Cytokine network in nonresponding chronic hepatitis C patients with genotype 1: role of triple therapy with interferon alpha, ribavirin, and ursodeoxycholate

Inflammation and Liver Cell Death in Patients with Hepatitis C Viral Infection

Hepatitis C virus (HCV)-induced liver disease contributes to chronic hepatitis. The immune factors identified in HCV include changes in the innate and adaptive immune system. The inflammatory mediators, known as "inflammasome", are a consequence of the metabolic products of cells and commensal or pathogenic bacteria and viruses. The only effective strategy to prevent disease progression is eradication of the viral infection. Immune cells play a pivotal role during liver inflammation, triggering fibrogenesis. The present paper discusses the potential role of markers in cell death and the inflammatory cascade leading to the severity of liver damage. We aim to present the clinical parameters and laboratory data in a cohort of 88 HCV-infected non-cirrhotic and 25 HCV cirrhotic patients, to determine the characteristic light microscopic (LM) and transmission electron microscopic (TEM) changes in their liver biopsies and to present the link between the severity of liver damage and the serum levels of cytokines and caspases. A matched HCV non-infected cohort was used for the comparison of serum inflammatory markers. We compared the inflammation in HCV individuals with a control group of 280 healthy individuals. We correlated the changes in inflammatory markers in different stages of the disease and the histology. We concluded that the serum levels of cytokine, chemokine, and cleaved caspase markers reveal the inflammatory status in HCV. Based upon the information provided by the changes in biomarkers the clinician can monitor the severity of HCV-induced liver damage. New oral well-tolerated treatment regimens for chronic hepatitis C patients can achieve cure rates of over 90%. Therefore, using the noninvasive biomarkers to monitor the evolution of the liver damage is an effective personalized medicine procedure to establish the severity of liver injury and its repair.

Diabetes mellitus is associated with impaired response to antiviral therapy in chronic hepatitis C infection

Insulin resistance may promote hepatic fibrosis in chronic hepatitis C (HCV) and has emerged as a cofactor in failure to achieve sustained viral response (SVR).

AIMS

(1) To assess the association of diabetes mellitus (DM) in HCV patients to the severity of hepatic fibrosis and to the response to antiviral treatment. (2) To assess the safety of pegylated interferon and ribavirin combination therapy (Peg IFN/RBV) in diabetic HCV patients. Methods HCV diabetics (n=61) were identified. A 2:1 matching control group was used to identify independent factors of advanced fibrosis and treatment failure.

RESULTS

Compared to HCV non-diabetics, HCV diabetics were more likely to have steatosis (P<0.0001) and advanced fibrosis (P=0.003). Patients' age, Caucasian ethnicity, obesity, and histologic activity index were independently associated with advanced fibrosis (P<0.05). Only 23% of HCV diabetics achieved SVR compared to 46% of HCV non-diabetics (P=0.003). DM, genotype 1, high baseline viral load, and African- American ethnicity were independently associated with less SVR (P<0.05). Significant adverse events were more common in HCV diabetics compared to HCV non-diabetics (P=0.001). Side effects did not increase in patients receiving PEG IFN/RBV and insulin sensitizers. Conclusion DM was associated with impaired virologic response to PEG IFN/RBV in HCV patients. Adverse events during therapy were more frequent in diabetic compared to non-diabetic HCV patients.

Inflammation and repair in viral hepatitis C

Hepatitis C viral infection (HCV) results in liver damage leading to inflammation and fibrosis of the liver and increasing rates of hepatic decompensation and hepatocellular carcinoma (HCC). However, the host's immune response and viral determinants of liver disease progression are poorly understood. This review will address the determinants of liver injury in chronic HCV infection and the risk factors leading to rapid disease progression. We aim to better understand the factors that distinguish a relatively benign course of HCV from one with progression to cirrhosis. We will accomplish this task by discussion of three topics: (1) the role of cytokines in the adaptive immune response against the HCV infection; (2) the progression of fibrosis; and (3) the risk factors of co-morbidity with alcohol and human immunodeficiency virus (HIV) in HCV-infected individuals. Despite recent improvements in treating HCV infection using pegylated interferon alpha (PEGIFN-alpha) and ribavirin, about half of individuals infected with some genotypes, for example genotypes 1 and 4, will not respond to treatment or cannot be treated because of contraindications. This review will also aim to describe the importance of IFN-alpha-based therapies in HCV infection, ways of monitoring them, and associated complications.

