Lack of optimal T-cell reactivity against the hepatitis C virus is associated with the development of fibrosis/cirrhosis during chronic hepatitis

Chronic Hepatitis C Infection Treated with Direct-Acting Antiviral Agents and Occurrence/Recurrence of Hepatocellular Carcinoma: Does It Still Matter?

Hepatitis C virus (HCV) infection is a significant risk factor for liver cirrhosis and hepatocellular carcinoma (HCC). Traditionally, the primary prevention strategy for HCV-associated HCC has focused on removing infection through antiviral regimes. Currently, highly effective direct-acting antivirals (DAAs) offer extraordinary success across all patient categories, including cirrhotics. Despite these advancements, recent studies have reported that even after sustained virologic response (SVR), individuals with advanced liver disease/cirrhosis at the time of DAA treatment may still face risks of HCC occurrence or recurrence. Based on this premise, this review tries to shed light on the multiple mechanisms that establish a tumorigenic environment, first, during chronic HCV infection and then, after eventual viral eradication by DAAs. Furthermore, it reviews evidence reported by recent observational studies stating that the use of DAAs is not associated with an increased risk of HCC development but rather, with a significantly lower chance of liver cancer compared with DAA-untreated patients. In addition, it seeks to provide some practical guidance for clinicians, helping them to manage HCC surveillance of patients who have achieved SVR with DAAs.

The Role of Epigenetic Mechanisms in the Pathogenesis of Hepatitis C Infection

Hepatitis C virus (HCV) is a hepatotropic virus that can be transmitted through unsafe medical procedures, such as injections, transfusions, and dental treatment. The infection may be self-limiting or manifest as a chronic form that induces liver fibrosis, cirrhosis, or progression into hepatocellular carcinoma (HCC). Epigenetic mechanisms are major regulators of gene expression. These mechanisms involve DNA methylation, histone modifications, and the activity of non-coding RNAs, which can enhance or suppress gene expression. Abnormal activity or the dysregulated expression of epigenetic molecules plays an important role in the pathogenesis of various pathological disorders, including inflammatory diseases and malignancies. In this review, we summarise the current evidence on epigenetic mechanisms involved in HCV infection and progression to HCC.

Hepatocellular Carcinoma Mechanisms Associated with Chronic HCV Infection and the Impact of Direct-Acting Antiviral Treatment

Hepatitis C virus (HCV) infection is the major risk factor for liver cirrhosis and hepatocellular carcinoma (HCC). The mechanisms of HCC initiation, growth, and metastasis appear to be highly complex due to the decade-long interactions between the virus, immune system, and overlapping bystander effects of host metabolic liver disease. The lack of a readily accessible animal model system for HCV is a significant obstacle to understand the mechanisms of viral carcinogenesis. Traditionally, the primary prevention strategy of HCC has been to eliminate infection by antiviral therapy. The success of virus elimination by antiviral treatment is determined by the SVR when the HCV is no longer detectable in serum. Interferon-alpha (IFN-α) and its analogs, pegylated IFN-α (PEG-IFN-α) alone with ribavirin (RBV), have been the primary antiviral treatment of HCV for many years with a low cure rate. The cloning and sequencing of HCV have allowed the development of cell culture models, which accelerated antiviral drug discovery. It resulted in the selection of highly effective direct-acting antiviral (DAA)-based combination therapy that now offers incredible success in curing HCV infection in more than 95% of all patients, including those with cirrhosis. However, several emerging recent publications claim that patients who have liver cirrhosis at the time of DAAs treatment face the risk of HCC occurrence and recurrence after viral cure. This remains a substantial challenge while addressing the long-term benefit of antiviral medicine. The host-related mechanisms that drive the risk of HCC in the absence of the virus are unknown. This review describes the multifaceted mechanisms that create a tumorigenic environment during chronic HCV infection. In addition to the potential oncogenic programming that drives HCC after viral clearance by DAAs, the current status of a biomarker development for early prediction of cirrhosis regression and HCC detection post viral treatment is discussed. Since DAAs treatment does not provide full protection against reinfection or viral transmission to other individuals, the recent studies for a vaccine development are also reviewed.

