Hepatic gene expression and prediction of therapy response in chronic hepatitis C patients

High sustained virological response to pegylated interferon and ribavirin for recurrent genotype 3 hepatitis C infection post-liver transplantation

INTRODUCTION

Treatment outcomes of recurrent HCV genotype 3 (GT-3) after liver transplantation (LT) are ill-defined.

AIMS

To determine efficacy, predictors, and long-term survival after treatment of recurrent HCV GT-3 infection, post-LT, with a combination of pegylated interferon (PEG) and ribavirin (RBV).

METHODS

We studied all LT recipients (LTR) in our program treated with PEG and RBV for recurrent HCV GT-3 between Jan 1st 2002 and Dec 31st 2013. Antiviral therapy (AVT) was started if histology showed recurrent HCV with ≥ stage 2 fibrosis. Treatment was intended for 24 or 36 weeks, depending on early virologic response, and/or 24 weeks consolidation. Primary endpoint was sustained virological response (SVR). We also studied predictors of SVR and long-term patient survival.

RESULTS

Among 492 LT for HCV-related cirrhosis and/or hepatocellular carcinoma performed during the study period, 110 (22%) had HCV GT-3 infection. Fifty-two (10.5%) HCV GT-3 patients had indications for AVT. Six were unable to complete the AVT, three because of clinical decompensation and one each because of metastatic disease involving the brain, lung cancer, and ductopenic rejection. Forty-seven (90%) patients achieved early virological response (EVR) and 37 (71%) achieved SVR. Predictors of SVR were EVR (p < 0.001), stage ≤ 3 fibrosis (p = 0.008), and 36 weeks treatment duration (p < 0.001). Less advanced fibrosis ≤ 3 was independent predictor of SVR (OR 0.18, 95% CI 0.05-0.67). SVR patients had actuarial (Kaplan-Meier) 1, 3, and 10 year post-treatment survival of 100, 100, and 95%, compared with 87, 78, and 20% for non-SVR patients (p < 0.001, log rank test).

CONCLUSION

Efficacy of AVT for recurrent HCV GT-3 post-LT is high, and comparable with that for non-transplant patients. Less advanced fibrosis is an independent predictor of SVR. SVR improves long-term survival.

Activation of endogenous type I IFN signaling contributes to persistent HCV infection

HCV infection is a major world health problem, leading to both end-stage liver disease and primary liver cancer. Great efforts have been made in developing new therapies for HCV infection; however, combination therapy with pegylated IFN-α and ribavirin (pegIFN-RBV) remains the first choice of treatment for chronic HCV infection in most countries. The treatment response to pegIFN-RBV remains relatively low. Understanding the molecular mechanisms of persistent HCV infection and pegIFN-RBV resistance will suggest ways of improving the current standard of care and offers new antiviral therapies for both HCV and other viral infections. Recent data suggest that increased expression of hepatic IFN-stimulated genes (ISGs) before treatment is associated with treatment nonresponse in patients chronically infected with HCV. Although ISGs are generally antiviral in nature, in the case of HCV, the virus may exploit some of them to its benefit. This is not unique to HCV: Blockade of type I IFN signaling has been shown to control persistent LCMV infection. Thus, in certain viral infections, preactivation or overactivation of type I IFN signaling may contribute to viral persistence. In this review, we briefly summarize the findings from high-throughput gene expression profiling from patients chronically infected with HCV, then focus on a novel ubiquitin-like signaling pathway (ISG15/USP18) and its potential role in HCV persistence. Finally, the role of activation of endogenous type I IFN signaling in persistent HCV infection will be discussed in the context of recent studies indicating that blocking IFN signaling controls persistent LCMV infection.

Polymorphisms in interleukin-10 and interleukin-28B genes in Egyptian patients with chronic hepatitis C virus genotype 4 and their effect on the response to pegylated interferon/ribavirin-therapy

BACKGROUND AND AIM

Recently, it has been suggested that single nucleotide polymorphisms (SNPs) in some cytokine genes may influence the production of the associated cytokines that affect the host immune response to pegylated interferon-α (Peg-IFN-α) with ribavirin (RBV) in hepatitis C virus (HCV) patients. The aim of the present study was to investigate the possible role of the SNPs of IL-10 and Il-28B and their serum levels in predicting the response to treatment of HCV-4.

METHODS

Egyptian patients were treated with Peg-IFN-α/RBV. A total of 100 HCV genotype 4-infected patients and 80 healthy control subjects were included in the present study. SNPs in the IL-10 (-592 A/C and -819 T/C) and IL-28B (rs8099917 T/G and rs12979860 C/T) genes and their serum levels were assessed. The IL-10-592-CC, IL-28-rs8099917-TT and IL-28-rs12979860-CC genotypes were significantly higher in responders than in non-responders.