Viral factors associated with cytokine expression during HCV/HIV co-infection

Co-infection with human immunodeficiency virus (HIV) is associated with reduced hepatitis C virus (HCV) treatment response and accelerated HCV disease. Cytokines, as mediators of immune responses, inflammation, and fibrogenesis, may underlie important differences in HCV pathogenesis during HIV co-infection. We previously found that serum interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) increased after HCV therapy with interferon (IFN) in HCV/HIV co-infected patients; however, cytokine levels were not predictive of HCV therapeutic response. Here, we examined viral factors associated with expression of IL-8, TNF-alpha, and transforming growth factor-beta1 (TGF-beta1) in uninfected, HCV mono-infected, HIV mono-infected, and HCV/HIV co-infected persons. HIV co-infection was associated with decreased IL-8 detection but not TNF-alpha detection. A significant interaction effect demonstrated that HIV infection was associated with elevated TGF-beta1 in HCV-positive individuals but not in HCV-negative individuals. The induction of a sustained profibrotic signal, such as TGF-beta1, by HIV may cause accelerated liver fibrosis during HCV/HIV co-infection and may hinder the host's ability to mount an effective HCV-specific immune response. Further studies are warranted to identify noninvasive markers of liver disease for the clinical management of HCV disease, particularly when liver biopsies have not been performed or are contraindicated.

Diabetes mellitus reduces the therapeutic effectiveness of interferon-alpha2b plus ribavirin therapy in patients with chronic hepatitis C

AIM

Patients with chronic hepatitis C (CHC) often have diabetes mellitus (DM). However, it is unknown whether DM affects patient response to interferon (IFN) plus ribavirin therapy. Therefore, the aim of this study was to examine the influence of DM on the outcome of IFN-alpha2b plus ribavirin therapy.

METHODS

In a cohort of 110 patients with CHC, the outcome of 6 months of IFN-alpha2b plus ribavirin therapy was evaluated by comparing the patients with and without DM.

RESULTS

There were 46 sustained-responders; 64 patients did not become sustained responders. Higher age (P = 0.015), lower platelet counts (P = 0.036), hepatitis C virus (HCV) serotype 1 (P = 0.001), advanced liver fibrosis (P = 0.004), and the presence of DM (P = 0.007) were significantly associated with not becoming a sustained-responder. Seventeen CHC (15%) patients had DM. Sex ratio, age, body mass index, alanine aminotransferase levels, HCV-RNA titer, and HCV serotypes did not significantly differ between the patients with and without DM, while fasting plasma glucose, hemoglobin A1c and liver histological staging were significantly different. On multiple logistic regression analysis, HCV serotype 1 (odds ratio 8.743, 95% confidence interval 2.215-34.517; P = 0.002) and the presence of DM (odds ratio 8.657, 95% confidence interval 1.462-51.276; P = 0.014) were independently associated with not becoming a sustained-responder.

CONCLUSIONS

The findings indicate that DM reduces the response to IFN-alpha2b plus ribavirin therapy in CHC patients.

Effects of HCV treatment on cytokine expression during HCV/HIV coinfection

There is growing evidence that cytokine expression is linked to hepatitis C virus (HCV) pathogenesis and treatment response rates among HCV-monoinfected persons. However, because of the profound effects of human immunodeficiency virus (HIV) coinfection on HCV, it is not clear if these observations are also true for HCV/HIV-coinfected individuals. Serum expression of the proinflammatory cytokines interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) and the fibrogenic cytokine transforming growth factor-beta1 (TGF-beta1) were measured in HCV/HIV-coinfected persons at baseline and at week 24 of HCV therapy. Higher levels of IL-8 and TGF-beta were demonstrated among nonwhite subjects at baseline. Increases in TNF-alpha and IL-8 expression were found at week 24 of HCV therapy, suggesting that enhanced proinflammatory cytokine production may occur during HCV treatment. However, cytokine levels were not predictive of HCV virologic, biochemical, or histologic response. Although previous studies conducted among HCV-monoinfected individuals have suggested that cytokine levels could predict the virologic response to therapy, no such associations were observed among HCV/HIV-coinfected persons, suggesting that they may respond differently to treatment than do their HCV-monoinfected counterparts.