Intrahepatic NK cells function suppressed in advanced liver fibrosis

BACKGROUND

Although numerous epidemiological studies indicate that hepatitis B virus-related liver fibrosis (HBV-LF), particularly cirrhosis, represents the main risk factor for liver cancer development, the mechanisms determining the persistence of fibrosis and liver cancer pathogenesis are still poorly defined. Few studies have investigated the status of NK cells during different stages of HBV-LF.

METHODS

Liver tissues at least 3 cm away from the tumour site and peripheral blood were obtained simultaneously from 32 HBV-infected patients undergoing surgery for HCC at the medical centre of Sun Yat-sen University. We detected the amount of NK cells and analysed the phenotype and function of NK cells by flow cytometry.

RESULTS

We found that there was no difference in the amount of circulating and intrahepatic NK cells between early and advanced HBV-LF. However, NKp46 expression on intrahepatic NK cells decreased and productions of IFN-γ and perforin of intrahepatic NK cells declined apparently in patients with advanced HBV-LF.

CONCLUSION

In the present study, we displayed that in patients with advanced HBV-LF, the expression of NKp46 on intrahepatic NK cells as well as productions of IFN-γ and perforin of intrahepatic NK cells decreased significantly. These results indicated that the immune function of intrahepatic NK cells in patients with advanced HBV-LF was suppressed distinctly, which provided new insight into the potential role of NK cells in the persistence of fibrosis and into the occurrence of HCC following cirrhosis.

Inflammatory status in human hepatic cirrhosis

This review focuses on new findings about the inflammatory status involved in the development of human liver cirrhosis induced by the two main causes, hepatitis C virus (HCV) infection and chronic alcohol abuse, avoiding results obtained from animal models. When liver is faced to a persistent and/or intense local damage the maintained inflammatory response gives rise to a progressive replacement of normal hepatic tissue by non-functional fibrotic scar. The imbalance between tissue regeneration and fibrosis will determine the outcome toward health recovery or hepatic cirrhosis. In all cases progression toward liver cirrhosis is caused by a dysregulation of mechanisms that govern the balance between activation/homeostasis of the immune system. Detecting differences between the inflammatory status in HCV-induced vs alcohol-induced cirrhosis could be useful to identify specific targets for preventive and therapeutic intervention in each case. Thus, although survival of patients with alcoholic cirrhosis seems to be similar to that of patients with HCV-related cirrhosis (HCV-C), there are important differences in the altered cellular and molecular mechanisms implicated in the progression toward human liver cirrhosis. The predominant features of HCV-C are more related with those that allow viral evasion of the immune defenses, especially although not exclusively, inhibition of interferons secretion, natural killer cells activation and T cell-mediated cytotoxicity. On the contrary, the inflammatory status of alcohol-induced cirrhosis is determined by the combined effect of direct hepatotoxicity of ethanol metabolites and increases of the intestinal permeability, allowing bacteria and bacterial products translocation, into the portal circulation, mesenteric lymph nodes and peritoneal cavity. This phenomenon generates a stronger pro-inflammatory response compared with HCV-related cirrhosis. Hence, therapeutic intervention in HCV-related cirrhosis must be mainly focused to counteract HCV-immune system evasion, while in the case of alcohol-induced cirrhosis it must try to break the inflammatory loop established at the gut-mesenteric lymph nodes-peritoneal-systemic axis.

The peritoneal macrophage inflammatory profile in cirrhosis depends on the alcoholic or hepatitis C viral etiology and is related to ERK phosphorylation

BACKGROUND

The development of ascites in cirrhotic patients generally heralds a deterioration in their clinical status. A differential gene expression profile between alcohol- and hepatitis C virus (HCV)-related cirrhosis has been described from liver biopsies, especially those associated with innate immune responses. The aim of this work was to identify functional differences in the inflammatory profile of monocyte-derived macrophages from ascites in cirrhotic patients of different etiologies in an attempt to extrapolate studies from liver biopsies to immune cells in ascites. To this end 45 patients with cirrhosis and non-infected ascites, distributed according to disease etiology, HCV (n=15) or alcohol (n=30) were studied. Cytokines and the cell content in ascites were assessed by ELISA and flow cytometry, respectively. Cytokines and ERK phosphorylation in peritoneal monocyte-derived macrophages isolated and stimulated in vitro were also determined.

