IL-1 beta and TNF-alpha produced by peripheral blood mononuclear cells before and during interferon therapy in patients with chronic hepatitis C

Novel Therapeutic Approaches to Psoriasis and Risk of Infectious Disease

Psoriasis is a chronic immune-mediated skin and joint disease, with a plethora of comorbidities, characterized by a certain genetic predisposition, and a complex pathogenesis based on the IL-23/IL-17 pathway. There is no doubt that the patients affected by psoriasis are more susceptible to infections as well as that the risk of infection is higher in psoriatic subjects than in the general population. The advent of biotechnological agents on the therapeutic arsenal actually available for the treatment of moderate-to-severe patients, given the fact that the severity of the disease is a predictor of the level of infectious risk, has raised the question of whether these ‘new’ drugs could be considered a safer option and how they can be used in selected cases. Old and newer strategies in cases of chronic infectious conditions are reviewed under the light of clinical trials and other studies present in literature.

Identification of Interleukin1β as an Amplifier of Interferon alpha-induced Antiviral Responses

The induction of an interferon-mediated response is the first line of defense against pathogens such as viruses. Yet, the dynamics and extent of interferon alpha (IFNα)-induced antiviral genes vary remarkably and comprise three expression clusters: early, intermediate and late. By mathematical modeling based on time-resolved quantitative data, we identified mRNA stability as well as a negative regulatory loop as key mechanisms endogenously controlling the expression dynamics of IFNα-induced antiviral genes in hepatocytes. Guided by the mathematical model, we uncovered that this regulatory loop is mediated by the transcription factor IRF2 and showed that knock-down of IRF2 results in enhanced expression of early, intermediate and late IFNα-induced antiviral genes. Co-stimulation experiments with different pro-inflammatory cytokines revealed that this amplified expression dynamics of the early, intermediate and late IFNα-induced antiviral genes can also be achieved by co-application of IFNα and interleukin1 beta (IL1β). Consistently, we found that IL1β enhances IFNα-mediated repression of viral replication. Conversely, we observed that in IL1β receptor knock-out mice replication of viruses sensitive to IFNα is increased. Thus, IL1β is capable to potentiate IFNα-induced antiviral responses and could be exploited to improve antiviral therapies.

Innate immune responses contribute to the control of viral infections and the induction of interferon alpha (IFNα)-mediated antiviral responses is an important component. However, IFNα induces a multitude of antiviral response genes and the expression dynamics of these genes can be classified as early, intermediate and late. Here we show, based on a mathematical modeling approach, that mRNA stability as well as the negative regulator IRF2 control the expression dynamics of IFNα-induced antiviral genes. Knock-down of IRF2 resulted in the amplified IFNα-mediated induction of the antiviral genes and this amplified expression of antiviral genes could be functionally mimicked by co-stimulation with IFNα and IL1β. We observed that co-stimulation with IFNα and IL1β enhanced the repression of virus replication and that knock-out of the IL1 receptor in mice resulted in increased replication of a virus sensitive to IFNα. In sum, our studies identified IL1β as an important amplifier of IFNα-induced antiviral responses.

Managing Psoriasis in Patients with HBV or HCV Infection: Practical Considerations

Considered more efficacious and safer than traditional systemic drugs, biologic therapies have dramatically improved the quality of life of patients with psoriasis. Recently, there has been a proliferation of new targeted treatment options, including anti-interleukin-17, anti-interleukin-12/23, as well as small-molecule drugs such as apremilast. There are nevertheless some concerns regarding their use, especially in patients with chronic infections such as hepatitis B virus (HBV) and hepatitis C virus (HCV). It has been estimated that two billion individuals are infected with HBV worldwide and approximately 240 million have chronic HBV infection. Moreover, there are approximately 71 million individuals with chronic HCV infection worldwide, with a high percentage of them unaware of being infected. As patients with HBV and HCV infections are excluded from controlled clinical trials investigating new drugs, data regarding their safety in patients with psoriasis are based almost exclusively on case reports and small retrospective cohort studies and need to be constantly updated. The risk of HBV reactivation can be defined as: high risk (≥ 10%), moderate risk (1-10%), and low risk (< 1%) depending on the type of immunosuppressive therapy stratified by the presence or absence of hepatitis B surface antigen but positivity to anti-hepatitis B core antigen. Hepatitis B surface antigen-positive patients treated with tumor necrosis factor-α inhibitors, ustekinumab, or cyclosporine carry a high or moderate risk of HBV reactivation and should be considered candidates for prophylactic anti-HBV therapy. Once therapy is commenced, it is important to check HBV DNA levels every 3 months. Hepatitis B virus reactivation typically occurs with immune reconstitution and therefore antiviral therapy should continue for 6-12 months after stopping immunosuppression. Hepatitis B surface antigen-positive patients who are prescribed methotrexate, acitretin, or apremilast have a low risk and need to be monitored for viral reactivation by determining alanine aminotransferase and HBV DNA levels every 3 months. No conclusive data are available for interleukin-17 and interleukin-23 inhibitors. Anti-hepatitis B core antigen-positive patients treated with tumor necrosis factor-α inhibitors, ustekinumab, and cyclosporine are linked to a moderate risk of reactivation, and they should preferably undergo HBV DNA or hepatitis B surface antigen and alanine aminotransferase testing rather than be subjected to routine pre-emptive therapy. Anti-hepatitis B core antigen-positive patients receiving methotrexate, acitretin, or apremilast have a low risk of reactivation and do not require anti-HBV therapy, nor should monitoring be considered mandatory. No conclusive data are available for interleukin-17 and interleukin-23 inhibitors.

