is durable, and HCV antibodies were markedly decreased (mainly those directed against the non-structural proteins), emphasizing an absence of ongoing infection. These results strongly suggest that HCV infection cured in patients who achieve an SVR.