RESULTS

A different pattern of leukocyte migration to the peritoneal cavity and differences in the primed status of macrophages in cirrhosis were observed depending on the viral or alcoholic etiology. Whereas no differences in peripheral blood cell subpopulations could be observed, T lymphocyte, monocyte and polymorphonuclear cell populations in ascites were more abundant in the HCV than the alcohol etiology. HCV-related cirrhosis etiology was associated with a decreased inflammatory profile in ascites compared with the alcoholic etiology. Higher levels of IL-10 and lower levels of IL-6 and IL-12 were observed in ascitic fluid from the HCV group. Isolated peritoneal monocyte-derived macrophages maintained their primed status in vitro throughout the 24 h culture period. The level of ERK1/2 phosphorylation was higher in ALC peritoneal macrophages at baseline than in HCV patients, although the addition of LPS induced a greater increase in ERK1/2 phosphorylation in HCV than in ALC patients.

CONCLUSIONS

The macrophage inflammatory status is higher in ascites of alcohol-related cirrhotic patients than in HCV-related patients, which could be related with differences in bacterial translocation episodes or regulatory T cell populations. These findings should contribute to identifying potential prognostic and/or therapeutic targets for chronic liver diseases of different etiology.

Temporal association between increased virus-specific Th17 response and spontaneous recovery from recurrent hepatitis C in a liver transplant recipient

BACKGROUND

Spontaneous clearance of hepatitis C virus (HCV) after orthotopic liver transplantation (OLT) is a rare occurrence. Here, we present detailed immunological analysis of an interferon naive OLT recipient receiving uninterrupted immunosuppression who cleared HCV spontaneously 2 years after transplantation.

METHODS

Enzyme-linked immunospot assay analysis of peripheral T-cell interferon gamma (IFN-γ), interleukin (IL)-10, and IL-17 response to HCV core and nonstructural antigen 4 and enzyme-linked immunosorbent assay (ELISA) to collagen (Col) subtypes I, II, IV, and V were performed in the index patient at the time of viral clearance and compared with an OLT cohort with persistent viremia matched for time from OLT, immunosuppression, and histology. Enzyme-linked immunospot assay and ELISA analysis were repeated on the patient 4 years after OLT. Transcription-mediated amplification assays were used to confirm viral clearance.

RESULTS

Compared with a cohort of post-OLT and nontransplanted viremic HCV patients, the index patient with HCV clearance demonstrated higher IL-17, IL-10, and lower IFN-γ response to nonstructural antigen 4 and core antigen and a higher titer of antibodies (Abs) to Col subtypes I, II, and V during clearance. On follow-up 2 years later, HCV-specific IFN-γ was increased in the index patient, with a decline in IL-17 and IL-10 response and Col I, II, and V Ab titer.

CONCLUSIONS

Virus-induced activation of Th-17 cells may contribute to HCV clearance post-OLT. Maintenance of viral suppression may be facilitated by restoration of Th1 (IFN-γ) responses. Modulation of Th17 immunity deserves further attention as a therapeutic strategy in the treatment of HCV recurrence post-OLT.

Immune response to extracellular matrix collagen in chronic hepatitis C-induced liver fibrosis

