American Gastroenterological Association technical review on the management of hepatitis C

Peginterferon/ribavirin treatment achieves a higher compliance rate than interferon/ribavirin combination in patients chronically infected with HCV on methadone maintenance

INTRODUCTION

Chronic hepatitis C virus infection (HCV) is the most common infectious disease among intravenous drug users.

AIMS

To determine and compare compliance rates between two groups of chronic HCV patients from the methadone substitution program of the National Greek Organization Against Drugs treated with either pegylated interferon alpha-2b/ribavirin or with interferon alpha-2b/ribavirin during 48 weeks of therapy and 24 weeks of follow-up. Furthermore, to evaluate the efficacy of each treatment modality.

METHODS

Forty-five consecutive methadone maintenance (MM) patients (group A, 36 males, nine females) were treated with pegylated interferon alpha-2b (weight-based dosing 1.5 microg/kg/week) and ribavirin 1000-1200 mg/day orally. Sixty-five consecutive MM patients (group B, 52 males, 13 females) were treated with interferon alpha-2b (6 MIU, three times/week) and ribavirin with the doses reported above. During the study, all patients were followed up periodically by hepatologists, internists, and psychiatrists.

RESULTS

Baseline characteristics were similar between the two groups. Thirty-four out of 45 patients (75.6%) from group A and 31 of 65 patients (47.7%) from group B completed therapy (P =0.006). Thirty-two (71.1%) patients from group A and 27 patients (41.5%) from group B were followed-up until the end of week 72 (P = 0.004). At the end of the follow-up, sustained virologic response was achieved in 23 of 45 (51.1%) patients from group A and 21 of 65 patients (32.3%) from group B (P =0.075).

CONCLUSION

Pegylated interferon alpha-2b/ribavirin treatment achieved a significantly higher compliance rate than interferon alpha-2b/ribavirin in MM patients with chronic HCV infection. After 24 weeks of follow-up, response rates were similar for patients who were compliant to treatment for both groups.

The disposition of hepatitis C antibody-positive patients in an urban hospital

Previous studies have indicated that only 26-61% of hepatitis C virus (HCV) antibody-positive patients are referred to specialists who treat HCV. However, these studies were conducted in homogeneous populations and before pegylated interferon and ribavirin became the standard of care for chronic HCV infection. The aims of this study were: (i) to determine the percentage of HCV antibody-positive patients who were referred to specialists for further management in an urban, racially diverse population, (ii) to determine the percentage of referred patients who attend specialty clinics, and (iii) to identify factors that predict referral and follow-up. All patients with a positive HCV antibody test in 2005 were identified by an inquiry of Epic, our electronic medical record system. All medical records were reviewed for demographics, location where the test was ordered (inpatient vs outpatient), specialty ordering the test, referral, clinic attendance, detectability of HCV RNA and liver function tests. Univariate and multivariate logistic regression were used to evaluate each variable's effect on referral and clinic attendance. Overall, 251 of 375 (67%) antibody positive patients were referred to HCV specialists. Of the 251 referrals, 166 (66%) attended at least one specialty clinic appointment. Patients were more likely to be referred if their HCV antibody was ordered in the outpatient setting (77% outpatient vs 38% inpatient, P < 0.001) ordered by a family practitioner (79% FP vs 64% for internal medicine doctor vs 58% for all other specialties, P = 0.01) had detectable RNA (88% detectable vs 65% not detectable vs 23% RNA status not available, P < 0.001) or elevation of alanine aminotransferase (75% elevated vs 56% not elevated, P < 0.001). Location, HCV RNA status and ALT elevation remained significant in a multivariate logistic regression model. These data confirm that up to one-third of HCV antibody-positive patients are not referred to HCV specialists, despite the availability of improved treatment regimens. Additional patients are lost to follow-up after being referred. The reasons for suboptimal referral and specialty clinic attendance rates are probably multifactorial. Institution of reflexive RNA testing for positive antibody tests and additional education of those physicians who encounter HCV-positive individuals may improve both rates.

A model of patient choice with mid-therapy information

For many treatments, a patient's prognosis may be refined by conducting a mid-therapy assessment (MTA). When therapy lasts some time, an MTA predicts a patient's ultimate outcome based on early signs of response. The availability and timing of such assessments also serve as a mechanism by which policy makers can influence patients' treatment-initiation decisions. In this article, we examine how patients evaluate treatment options using MTAs of treatment effectiveness and discuss the policy implications of patient decision making in such contexts. To this end, we use indifference-curve analysis to characterize trade-offs between potential treatment success versus potential adverse effects in therapeutic situations where patients are encouraged to consider their own motivations for initiating treatment. Treatment initiation for chronic hepatitis C virus (HCV) infection is used for illustration, but the analysis can be easily adapted to a variety of clinical scenarios.Analysis shows that the existence of MTAs influences patients' initial treatment decisions by affecting the expectations of treatment success and adverse effects. Earlier MTAs have lower sensitivity and higher specificity, and the prior expectation of adverse effects is accordingly lower for two reasons. First, the lower chance for a false signal of treatment response and the higher chance for a false signal of no response make it more likely that the patient receives a signal leading to discontinuation. Second, if a signal to discontinue is received, fewer weeks of adverse effects have been endured before discontinuation occurs. Both factors make the expected burden of adverse effects lower when the MTA occurs earlier. Later MTAs have higher sensitivity and lower specificity, both of which serve to increase the probability of treatment completion, causing a higher prior likelihood of treatment success.These findings indicate that treatment demand may be increased by changing the timing of MTAs, depending on the information content of the alternative mid-therapy signals and the nature of patient preferences. In HCV infection and other diseases, clinical practice guidelines for conducting MTAs might be modified to better achieve public health or other policy objectives by studying the economics of patient choice.

Predicting the probable outcome of treatment in HCV patients

Hepatitis C virus (HCV) is a major cause of chronic liver disease infecting more than 170 million people worldwide. HCV produces a wide gamut of manifestations varying from mild self-limiting disease to cirrhosis and hepatocellular carcinoma. A variety of viral, environmental and host genetic factors contribute to the clinical spectrum of patients infected with HCV and influence response to interferon (IFN) therapy. Predicting the probable outcome of treatment in patients with HCV infection has always been a challenging task. Treatment of HCV by pegylated interferon (peg-IFN) plus ribavirin eradicates the virus in approximately 60% of patients - HCV genotype 1 (42-51% response rates) and genotypes 2 and 3 (76-84% response rates); however, a significant number of patients do not respond to therapy or relapse following discontinuation of treatment or have significant side effects that preclude further treatment. Accurately predicting the patients who will respond to therapy is becoming increasingly important, both from the point of patient care and also with respect to the healthcare cost as clinicians need to continue treatment in patients who will respond and stop treatment in patients who are unlikely to respond. Viral RNA measurements and genotyping are used to optimize treatment as a low viral load and nongenotype 1 is more likely to be associated with sustained virological response (SVR). Rapid virological response (RVR) defined by undetectable HCV RNA at 4 weeks of treatment is increasingly being recognized as a powerful tool for predicting treatment response. A variety of host factors including single nuclear polymorphisms (SNPs) of IFN response genes, insulin resistance, obesity, ethnicity, human leukocyte antigens and difference in T-cell immune response has been found to modulate the response to antiviral treatment. The presence of severe fibrosis/cirrhosis on pretreatment liver biopsy predicts a poor response to treatment. Recent studies on gene expression profiling and characterization of the liver and serum proteome provide options to accurately predict the outcome of patients infected with HCV in the future. Future studies on the factors that predict treatment response and tailoring treatment based on this is required if we are to conquer this disease.