RESULTS

Interestingly, the serum levels of IL-10 were significantly increased; in contrast, the serum levels of Il-28B were significantly decreased in HCV patients compared with normal patients. Polymorphisms in IL-28B are more sensitive (P < 0.001) than those in IL-10-592 (P = 0.03). However, the serum level of IL-10 is higher than that of IL-28, and this difference can serve as a prognostic marker using a receiver operator characteristic (ROC) analysis.

CONCLUSIONS

It can be concluded that SNPs in IL-28B and the serum levels of Il-10 and IL-28 may be promising predictors for HCV therapy.

Analysis of human liver disease using a cluster of differentiation (CD) antibody microarray

BACKGROUND

A CD antibody microarray has been previously developed allowing semi-quantitative identification of greater than 80 CD antigens on circulating leucocytes from peripheral blood samples. This assay, which uses a live cell-capture technique, enables an extensive leucocyte immunophenotype determination in a single analysis and to date this has been used successfully to characterise diseases including human leukaemias and HIV infection.

AIMS

To determine CD antigen expression profiles for patients with various liver diseases and to look for preserved disease-specific signatures.

METHODS

Three liver disease groups including hepatitis C (HCV) (n = 35), non-alcoholic steatohepatitis (NASH) (n = 21) and alcohol-related liver disease (n = 14) were compared with a normal group (n = 23). Hierarchal Clustering (HCL) and Principal Component Analysis (PCA) of the data revealed distinct binding patterns for patients with and without cirrhosis.

RESULTS

Patients with cirrhosis and portal hypertension compared with those without cirrhosis had significantly reduced expression of several markers of T-cell function including CD45, CD8, CD28 and TCR α/β. Disease prediction algorithms based on the expression data were able to discriminate cirrhotics from non-cirrhotics with 71% overall success, which improved to 77% when only patients with HCV were considered.

CONCLUSIONS

These results demonstrate disease-specific consensus patterns of expression of CD antigens for patients with chronic liver disease, suggesting that the CD antibody array is a promising tool in the analysis of human liver disease, and with further refinement may have future research and clinical utility.

The treatment response of chronically hepatitis C virus-infected patients depends on interferon concentration but not on interferon gene expression in peripheral blood mononuclear cells

The current treatment of chronic hepatitis C is based on pegylated alpha interferon (PEG-IFN-α) and ribavirin. The aim of this study was to identify biological and clinical variables related to IFN therapy that could predict patient outcome. The study enrolled 47 patients treated with PEG-IFN and ribavirin combined therapy. The interferon concentration was measured in serum by a bioassay. The expression of 93 interferon-regulated genes in peripheral blood mononuclear cells was quantified by real-time quantitative reverse transcription-PCR (RT-PCR) before and after 1 month of treatment. The interferon concentration in the serum was significantly lower in nonresponders than in sustained virological responders. Moreover, a significant correlation was identified between interferon concentration and interferon exposition as well as body weight. The analysis of interferon-inducible genes in peripheral blood mononuclear cells among the genes tested did not permit the prediction of treatment outcome. In conclusion, the better option seems to be to treat patients with weight-adjusted PEG-IFN doses, particularly for patients with high weight who are treated with PEG-IFN-α2a. Although the peripheral blood mononuclear cell samples are the easiest to obtain, the measurement of interferon-inducible genes seems not be the best strategy to predict treatment outcome.

Drug safety evaluation of adefovir in HBV infection

INTRODUCTION

Several nucleos(t)ide analogs (NUC) are available for the management of patients with chronic hepatitis B (CHB). In most patients, NUC need to be administered on a long-term basis, thus increasing the risk of adverse effects. Adefovir dipivoxil (ADV), the first nucloeotide analog developed to treat CHB, may indeed cause nephrotoxicity.

AREAS COVERED

The pharmacokinetic mechanism of action, potential mechanism of renal damage and long-term safety profile of ADV in CHB patients have been reported. The current monitoring modalities, together with dosage adjustments, treatment of patients with ADV-related kidney impairment and the therapeutic algorithm in place at the authors' Liver Center are also summarized. Although, in short-term clinical trials, a daily dose of 10 mg of ADV was safe owing to a low rate of negligible nephrotoxic effects, the same dose may be associated with a usually reversible, proximal renal tubular toxicity as reflected by hypophosphatemia and elevated creatinine levels. Occasionally, Fanconi syndrome occurred in ADV-treated patients.