Hepatitis C virus (HCV) infection and its recurrence after orthotopic liver transplantation (OLT) are associated with the remodeling of extracellular matrix (ECM) components [particularly collagen (Col)], which leads to fibrosis. Our aim was to determine whether the development of antibodies (Abs) to self-antigen Col in HCV-infected patients correlates with the fibrosis stage and the peripheral cytokine response. Patients with chronic HCV infection, patients with HCV recurrence after OLT who had undergone a biopsy procedure, and healthy control subjects were enrolled. The HCV subjects (n = 70) were stratified as follows: (1) a non-OLT group without fibrosis (Scheuer stages 0-2), (2) a non-OLT group with fibrosis (Scheuer stages 3-4), (3) a post-OLT group without fibrosis (Scheuer stages 0-2), and (4) a post-OLT group with fibrosis (Scheuer stages 3-4). Serum samples were analyzed for Abs against Col1, Col2, Col4, Col5, and vimentin with enzyme-linked immunosorbent assays. Serum levels of cytokines were measured with multiplex bead immunoassays. The levels of Abs to Col1 were higher in the fibrosis groups versus the no-fibrosis groups and the controls for both non-OLT patients (P < 0.001) and post-OLT patients (P = 0.01). There were increased levels of Abs to Col2, Col4, Col5, and vimentin in the non-OLT fibrosis group (Col2, P = 0.0001; Col4, P = 0.122; Col5, P < 0.0001; vimentin, P = 0.36) and in the post-OLT fibrosis group (Col2, P = 0.006; Col4, P = 0.19; Col5, P < 0.0001; vimentin, P = 0.24) in comparison with the no-fibrosis groups. The non-OLT and post-OLT fibrosis groups demonstrated significantly higher T helper 2 (T(h) 2) and T helper 17 (T(h) 17) cytokine levels and lower T helper 1 cytokine levels in comparison with the no-fibrosis groups. Our results demonstrate that in HCV-infected patients, the levels of Abs to ECM Col1, Col2, and Col5 positively correlate with liver fibrosis, which is associated with a predominantly T(h) 2 and T(h) 17 cytokine profile.

Lymphocyte subset characterization associated with persistent hepatitis C virus infection and subsequent progression of liver fibrosis

This study aims to deepen the understanding of lymphocyte phenotypes related to the course of hepatitis C virus (HCV) infection and progression of liver fibrosis in a cohort of atomic bomb survivors. The study subjects comprise 3 groups: 162 HCV persistently infected, 145 spontaneously cleared, and 3,511 uninfected individuals. We observed increased percentages of peripheral blood T(H)1 and total CD8 T cells and decreased percentages of natural killer (NK) cells in the HCV persistence group compared with the other 2 groups after adjustment for age, gender, and radiation exposure dose. Subsequently, we determined that increased T(H)1 cell percentages in the HCV persistence group were significantly associated with an accelerated time-course reduction in platelet counts-accelerated progression of liver fibrosis-whereas T(C)1 and NK cell percentages were inversely associated with progression. This study suggests that T(H)1 immunity is enhanced by persistent HCV infection and that percentages of peripheral T(H)1, T(C)1, and NK cells may help predict progression of liver fibrosis.

Characterization of HCV-specific CD4+Th17 immunity in recurrent hepatitis C-induced liver allograft fibrosis

Hepatitis C virus (HCV) recurrence with accelerated fibrosis following orthotopic liver transplantation (OLT) is a universal phenomenon. To evaluate mechanisms contributing to HCV induced allograft fibrosis/cirrhosis, we investigated HCV-specific CD4+Th17 cells and their induction in OLT recipients with recurrence utilizing 51 HCV+ OLT recipients, 15 healthy controls and 9 HCV- OLT recipients. Frequency of HCV specific CD4+ Tcells secreting IFN-γ, IL-17 and IL-10 was analyzed by ELISpot. Serum cytokines and chemokines were analyzed by LUMINEX. Recipients with recurrent HCV induced allograft inflammation and fibrosis/cirrhosis demonstrated a significant increase in frequency of HCV specific CD4+Th17 cells. Increased pro-inflammatory mediators (IL-17, IL-1β, IL-6, IL-8 and MCP-1), decreased IFN-γ, and increased IL-4, IL-5 and IL-10 levels were identified. OLT recipients with allograft inflammation and fibrosis/cirrhosis demonstrated increased frequency of Foxp3+ regulatory T cells (Tregs) that inhibited HCV specific CD4+Th1 but not Th17 cells. This suggests that recurrent HCV infection in OLT recipients induces an inflammatory milieu characterized by increased IL-6, IL-1β and decreased IFN-γ which facilitates induction of HCV specific CD4+Th17 cells. These cells are resistant to suppression by Tregs and may mediate an inflammatory cascade leading to cirrhosis in OLT recipients following HCV recurrence.