Decline in male sexual desire, function, and satisfaction during and after antiviral therapy for chronic hepatitis C

BACKGROUND & AIMS

The recommended therapy for chronic hepatitis C, pegylated interferon and ribavirin for 24 or 48 weeks, has many known adverse side effects. The aim of this study was to evaluate the impact of antiviral therapy on male sexual health.

METHODS

As part of the Study of Viral Resistance to Antiviral Therapy of Chronic Hepatitis C (Virahep-C), 260 men treated with pegylated interferon alfa-2a and ribavirin completed self-administered questionnaires concerning sexual desire, sexual function, including erectile and ejaculatory function, and sexual satisfaction before, during, and after treatment.

RESULTS

Before therapy, 37% of men reported at least some degree of impairment in sexual desire and 44% reported dissatisfaction with their sexual life, while 26% reported impairment in erectile and 22% in ejaculatory function. During therapy, significant declines were observed in all components of sexual health compared with pretreatment. At the end of therapy (24 or 48 weeks), an estimated 38%-48% of men reported that overall sexual function was worse than before treatment. African American patients reported less impairment in sexual desire and satisfaction than Caucasian American patients during therapy. By 24 weeks after treatment, sexual desire and satisfaction improved and were comparable to baseline levels. However, among men who received 48 weeks of therapy, the estimated percentage of men reporting posttreatment erectile or ejaculatory problems remained higher than baseline, although persistent erectile impairment was limited to Caucasian American patients.

CONCLUSIONS

Sexual impairment is common among men with chronic hepatitis C undergoing therapy with pegylated interferon and ribavirin and should be considered as a potential side effect of antiviral therapy.

Cyclophilin inhibitors

The percentage of patients chronically infected with hepatitis C virus (HCV) who have reached sustained antiviral response has increased since the introduction of the pegylated interferon-alpha (pIFNa) and ribavirin (RBV) treatment. However, the current standard pIFNa/RBV therapy not only has a low success rate (about 50%) but is often associated with serious side effects. Thus, there is an urgent need for the development of new anti-HCV agents. Cyclophilin (Cyp) inhibitors are among the most promising of the new anti-HCV agents under development. Recent clinical studies demonstrate that Cyp inhibitors are potent anti-HCV drugs, with a novel mechanism of action and efficacy profiles that make them attractive candidates for combination with current and future HCV treatments.

Patients' preferences for treatment of hepatitis C

BACKGROUND

The objective of this study was to ascertain patient preferences for treatment of hepatitis C virus (HCV).

METHODS

The authors recruited consecutive patients eligible for treatment of HCV and used adaptive conjoint analysis (ACA), a hybrid approach of conjoint analysis that uses both self-explicated ratings and pair-wise comparisons, to elicit preferences for pegylated-interferon and ribavirin. They examined the association between patient characteristics and treatment preferences using the Mann-Whitney U test and chi(2) statistic for continuous and categorical variables, respectively, and subsequently calculated adjusted odds ratios and 95% confidence intervals using logistic regression.

RESULTS

A total of 140 subjects completed the ACA task. The mean (+/-SD) age of the sample was 51+/-8 y; 85% were male, and 59% were white. When described as being associated with mild side effects, 67% (n = 94) of subjects preferred treatment for HCV. The percentage of subjects preferring therapy decreased to 51% (n = 72) when it was described as being associated with severe side effects. Preferences for treatment of HCV were stronger among subjects with a higher perceived risk of developing cirrhosis, more severe underlying liver disease, and worse HCV-related quality of life. Subjects having more severe disease placed greater weight on the importance of expected benefits and less on the risk of toxicity compared with those with mild or no fibrosis.

CONCLUSIONS

Whether to choose treatment for HCV is a difficult decision for many patients. Treatment is usually recommended for those with moderate to severe liver disease, and these results demonstrate that most patients' preferences are concordant with this practice.

Chronic hepatitis B and C infection in children in New South Wales

OBJECTIVE

To characterise epidemiological, clinical and laboratory features of children in New South Wales with chronic hepatitis B (HBV) or C (HCV) infections.

DESIGN AND SETTING

Retrospective record review of epidemiological, clinical, laboratory, liver biopsy and treatment data for children (aged < 18 years) referred to tertiary referral paediatric and refugee clinics in NSW with chronic HBV or HCV during 2000-2007; and comparison with NSW Health notification data for the same period.

MAIN OUTCOME MEASURES

Numbers and characteristics of referred children with HBV and HCV, and notifications to NSW Health.

RESULTS

During 2000-2007, 79 children with chronic HBV and 29 with HCV infection were referred to specialist clinics, while 930 children with HBV and 777 with HCV infection were reported to NSW Health. Most of the referred children with HBV were born overseas, while most with HCV were born in Australia to mothers with a history of intravenous drug use. Of the 79 HBV-infected children, 56 were e-antigen positive. Most HCV-infected children (23/29) had alanine aminotransferase levels < or = 2 times the upper limit of normal, and more than half of those who had genotype determined had type 2 or 3. Fibrosis was evident in liver biopsies performed for both HBV and HCV.

CONCLUSIONS

Although advanced liver disease was uncommon in children referred with HBV or HCV infection, a large number of infected children in NSW were not referred for specialist medical care, indicating that opportunities to intervene early in the natural history of these infections, particularly HCV, are being missed.

Association of genetic polymorphisms with interferon-induced haematologic adverse effects in chronic hepatitis C patients

Interferon (IFN)-based combination therapy with ribavirin has become the gold standard for the treatment of chronic hepatitis C virus infection. Haematologic toxicities, such as neutropenia, thrombocytopenia, and anaemia, however, frequently cause poor treatment tolerance, resulting in poor therapeutic efficacy. The aim of this study was to identify host genetic polymorphisms associated with the efficacy or haematologic toxicity of IFN-based combination therapy in chronic hepatitis C patients. We performed comprehensive single nucleotide polymorphism detection in all exonic regions of the 12 genes involved in the IFN signalling pathway in 32 healthy Japanese volunteers. Of 167 identified polymorphisms, 35 were genotyped and tested for an association with the efficacy or toxicity of IFN plus ribavirin therapy in 240 chronic hepatitis C patients. Multiple logistic regression analysis revealed that low viral load, viral genotypes 2 and 3, and a lower degree of liver fibrosis, but none of the genetic polymorphisms, were significantly associated with a sustained virologic response. In contrast to efficacy, multiple linear regression analyses demonstrated that two polymorphisms (IFNAR1 10848-A/G and STAT2 4757-G/T) were significantly associated with IFN-induced neutropenia (P = 0.013 and P = 0.011, respectively). Thrombocytopenia was associated with the IRF7 789-G/A (P = 0.031). In conclusion, genetic polymorphisms in IFN signalling pathway-related genes were associated with IFN-induced neutropenia and thrombocytopenia in chronic hepatitis C patients. In contrast to toxicity, the efficacy of IFN-based therapy was largely dependent on viral factors and degree of liver fibrosis.

