HCV Core Protein Augments Cyclosporine Immunosuppression

Reactivation of Herpesvirus in Patients With Hepatitis C Treated With Direct-Acting Antiviral Agents

We performed a case-series analysis of reactivation of herpesvirus in patients with hepatitis C virus (HCV) infection treated with direct-acting antiviral (DAA) agents. We collected data from 576 patients with HCV infection treated with DAA combinations at 3 hospitals in Spain, from November 2014 through November 2015. We also collected data from a control population (230 HCV-infected patients, matched for sex and age; 23 untreated and 213 treated with interferon-based regimens). Herpesvirus was reactivated in 10 patients who received DAA therapy (7 patients had cirrhosis and 3 patients had received liver transplants), a median of 8 weeks after the therapy was initiated. None of the controls had herpesvirus reactivation. Patients with herpesvirus reactivation were receiving the DAA agents sofosbuvir with ledipasvir (with or without ribavirin, 7/10), ombitasvir with paritaprevir and ritonavir plus dasabuvir (with or without ribavirin, 2/10), or sofosbuvir with simeprevir plus ribavirin (1/10). Two of the 10 patients developed postherpetic neuralgia and 1 patient developed kerato-uveitis. All 10 patients with herpesvirus reactivation achieved a sustained virologic response. Immune changes that follow clearance of HCV might lead to reactivation of other viruses, such as herpesvirus. Patients with HCV infection suspected of having herpesvirus infection should be treated immediately. Some groups also might be screened for herpesvirus infection.

Enhancement of Programmed Death Ligand 2 on Hepatitis C Virus Infected Hepatocytes by Calcineurin Inhibitors

Post orthotopic liver transplantation (OLT) viral hepatitis is an immunological condition where immune cells induce hepatitis during conditions of immune-suppression. The immune-regulatory programmed death-1 (PD-1)/PD-ligand 1 system is acknowledged to play important roles in immune-mediated diseases. However, the PD-1/PD-L2 interaction is not well characterized, with PD-L2 also exhibiting an immunostimulatory function. We hypothesized that this atypical molecule could affect the recurrence of post-OLT hepatitis. To test this hypothesis, we conducted immunohistochemical staining analysis and in vitro analysis of PD-L2.

Translational study of before and after liver transplantation for hepatitis B and C shows that calcineurin inhibitors (CNI) increase the expression of functional programmed death-1 on hepatocytes. The results suggest an important contribution of CNI on post transplant hepatitis occurrence and severity.

Recurrent hepatitis C virus infection post liver transplantation: impact of choice of calcineurin inhibitor

Recurrence of hepatitis C virus infection following liver transplantation (LT) for hepatitis C is universal. After LT, hepatitis C is associated with accelerated fibrosis progression and reduced graft and patient survival. Furthermore, responses to antiviral therapy in patients with recurrent hepatitis C virus post-transplant are consistently sub-optimal. Calcineurin inhibitors (CNIs) like cyclosporine A (CsA) and tacrolimus continue to dominate immunosuppressive regimens in this population; however, there is still uncertainty as to whether either offers an advantage in terms of patient outcomes. Although tacrolimus demonstrates improved efficacy in the general LT population, differences have begun to emerge between these agents regarding diabetogenic potential, antiviral activity, and fibrosis progression in patients with hepatitis C. This review critically evaluates the existing literature, providing an overview of the reported differences, concluding that despite conflicting evidence, a potential benefit of CsA in patients with hepatitis C is supported by the data and warrants further investigation. Future studies examining the role of CNIs in hepatitis C virus-positive LT recipients are required to accurately examine the effects of CNIs on outcomes such as fibrosis progression, survival, and effects on response to antiviral therapy, to provide robust information that allows clinicians to make an informed choice concerning which CNI is best for their patients.

Harmful effects of viral replication in seropositive hepatitis C virus renal transplant recipients

BACKGROUND

Seropositivity for hepatitis C virus (HCV) predicts lower patient and graft survival after renal transplantation (RT). However, the influence of viral replication at transplantation on long-term outcome remains to be determined.

METHODS

This was a retrospective study conducted in four Spanish hospitals, from 1997 to 2006. Data of all patients with RT, who displayed HCV+ (enzyme-linked immunosorbent assay), and with negative viremia at RT (NEG group) were collected (n=41). For each NEG patient enrolled, data of two patients with RT nearest in time, HCV+, and positive viremia (POS group) were also collected (n=78).