T-helper cells and liver fibrosis in hepatitis C virus-monoinfected patients

Limited data suggest that low T-helper cell levels may be observed in hepatitis C virus (HCV) monoinfected patients with decompensated liver disease. We sought to determine the distribution and relationship of T-helper cells (CD4) to liver fibrosis in HCV-monoinfected patients before and during pegylated interferon (PegIFN) therapy. CD4 populations were prospectively determined using flow cytometry. All subjects had compensated liver disease. Baseline and subsequent CD4 counts at treatment weeks 12, 24, 36 and 48 and at two time points following treatment discontinuation (weeks 60 and 72) were evaluated. Ishak score was determined by a central pathologist. At baseline, data from 267 subjects were available. Mean age was 50 and 68% were male/Caucasian. HCV viral load was >800 000 IU/mL in 55%. Nearly half (48%) were Ishak 4-6 with all stages represented. Mean CD4 count was 1004 cells/mm(3) + or - 400, and 6% had counts <500. There was a trend towards lower CD4 counts among cirrhotic subjects (P = 0.07). A CD4 decrease was noted following PegIFN initiation. Mean CD4 decline was 38.9% and was statistically significant for all fibrosis stages compared with baseline levels, but not between fibrosis levels. CD4 counts <500 cells/mm(3) are seen in <10% of HCV-monoinfected subjects. A trend towards lower CD4 counts in subjects with advanced fibrosis was observed. However, at baseline and during/after PegIFN therapy, no significant differences were observed between groups. CD4 counts declined during PegIFN treatment, but returned to baseline after completion. The significance of these findings in terms of disease progression and treatment response requires further evaluation.

Monitoring peripheral blood CD4+ adenosine triphosphate activity in recurrent hepatitis C and its correlation to fibrosis progression

The recurrence of hepatitis C virus (HCV) after orthotopic liver transplantation (OLT) is often associated with rapid fibrosis progression attributed to the state of impaired cellular immunity. At present, there are no means to predict those at risk for progression. Peripheral blood CD4+ adenosine triphosphate (ATP) release (the ImmuKnow assay) correlates with immunoreactivity and has been used to monitor global cellular immune function in transplant recipients. The aim of this study was to assess the relationship between cellular immune function measured by the ImmuKnow assay and fibrosis progression in patients with HCV recurrence after OLT. The ImmuKnow assay was prospectively performed in adult HCV patients at 4 and 12 months post-OLT. Protocol liver biopsies were performed (on day 7, in month 4, and yearly) after OLT. The first biopsy that showed fibrosis post-OLT was used to determine the time interval for developing fibrosis. Sixty-two patients met the inclusion criteria. The median follow-up time was 12 (6.5-12.1) months. Fibrosis progression was observed in 61.3% of the patients. ATP levels were lower in patients with fibrosis progression in comparison with patients without progression at 4 months (145 versus 259 ng/mL, P < 0.001) and at 12 months (152 versus 264 ng/mL, P = 0.008). ATP levels at 4 and 12 months post-OLT were found to be significantly associated with a higher hazard of progression. For each 25-unit increase in ATP levels at 4 and 12 months after transplantation, the hazard of fibrosis progression decreased by 22% (P = 0.001) and 12% (P = 0.015), respectively. In conclusion, greater suppression of cellular immunity, as measured by the ImmuKnow assay, is associated with more rapid progression of fibrosis in patients with recurrent HCV post-OLT. Post-OLT monitoring of CD4+ ATP activity may identify a subset of patients at greatest risk for early fibrosis progression.

Characterization of virus-specific T-cell immunity in liver allograft recipients with HCV-induced cirrhosis

Recurrent hepatitis C infection (HCV) following liver transplantation causes accelerated allograft cirrhosis. Here we characterized HCV-specific immunity in adult liver transplant recipients (n = 74) with and without allograft cirrhosis. Patients were divided into hepatic inflammation/no cirrhosis (METAVIR scores 0-2, HIN) and hepatic cirrhosis (score 3-4, HFC). As control, 20 normal subjects and 10 non-HCV liver transplant patients were included. Twenty-five different serum cytokines were analyzed using LUMINEX. Frequency of T-cells specific to HCV-derived proteins (NS3, NS4, NS5, Core) was characterized using ELISPOT immunoassays. There was no difference in clinical characteristics between HIN (n = 49) and HFC (n = 25) groups. HIN group had high serum IFN-gamma and IL-12 while HFC demonstrated elevated IL-4, IL-5 and IL-10 (p < 0.01). HCV (NS3, NS4, NS5, Core)-specific IFN-gamma-producing CD4+ T-cells were elevated in the HIN group whereas the HFC patients showed predominance of HCV-specific IL-5 and IL-10-producing CD4+ T-cells.