Re-treatment with peginterferon alfa-2a and ribavirin in patients with chronic hepatitis C who have relapsed or not responded to a first course of pegylated interferon-based therapy

BACKGROUND

Pegylated interferon (pegIFN) and ribavirin combination therapy remains the first-line treatment for chronic hepatitis C virus (HCV) infection. In contrast to the wealth of studies in treatment-naive patients, the effectiveness of retreatment in patients who have previously failed pegIFN-based therapy is largely unreported.

AIM

To assess the effectiveness of the retreatment of patients who have previously failed an initial course of pegIFN-based therapy with pegIFNalpha-2a and ribavirin.

METHODS

A post-hoc analysis of a multicentre open-label study was performed. Patients received pegIFNalpha-2a and ribavirin at a dose of 800 mg/day and later 1000 mg/day to 1200 mg/day for 24 to 48 weeks at the discretion of the investigator. Outcomes at week 12 (early virological response [EVR]) and week 24 (sustained virological response [SVR]) were analyzed.

RESULTS

Eighty-seven patients who had relapsed after previous pegIFN-based therapy (n=28; 78% genotype 1) or were nonresponders (n=59; 71% genotype 1) were analyzed. Of the relapsers, 86% achieved an EVR and 68% achieved an SVR. In relapsers to pegIFN monotherapy (n=15) or pegIFN plus ribavirin (n=13), 60% and 77% achieved an SVR, respectively. Fibrosis and genotype did not affect the likelihood of SVR in relapsers although this may be the result of the relatively small number of patients. In previous nonresponders, an EVR was achieved in 53% but an SVR occurred in only 17%. In nonresponders to pegIFN monotherapy (n=9) and pegIFN plus ribavirin (n=50), 33% and 14% achieved an SVR, respectively. Genotype did not affect SVR in nonresponders. Only 10% with a METAVIR score of F3 or F4 on liver biopsy achieved an SVR.

CONCLUSIONS

Relapse after previous pegIFN-based therapy is associated with a strong probability of treatment success whereas retreatment of those with previous nonresponse does not.

A randomized trial of 24 versus 48 weeks of peginterferon α-2a in patients infected with chronic hepatitis C virus genotype 2 or low viral load genotype 1: a multicenter national study in Japan

In a country such as Japan with the average age of patients with chronic hepatitis C treated with antivirals sometimes well above 60 years, the standard combination therapy is not well tolerated. In this randomized, prospective, controlled trial, we investigated the efficacy of 24-week peginterferon α monotherapy for easy-to-treat patients. A total of 132 patients chronically infected with hepatitis C virus (HCV) genotype 2 (n = 115) or low viral load HCV genotype 1 (<100 kIU/ml, n = 17) were treated with peginterferon α-2a (180 μg/week). Patients with a rapid virological response (RVR, HCV RNA negative or <500 IU/ml at week 4) were randomized for a total treatment duration of 24 (group A) or 48 (group B) weeks. Patients who did not show RVR (group C) were treated for 48 weeks. Sustained virological response (SVR) was assessed by qualitative reverse-transcription polymerase chain reaction. One hundred eight of 132 (82%) patients with RVR were randomized. SVR rates were 60% (group A), 79% (group B), and 27% (group C), respectively. Similar SVR rates were achieved in patients infected with HCV genotype 2 with low pretreatment viral load (<1000 kIU/ml) in group A (81%) and group B (79%) (P = 0.801), whereas in those with higher viral load (≥1000 kIU/ml), a lower SVR rate was identified in group A (26%) than in group B (67%) (P = 0.041). In conclusion, in patients infected with HCV genotype 2 and pretreatment viral load below 1000 kIU/ml who achieve RVR, 24-week treatment with peginterferon α-2a alone is clinically sufficient. Those who show no RVR or have higher baseline viral load, require alternative therapies.

Role of growth factors and thrombopoietic agents in the treatment of chronic hepatitis C

Advanced liver disease and interferon-based treatment are both associated with varying degrees of cytopenia in patients with chronic hepatitis C. Growth factors to increase hemoglobin and neutrophils are commonly used in clinical practice, despite the absence of data to indicate benefits in terms of sustained viral response. Thrombocytopenia is observed frequently, is multi-factorial in etiology, and may result in significant limitations on interventional and therapeutic options. A small-molecule thrombopoietin mimetic, eltrombo-pag, has demonstrated a dose-response associated increase in platelet count in a phase 2 study, allowing initiation and completion of a 12-week course of peginterferon plus ribavirin in 36%, 53%, and 65% of patients receiving 30 mg, 50 mg, or 75 mg of eltrombopag daily, respectively, compared with 6% in the placebo arm. Phase 3 studies are currently evaluating whether initiating and maintaining antiviral therapy with eltrombopag will lead to an increase in sustained virologic response in chronic hepatitis C infection.

An evaluation of the cyclophilin inhibitor Debio 025 and its potential as a treatment for chronic hepatitis C

Debio 025 is a cyclophilin (Cyp) inhibitor without calcineurin-binding properties. The drug inhibits viral replication of genotype 1b and 2a replicons in nanomolar concentrations and shows an additive to synergistic antiviral effect with interferon, ribavirin, and specifically targeted antiviral therapy for hepatitis C (STAT-C) drugs. There is no cross-resistance with protease and polymerase inhibitors. In humans, Debio 025 has shown activity against genotypes 1, 2, 3, and 4, and displays an additive antiviral effect with pegylated interferon (peg-IFN)alpha2a in genotype 1 and 4 patients. The most prominent side effect is reversible hyperbilirubinaemia caused by inhibition of biliary transporters. Debio 025 is a potent anti-HCV drug, with a novel mechanism of action and an efficacy profile that makes it an attractive candidate for combination with current and future HCV treatments.