RESULTS

The POS group showed a higher incidence of long-term liver disease (56.4% vs. 24.4%, P=0.0009) and episodes of transaminase elevation (38.5% vs. 7.3%, P=0.0003) and worse renal function (serum creatinine [sCr], 3.0 [2.7] vs. 1.9 [1.6] mg/dl, P=0.032; glomerular filtration rate, 43.7 [22.4] vs. 56.9 [27.9] ml/min, P=0.075). Noteworthy, 24.4% of NEG patients reactivated after RT, showing a worse patient survival (P=0.039). Active viral replication at RT and dialysis requirement in the first week remained as independent predictors of lower graft survival (death censored): hazards ratio, 3.11 (95% confidence interval, 1.34-7.19; P=0.009) and hazards ratio 3.13 (95% confidence interval, 1.53-6.37; P=0.002).

CONCLUSIONS

This study shows that active viral replication at transplantation is an independent risk factor for graft failure in patients with positive serology for HCV.

The human fetal immune response to hepatitis C virus exposure in utero

BACKGROUND

Although the rate of mother-to-child transmission of hepatitis C virus (HCV) is low, the effect of HCV exposure in utero on the fetal immune system is unknown.

METHODS

Umbilical cord blood was obtained from 7 neonates born to HCV-seropositive, HCV RNA-positive women and 8 neonates born to HCV-seronegative women. Cord blood mononuclear cells were analyzed by immunophenotyping and by intracellular cytokine staining after HCV-specific and polyclonal stimulation. Plasma was analyzed for anti-HCV immunoglobulin M (IgM), cytokine/granzyme concentrations, and indoleamine 2,3-dioxygenase (IDO) activity.

RESULTS

HCV-exposed neonates had significantly lower levels of regulatory T cells expressing HLA-DR, lower CD4(+) and CD8(+) T cell activation, and lower plasma levels of pro-inflammatory markers than did controls. However, CD4(+) and CD8(+) T cells from HCV-exposed neonates had higher IFN-γ production in response to polyclonal stimulation than did T cells from controls. IDO activity was similar between groups. No HCV-specific T cell responses or anti-HCV IgM were detected in any neonates.

CONCLUSIONS

HCV-exposed neonates showed a relative suppression of immune activation and pro-inflammatory markers, which was counterbalanced by an increased production capacity for IFN-γ. These results suggest that HCV encounters the fetal immune system in utero, and alters the balance between suppressive and pro-inflammatory responses.

Oral immunization with attenuated Salmonella carrying a co-expression plasmid encoding the core and E2 proteins of hepatitis C virus capable of inducing cellular immune responses and neutralizing antibodies in mice

Hepatitis C virus (HCV) core protein has long been considered an attractive candidate for inclusion in a protective vaccine. However, this protein may hamper the development of systemic immune responses because of its immune suppressive properties. We previously reported that immune responses to HCV core protein could be efficiently induced by attenuated Salmonella carrying the HCV core protein, but not the HCV core DNA vaccine. To optimize the combination of the core protein and envelope protein 2 (E2) into a vaccine formulation to induce cellular immune responses and neutralizing antibodies, we constructed a plasmid containing two expression cassettes. One expression cassette was included to regulate the expression of HCV core protein by an inducible in vivo-activated Salmonella promoter, the other was included to regulate the expression of HCV E2 protein by the cytomegalovirus enhancer/promoter. Oral immunization of BALB/c mice with the attenuated Salmonella strain SL7207 carrying this plasmid efficiently induced HCV core and E2-specific cellular immune responses and antibodies. IgG purified from immunized mice could neutralize the infectivity of HCV pseudoparticles (HCVpp) of both the autologous Con 1 isolate and the heterologous H77 isolate, and cell culture produced HCV (HCVcc) of Con1-JFH1 chimera. These results indicated that this vaccine strategy can effectively deliver core and E2 protein to the immune system and provide a promising approach for the development of prophylactic and therapeutic vaccines against HCV infection.