Sustained virological response to peginterferon plus ribavirin in chronic hepatitis C genotype 1 patients is associated with a persistent Th1 immune response

BACKGROUND

An impairment of cellular immune response may contribute to the persistency of hepatitis C virus infection.

AIM

To analyse the Th1/Th2 cytokine profile in peripheral blood CD4(+) and CD8(+) T cells from patients with chronic hepatitis C (CHC) during treatment with pegylated interferon-alpha2a plus ribavirin and to correlate the Th1/Th2 balance with virological response (SVR).

METHODS

Prospective longitudinal study: 44 naïve genotype 1 CHC patients received PEG-IFNalpha2a plus ribavirin for 48 weeks: 26 (59.1%) achieved a SVR, 13 relapsed (29.5%) and 5 (11.4%) were non-responders. Sixteen healthy controls were analysed. The production of IL-4, IFNgamma and TNFalpha by CD4(+) and CD8(+) T cells was measured using flow cytometry, both in resting and phorbol-ester-stimulated cells.

RESULTS

First three months of treatment: the synthesis of TNFalpha by phorbol-ester-stimulated-CD4(+) T cells was higher in patients with SVR (P < 0.01). At the end of treatment, SVR was associated with higher intracellular expression of IFNgamma by stimulated-CD4(+) and CD8(+) T cells (P < 0.05). At the end of follow-up, a higher intracellular expression of IFNgamma by CD4(+) T cells was associated with a SVR.

CONCLUSIONS

A Th1-type immune response was associated with achievement of a SVR, as indicated by the persistent elevation of intracellular IFNgamma and TNFalpha.

The potential anti-HBV effect of amantadine in combination with ursodeoxycholic acid and biphenyl dimethyl dicarboxylate in HepG2 2.2.15 cells

Experimental studies have demonstrated that the triple combination of amantadine (A)/ ursodeoxycholic acid (UDCA, U)/ biphenyl dimethyl dicarboxylate (DDB, D) might have a preferential antiviral effect compared with that observed in interferon-induced antiviral signal pathways, such as those of STAT1alpha and the 6-16 genes. To confirm the result, this study examined whether the signal transduction for the antiviral activity in HepG2 2.2.15 was induced dependently or independently of interferon. To accomplish this, the correlation between the STAT1alpha and 6-16 genes, and nitric oxide, for the mediation of the antiviral activity was assessed. The increase in nitric oxide in the UDCA groups suggests that the inhibition of viral gene replication was enhanced by the amantadine combinations (AU and AUD), and might be more effective if incubated for longer periods. It was found that STAT1alpha was activated by the amantadine combination, although to a lesser extent than that of interferon-alpha, and the primary endpoints examined for the inhibition of gene expression (HBsAg and HBcAg) were remarkably well regulated. This suggests that the amantadine triple, or at least the double, combination had better clinical benefits than those of IFN-alpha and the nucleoside analogue single treatment. This demonstrates that the amantadine combination might be a substitute for the existing HBV therapy if the results of in vivo and in vitro studies concur.

Steatosis in chronic hepatitis C: association with increased messenger RNA expression of collagen I, tumor necrosis factor-alpha and cytochrome P450 2E1

BACKGROUND

Increased levels of tumor necrosis factor (TNF)-alpha and oxidative stress have been implicated as factors contributing to hepatic injury in fatty liver diseases. As steatosis is associated with an accelerated progression of fibrosis in chronic hepatitis C (HCV), we hypothesized that the messenger (m)RNA expression of genes involved with the production of reactive oxygen species, inflammation and cellular injury would be increased in liver tissue from subjects with steatosis and chronic HCV.

METHODS

Real-time polymerase chain reaction was performed to determine relative mRNA expression levels of collagen I, TNF-alpha, cytochrome P450 2E1 (CYP 2E1), transforming growth factor-beta1 and CD14 in liver biopsies from 38 patients with chronic HCV. The mRNA expression levels were compared between subjects with and without steatosis, fibrosis, and inflammation.

RESULTS

Multivariate analysis demonstrated that collagen I mRNA expression was increased by 199% in steatosis (P = 0.02), 85% in moderate to severe fibrosis (P = 0.02) and 157% in inflammation (P = 0.03). Livers of patients with steatosis also had an increase in TNF-alpha mRNA expression by 50% (P = 0.03) and CYP 2E1 expression by 37% (P = 0.04) compared with non-steatotic livers. Tumor necrosis factor-alpha protein was localized to Kupffer cells, bile ducts and portal inflammatory cells by immunohistochemistry.