The cyclophilin inhibitor Debio 025 combined with PEG IFNalpha2a significantly reduces viral load in treatment-naïve hepatitis C patients

The anti-hepatitis C virus (HCV) effect and safety of three different oral doses of the cyclophilin inhibitor Debio 025 in combination with pegylated interferon-alpha2a (PEG IFN-alpha2a) were investigated in a multicenter, randomized, double-blind, placebo-controlled escalating dose-ranging phase II study in treatment-naïve patients with chronic hepatitis C. Doses of 200, 600, and 1,000 mg/day Debio 025 in combination with PEG IFN-alpha2a 180 microg/week for 4 weeks were compared with monotherapy with either 1,000 mg/day Debio 025 or 180 microg/week PEG IFN-alpha2a. In patients with genotypes 1 and 4, the 600- and 1,000-mg combination treatments induced a continuous decay in viral load that reached -4.61 +/- 1.88 and -4.75 +/- 2.19 log(10) IU/mL at week 4, respectively. In patients with genotypes 2 and 3, HCV RNA levels at week 4 were reduced by -5.91 +/- 1.11 and -5.89 +/- 0.43 log(10) IU/mL, respectively, with the same treatment regimens. Adverse events were comparable between treatment groups apart from a higher incidence of neutropenia associated with PEG IFN-alpha2a and an increased incidence of isolated hyperbilirubinemia at the highest dose of Debio 025 (1,000 mg/day).

CONCLUSION

These results confirm that Debio 025 has a potent activity and an additive effect on HCV RNA reduction in genotype 1 and 4 patients at 600 and 1,000 mg/day when combined with PEG IFN-alpha2a.

Antiviral Treatment for Chronic Hepatitis C in Illicit drug Users: A Systematic Review

According to recent World Health Organization data, approximately 170–200 million people worldwide are infected with hepatitis C virus (HCV). At present, illicit drug users (IDUs) constitute the largest group of individuals infected with HCV in industrial countries. Between 50% and 90% of IDUs are estimated to be positive for anti-HCV antibodies and most of the new infections occur in IDUs. The aim of our review is to focus on tertiary prevention of HCV infection among IDUs. We review strategies to prevent HCV infection and disease progression, attitude to antiviral treatment, access to specific HCV therapy and data of efficacy and safety of antiviral treatment among IDUs.

Telaprevir with peginterferon and ribavirin for chronic HCV genotype 1 infection

BACKGROUND

Current therapy for chronic hepatitis C virus (HCV) infection is effective in less than 50% of patients infected with HCV genotype 1. Telaprevir, a protease inhibitor specific to the HCV nonstructural 3/4A serine protease, rapidly reduced HCV RNA levels in early studies.

METHODS

We randomly assigned patients infected with HCV genotype 1 to one of three telaprevir groups or to the control group. The control group (called the PR48 group) received peginterferon alfa-2a (180 microg per week) and ribavirin (1000 or 1200 mg per day, according to body weight) for 48 weeks, plus telaprevir-matched placebo for the first 12 weeks (75 patients). The telaprevir groups received telaprevir (1250 mg on day 1 and 750 mg every 8 hours thereafter) for 12 weeks, as well as peginterferon alfa-2a and ribavirin (at the same doses as in the PR48 group) for the same 12 weeks (the T12PR12 group, 17 patients) or for a total of 24 weeks (the T12PR24 group, 79 patients) or 48 weeks (the T12PR48 group, 79 patients). The primary outcome was a sustained virologic response (an undetectable HCV RNA level 24 weeks after the end of therapy).

RESULTS

The rate of sustained virologic response was 41% (31 of 75 patients) in the PR48 group, as compared with 61% (48 of 79 patients) in the T12PR24 group (P=0.02), 67% (53 of 79 patients) in the T12PR48 group (P=0.002), and 35% (6 of 17 patients) in the T12PR12 group (this group was exploratory and not compared with the control group). Viral breakthrough occurred in 7% of patients receiving telaprevir. The rate of discontinuation because of adverse events was higher in the three telaprevir-based groups (21%, vs. 11% in the PR48 group), with rash the most common reason for discontinuation.

CONCLUSIONS

Treatment with a telaprevir-based regimen significantly improved sustained virologic response rates in patients with genotype 1 HCV, albeit with higher rates of discontinuation because of adverse events. (ClinicalTrials.gov number, NCT00336479.)

Drug-Induced Liver Injury Network (DILIN) prospective study: rationale, design and conduct

BACKGROUND

Drug-induced liver injury (DILI) is an uncommon adverse drug reaction of increasing importance to the medical community, pharmaceutical industry, regulatory agencies and the general public.

OBJECTIVES

The Drug-Induced Liver Injury Network (DILIN) was established to advance understanding and research into DILI by initiating a prospective registry of patients with bona fide DILI for future studies of host clinical, genetic, environmental and immunological risk factors. The DILIN was also charged with developing standardized nomenclature, terminology and causality assessment instruments.

METHODS

Five clinical sites, a data coordinating centre and senior scientists from the National Institute of Diabetes and Digestive and Kidney Diseases initiated the DILIN prospective study in September 2004. Eligible patients are required to meet minimal laboratory or histological criteria within 6 months of DILI onset and have other competing causes of liver injury excluded. Patients in the general community setting with pre-existing HIV, hepatitis B virus or hepatitis C virus infections and/or abnormal baseline liver biochemistries are eligible for enrollment. In addition, subjects with liver injury due to herbal products are eligible to participate. Control patients without DILI are also to be recruited in the future.

RESULTS

All referred subjects undergo an extensive review of available laboratory, pathology and imaging studies. Subjects who meet pre-defined eligibility criteria at the 6-month study visit are followed for 2 years to better define the natural history of chronic DILI. Causality assessment is determined by a panel of three hepatologists who independently assign a causality score ranging from 1 (definite) to 5 (unlikely) as well as a severity score ranging from 1 (mild) to 5 (fatal). During the first 3 years, 367 subjects were enrolled into the DILIN prospective study.

CONCLUSION

DILIN is a multicentre research network charged with improving our understanding of the aetiologies, risk factors and outcomes of DILI in the US. The network is meeting the targeted enrollment of ten patients per month and is developing a repository of clinical data and biological samples for future studies of DILI pathogenesis and outcome.

Drug-Induced Liver Injury Network (DILIN) prospective study: rationale, design and conduct

BACKGROUND

Drug-induced liver injury (DILI) is an uncommon adverse drug reaction of increasing importance to the medical community, pharmaceutical industry, regulatory agencies and the general public.

OBJECTIVES

The Drug-Induced Liver Injury Network (DILIN) was established to advance understanding and research into DILI by initiating a prospective registry of patients with bona fide DILI for future studies of host clinical, genetic, environmental and immunological risk factors. The DILIN was also charged with developing standardized nomenclature, terminology and causality assessment instruments.

METHODS

Five clinical sites, a data coordinating centre and senior scientists from the National Institute of Diabetes and Digestive and Kidney Diseases initiated the DILIN prospective study in September 2004. Eligible patients are required to meet minimal laboratory or histological criteria within 6 months of DILI onset and have other competing causes of liver injury excluded. Patients in the general community setting with pre-existing HIV, hepatitis B virus or hepatitis C virus infections and/or abnormal baseline liver biochemistries are eligible for enrollment. In addition, subjects with liver injury due to herbal products are eligible to participate. Control patients without DILI are also to be recruited in the future.

RESULTS

All referred subjects undergo an extensive review of available laboratory, pathology and imaging studies. Subjects who meet pre-defined eligibility criteria at the 6-month study visit are followed for 2 years to better define the natural history of chronic DILI. Causality assessment is determined by a panel of three hepatologists who independently assign a causality score ranging from 1 (definite) to 5 (unlikely) as well as a severity score ranging from 1 (mild) to 5 (fatal). During the first 3 years, 367 subjects were enrolled into the DILIN prospective study.