Inflammatory and cardiovascular diseases biomarkers in chronic hepatitis C virus infection: A review

Hepatitis C virus (HCV) infects 180 million people worldwide and over 4 million people in the United States. HCV infection is a major cause of chronic liver disease and is recognized as a risk factor for clinical cardiovascular disease (CVD). Many studies have shown increased prevalence of cardiac and inflammatory biomarkers in patients with chronic HCV infection (CHC), and though these markers may be used to risk stratify people for cardiac disease in the general population their role in the HCV population is unknown. Patients with CHC have elevated cardiac and inflammatory biomarkers compared to noninfected controls which may play a role in CVD risk stratification. We undertook a systematic review of inflammatory and cardiac biomarkers in people with HCV infection with a focus on the effect of CHC on serum levels of these markers and their utility as predictors of CVD in this population. Medline, EMBASE, and Cochrane databases were searched for relevant articles until June 2019. A total of 2430 results were reviewed with 115 studies included. Our review revealed that HCV infection significantly alters serum levels of markers of inflammation, endothelial function, and cardiac dysfunction prior to HCV treatment, and some of which may change in response to HCV therapy. Current risk stratification tools for development of CVD in the general population may not account for the increased inflammatory markers that appear to be elevated among HCV‐infected patients contributing to increased CVD risk.

Tuberculosis and viral hepatitis infection in Eastern Europe, Asia, and Latin America: impact of tumor necrosis factor-α inhibitors in clinical practice

Tumor necrosis factor-α (TNF-α) inhibitors are increasingly becoming the standard of care for treating a number of inflammatory diseases. However, treatment with TNF-α inhibitors carries an inherent risk of compromising the immune system, resulting in an increased susceptibility to infections and malignancies. This increased risk of infection is of particular concern in Asia, Eastern Europe, and Latin America where tuberculosis (TB) and viral hepatitis are endemic. In this brief review, we examine the literature and review the impact of TNF-α inhibitors on the incidence and the reactivation of latent disease with respect to TB, hepatitis C infection, and hepatitis B infection. Our findings show that TNF-α inhibitors are generally safe, if used with caution. Patients should be screened prior to the initiation of TNF-α inhibitor treatment and given prophylactic treatment if needed. In addition, patients should be monitored during treatment with TNF-α inhibitors and after treatment has stopped to ensure that infections, if detected, are treated promptly and effectively. Our analysis is consistent with other reports and guidelines.

The influence of anti-TNF therapy on the course of chronic hepatitis C virus infection in patients with inflammatory bowel disease

BACKGROUND

The immunosuppressive potential of anti-tumor necrosis factor (TNF) in exacerbating chronic hepatitis C virus (HCV) infection has been a major concern. We aim to critically analyze the impact of anti-TNF on the course of chronic HCV infection in patients with concurrent inflammatory bowel disease (IBD) and HCV infection.

MATERIALS AND METHODS

Patients with diagnosis of IBD and HCV were identified retrospectively through the University of Pennsylvania Health System electronic database. Data assessed included demographics, duration of IBD and HCV infection, HCV RNA levels, HCV genotype, liver histology, hepatic biochemical tests (HBT) and IBD disease activity index.

RESULTS

A total of 4,274 IBD and 3,523 HCV patients were identified from 10/1998 to 05/2010. Thirty-seven patients had concurrent HCV infection and IBD, of which 23 patients were eligible (61 % CD; 39 % UC). Five patients (22 %) received anti-TNF therapy (infliximab). Two patients received pegylated interferon and ribavirin (both were non-responders). Overall, three patients had clinical remission and one patient had clinical response to infliximab. When compared to baseline, one patient had HBT improvement, three patients remained stable and one patient had HBT elevation, which was likely due to progressive liver disease in view of HIV co-infection.

CONCLUSION

This represents the first critical analysis assessing the impact of anti-TNF therapy on the course of chronic HCV in IBD patients. Concurrent HCV infection in IBD patients is uncommon. Treatment of IBD with infliximab in HCV patients did not result in flares in hepatic biochemical tests while there was an improvement in the IBD disease activity score.

Sex hormones and HCV: an unresolved mystery

The biological differences between males and females advocate the ultimate need for gender-specific medicine. The variation in response to viral infection as well as therapy among different genders makes it very intriguing to reveal the responsible factors for causing this discrepancy. HCV is one of the most noxious infectious diseases, however the impact of gender on the response to HCV has received negligible attention in the literature. The controversial studies concerning the effect of gender on the outcome of interferon-based therapy urge a need to judge the gender discrepancy in host factors responsible for both interferon release and action. The main aim of this review is to disentangle the interplay between sex hormones and several viral and host factors responsible for viral clearance in an attempt to clarify the role of gender in modulating the response to HCV as well as interferon-based therapy.

Effect of hepatitis C virus infection on the mRNA expression of drug transporters and cytochrome p450 enzymes in chimeric mice with humanized liver

The expression of drug transporters and metabolizing enzymes is a primary determinant of drug disposition. Chimeric mice with humanized liver, including PXB mice, are an available model that is permissive to the in vivo infection of hepatitis C virus (HCV), thus being a promising tool for investigational studies in development of new antiviral molecules. To investigate the potential of HCV infection to alter the pharmacokinetics of small molecule antiviral therapeutic agents in PXB mice, we have comprehensively determined the mRNA expression profiles of human ATP-binding cassette (ABC) transporters, solute carrier (SLC) transporters, and cytochrome P450 (P450) enzymes in the livers of these mice under noninfected and HCV-infected conditions. Infection of PXB mice with HCV resulted in an increase in the mRNA expression levels of a series of interferon-stimulated genes in the liver. For the majority of genes involved in drug disposition, minor differences in the mRNA expression of ABC and SLC transporters as well as P450s between the noninfected and HCV-infected groups were observed. The exceptions were statistically significantly higher expression of multidrug resistance-associated protein 4 and organic anion-transporting polypeptide 2B1 and lower expression of organic cation transporter 1 and CYP2D6 in HCV-infected mice. Furthermore, the enzymatic activities of the major human P450s were, in general, comparable in the two experimental groups. These data suggest that the pharmacokinetic properties of small molecule antiviral therapies in HCV-infected PXB mice are likely to be similar to those in noninfected PXB mice. However, caution is needed in the translation of this relationship to HCV-infected patients as the PXB mouse model does not accurately reflect the pathology of patients with chronic HCV infection.