CONCLUSIONS

Lack of HCV-specific Th1-type T-cell immunity is observed in liver transplant recipients with advanced allograft cirrhosis.

A novel hepatitis C virus vaccine approach using recombinant Bacillus Calmette-Guerin expressing multi-epitope antigen

Hepatitis C virus (HCV) is a major cause of liver disease worldwide. HCV infection is associated with high morbidity and has become a major problem in public health. Until now, there has been no effective prophylactic or therapeutic vaccine. BCG, a live vaccine typically used for tuberculosis prevention, has been increasingly utilized as a vector for the expression of recombinant proteins that will induce specific humoral and cellular immune responses. In this study, recombinant BCG (rBCG) was engineered to express a HCV multi-epitope antigen CtEm, and HLA-A2.1 transgenic mice were immunized with rBCG-CtEm. High levels of specific anti-HCV antibodies targeted to mimotopes of HVR1 were detected in the serum. HCV-specific lymphocyte proliferation assay, cytokine determination and cytotoxicity assay indicated that HCV epitope-specific cellular immune responses were elicited in vitro. The rBCG-CtEm immunization conferred protection against infection with the recombinant vaccinia virus (rVV-HCV-CNS) in vivo. These results suggest that rBCG expressing multi-epitope antigen may serve as an effective vaccine against HCV infection.

Elevated soluble CD30 characterizes patients with hepatitis C virus-induced liver allograft cirrhosis

Hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (OLT) significantly accelerates progression to allograft cirrhosis. Current biochemical parameters to monitor progression of chronic HCV after OLT have yielded low specificity and sensitivity. Here we investigated the HCV-specific immunity and serum levels of soluble CD30 (sCD30), a novel marker of Th2 immunity, in patients with and without allograft cirrhosis. Patients with hepatic inflammation but no cirrhosis (HIN, n=20) revealed elevated serum interferon (IFN)-gamma and high frequency of IFN-gamma producing CD4 T(h1) cells compared to those with hepatic cirrhosis (HFC, n=20) that had high interleukin (IL)-5 and IL-5 producing CD4 T(h2) cells. Patients with HFC, but not HIN, were found to have significantly higher levels of sCD30. Therefore, we conclude that lack of optimal Th1-type CD4 T cells is associated with HCV-induced allograft cirrhosis. Further, sCD30 may represent a novel marker for surveillance of hepatic cirrhosis in transplant recipients with chronic HCV infection.

Effects of interferon-alpha subtypes on the TH1/TH2 balance in peripheral blood mononuclear cells from patients with hepatitis virus infection-associated liver disorders

Interferon-alpha (IFN-alpha) has recently been shown to modulate in vitro T helper (Th) 1-driven responses in the peripheral blood mononuclear cells (PBMC) of patients with hepatitis B virus or C virus infection. In this study, we examined the in vitro effects of IFN-alpha subtypes (IFN-alpha1, -alpha2, -alpha5, -alpha8, and -alpha10) on the Th1/Th2 balance in PBMC obtained from patients with hepatitis virus infection-associated liver disorders and chronic hepatitis (CH), in comparison with the effect on healthy control volunteer PBMC. The Th1-type cell percentages and Th1/Th2 ratios were significantly higher in the PBMC of patients when compared with controls both before and after cultivation in vitro, with the IFN-alpha subtypes. The IFNalpha-5 induced an increase in the Th2-type cell percentages in both control and patient PBMC, resulting in that IFN-alpha5 lowered the Th1/Th2 ratio in patients with CH. Furthermore, statistical analysis revealed that IFN-alpha8 significantly promoted an increase in the Th1/Th2 ratios of PBMC from patients with CH and liver cirrhosis (LC) but not that of PBMC from patients with LC-hepatocellular carcinoma (HCC) and HCC. These findings imply that hepatitis virus infection and its disease status modify the effects of IFN-alpha subtypes on Th1 and Th2 immune balance in patients. Our findings should help to elucidate the mechanisms underlying successful IFN therapy for hepatitis virus infection and prevention of hepatocellular carcinogenesis.

Is vaccine therapy the future in cancer prevention?