CONCLUSION

DILIN is a multicentre research network charged with improving our understanding of the aetiologies, risk factors and outcomes of DILI in the US. The network is meeting the targeted enrollment of ten patients per month and is developing a repository of clinical data and biological samples for future studies of DILI pathogenesis and outcome.

Virological relapse in chronic hepatitis C

Approximately one-third of all patients infected with hepatitis C virus (HCV) genotype 1 who complete pegylated interferon α-based therapy and have undetectable serum HCV RNA at the end of treatment will experience relapse. Although relapse is a common outcome of therapy, its pathology and strategies for optimal management are poorly understood; however, optimized ribavirin dosing is recognized as pivotal in mitigating relapse. Recent data also suggest that early viral kinetics might help identify particular patient groups, such as slow responders, who are predisposed to relapse. This review provides a comprehensive overview of the importance of relapse in patients with chronic hepatitis C, including its underlying pathobiology, potential predictors and strategies to optimize the retreatment of previous relapsers.

Hepatic SOCS3 expression is strongly associated with non-response to therapy and race in HCV and HCV/HIV infection

BACKGROUND/AIMS

The response rates of HCV infection to interferon therapy vary depending on viral and host factors. We hypothesized that key regulators of the IFN signaling pathway are predictive of treatment outcome.

METHODS

We measured the expression of signal transducer and activator of transcription 1 (STAT1) and suppressor of cytokine signaling 3 (SOCS3) in pretreatment liver biopsies. Staining quantitation was compared to treatment outcomes.

RESULTS

Forty-nine patients with HCV and 25 patients with HCV/HIV infection treated with peginterferon/ribavirin were analyzed. Pretreatment hepatic SOCS3 expression was higher in non-responders than responders. Genotype 1 responders had similar levels of SOCS3 as genotype 2/3 responders. African Americans (AA) had higher hepatic SOCS3 than non-AA. Pretreatment hepatic SOCS3 was the most powerful independent predictor of sustained virologic response (SVR), even more so than genotype by logistic regression analysis. Failure to achieve SVR and AA race were independently associated with high hepatic SOCS3 levels. The hepatic expression of STAT-1 did not differ between responders and non-responders.

CONCLUSIONS

Our data indicate that hepatic SOCS3 is a stronger baseline predictor of antiviral response than viral genotype. Poor response to antiviral therapy in AA may be associated with higher hepatic SOCS3 expression.

Optimizing the dose and duration of therapy for chronic hepatitis C

Recent studies indicate that antiviral treatment with pegylated interferon alfa and ribavirin for hepatitis C can be individualized based on viral and host characteristics and the pattern of virologic response during the initial months of antiviral treatment. Patients with a low initial viral load who demonstrate a rapid virologic response to antiviral therapy may be treated with a shorter duration of therapy and are less sensitive to reduced dosing of ribavirin. Patients with delayed virologic response will require a longer duration of therapy - up to 72 weeks for patients with genotype 1 - in order to optimize chances of a sustained virologic response. Patients who were nonresponders or relapsed after an acceptable course of antiviral therapy may be retreated using a more intensive regimen and/or a longer duration of therapy. Previous nonresponders to pegylated interferon alfa and ribavirin are less likely to respond to retreatment unless they demonstrate a virologic response within the first three months of retreatment, lack advanced fibrosis, and can tolerate a more intensive and/or lengthier treatment. Individualized treatment based on viral genotype, viral load, the presence of advanced fibrosis, and initial virologic response can improve therapy for some patients and save resources in others.

Combined therapy of interferon plus ribavirin promotes multiple adaptive solutions in hepatitis C virus

Hepatitis C virus (HCV) presents several regions involved potentially in evading antiviral treatment and host immune system. Two regions, known as PKR-BD and V3 domains, have been proposed to be involved in resistance to interferon. Additionally, hypervariable regions in the envelope E2 glycoprotein are also good candidates to participate in evasion from the immune system. In this study, we have used a cohort of 22 non-responder patients to combined therapy (interferon alpha-2a plus ribavirin) for which samples obtained just before initiation of therapy and after 6 or/and 12 months of treatment were available. A range of 25-100 clones per patient, genome region and time sample were obtained. The predominant amino acid sequences for each time sample and patient were determined. Next, the sequences of the PKR-BD and V3 domains and the hypervariable regions from different time samples were compared for each patient. The highest levels of variability were detected at the three hypervariable regions of the E2 protein and, to a lower extent, at the V3 domain of the NS5A protein. However, no clear patterns of adaptation to the host immune system or to antiviral treatment were detected. In summary, although high levels of variability are correlated to viral adaptive response, antiviral treatment does not seem to promote convergent adaptive changes. Consequently, other regions must be involved in evasion strategies likely based on a combination of multiple mechanisms, in which pools of changes along the HCV genome could confer viruses the ability to overcome strong selective pressures.

Ribavirin: current role in the optimal clinical management of chronic hepatitis C

Ribavirin in combination with peginterferon alfa shows strong clinical efficacy against chronic hepatitis C, and is now established as the standard of care. However, the precise role of ribavirin is still being defined, suggesting that optimal ribavirin dose should be maintained over the whole treatment period. Ribavirin dosage varies by bodyweight for genotype 1 disease (1000mg/day in patients <or =75kg and 1200mg/day in patients >75kg), whereas 800mg/day is sufficient to ensure optimal response in all genotype 2/3 patients. Similarly, genotype 1 patients benefit from 48 weeks of therapy, while 24 weeks is sufficient for genotype 2/3 disease. Recent data suggest treatment success is dependent on cumulative ribavirin exposure, as patients who receive <60% of the planned dose have lower response rates, regardless of whether reductions are from temporary interruptions or premature cessation of therapy. All patients should be monitored for hemolytic anemia, as early diagnosis allows management through small dose reductions and stepwise return to the target dose, maximizing cumulative exposure. Despite these recent advances in our knowledge, many questions remain, such as whether the role of ribavirin will change or even be eliminated as new therapies are developed.

Trends in the Treatment of Chronic Hepatitis C Virus Infection

Despite reductions in the incidence of new hepatitis C virus infections, infections from previous decades continue to place a substantial burden on our health care system. Although the course of the disease is highly variable, approximately 20% to 30% of patients develop cirrhosis, end-stage liver disease, or hepatocellular carcinoma. Fortunately, treatment with our current standard of care, peginterferon a and ribavirin, can reduce the complications of chronic liver disease. However, these drugs are associated with significant adverse effects, many patients are ineligible for treatment, and only 50% are cured. Thus, there is a tremendous need to improve our current therapies and develop new compounds for this disease. This review highlights the transmission, pathophysiology, and course of illness; the pharmacokinetics, proposed mechanisms of action, adverse events, and potential drug interactions with peginterferon a and ribavirin; current treatment trends; the role of the pharmacist in the treatment of this disease; and investigational drugs in later stages of clinical development. Despite the initial hope that these new drugs would replace our current standard of care, it has become clear that ribavirin and peginterferon a will continue to play an important role in the treatment of chronic hepatitis C virus in the years to come.