Effects of estradiol and progesterone on the proinflammatory cytokine production by mononuclear cells from patients with chronic hepatitis C

AIM: To investigate the effects of estradiol (E2) and progesterone on the unstimulated and oxidative stress-stimulated production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-8, and macrophage chemotactic protein (MCP)-1 by peripheral blood mononuclear cells (PBMCs) from patients with chronic hepatitis C and healthy controls.

METHODS: The PBMCs were separated from age-matched 72 males and 71 females with and without chronic hepatitis C, who were divided into two groups based on a mean menopausal age of 50 years. Oxidative stress was induced by hydrogen peroxide in the cells incubated in serum-free media. Cytokines in the culture supernatant were measured by an enzyme-linked immunosorbent assay.

RESULTS: The highest levels of the spontaneous production of TNF-α, IL-1β, IL-8, and MCP-1 by the unstimulated PBMCs were in the older male patients with chronic hepatitis C and the lowest levels were in the pre-menopausal female healthy controls. E2 inhibited the cytokine production by the unstimulated PBMCs from the older male and post-menopausal female patients, which was further stimulated by progesterone. The exposure to hydrogen peroxide in the PBMCs from the younger male and pre-menopausal female healthy subjects induced the production of cytokines. The change rates of the hydrogen peroxide-stimulated cytokine production were suppressed by E2 and enhanced by progesterone.

CONCLUSION: These findings suggest that E2 may play a favorable role in the course of persistent liver injury by preventing the accumulation of monocytes-macrophages and by inhibiting proinflammatory cytokine production, whereas progesterone may counteract the favorable E2 effects.

Role of paroxetine in interferon-alpha-induced immune and behavioural changes in male Wistar rats

Treatment with pro-inflammatory cytokine, IFNalpha was documented to result in neuropsychiatric complications including depression and treatment with antidepressant, paroxetine could improve the depressive symptoms. Therefore, the effects of IFNalpha on behaviour and cytokine changes in the whole blood culture and in the prefrontal cortex, hypothalamus and hippocampus areas of the brain in wistar rats were investigated with emphasis on the role of paroxetine in the prevention of depressive behaviour induced by pro-inflammatory cytokines. The group of rats treated with IFNalpha (s.c. 50,000 IU/kg for 3 days/week for 5 weeks) was compared with three other groups; 1) saline control group (s.c. normal saline 0.2 ml/kg/day for 7 weeks), 2) paroxetine control group (paroxetine suspension orally 10 mg/kg/day for 7 weeks) and 3) group treated with paroxetine for 2 weeks followed by IFNalpha for 5 weeks. In open filed, the IFNalpha treated rats showed anxiety behaviour compared to the rats from the other groups. There was no significant difference in home cage emergence test, Morris water maze and object recognition test. There is no significant difference in plasma corticosterone between groups. The pro-inflammatory cytokines (TNFalpha, IL1beta and IFNgamma), were significantly higher whereas the anti-inflammatory cytokine, IL10 was lower in the stimulated whole blood culture of IFNalpha treated rats. In the brain, both pro-inflammatory cytokine IL1beta and anti-inflammatory cytokine IL10 were higher in hypothalamus of the IFNalpha treated rats; by contrast the concentration of IL10 was lowest in hippocampus region of this group compared to the other groups. The paroxetine pretreated rats did not show these cytokine changes following IFNalpha treatment. Thus it appears that paroxetine pretreatment prevents the pro-inflammatory changes in blood and brain following IFNalpha treatment in turn prevents the anxiety behaviour.

Female hepatology: Favorable role of estrogen in chronic liver disease with hepatitis B virus infection

Chronic hepatitis B virus (HBV) infection is the most common cause of hepatic fibrosis and hepatocellular carcinoma (HCC), mainly as a result of chronic necroinflammatory liver disease. A characteristic feature of chronic hepatitis B infection, alcoholic liver disease and nonalcoholic fatty liver disease (NAFLD) is hepatic steatosis. Hepatic steatosis leads to an increase in lipid peroxidation in hepatocytes, which, in turn, activates hepatic stellate cells (HSCs). HSCs are the primary target cells for inflammatory and oxidative stimuli, and these cells produce extracellular matrix components. Chronic hepatitis B appears to progress more rapidly in males than in females, and NAFLD, cirrhosis and HCC are predominately diseases that tend to occur in men and postmenopausal women. Premenopausal women have lower hepatic iron stores and a decreased production of proinflammatory cytokines. Hepatic steatosis has been observed in aromatase-deficient mice, and has been shown to decrease in animals after estradiol treatment. Estradiol is a potent endogenous antioxidant which suppresses hepatic fibrosis in animal models, and attenuates induction of redox sensitive transcription factors, hepatocyte apoptosis and HSC activation by inhibiting a generation of reactive oxygen species in primary cultures. Variant estrogen receptors are expressed to a greater extent in male patients with chronic liver disease than in females. These lines of evidence suggest that the greater progression of hepatic fibrosis and HCC in men and postmenopausal women may be due, at least in part, to lower production of estradiol and a reduced response to the action of estradiol. A better understanding of the basic mechanisms underlying the sex-associated differences in hepatic fibrogenesis and carciogenesis may open up new avenues for the prevention and treatment of chronic liver disease.

Protection of estrogens against the progression of chronic liver disease

Hepatitis C virus infections are recognized as a major causative factor of chronic liver disease. A characteristic feature of chronic hepatitis C, alcoholic liver disease and non-alcoholic fatty liver disease is hepatic steatosis. Hepatic steatosis leads to an increase in lipid peroxidation in hepatocytes, which, in turn, activates hepatic stellate cells (HSCs). HSCs are also thought to be the primary target cells for inflammatory and oxidative stimuli, and to produce extracellular matrix components. Based on available clinical information, chronic hepatitis C appears to progress more rapidly in men than in women, and cirrhosis is predominately a disease of men and postmenopausal women. Estradiol is a potent endogenous antioxidant. Hepatic steatosis was reported to become evident in an aromatase-deficient mouse and was diminished in animals after treatment with estradiol. Our previous studies showed that estradiol suppressed hepatic fibrosis in animal models, and attenuated HSC activation by suppressing the generation of reactive oxygen species in primary cultures. Variant estrogen receptors were found to be expressed to a greater extent in male patients with chronic liver disease than in female subjects. A better understanding of the basic mechanisms underlying the gender-associated differences observed in the progression of chronic liver disease would provide valuable information relative to the search for effective antifibrogenic therapies.