CONCLUSION

Increased expression of TNF-alpha may be involved in the pathogenesis of liver injury and progression of fibrosis in individuals who have steatosis in association with chronic HCV.

Th1/Th2 cytokine imbalance in patients with Sjögren syndrome secondary to hepatitis C virus infection

OBJECTIVE

To investigate if the serum immunologic profile, as delineated by serum circulating levels of Th1/Th2 cytokines and autoantibodies, is different in patients with Sjögren syndrome (SS) with and without hepatitis C virus (HCV) infection.

METHODS

This study included 20 patients with HCV-related SS and 47 consecutive patients with primary SS. All fulfilled 4 or more of the modified 1996 European criteria for SS. Serum levels of interleukin (IL)-2 (pg/mL), srIL-2 (pM), tumor necrosis factor (TNF)-alpha (pg/mL), IL-6 (pg/mL), and IL-10 (pg/mL) were determined using enzyme immunoassay. We also analyzed the following immunologic tests: anti-nuclear antibodies (ANA), anti-mitochondrial antibodies (AMA), anti-parietal cell antibodies (PCA), anti-smooth muscle antibodies (SMA), anti-liver-kidney microsome antibodies type-1 (LKM-1), anti-Ro/SS-A, anti-La/SS-B, rheumatoid factor (RF), complement factors (C3 and C4), and cryoglobulins.

RESULTS

Of the 20 patients with HCV-related SS, 18 were women and 2 men (mean age, 66 years). Patients with HCV-related SS had a different cytokine profile compared with patients with primary SS, with higher circulating levels of IL-6 (73.6 v 33.0 pg/mL, P =.045), IL-10 (6.7 v 3.1 pg/mL, P =.01), srIL-2 (124.6 v 72.7 pM, P =.001), and TNF-alpha (59.8 v 31.7 pg/mL, P =.003). The main immunologic features were ANA, detected in 75% of patients, RF in 63%, cryoglobulinemia in 50%, hypocomplementemia in 40%, SMA in 30%, PCA in 25%, anti-Ro/SS-A in 25%, AMA in 20% and anti-La/SS-B in 16%. When compared with primary SS patients, those with HCV-related SS had a higher prevalence of AMA (20% v 2%, P =.025), hypocomplementemia (40% v 11%, P =.015), and cryoglobulinemia (50% v 12%, P =.003).

CONCLUSION

Although chronic HCV infection may mimic the main clinical, histologic and immunologic features of primary SS, patients with HCV-related SS showed some differentiated characteristics, including a predominant Th2 pattern and a higher frequency of cryoglobulinemia and hypocomplementemia (features closely related to HCV). This suggests that the SS observed in some HCV patients should be interpreted as one of the extrahepatic manifestations of chronic HCV infection.

Kinetics of serum cytokines reflect changes in the severity of chronic hepatitis C presenting minimal fibrosis

Our aims were to measure the kinetics of serum tumour necrosis alpha (TNF-alpha) and transforming growth factor beta (TGF-beta) levels as markers of progression of disease in nontreated chronic hepatitis C virus (HCV)-infected patients with minimal or no fibrosis and minimal histology activity index (HAI) scores. Our study group consisted of 56 patients diagnosed with minimal (1) or no fibrosis (0) and minimal HAI (0-1) on their first biopsy as defined by Knodell and METAVIR scores. We compared their initial (entry of study) cytokine levels with a group of 103 HCV controls with minimal (0-1) to mild fibrosis (0-3) and mild HAI (5.5). Serum TNF-alpha and TGF-beta levels were measured by enzyme-linked-immunosorbent-assay. A significant difference was seen in TNF-alpha levels at baseline in the study group vs. controls. Regardless of their HAI, there was a correlation between TGF-beta and degree of fibrosis. As shown by their biopsies, during the 3 years (from entry to follow up), many of the patients that initially had minimal fibrosis progressed to higher degree of fibrosis. This progression is paralleled by an increase in TGF-beta levels when comparing initial and follow-up levels. In conclusion, serum TNF-alpha reflects the progression of inflammation as seen in liver biopsies and TGF-beta reflects the degree of fibrosis in HCV patients.

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.