Treatment options for patients with hepatitis C: role of pharmacists in optimizing treatment response and managing adverse events

Chronic hepatitis C is associated with substantial morbidity and mortality and poses a considerable socioeconomic burden. Improved treatment regimens, including the standard of care pegylated interferon alfa and ribavirin, have increased sustained virologic response rates; however, treatment has a long duration and is often associated with adverse events that may affect adherence. The goal of therapy is viral eradication and reduced disease-related complications such as fibrosis, cirrhosis, and hepatocellular carcinoma. The clinical outcome of hepatitis C virus infection is altered with antiviral treatment, which can be influenced by host (e.g., weight, ethnicity, health) and viral (e.g., genotype, baseline viremia) factors. Overall, sustained virologic response was attained by 54-63% of patients in clinical trials treated with pegylated interferon alfa-2a or -2b and ribavirin. However, this benefit is not without risk. Interferon-induced adverse events include flu-like symptoms, bone marrow suppression, and emotional or cognitive effects, whereas hemolytic anemia accounts for most ribavirin dosage reductions. These adverse events may be ameliorated with dosage adjustments, symptom therapy, and judicious use of preventive strategies (e.g., antidepressants, hematopoietic growth factors). Appropriate management of adverse events can increase treatment adherence, thereby enhancing outcomes and improving quality of life. Pharmacists are in an ideal position to improve the treatment of patients with chronic hepatitis C by providing education about the disease and its treatments and associated adverse events and by emphasizing the importance of treatment adherence for successful outcomes.

Early discontinuation of ribavirin in HCV-2 and HCV-3 patients responding to Peg-interferon alpha-2a and ribavirin

Guidelines for the treatment of patients infected with hepatitis C virus of genotypes 2 and 3 (HCV-2 and HCV-3, respectively) recommend a 24-week course of Peg-interferon (Peg-IFN) alpha-2a combined with ribavirin, despite 50% of patients in registration trials attaining a sustained virologic response (SVR) following Peg-IFN alpha-2a monotherapy. The aim of this study was to delineate patient characteristics that might help to identify individuals likely to benefit from ribavirin discontinuation. One hundred and forty-four HCV-2- and HCV-3-infected patients initiated Peg-IFN alpha-2a (180 microg/week) and ribavirin (1000 or 1200 mg/day); those with viral clearance at week 4 were randomized to either Peg-IFN alpha-2a monotherapy (n = 59) or continuing combination therapy (n = 61) until week 12. Overall, all but one patient with a rapid virologic response (RVR) responded by the end of therapy and the overall SVR rates were lower after discontinuation of ribavirin (54%vs 82%; P < 0.001). In RVR patients who discontinued ribavirin, low baseline viraemia helped predict SVR (odds ratio 11.2, 95% CI 2.7-47.1). SVR rates were similar in patients receiving mono- or combination therapy with low (< or =300,000 IU/mL) and intermediate viraemia (86%vs 81% and 70%vs 71%, 86% refers to low viraemic patients receiving monotherapy and 81% to those receiving combination therapy. Similarly, 70% refers to patients with intermediate viraemic levels receiving monotherapy and 71% to those receiving combination therapy), but different in those with high (>700,000 IU/mL) viraemia (37%vs 88%; P = 0.004). Thus in HCV-2- and HCV-3-infected patients, withdrawal of ribavirin and continuation of Peg-IFN alpha-2a monotherapy may be appropriate to attain an SVR, providing viraemia is cleared early during therapy and associated with low baseline viral load. These results warrant future investigations, as discontinuing ribavirin could lead to considerable savings in cost and quality of life related to over-treatment.

Optimizing the treatment of chronic hepatitis due to hepatitis C virus genotypes 2 and 3: a review

Recently several randomized trials involving exclusively HCV 2 and 3 patients have explored the possibility of reducing the duration of therapy with PEG IFNs and ribavirin to 12-16 weeks. Among these, the largest studies (ACCELERATE, NORTH-C and NORDynamIC) have failed to demonstrate, by intention-to-treat analysis, that short treatment is non-inferior to the standard duration of 24 weeks originated by phase 3 trials. Even though obtaining univocal conclusions from these studies are difficult to obtain due to some critical differences (trial design, genotypes 2/3 ratio, rate of cirrhosis at baseline, ribavirin dose, assays to detect HCV-RNA etc), all have proved that a rapid virological response (HCV-RNA negative at 4 weeks) is the strongest predictor of SVR. Therefore, excluding risk factors for virological relapse at baseline, and identifying in the early phase of treatment, features related to a sustained response, the decision to reduce the duration of treatment to less than 24 weeks in HCV-2 and 3 patients can be response-guided appropriately. Ongoing studies will assess whether extended 48 week regimens can benefit non-RVR patients with HCV 2 or 3, especially those with more severe fibrosis.

Drug-Induced Liver Injury Network (DILIN) prospective study: rationale, design and conduct

BACKGROUND

Drug-induced liver injury (DILI) is an uncommon adverse drug reaction of increasing importance to the medical community, pharmaceutical industry, regulatory agencies and the general public.

OBJECTIVES

The Drug-Induced Liver Injury Network (DILIN) was established to advance understanding and research into DILI by initiating a prospective registry of patients with bona fide DILI for future studies of host clinical, genetic, environmental and immunological risk factors. The DILIN was also charged with developing standardized nomenclature, terminology and causality assessment instruments.

METHODS

Five clinical sites, a data coordinating centre and senior scientists from the National Institute of Diabetes and Digestive and Kidney Diseases initiated the DILIN prospective study in September 2004. Eligible patients are required to meet minimal laboratory or histological criteria within 6 months of DILI onset and have other competing causes of liver injury excluded. Patients in the general community setting with pre-existing HIV, hepatitis B virus or hepatitis C virus infections and/or abnormal baseline liver biochemistries are eligible for enrollment. In addition, subjects with liver injury due to herbal products are eligible to participate. Control patients without DILI are also to be recruited in the future.

RESULTS

All referred subjects undergo an extensive review of available laboratory, pathology and imaging studies. Subjects who meet pre-defined eligibility criteria at the 6-month study visit are followed for 2 years to better define the natural history of chronic DILI. Causality assessment is determined by a panel of three hepatologists who independently assign a causality score ranging from 1 (definite) to 5 (unlikely) as well as a severity score ranging from 1 (mild) to 5 (fatal). During the first 3 years, 367 subjects were enrolled into the DILIN prospective study.

CONCLUSION

DILIN is a multicentre research network charged with improving our understanding of the aetiologies, risk factors and outcomes of DILI in the US. The network is meeting the targeted enrollment of ten patients per month and is developing a repository of clinical data and biological samples for future studies of DILI pathogenesis and outcome.