Effect of pentoxifylline on levels of pro-inflammatory cytokines during chronic hepatitis C

The cellular and humoral natural immune response induced by hepatitis C virus (HCV) is commonly unable to eradicate the virus. HCV is a highly mutable, hepatotropic RNA virus that causes acute and chronic hepatitis, an infection that involves the production of various cytokines. The aim of the study is to analyse the expression of pro-inflammatory cytokines IL-1beta, TNF-alpha, IFN-gamma and the chemokine CXCL8 (IL-8) in liver tissue and their expression and secretion in PBMC of patients with chronic hepatitis C (CHC), in response to pentoxyfilline (PTX). We studied six CHC patients, naive to treatment. Patients received PTX 400 mg twice a day/8 weeks. Pentoxyfilline resulted in decreased expression of mRNA of liver IL-1beta, TNF-alpha and IFN-gamma: 144.2 versus 83.5 molecules of IL-1beta (P < 0.05), TNF-alpha 194.3 versus 17.6 molecules (P = 0.03) and IFN-gamma 26.1 versus 0.5 molecules (P = 0.04). Following PTX, PBMC exhibited a decrease in IFN-gamma mRNA 12.2 versus 1.5 molecules (P = 0.028) and CXCL8 4.2 versus 2.5 molecules (P = 0.027). In PBMC, only the secretion of TNF-alpha was decreased 1109 versus 933.5 pg/ml, P = 0.046. Production of cytokines both locally (within the liver) and systemically (PBMC) may serve as biomarkers of the infection with hepatitis C. PTX inhibits the expression of several pro-inflammatory cytokines in the liver. These results indicate that it is worth exploring PTX in hepatitis in future clinical trials in nonresponders to antiviral treatment.

Etanercept as an adjuvant to interferon and ribavirin in treatment-naive patients with chronic hepatitis C virus infection: a phase 2 randomized, double-blind, placebo-controlled study

BACKGROUND/AIMS

Current therapies for patients with chronic hepatitis C virus (HCV) do not achieve sustained viral clearance in most patients, and are associated with severe toxic effects. Our aim was to investigate the efficacy and safety of etanercept as adjuvant to interferon and ribavirin in treatment-naive patients with HCV.

METHODS

Double-blind, randomized, placebo controlled trial. Fifty patients with chronic HCV were randomly assigned to receive interferon alfa-2b and ribavirin with either etanercept or placebo for 24 weeks. The main outcome measure was the absence of HCV RNA at 24 weeks, the on treatment response at the end of the etanercept randomization period.

RESULTS

At 24 weeks, HCV RNA was absent in 63% (12/19) etanercept patients compared to 32% (8/25) placebo patients (P=0.04). In addition, patients receiving etanercept had lower frequency of most adverse events categories compared to placebo.

CONCLUSIONS

Etanercept given for 24 weeks as adjuvant therapy to interferon and ribavirin significantly improved virologic response at the end of the etanercept randomization period among patients with HCV, and was associated with decreased incidence of most adverse effects associated with interferon and ribavirin.

Safety of antitumour necrosis factor (anti-TNF) therapy in patients with chronic viral infections: hepatitis C, hepatitis B, and HIV infection

Tumour necrosis factor alpha (TNFalpha) is a pivotal cytokine in host defences with broad ranging effects on the innate and adaptive immune systems. Clinically, TNFalpha inhibitors have demonstrated remarkable efficacy in a wide range of autoimmune and inflammatory disorders but clearly at the cost of heightened susceptibility to a variety of infections in those treated with these agents. Most reports to date have described increased susceptibility to intracellular pathogens in patients with underlying chronic viral infections, but little in the way of adverse event reporting in these patients has occurred. While the reported experience to date is rather limited, TNFalpha inhibitors have displayed a reasonable safety profile in the setting of some chronic viral infections and in certain circumstances have demonstrated adjunctive activity in the treatment of these infections. Given the high prevalence of chronic viral infections in patients who are candidates for anti-TNF therapy and the potential for these agents in the treatment of chronic viral illness, additional studies are urgently needed to assess the risks and benefits of such therapy in these populations.

Changes in TNF-α mRNA Levels in the Peripheral Blood of Patients with Chronic Hepatitis C Virus (HCV) Infection during α-Interferon and Ribavirin Therapy

HCV virus infections have become a serious epidemiological problem throughout the world. Hepatitis C therapy includes the administration of IFN-alpha and ribavirin, but results in the complete eradication of HCV viremia in only 30% of patients. TNF-alpha is one of the factors involved in hepatitis C pathogenesis and the results of therapy. In this study, we present the results of applying real-time RT-PCR for assessing the TNF-alpha mRNA level in the peripheral blood of patients treated with IFN-alpha and ribavirin. We found the TNF-alpha mRNA level to be higher in HCV-infected patients compared with healthy controls when analyzed after 4 weeks (p = 0.001) and 3 months (p = 0.003) of IFN-alpha/RIBA therapy. The pretreatment level and the level after six months of therapy were not significantly different from the level of healthy controls. There were no significant differences in TNF-alpha mRNA levels between patients who responded to anti-HCV therapy, resulting in a decrease in HCV viremia below detection limit over 6 months and patients whose HCV RNA was not eliminated (p = 0.881). These results indicate that there is a transient increase of TNF-alpha gene expression during anti-HCV therapy. This fact may be connected with the host organism's response to IFN-alpha/RIBA therapy.