Kidney grafts from HCV-positive donors: advantages and disadvantages

The Organ Procurement and Transplantation Network database (2001-2006) was reviewed for kidney transplant (KT) recipients, to evaluate the effects of use of grafts from donors positive for hepatitis C virus (HCV) on recipient outcome. Data for 76,787 de novo adult KT recipients were included in the analysis. Serologic tests revealed HCV positivity in 6.25% of cadaver kidneys and 2.97% of living-donor kidneys. Median follow-up in patients still alive was 36 months. At multivariable Cox regression analysis in recipients of cadaver kidney, HCV serostatus was significantly associated with overall and graft survival (both P < .001), with a hazard ratio for HCV-positive patients of 1.43 for overall survival and 1.48 for graft survival. Similar results were obtained for living-donor kidney recipients. Recipients of HCV-positive organs tended to be male and African American and to have a shorter waiting time. Infection was the most commonly reported cause of death in recipients of organs from HCV-positive donors. In patients willing to accept HCV-positive grafts (929 [25.6%]), waiting time was significantly shortened (P < .001). However, this benefit was offset by decreased patient survival (P < .001) and graft survival (P = .007).

Measurement of CD4+ T-cell function in predicting allograft rejection and recurrent hepatitis C after liver transplantation

Recurrence of hepatitis C virus (HCV) can be difficult to distinguish from acute cellular rejection (ACR) following liver transplantation. The Cylex Immune Function Assay (ImmuKnow) provides objective measure of recipient's immune function. The goal is to assess the ability of this assay to distinguish these similar conditions. A retrospective review was performed in 54 recipients with HCV. ImmuKnow assays were measured with allograft biopsies. Levels of adenosine triphosphate (ATP) release from CD4+ T cells (ng/mL) were compared with the following biopsy result classifications: 365 ± 130 with ACR (n = 11), 152 ± 100 with recurrent HCV (n = 26), 240 ± 71 with normal biopsies (n = 12), and 157 ± 130 with overlapping features of ACR and recurrent HCV (n = 5). Recipients with recurrent HCV had lower immune response than those with ACR (p < 0.0001).Using a cutoff level of 220, the sensitivity and specificity for distinguishing two conditions were 88.5% and 90.9%, respectively. When recipients with overlapping features had low immune response, three of four recipients' subsequent biopsies showed recurrent HCV. In conclusion, the ImmuKnow assay can be a sensitive and specific additional test for distinguishing recurrent HCV from ACR and may be useful for predicting which recipients may be most vulnerable to recurrent HCV.

Hepatitis C virus core proteins derived from different quasispecies of genotype 1b inhibit the growth of Chang liver cells

AIM: To investigate the influence of different quasispecies of hepatitis C virus (HCV) genotype 1b core protein on growth of Chang liver cells.

METHODS: Three eukaryotic expression plasmids (pEGFP-N1/core) that contained different quasispecies truncated core proteins of HCV genotype 1b were constructed. These were derived from tumor (T) and non-tumor (NT) tissues of a patient infected with HCV and C191 (HCV-J6). The core protein expression plasmids were transiently transfected into Chang liver cells. At different times, the cell cycle and apoptosis was assayed by flow cytometry, and cell proliferation was assayed by methyl thiazolyl tetrazolium (MTT) assay.

RESULTS: The proportion of S-phase Chang liver cells transfected with pEGFP-N1/core was significantly lower than that of cells transfected with blank plasmid at three different times after transfection (all P < 0.05). The proliferation ratio of cells transfected with pEGFP-N1/core was significantly lower than that of cells transfected with blank plasmid. Among three different quasispecies, T, NT and C191 core expression cells, there was no significant difference in the proportion of S- and G₀/G₁-phase cells. The percentage of apoptotic cells was highest for T (T > NT > C191), and apoptosis was increased in cells transfected with pEGFP-N1/core as the transfection time increased (72 h > 48 h > 24 h).

CONCLUSION: These results suggest that HCV genotype 1b core protein induces apoptosis, and inhibits cell-cycle progression and proliferation of Chang liver cells. Different quasispecies core proteins of HCV genotype 1b might have some differences in the pathogenesis of HCV persistent infection and hepatocellular carcinoma.

An assessment of interactions between hepatitis C virus and herpesvirus reactivation in liver transplant recipients using molecular surveillance

Hepatitis C virus (HCV) has been proposed to have immunomodulatory effects in transplant recipients and may promote herpesvirus reactivation. To assess this, we compared the incidence of herpesvirus reactivation in HCV-positive and HCV-negative liver transplant recipients. Quantitative viral load testing was performed at regular intervals posttransplantation for cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesviruses (HHV) 6, 7, and 8, and varicella zoster virus (VZV) in 177 liver transplant patients who were HCV-positive (n=60) or HCV-negative (n=117). The incidence of CMV disease, CMV viremia, and the peak CMV viral load was not significantly different in HCV-positive vs. HCV-negative patients. Similarly, no differences in HHV-6 or EBV reactivation were observed. HHV-8 or VZV viremia was not detected in any patient in the study. A lower incidence of HHV-7 infection occurred in HCV-positive patients vs. HCV-negative patients (47.6% vs. 72.7%; P=0.006). In conclusion, these results suggest that HCV infection does not appear to promote herpesvirus reactivation after liver transplantation.