Predictors of sustained virological response to a 48-week course of pegylated interferon alfa-2a and ribavirin in patients infected with hepatitis C virus genotype 4

BACKGROUND AND OBJECTIVES

Knowledge of the predictors of sustained viral response (SVR) to pegylated interferon (PEG-INF) alfa-2a and ribavirin (RBV) therapy in patients with hepatitis C genotype-4 (HCV-4) is crucial for selecting patients who would benefit most from therapy. We assessed the predictors of SVR to this combination therapy in Saudi patients with chronic HCV-4 infection.

PATIENTS AND METHODS

This retrospective study included 148 patients with HCV-4 infection who underwent clinical, biochemical and virological assessments before treatment and at 12, 24, 48 and 72 weeks post-treatment.

RESULTS

Of the 148 patients, 90 (60.8%) were males. Mean (SD) for age was 48.5 (12.7) years and BMI was 27.9 (7.5) kg/m(2). Seventy-nine of 148 (60.1%) patients were treatment naïve and 110 (74.3%) underwent pre-treatment liver biopsy. Eighteen (12.2%) patients did not complete therapy because of side effects or they were lost to follow up. Early virological response was achieved in 84 of 91 (92.3%) patients. In the 130 (87.8%) patients who completed therapy, 34 (26.2%) were non-responders and 96 (63.8%) achieved end-of-treatment virological response (ETVR). SVR and virological relapse (24 weeks after ETVR) occurred in 66/130 (50.7%) and 30/130 (31.2%) patients, respectively. Compared to relapsers, sustained responders were significantly younger (P=.005), non-diabetic (P=.005), had higher serum albumin (P=.028), lower alpha-fetoprotein level (P=.026), lower aspartate aminotransferase (AST) (P=.04) levels, and were treatment-naïve (P=.008). In a multivariate regression analysis, the independent predictors of SVR were younger age (P=.016), lower serum AST (P=.012), and being treatment naïve (P=.021).

CONCLUSION

Approximately half of HCV-4 patients who complete the course of combination therapy achieve an SVR, especially if they are young, treatment naA ve and have lower AST levels.

Assessment of hepatitis C: non-invasive fibrosis markers and/or liver biopsy

Chronic viral hepatitis is a prolonged inflammatory disease of the liver that may lead to the development of fibrosis, necro-inflammation and other associated pathological features. Because fibrosis and its end-point cirrhosis are the main causes of morbidity and mortality, fibrosis assessment is considered as the most relevant information for the evaluation of the severity of the disease and as a useful indicator for prognosis and treatment decision. Because fibrosis implies morphological damage, liver biopsy has come to be the natural gold standard for staging the disease. However, the high prevalence of chronic hepatitis C in addition to the cost and constraints generated by this procedure have triggered an intensive search for alternative methods for fibrosis evaluation. In this article, the strengths and weaknesses of liver biopsy and of non-invasive markers will be reviewed and their respective roles in management of patients with chronic hepatitis C will be discussed.

The impact of diet on liver fibrosis and on response to interferon therapy in patients with HCV-related chronic hepatitis

BACKGROUND AND AIMS

A deranged metabolic status and alcohol intake may trigger induction and progression of chronic hepatitis C virus (HCV) liver disease. The aim of this study was to evaluate whether dietary composition affects the severity of liver damage and response to therapy in patients with HCV-related chronic hepatitis.

METHODS

We enrolled 1,084 patients with biopsy-proven HCV-related chronic hepatitis (432 treated with interferon plus ribavirin) and 2,326 healthy subjects in this prospective study conducted in a university hospital. Dietary habits were recorded in enrolled individuals, and their alcohol consumption was evaluated with a questionnaire (AUDIT). Body mass index, and plasma levels of blood glucose, nitrogen, creatinine, cholesterol, and triglycerides were also measured. All individuals underwent routine liver tests and HCV genotyping.

RESULTS

At study onset, there were no differences in metabolic status or alcohol consumption between patients and controls. About 50% of each group was overweight, and about 60% consumed alcohol. Patients and controls had similar dietary habits. Intake of carbohydrates, lipids and polyunsaturated fatty acids, and alcohol consumption were independent factors of liver damage at histology (logistic regression analysis). Some dietary components (unsaturated fatty acids, iron, zinc, vitamin A, and niacin) and alcohol intake differed significantly (P < 0.05 and P 0.01, respectively; univariate analysis) between responders and nonresponders to interferon therapy. Genotype, age, body mass index, steatosis, and fibrosis were independent predictors of therapy outcome (P < 0.02; multivariate analysis).

CONCLUSIONS

The severity of HCV-related chronic hepatitis depends on a variety of factors. Our results show that dietary composition is related to the extent of liver damage. Although traditional risk factors independently affected treatment response, some dietary components were associated with nonresponse to therapy in our patients. This suggests that HCV patients may benefit from instructions regarding their diet.

Peginterferon and ribavirin in HCV: improvement of sustained viral response

Peginterferon alfa in combination with ribavirin is and will remain for the next years the current standard for treatment of chronic hepatitis C. The new antivirals currently investigated in phase II of III trials may augment the overall response rates but require peginterferon/ribavirin as backbone. The cure rate of peginterferon/ribavirin treatment can be improved by better education of treating physicians to identify and treat conditions which negatively influence the final outcome of therapy. Specific focus is the prevention and/or early treatment of common side effects of therapy including anaemia, cytopenia and depression. In selected patients increasing the dose of peginterferon and/or ribavirin may augment response rates. Measuring the viral response at various time points during treatment allows individualization of treatment duration. Treatment duration may be shortened in patients with undetectable HCV-RNA after 4 weeks of therapy, on the other hand slow virologic responders may benefit from prolonged treatment.

KDOQI US commentary on the KDIGO clinical practice guideline for the prevention, diagnosis, evaluation, and treatment of hepatitis C in CKD

KDIGO (Kidney Disease: Improving Global Outcomes) is an international initiative with a key mission of developing clinical practice guidelines in the area of chronic kidney disease (CKD). KDIGO recently published evidence-based clinical practice guidelines for the prevention, diagnosis, evaluation, and treatment of hepatitis C virus infection in individuals with CKD. The process of adaptation of international guidelines is an important task that, although guided by general principles, needs to be individualized for each region and country. Therefore, the National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (KDOQI) convened a multidisciplinary group to comment on the application and implementation of the KDIGO guidelines for patients with CKD in the United States. This commentary summarizes the process undertaken by this group in considering the guidelines in the context of health care delivery in the United States. Guideline statements are presented, followed by a succinct discussion and annotation of the rationale for the statements. Research recommendations that are of particular interest to the United States are then summarized to highlight future areas of inquiry that would enable updating of the guidelines.