Global effect of PEG-IFN-alpha and ribavirin on gene expression in PBMC in vitro

Using oligonucleotide microarrays, we have examined the expression of 22,000 genes in peripheral blood cells treated with pegylated interferon-alpha2b (PEG-IFN-alpha) and ribavirin. Treatment with ribavirin had very little effect on gene expression, whereas treatment with PEG-IFN-alpha had a dramatic effect, modulating the expression of approximately 1000 genes (at p < 0.001). In addition to genes previously reported to be induced by type I or type II IFNs, many novel genes were found to be upregulated, including transcription factors, such as ATF3, ATF4, properdin, a key regulator of the complement pathway, a homeobox gene (HESX1), and an RNA editing enzyme (apobec3). Chemokines CXCL10 and CXCL11 were upregulated, whereas CXCL5 was downregulated. Cytokines interleukin-15 (IL-15) and IL-18 were also significantly induced, whereas IL-1alpha and IL-1beta were downregulated. Most other interleukins were not affected. The results of the microarrays were confirmed by kinetic real-time PCR. These data indicate that IFN treatment causes upregulation of genes associated with the stress response, apoptosis, and signaling, and an equal number of genes are downregulated, including those associated with protein synthesis, specific cytokines and chemokines and other biosynthetic functions.

Host factors and failure of interferon-alpha treatment in hepatitis C virus

Failure of interferon-alpha (IFN-alpha) treatment in patients with chronic hepatitis C virus (HCV) infection is a challenging obstacle for clinical and experimental hepatology. Both viral and host factors have been implicated in reducing responsiveness to IFN-alpha therapy. The role of viral factors has been studied extensively and has been summarized in several review articles; however, much less attention has been paid to host factors. In this paper, we review evidence of host factor involvement in IFN-alpha treatment failure. We discuss possible underlying mechanisms responsible for these effects. Potential therapeutic strategies to enhance the effectiveness of IFN-alpha therapy for HCV are also proposed.

Interleukin-1beta induces macrophage inflammatory protein-1beta expression in human hepatocytes

The investigation of factors that regulate expression of CC-chemokines, the important mediators in immune responses and inflammation processes, has an important significance in understanding the immunopathogenesis of liver diseases. We examined the role of interleukin-1beta (IL-1beta), a multifunctional cytokine, in regulating the expression of macrophage inflammatory protein (MIP)-1beta in human hepatocytes (Huh7 and HepG2). IL-1beta significantly enhanced MIP-1beta expression in these cells at both the mRNA and protein levels. Cytokine-enriched supernatants from monocyte-derived macrophage (MDM) cultures also induced MIP-1beta expression. IL-1beta is responsible for MDM supernatant-mediated up-regulation of MIP-1beta since the antibody to IL-1beta abolished MDM supernatant action. Investigation of the mechanism involved in MIP-1beta induction by IL-1beta showed that IL-1beta activated the nuclear factor kappa B (NF-kappaB) promoter in Huh7 cells. In addition, caffeic acid phenethyl ester (CAPE), a specific inhibitor of the activation of NF-kappaB, not only abolished IL-1beta-mediated NF-kappaB promoter activation, but also blocked IL-1beta-induced MIP-1beta expression. These observations suggest that IL-1beta-mediated up-regulation of MIP-1beta production in the hepatic cells may contribute a critical mechanism for continuous recruitment of inflammatory cell to liver and maintenance of inflammation.

The effects of a herbal medicine (Mao-to) in patients with chronic hepatitis C after injection of IFN-beta

We found that a herbal medicine (Mao-to) relieves the side effects of interferon (IFN)-beta and the combination therapy improves the biochemical response rate. However, the exact mechanism by which Mao-to is effective remains to be established. We conducted a controlled trial to clarify the effects of Mao-to. The study was carried out in 18 patients with chronic hepatitis C, and we examined subjective symptoms, body temperature and cytokines such as interleukin (IL)-beta, IL-1receptor antagonist (ra), IL-6 and TNF-alpha. Each patient received 6 million units of IFN-beta intravenously. Mao-to was given orally just before, just after, and 1 hour after IFN administration. The control study was carried out 6 months after the combination therapy of Mao-to and IFN-beta. The scores for general malaise, arthralgia and discomfort were significantly lower in the combination group than in control group. Body temperature did not significantly differ between the two groups. Plasma IL-6 level and IL-1ra were significantly elevated in the combination group compared to control (P = 0.0057 and 0.0003, respectively). Mao-to did not affect plasma concentrations of IL-1beta and TNF-alpha. We considered the increment of IL-1ra caused by Mao-to is to be one of the key factors involved in reducing the flu-like symptoms accompanying IFN-beta and improving the biochemical response rate.

Impact of oestrogens on the progression of liver disease

As of this writing, the most common cause of hepatic fibrosis is chronic hepatitis C virus infection (HCV), the characteristic feature of which is hepatic steatosis. Hepatic steatosis leads to an increase in lipid peroxidation in hepatocytes, which in turn activates hepatic stellate cells (HSCs). HSCs are also thought to be the primary target cells for inflammatory stimuli, and produce extracellular matrix components. Based on available clinical information, chronic hepatitis C appears to progress more rapidly in men than in women, and cirrhosis is predominately a disease of men and postmenopausal women. It should be noted that estradiol (E2) is a potent endogenous antioxidant. A recent study has shown that hepatic steatosis became evident in an aromatase-deficient mouse and was diminished in animals, after treatment with E2. Our studies showed that E2 suppressed hepatic fibrosis in hepatic fibrosis models, inhibited the activation of activator protein 1 and nuclear factor-kappa B in cultured hepatocytes undergoing oxidative stress, and attenuated HSC activation in primary culture. Recently, variant oestrogen receptors (ERs) were found to be expressed to a greater extent in male patients with chronic liver disease than in female subjects. We also demonstrated decreased levels of ERs in postmenopausal women and cirrhotic patients of both genders. The actions of E2 are mediated through ER alpha and beta. HSCs have also been found to possess functional ER beta but not ER alpha. A better understanding the basic mechanisms underlying the gender-associated differences observed in the development of hepatic fibrosis would provide valuable information relative to the search for effective antifibrogenic therapies.