EXPERT OPINION

Renal function at baseline and during treatment should be carefully assessed in all patients receiving ADV to adjust the dose according to creatinine clearance, aimed to prevent or minimize nephrotoxicity.

The Role of FGL2 in the Pathogenesis and Treatment of Hepatitis C Virus Infection

Chronic hepatitis C virus (HCV) infection is a leading cause of liver disease worldwide and remains the most common indication for liver transplantation. The current standard of care leads to a sustained viral response of roughly 50% of treated patients at best. Furthermore, anti-viral therapy is expensive, prolonged, and associated with serious side-effects. Evidence suggests that a poor response to treatment may be the result of a suppressed anti-viral immunity due to the presence of increased numbers and activity of CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg cells). We and others have recently identified fibrinogen-like protein 2 (FGL2) as a putative effector of Treg cells, which accounts for their suppressive function through binding to Fc gamma receptors (FcγR). In an experimental model of fulminant viral hepatitis, our laboratory showed that increased plasma levels of FGL2 pre- and post-viral infection were predictive of susceptibility and severity of disease. Moreover, treatment with antibody to FGL2 fully protected susceptible animals from the lethality of the virus, and adoptive transfer of wild-type Treg cells into resistant fgl2-deficient animals accelerated their mortality post-infection. In patients with HCV infection, plasma levels of FGL2 and expression of FGL2 in the liver correlated with the course and severity of the disease. Collectively, these studies suggest that FGL2 may be used as a biomarker to predict disease progression in HCV patients and be a logical target for the development of novel therapeutic approaches for the treatment of patients with HCV infection.

Simultaneous determination of multiple mRNA levels utilizing MALDI-TOF mass spectrometry and biotinylated dideoxynucleotides

Here we report an efficient method to simultaneously measure multiple mRNA levels utilizing mass spectrometry (MS) and molecular affinity isolation. In this approach, reverse transcription products of a group of mRNAs are subjected to competitive PCR with competitors and internal standards of known concentrations, and the PCR products are differentiated and quantified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS to determine the mRNA levels. The method provides high accuracy in quantitative MS analysis due to the facilitated purification of oligonucleotides by molecular affinity isolation. Additionally, owing to the molecular affinity isolation, only those oligonucleotides required for expression level determination are introduced into the mass spectrometer, while other irrelevant reaction components that could overlap with peaks of gene transcripts or competitors are removed prior to MS analysis. Thus the approach enhances the parallel analysis of multiple gene transcripts by MS. Utilizing the method we have simultaneously measured mRNA levels of four genes (Rho, Nrl, Hprt, and Lhx2) in mouse retinal tissue.

Cell-type specific gene expression signature in liver underlies response to interferon therapy in chronic hepatitis C infection

BACKGROUND & AIMS

Chronic hepatitis C virus (CHC) infection is treated with interferon/ribavirin, but only a subset of patients respond. Treatment nonresponders have marked pretreatment up-regulation of a subset of interferon stimulated genes (ISGs) in their livers, including ISG15. We here study how the nonresponder gene expression phenotype is influenced by clinical factors and uncover the cellular basis of the phenotype through ISG15 protein expression.

METHODS

Seventy-eight CHC patients undergoing treatment were classified by clinical (gender, viral genotype, viral load, treatment outcome) and histologic (inflammation, fibrosis) factors and subjected to gene expression profiling on their pretreatment liver biopsies. An analysis of variance model was used to study the influence of individual factors on gene expression. ISG15 immunohistochemistry was performed on a subset of 31 liver biopsy specimens.

RESULTS

One hundred twenty-three genes were differentially expressed in the 78 CHC livers when compared with 20 normal livers (P < .001; fold change, > or =1.5-fold). Of genes influenced by a single factor, genotype (1 vs 2/3) influenced more genes (17) than any other variable; when treatment outcome was included in the analysis, this became the predominant influence (24 genes), and the effect of genotype was diminished. Treatment response was linked to cell-specific activation patterns: ISG15 protein up-regulation was more pronounced in hepatocytes in treatment nonresponders but in Kuppfer cells in responders.

CONCLUSIONS

Genotype is a surrogate marker for the nonresponder phenotype. This phenotype manifests as differential gene expression and is driven by activation of different cell types: hepatocytes in treatment nonresponders and macrophages in treatment responders.

Antiviral treatment of recurrent hepatitis C after liver transplantation: predictors of response and long-term outcome

BACKGROUND

Efficacy and long-term outcome of antiviral therapy for recurrent hepatitis C after liver transplantation is poorly defined.

AIM

This study aimed at assessing the efficacy of antiviral therapy regarding sustained hepatitis C virus (HCV) clearance, liver histology, and patient survival.