Current and future anti-fibrotic therapies for chronic liver disease

Chronic injury results in a wound healing response that eventually leads to fibrosis. The response is generalized, with features common among multiple organ systems. In the liver, various different types of injury lead to fibrogenesis, implying a common pathogenesis. Although several specific therapies for patients who have different liver diseases have been successfully developed, including antiviral therapies for those who have hepatitis B and hepatitis C virus infection, specific and effective antifibrotic therapy remains elusive. Over the past 2 decades, great advances in the understanding of fibrosis have been made and multiple mechanisms underlying hepatic fibrogenesis uncovered. Elucidation of these mechanisms has been of fundamental importance in highlighting novel potential therapies. Preclinical studies have indicated several putative therapies that might abrogate fibrogenesis. This article emphasizes mechanisms underlying fibrogenesis and reviews available and future therapeutics.

Treatment of chronic hepatitis C in hemodialysis patients

Hepatitis C virus (HCV) infection is especially problematic in patients with end-stage renal disease (ESRD) who are undergoing hemodialysis. Rates of HCV infection are higher among hemodialysis patients than in the general population, and several routes of transmission are thought to stem from the dialysis unit. Management of chronic hepatitis C is also more complicated in hemodialysis patients because of altered pharmacokinetics and a predisposition for drug-related toxicity, particularly ribavirin-induced anemia. Clinical trials of patients with chronic hepatitis C and healthy, functioning kidney grafts are rare because of the inherent dangers of graft rejection. As a result, most studies in patients with ESRD have focused on patients waiting for a kidney transplant. Additionally, because ribavirin is contraindicated in this patient population, many studies have examined monotherapy treatments. According to meta-analyses, conventional interferon alfa treatment yields a sustained virological response (SVR) rate of 37%, whereas studies of pegylated interferon alfa monotherapy have yielded SVR rates between 13% and 75%. Several small studies have also used the monitoring of ribavirin plasma concentrations or hemoglobin levels to facilitate the use of combination therapy. In light of the results from these clinical trials, we herein review treatment guidelines and recommend strategies to help optimize the treatment of patients with ESRD.

CONCLUSION

There remains a lack of clarity surrounding the most effective treatment options for patients with chronic hepatitis C and ESRD. Treatment can be effective with many patients attaining SVR; however, unfavorable tolerability with interferon alfa-based therapy remains a concern and thus close supportive care should be aggressively pursued to help maintain adherence.

Recognition of genetic factors influencing the progression of hepatitis C : potential for personalized therapy

Infection with hepatitis C virus (HCV) is a major cause of chronic liver disease. Hepatic fibrosis may develop in subjects with chronic HCV infection, culminating in cirrhosis and an increased risk of hepatocellular carcinoma. The rate of development of fibrosis varies substantially between individuals; while it is influenced by a number of demographic and environmental factors, these account for only a small proportion of the variability. There are no clinical markers or tests that predict the rate of fibrosis progression in an individual subject. Thus, there has been increasing interest in the influence of host genetic factors on the rate of disease progression, and whether a genetic signature can be developed to reliably identify individuals at risk of severe disease. Numerous case-control, candidate gene, allele-association studies have examined the relationship between host single nucleotide polymorphisms or other genetic mutations and fibrosis in patients with chronic HCV infection. However, these studies have generally been irreproducible and disappointing. As seen with genetic studies for other diseases, small study cohorts and poor study design have contributed to limited meaningful findings. The successful determination of genetic signatures for fibrosis progression in chronic HCV will require multicenter collaborations using genome-wide association studies, with large, phenotypically well-defined sample sets. While these studies will require a significant financial commitment, a successful outcome offers the potential for personalized therapy and better patient management.

Acute hepatitis C: current status and remaining challenges

The acute phase of hepatitis C virus (HCV) infection represents a key point in the evolution of hepatitis C. In some patients, the infection resolves spontaneously, whereas in others it develops into chronic disease. However, because acute hepatitis C is often asymptomatic, detection and diagnosis are usually difficult. What is more, there are no established treatment guidelines, leaving physicians to make several challenging decisions, such as whether to treat, when to treat and what treatment regimen to use. Pegylated interferon alfa monotherapy is most commonly used to treat patients with acute hepatitis C; the role of ribavirin has yet to be established. In this review, we discuss the epidemiology of acute hepatitis C, its risk factors and routes of transmission and current treatment practices. We also discuss data from published clinical studies and focus on unresolved issues for which additional studies are needed in order to establish standardized treatment guidelines for the management of acute hepatitis C.

Prospective analysis of effector and regulatory CD4+ T cells in chronic HCV patients undergoing combination antiviral therapy

BACKGROUND/AIMS

The role of HCV-specific CD4(+) T cells and regulatory T cells in influencing the outcome of antiviral therapy is incompletely defined.

METHODS

CD4(+) IFN-gamma ELISPOT assays (n=58) and flow cytometric analysis of FoxP3-expressing T regulatory cells (n=62) were performed on patients from the Virahep-C study at baseline, during and after cessation of antiviral therapy.

RESULTS

Total HCV-specific IFN-gamma CD4(+) T cell ELISPOT responses did not increase with therapy, but rather decreased by 8 weeks and remained below baseline 24 weeks after cessation of therapy. There were no statistically significant differences with respect to viral kinetics, race and virologic outcome. In contrast, viral relapse after treatment was associated with a three-fold increase in HCV-specific responses. The frequency and phenotype of regulatory T cells during therapy were not significantly different in terms of race, viral kinetic groups or virologic outcome.

CONCLUSIONS

A contraction of HCV-specific CD4(+) T cell responses was found during treatment with recovery of responses in patients experiencing virologic relapse after treatment. The levels of FoxP3-expressing regulatory T cells did not vary by race and were not predictive of virologic outcome. Work is ongoing to explore the contribution of mechanisms independent of CD4(+) T cells in therapy-induced viral clearance.

Dynamic Evolution of Therapy for Chronic Hepatitis C: How will Novel Agents be Incorporated into the Standard of Care?

There is a need for improved treatment strategies and new therapeutic agents to increase cure rates in chronic hepatitis C virus (HCV) infection. Ongoing trials are aimed at optimizing sustained virological response rates with pegylated interferon (PEG-IFN) plus ribavirin. For a new agent to supplant the standard of care it must augment the strengths or compensate for the weaknesses of PEG-IFN plus ribavirin. To improve cure rates on its own, a new agent must not only suppress replication of the virus, but also clear infected hepatocytes. It is now clear that new anti-HCV agents will be used, at least initially, against a backbone of PEG-IFN plus ribavirin. A broad spectrum of agents is under investigation and it is hoped that these drugs will ultimately increase cure rates, reduce the required duration of therapy, improve tolerability and possibly simplify therapy. Reductions in serum HCV RNA ranging from 2 to 5 log10 IU/ml have been obtained in human trials with NS3/4A protease inhibitors and polymerase inhibitors. A minimum of additive reductions in serum HCV RNA levels have been observed when agents in these classes have been administered with PEG-IFN plus ribavirin in treatment-naive patients. Preliminary results in non-responders to IFN are less promising. Combinations of small molecules will be needed in order to produce sustained suppression of HCV replication in the absence of the standard of care, and such large clinical trials are several years away. The treatment paradigm for chronic hepatitis C continues to evolve and will eventually incorporate new drugs as they are approved.