Interleukin-1beta gene polymorphisms associated with hepatocellular carcinoma in hepatitis C virus infection

Hepatitis C virus (HCV) infection is a major risk factor for developing hepatocellular carcinoma (HCC), a life-threatening sequel. However, the factors that affect disease progression to HCC have not been thoroughly elucidated. Genetic polymorphisms in proinflammatory cytokines, the interleukin 1 (IL-1) family (IL-1beta and IL-1ra) and tumor necrosis factor-alpha (TNF-alpha), were studied in 274 Japanese patients with chronic HCV infection and 55 healthy individuals using standard polymerase chain reaction-based genotyping techniques. The association between these polymorphisms and disease status was evaluated while controlling for confounding clinical variables. The proportion of patients with HCC in the IL-1beta-31 T/T (55%, odds ratio to C/C was 2.63, P =.009) genotype was higher than in the T/C (44%, odds ratio to C/C was 1.64, P =.149) and C/C genotypes (35%). The IL-1beta-31 and -511 loci were in near complete linkage disequilibrium, and the IL-1beta-511/-31 haplotype C-T was significantly associated with the presence of HCC (odds ratio of 1.51, P =.02). Polymorphisms in the TNF-alpha gene were not associated with disease. A multivariate analysis revealed that the IL-1beta-31 T/T genotype, alpha-fetoprotein >20 microg/L, presence of cirrhosis, male sex, and age >60 years were associated with the presence of HCC at odds ratios of 3.73 (T/T vs. C/C), 4.12, 4.03, 3.89, and 3.27, respectively. In conclusion, the IL-1beta-31 genotype T/T or the IL-1beta-511/-31 haplotype C-T is associated with the presence of HCC in Japanese patients with chronic HCV infection.

HCV-specific cytokine induction in monocytes of patients with different outcomes of hepatitis C

AIM

Cytokine release by macrophages critically determines the type of immune response to an antigen. Therefore, we studied hepatitis C virus (HCV)-specific induction of interleukins-1 beta, -10, -12 (IL-1 beta, IL-10, IL-12), and tumor necrosis factor-alpha (TNF-alpha) in monocytes.

METHODS

Intracellular cytokine expression was studied by flow cytometry in 23 patients with chronic hepatitis C, 14 anti-HCV seropositives without viremia and 11 controls after stimulation of peripheral blood mononuclear cells with recombinant core, NS3, NS4, NS5a and NS5b proteins.

RESULTS

Patients with HCV viremia revealed greater spontaneous expression of IL-1beta, TNF-alpha, and IL-10. Furthermore, greater than twofold higher IL-10 expression was induced by the HCV antigens in chronic hepatitis C than in the other two groups (P<0.05). In contrast, neither IL-12 nor TNF-alpha was induced preferentially.

CONCLUSION

In chronic hepatitis C antigen-specific cytokine induction in monocytes is apparently shifted towards predominant IL-10 induction - not counterbalanced by antiviral type 1 cytokines. This may contribute to persistent viral replication.

Serum tumour necrosis factor-alpha and transforming growth factor-beta levels in chronic hepatitis C patients are immunomodulated by therapy

Our aims were: (i) to characterize serum levels of tumour necrosis factor alpha (TNF-alpha) and transforming growth factor beta (TGF-beta) in non-cirrhotics with hepatitis C; (ii) to correlate levels of theses cytokines with degree of disease at baseline; (iii) to characterize the immunomodulatory effects of therapy with response and (iv) to compare profiles of cytokines in patients treated with pegylated-interferon alpha-2b monotherapy (PMT) vs its combination with ribavirin (PCT1-low dose ribavirin and PCT2-high dose ribavirin). We studied 56 patients that were part of two randomized, controlled, clinical trials. At baseline, high TNF-alpha levels paralleled the degree of inflammation as determined by histology. In PCT2, a significant reduction was seen in levels of TNF-alpha, TGF-beta and fibrosis scores when comparing baseline with follow-up. In sustained responders, regardless of therapy, the histological activity scores were lower at follow-up as compared to baseline. In conclusion, PCT2 is able to constantly reduce and sustain TNF-alpha levels, which is responsible for the sustained decline in liver inflammation as shown by the histological activity index and it is also able to reduce fibrosis as judged both by TGF-beta levels and fibrosis scores.

An analysis of acute changes in interleukin-6 levels after treatment of hepatitis C with consensus interferon

Cytokine production has been implicated in the antiviral response to interferon-alpha (IFN-alpha) in hepatitis C and in the development of IFN-alpha-related side effects. We characterized acute changes in serum cytokine levels following administration of a single dose of consensus IFN (IFN-con1) and during continuous treatment of chronic hepatitis C patients. Serum samples were collected at baseline, at multiple times early after IFN administration, and weekly thereafter. Viral RNA titers were assessed by RT-PCR, and viral kinetics were followed. ELISA assays were used to measure IFN-gamma, tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), IL-4, IL-6, and IL-16. Serum cytokine levels were low at baseline. IL-6 was detected in patients with hepatitis C but not in healthy control subjects by either ELISA or RT-PCR, indicating that low levels of circulating IL-6 were associated with hepatitis C infection. None of the cytokines measured increased significantly after IFN administration except for IL-6. IL-6 levels rose rapidly, peaked at 6-15 h in a dose-dependent manner, and returned to baseline by 48 h in both patients receiving a single dose of IFN and those receiving continuous treatment. This was confirmed by RT-PCR. Pretreatment IL-6 levels were directly correlated with area under the curve (AUC) for IL-6 during the 24 h after IFN dosing (r = 0.611, p = 0.007). Viral titers decreased within 24-48 h after a single dose of IFN-con1. Changes in hepatitis C RNA titers were not significantly associated with pretreatment IL-6 levels or with changes in IL-6 levels. In conclusion, (1) baseline serum cytokine levels, except for IL-6, were low or within the normal range in patients with hepatitis C, (2) IL-6 levels were detected in some patients with hepatitis C before treatment but not in healthy controls, (3) IL-6 levels increased acutely after a single dose of IFN-alpha, and IL-6 induction was related to baseline IL-6 level, and (4) changes in IL-6 levels did not correlate with the early virologic response to IFN.