One vaccine designed to prevent cancer by preventing a precursor infection is already in common use, and at least one more is in the latter stages of clinical development. These vaccines are part of a new era of cancer immunoprophylaxis. Several further vaccines are in preclinical and clinical development, targeted at preventing cancer precursor infections, and these should add to our ability to prevent this common human disorder. However, vaccines to prevent cancers not triggered by infection are a more remote prospect, for a variety of reasons.

A pilot study of interleukin-11 in subjects with chronic hepatitis C and advanced liver disease nonresponsive to antiviral therapy

OBJECTIVES

To evaluate the effects of recombinant human interleukin (rhIL)-11 on liver histology in patients with chronic hepatitis C virus (HCV) infection and advanced liver disease who had failed antiviral therapy.

METHODS

This was an open-label study of rhIL-11 (Neumega), Wyeth Laboratories, Collegeville, PA) at a dose of 5 microg/kg administered by subcutaneous injection daily for 12 wk. The primary efficacy endpoint was the change in the Knodell Histology Activity Index (HAI) between pre- and posttreatment liver biopsies. Secondary efficacy endpoints included changes in plasma alanine transaminase (ALT) concentrations and in the number of platelets.

RESULTS

The Knodell HAI improved in 11 (55%) of the 20 subjects enrolled, with the mean score improving from 7.3 to 5.9 (p= 0.006). Eight subjects (40%) experienced significant improvement as defined by a decrease of at least two points in the HAI. IL-11 treatment was also associated with a decrease in ALT levels from a mean level of 113 IU/L at baseline to 65 IU/L at week 12 (p < 0.001). Platelet levels increased from a mean of 143 x 10(3)/microl at baseline to 198 x 10(3)/mul at week 12 of treatment (p < 0.001). Overall, rhIL-11 was well tolerated and no serious adverse events (AEs) were reported. The most common AE was edema of the lower extremities, which occurred in all subjects.

CONCLUSIONS

The findings from this pilot study suggest that rhIL-11 may be beneficial for patients with hepatic inflammation and advanced liver disease associated with chronic HCV infection. Larger clinical trials are warranted to further evaluate the long-term antiinflammatory and antifibrotic effects of rhIL-11.

Review of cytokine profiles in patients with hepatitis

The development of T helper 1 versus T helper 2 cells is a major branch point in the immune response and is an important determinant of the body’s response to an infectious pathogen, leading to protection of the host or dissemination of the disease. Resent studies have shown that there exist macrophage activation states in parallel to the T helper cell type 1/2 paradigm, and the T helper 1 development process is governed to a great degree by cytokine IL-12 provided mainly by antigen presenting cells such as macrophages and dendritic cells. A model in patients with hepatitis is proposed that links the pathogen, macrophage activation and T helper cell polarization.

Concomitant augmentation of type 1 CD4+ and CD8+ T-cell responses during successful interferon-alpha and ribavirin treatment for chronic hepatitis C virus infection

The combined interferon-alpha (IFN-alpha) and ribavirin (IFN-alpha/ribavirin) therapy for chronic hepatitis C virus (HCV) infection results in sustained viral eradication in 31%-64% of the patients. Previous studies have strongly suggested that HCV-specific T-cell responses maybe modulated during this therapy. The objective of this study was to further define the effect of IFN-alpha/ribavirin therapy on type 1 and type 2 HCV-specific CD4(+) and CD8(+) T-cell responses during IFN-alpha/ribavirin therapy. Toward this, serial CD8(+) T-cell responses to HCV-derived epitopes and CD4(+) T-cell responses to the HCV core antigen were analyzed in four patients before (baseline), during (at 24 weeks), and at the end (at 48 weeks) of IFN-alpha/ribavirin therapy. Therapy-induced viral clearance in three patients was associated with a significant augmentation of HCV-specific type 1 CD4(+) and CD8(+) T-cell responses. In contrast, in a patient who did not respond to therapy, a significant HCV-specific CD4(+) Th2 cell reactivity was observed accompanied by a lack of augmentation of the HCV-specific CD8(+) T-cell reactivity. These results indicate that enhancement of HCV-specific CD4(+) and CD8(+) T-cell responses is an important factor in determining the response to the IFN-alpha/ribavirin therapy and the outcome of the HCV infection.