METHODS

We retrospectively reviewed all 446 patients who received a liver allograft at our institution for HCV-related cirrhosis between January 1992 and December 2006. Two hundred thirty-two patients (52%) were eligible for antiviral therapy based on predefined criteria (Metavir stage > or =1 and/or grade > or =2; protocol biopsies). One hundred seventy-two patients (39%) had no contraindication for treatment, received more than or equal to 1 dose of interferon-alpha-based combination therapy, and form the basis of this analysis. Therapy was aimed for 48 weeks; median posttreatment follow-up was 68 months.

RESULTS

The overall sustained virological response (SVR) rate was 50% (genotype 1/4: 40%; genotype 2/3: 76%). SVR was higher on cyclosporine A (CsA) (56%) than on tacrolimus (44%, P=0.05), largely because of a lower relapse rate (6% vs. 19%, P=0.01). In multivariate analysis, genotype 2/3, CsA use, donor age, and pretreatment necroinflammatory activity were independently associated with SVR. SVR significantly improved histology and long-term survival (actuarial 5-year survival 96% vs. 69% in nonresponders, P<0.0001).

CONCLUSION

Antiviral therapy of recurrent hepatitis C after liver transplantation is able to clear HCV in half the patients, more likely on CsA than on tacrolimus, and markedly improves outcome.

Management of chronic hepatitis C patients who have relapsed or not responded to pegylated interferon alfa plus ribavirin

Development of therapeutic strategies for patients with chronic hepatitis C who experience virological breakthrough, relapse or nonresponse lag behind those for treatment-naïve patients. The probability of a previously treated patient responding to re-treatment depends on the nature of the previous regimen, the magnitude of the response to previous treatment and the patient's characteristics. Relapsers have higher sustained virological response rates than nonresponders when re-treated with pegylated interferon plus ribavirin. Re-treatment of nonresponders to pegylated interferon plus ribavirin with the standard 48-week regimen resulted in an approximate 6% sustained response rate in the EPIC-3 program. In the REPEAT trial, the sustained response rate was significantly higher in nonresponders to pegylated interferon alfa-2b (12 kD) plus ribavirin randomized to 72 weeks of peginterferon alfa-2a (40 kD) plus ribavirin, compared with a 48-week regimen (16%vs 8%, P = 0.0006). Based on available data, extended treatment is the best option for these individuals. Undetectable viral RNA at week 12 is an important criterion for re-treatment in the REPEAT and EPIC studies. Maintenance therapy with pegylated interferon is generally ineffective in nonresponders and cannot be recommended. Directly acting antivirals may increase response rates and the burden of adverse events when combined with the standard of care, but will not be available for some years. In conclusion, after careful evaluation of an individual's benefit-risk ratio, a 72-week regimen is the preferred strategy for optimizing sustained response rates in patients who have not responded to the standard of care, provided that viral RNA is undetectable at week 12 of re-treatment.

Interleukin-10 promoter polymorphisms in hepatitis C patients with and without Schistosoma mansoni co-infection

BACKGROUND/AIM

Interleukin (IL-10) plays a major role in chronic hepatitis C virus (HCV) disease pathogenesis, in particular in Schistosoma mansoni (S. mansoni) co-infected patients. Given that interindividual variations in IL-10 production are influenced by functional polymorphisms in the IL-10 gene promoter, we determined the frequencies of common (-1082, -819 and -592) IL-10 promoter polymorphisms in chronic HCV patients with and without S. mansoni co-infection and healthy controls, and investigated their association with the degree of histological activity index (HAI) and response to interferon-ribavirin therapy.

METHODS

Genomic DNA from 99 patients and 62 healthy controls, born in the same geographical hyperendemic area, was studied by the polymerase chain reaction, followed by restriction enzyme digestion. Sera were assessed for S. mansoni antibodies.

RESULTS

The frequencies of IL-10 polymorphisms at positions -1082, -819 and -592 from the transcription start site were comparable between HCV patients and controls, as well as between HCV mono-infected and either S. mansoni co-infected patients or controls. The grade of inflammation and the stage of fibrosis showed no association with IL-10 polymorphisms. The frequencies of S. mansoni co-infection and IL-10 genotypes/haplotypes were insignificantly different between non-responders and responders to combination therapy. No effect of other factors like age, gender, HAI group scores and serum alanine aminotransferase and aspartate aminotransferase levels was observed on response to therapy in our patients.

CONCLUSION

Our findings suggest that common IL-10 (-1082, -819 and -592) genotypes/haplotypes do not influence the degree of HAI and response to combination therapy or susceptibility to HCV infection with and without S. mansoni co-infection.