Association between insulin resistance and hepatitis C virus chronic infection in HIV-hepatitis C virus-coinfected patients undergoing antiretroviral therapy

Insulin resistance (IR) in the context of highly active antiretroviral therapy (HAART) is becoming more common in HIV-infected patients. Patients with chronic hepatitis C virus (HCV) infection have an increased risk of IR and type 2 diabetes mellitus. A cross-sectional study was performed to investigate whether chronic HCV infection constitutes a risk factor for IR in HIV-HCV-coinfected patients undergoing HAART. Inclusion criteria were positive HCV viremia and a sustained increase of alanine aminotransferase of at least twice the normal value. A total of 29 HIV-HCV patients, 76 HIV patients, and 121 HCV controls were tested for IR and body mass index (BMI). IR was measured using the homeostasis model assessment. In HIV-HCV and HIV patients, fat redistribution and lipid profile were assessed. There was no significant difference in age, CD4 cell count, HIV viral load, or duration of HAART between the HIV-HCV and HIV groups. HIV-HCV patients and HCV controls had a significant increase in IR when compared with HIV patients (0.25 +/- 0.28 and 0.21 +/- 0.34 versus 0.04 +/- 0.37; p =.01 and p =.003, respectively). Lipoatrophy was observed more frequently in HIV-HCV patients in comparison with HIV patients (41% versus 14%; p =.003). In HIV-HCV patients, total cholesterol and triglyceride levels were significantly lower than in HIV patients. In multivariate analysis, IR, BMI, triglyceride levels, and peripheral fat wasting were the independent variables associated with HCV infection. Our findings suggest that chronic HCV infection is a significant factor associated with the development of metabolic abnormalities and with modifications in body composition in HIV patients receiving antiretroviral treatment.

Recurrence of hepatitis C after liver transplantation is associated with increased systemic IL-10 levels

BACKGROUND

Recurrence of hepatitis C after liver transplantation is an almost universal occurrence. T-cell derived cytokines have an important role in the development of liver damage associated with chronic hepatitis C, their post-transplant levels, however, have not been correlated with histologic recurrence of the disease.

AIMS

We sought to analyze levels of TNF-alpha, soluble IL-2 receptor, IL-4 and IL-10 at 1 month, 6 months and 1 year after transplantation in 27 patients undergoing transplantation for hepatitis C related end-stage liver disease.

METHODS

HCV RNA levels were monitored by a branched-chain DNA signal amplification assay. Diagnosis of recurrent hepatitis was based on 1-year protocol biopsies and on biopsies performed for liver enzyme elevations.

RESULTS

Recurrent hepatitis C was detected in 52% (n=14) of the 27 patients. HCV RNA levels rose over time in all patients regardless of histologic recurrence. TNF-alpha, and IL-4 levels, although elevated, did not show specific patterns over time or in correlation with recurrence. Similarly, the early elevation followed by a gradual decrease over the first year in the amount of soluble IL-2 receptor was not related to histologic recurrence. We observed a significant increase in circulating IL-10 levels over the first year in patients with biopsy-proven recurrence, while patients with no signs of histologic recurrence displayed increased, but steady levels.

CONCLUSIONS

These results suggest that while these cytokines are associated with post-transplant recurrence of hepatitis C, their production may be altered by additional factors.

Serum cytokine values and fatigue in chronic hepatitis C infection

Patients with chronic hepatitis C infection often experience fatigue. In many clinical situations, an association between fatigue and altered serum cytokine levels has been found. Altered cytokine levels in patients with hepatitis C have not shown a correlation with the degree of serum transaminase elevation or pathological change on liver biopsy. The aim of our study was to examine whether there was an association between abnormal serum cytokine levels and fatigue in patients with compensated chronic hepatitis C. Patients referred to a tertiary care hepatology clinic who were hepatitis C antibody positive and who had elevated alanine aminotransferase (ALT) levels were eligible for entry into the study. A control group was also included. Subjects in both groups who had characteristics other than hepatitis C that were known to alter cytokine values and/or cause fatigue were excluded. Patients completed a validated questionnaire to determine their fatigue severity score (FSS). Bioassays were used to measure interleukin (IL)-1, IL-6 and tumour necrosis factor-alpha (TNF-alpha) levels in early morning serum samples taken from patients and controls. Altered cytokine values were defined as those more than two standard deviations above the mean control value. Data was analysed using SPSS, version 8.01. Of the 78 patients with chronic hepatitis C who participated in the study, 19 (24%), 24 (30%) and 45 (56%) had elevated levels of IL-1, IL-6 and TNF-alpha, respectively, compared with only two (6%) of the control group who had elevation of any of the three cytokines. No correlation was found between the FSS and serum cytokine levels, when analysed singly or in combination, in patients with chronic hepatitis C. Hence, alteration in early morning serum levels of IL-1, IL-6 and TNF-alpha in patients with chronic hepatitis C infection and elevated ALT levels bear no correlation with the symptom of fatigue.

Increased frequency of interferon-gamma-producing peripheral blood CD4+ T cells in chronic hepatitis C virus infection

OBJECTIVES

To determine the profile of cytokine secretion by CD4+ T helper (Th) cells in chronic hepatitis C virus (HCV) infection, we used flow cytometry to determine the percentage of interferon (IFN)-gamma and interleukin (IL)-4 producing cells from CD4+ T lymphocytes in peripheral blood obtained from patients chronically infected with HCV.

METHODS

Peripheral blood mononuclear cells isolated from 89 HCV infected subjects (22 asymptomatic carriers, 56 patients with chronic hepatitis, and 11 patients with liver cirrhosis) and 24 healthy controls were stained with surface CD4 and intracellular IFN-gamma and IL-4. Serum soluble IL-2 receptor (sIL-2R) levels were analyzed by ELISA.