Hepatitis C virus infection and kidney transplantation: predictors of patient and graft survival

BACKGROUND

The effect of hepatitis C virus (HCV) infection on patients undergoing kidney transplantation (KTx) is uncertain. This study aimed to evaluate the outcomes of our HCV+/end-stage renal disease (ESRD) patient population based on the therapeutic option including KTx or continuation in dialysis.

METHODS

KTx performed at Virginia Commonwealth University Hospital between January 2000 and December 2004 were tracked prospectively. Forty-three out of a total of 394 KTx patients included in the analysis were HCV+. A group of 52 contemporaneous HCV+/ESRD patients listed, but never transplanted, was also analyzed. HCV-negative transplanted patients were used as the control group.

RESULTS

Patient survival posttransplantation was 81.4% and 68.5% at 1 and 3 years in the HCV+ group, and 97.1% and 92.9% at 1 and 3 years in the HCV- group, respectively (P=0.001). Graft survival was 81.2% and 64.1% at 1 and 3 years in the HCV+ group, and 93.2% and 84.1% at 1 and 3 years posttransplantation in the HCV- group (P=0.01). Univariate analysis identified Knodell score as a predictor of mortality in HCV+ patients (P=0.04). Cox proportional hazards multivariate analysis identified deceased donor (P=0.02), previous kidney transplant (P=0.007), pretransplant diabetes (P=0.05), and Knodell Score (P=0.012) as predictors of patient mortality. Patient survival was superior in HCV+ patients undergoing KTx versus remaining on dialysis.

CONCLUSIONS

Patients with ESRD/HCV+ benefit from KTx without achieving the excellent survival of HCV-/ESRD patients. Liver biopsy is a useful tool to identify advanced liver disease at pretransplantation time.

A prospective evaluation of fibrosis progression in patients with recurrent hepatitis C virus following liver transplantation

Recurrence of hepatitis C virus (HCV) following liver transplantation (LT) is universal. A subset of these patients develop advanced fibrosis and cirrhosis and it is believed that this leads to increased posttransplantation mortality. The specific aims of this study were to determine the incidence of advanced fibrosis and those factors associated with this process, and to evaluate causes for mortality in patients with recurrent HCV. A total of 227 patients who underwent LT with chronic HCV were monitored prospectively. The mean age of this group at LT was 49.5 yr; 76% were male and 85% were Caucasian. Fibrosis progression was monitored by protocol liver biopsy, initially performed 6 months after LT and then at 6- to 24-month intervals. Advanced fibrosis, defined as the bridging fibrosis or cirrhosis, developed in 1%, 11%, 25%, and 41% of patients after 1, 3, 5, and 6-10 yr, respectively. Acute cellular rejection hepatic steatosis, a persistent elevation in serum alanine aminotransferase and donor-race were associated with the development of advanced fibrosis. In contrast, the development of advanced fibrosis was not affected by the use of interferon prior to undergoing LT, cytomegalovirus disease, or donor age. A total of 60 patients (26%) died over 15 yr of follow-up. Although graft failure accounted for 45% of deaths in patients with advanced fibrosis, this represented only 8% of all deaths in patients with recurrent HCV. Sepsis was the most common cause of death and this was observed with similar frequency in patients who developed advanced fibrosis (45%) and in those with less advanced fibrosis (47%). In conclusion, approximately 41% of patients with recurrent HCV developed advanced fibrosis 6-10 yr after LT. However, complications associated with sepsis, not recurrent cirrhosis, was the most common cause of death in patients with recurrent HCV and this was similar in patients with or without advanced fibrosis.

Hepatitis C virus core protein: an update on its molecular biology, cellular functions and clinical implications

The present review article is an update on various features of hepatitis C virus (HCV) core protein including its molecular biology, role in HCV replication, involvement in HCV pathogenesis, etiological role in hepatocellular carcinogenesis, significance in diagnosis and vaccination against HCV infection. Core protein is a structural protein of HCV virus and has only recently been characterized. It was found to play a major role in HCV-induced viral hepatitis. Although published information shows a lot about the clinical significance of HCV core protein, several studies are still needed to demonstrate its exact significance in viral biology and underlying HCV pathogenesis.