RESULTS

The frequency of IFN-gamma producing CD4+ cells in asymptomatic HCV carriers, patients with chronic hepatitis, and patients with liver cirrhosis were significantly higher than those of healthy controls (p<0.01, respectively). In contrast, the percentages of IL-4-producing CD4+ cells were very low, and there were no significant correlations with disease progression. A significant elevation in serum sIL-2R levels was found in chronic HCV infection compared to healthy controls, and serum sIL-2R levels significantly correlated with the frequency of IFN-gamma-producing cells.

CONCLUSIONS

In HCV infected subjects, both serum sIL-2R and IFN-gamma are increased in chronic HCV infection no matter the stage of disease, meaning they are no different in asymptomatic carriers, patients with chronic hepatitis, and patients with liver cirrhosis, and that Th1 cytokine or Th1 cells may participate in the pathogenesis of liver damage in chronic HCV infection.

Predictors of sustained response to alpha interferon therapy in chronic hepatitis C

OBJECTIVES

To utilize cytokine levels to predict sustained response (SR) to alpha interferon (IFN alpha) therapy in chronic hepatitis C patients, and to determine the relationship between serum tumor necrosis factor alpha (TNF alpha), interleukin (IL) IL 6, IL 8, IL 12, transforming growth factor beta (TGF beta 1) and the degree of liver damage as reflected by traditional markers.

DESIGN AND METHODS

Serum cytokine levels were assessed using ELISA in 18 patients included in a controlled clinical trial of IFN alpha.

RESULTS

Of the 18 patients, 27% were sustained responders (SR), 27% were response and relapse responders (RR), and 46% were non-responders (NR). Multivariate analysis showed that a low serum TNF alpha level and high serum IL 8 levels were independent factors associated with SR to IFN alpha therapy. Serum TNF alpha level highly correlated with viral load and genotype predictive values (p < 0.001). Therapy lowered the IL 6 and IL 12 profile. TGF beta 1 levels in serum are positively correlated with fibrinogenesis.

CONCLUSIONS

IFN alpha therapy modulates immune response to hepatitis C virus, contributing to sustained response.

Activation of tumor necrosis factor-alpha system in chronic hepatitis C virus infection

Tumor necrosis factor-alpha (TNF-alpha) plays a central role in the host's immunomodulatory response to infective agents. To evaluate the TNF-alpha system in patients with chronic hepatitis C virus (HCV) infection, plasma, serum, and peripheral blood mononuclear cells (PBMC) were prospectively collected from 53 patients and 33 healthy control subjects. Circulating TNF-alpha and TNF receptors were assayed by their respective enzyme immunoassays. In addition, TNF-alpha mRNA was quantitated in PBMC using a branched DNA assay, and production of TNF-alpha by PBMC with and without lipopolysaccharide was also assessed. Patients with chronic HCV infection had a higher level of circulating TNF-alpha compared to healthy control subjects (9.62 +/- 6.01 vs 3.66 +/- 1.23 pg/ml, P < 0.001). They also had higher circulating levels of TNF receptors compared to control (CD120a: 3323 +/- 1267, pg/ml, N = 49 vs 1855 +/- 422 pg/ml, N = 33, P < 0.001; CD120b: 1290 +/- 650 pg/ml, N = 51, vs 863 +/- 207 pg/ml, N = 33, P < 0.001). Plasma TNF-alpha level correlated with circulating CD120a (r = 0.52, N = 49, P < 0.001) and weakly with CD120b (r = 0.32, N = 51, P = 0.02). Plasma TNF-alpha also correlated with markers of hepatocellular injury, including ALT (r = 0.34, N = 53, P = 0.01) and alpha-GST (r = 0.31, N = 43, P = 0.042), but not with serum HCV RNA levels. There was no difference in the TNF-alpha mRNA levels in PBMC between patients with chronic HCV infection (1.4 +/- 1.9 units/10[6] cells, N = 8) and healthy control subjects (2.1 +/- 1.4 units/10[6] cells, N = 8, P = NS). There was also no difference in the spontaneous production of TNF-alpha by PBMC (1 x 10[6] cells/ml) between patients with chronic HCV infection (14.2 +/- 36.5 pg/ml, N = 11) and healthy subjects (11.9 +/- 14.0 pg/ml, N = 14, P = NS). However, patients with chronic HCV infection produced more TNF-alpha upon stimulation with lipopolysaccharide compared to healthy control subjects (1278 +/- 693 pg/ml, N = 11, vs 629 +/- 689 pg/ml, N = 14, P < 0.05). These data indicate that the TNF-alpha system is activated in patients with chronic HCV infection.

Effects of interferon-alpha treatment on neutrophil oxidative metabolism, lymphocyte proliferation and monocyte HLA class I antigen expression in patients with chronic hepatitis C

Polymorphonuclear cell (PMN) oxidative metabolism, lymphocyte polyclonal proliferation and monocyte HLA class I antigen expression were evaluated at different intervals of time in patients with chronic hepatitis C (CH-C) subjected to a 6 month interferon alpha (IFN-alpha) treatment and divided into Responder ('R') and Nonresponder ('NR') subsets according to clinical outcome. Before therapy, all subjects exhibited multiple immune alterations even if to a different extent between 'R' and 'NR' subsets: an elevated superoxide anion (O2-) generation by suspended PMN, a failure to further increase neutrophil oxidative responsiveness under adherence conditions, an augmented phytohaemagglutin-induced lymphocyte proliferative capacity and an enhanced HLA class I antigen expression on CD14+ cells. IFN-alpha administration gave rise to a modulation of oxidative response in 'R' group only, since these individuals displayed an O2- release by suspended and adherent PMN which fell within normal values. At the same time, a decrease of lymphocyte proliferation occurred in both groups of patients during IFN-alpha therapy, even if it reached statistical significance in 'R' group only. Finally, a more marked difference between 'R' and 'NR' individuals was noted in terms of HLA class I antigen induction on CD14+ cells at the end of therapy, as a consequence of a reduced expression of these structures in 'NR' subjects. Altogether, these findings suggest the occurrence of a strict relationship between immunoresponsiveness and IFN-alpha induced therapeutical effects in CH-C patients.