10-Year follow-up after interferon-alpha therapy for chronic hepatitis C

Digital pathology and spatial omics in steatohepatitis: Clinical applications and discovery potentials

Steatohepatitis with diverse etiologies is the most common histological manifestation in patients with liver disease. However, there are currently no specific histopathological features pathognomonic for metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, or metabolic dysfunction-associated steatotic liver disease with increased alcohol intake. Digitizing traditional pathology slides has created an emerging field of digital pathology, allowing for easier access, storage, sharing, and analysis of whole-slide images. Artificial intelligence (AI) algorithms have been developed for whole-slide images to enhance the accuracy and speed of the histological interpretation of steatohepatitis and are currently employed in biomarker development. Spatial biology is a novel field that enables investigators to map gene and protein expression within a specific region of interest on liver histological sections, examine disease heterogeneity within tissues, and understand the relationship between molecular changes and distinct tissue morphology. Here, we review the utility of digital pathology (using linear and nonlinear microscopy) augmented with AI analysis to improve the accuracy of histological interpretation. We will also discuss the spatial omics landscape with special emphasis on the strengths and limitations of established spatial transcriptomics and proteomics technologies and their application in steatohepatitis. We then highlight the power of multimodal integration of digital pathology augmented by machine learning (ML)algorithms with spatial biology. The review concludes with a discussion of the current gaps in knowledge, the limitations and premises of these tools and technologies, and the areas of future research.

Manipulation of Type I Interferon Signaling by HIV and AIDS-Associated Viruses

Type I Interferons were first described for their profound antiviral abilities in cell culture and animal models, and later, they were translated into potent antiviral therapeutics. However, as additional studies into the function of Type I Interferons progressed, it was also seen that pathogenic viruses have coevolved to encode potent mechanisms allowing them to evade or suppress the impact of Type I Interferons on their replication. For chronic viral infections, such as HIV and many of the AIDS-associated viruses, including HTLV, HCV, KSHV, and EBV, the clinical efficacy of Type I Interferons is limited by these mechanisms. Here, we review some of the ways that HIV and AIDS-associated viruses thrive in Type I Interferon-rich environments via mechanisms that block the function of this important antiviral cytokine. Overall, a better understanding of these mechanisms creates avenues to better understand the innate immune response to these viruses as well as plan the development of antivirals that would allow the natural antiviral effect of Type I Interferons to manifest during these infections.

Combining liver stiffness with hyaluronic acid provides superior prognostic performance in chronic hepatitis C

Background

Non-invasive methods are the first choice for liver fibrosis evaluation in chronic liver diseases, but few studies investigate the ability of combined methods to predict outcomes.

Methods

591 chronic hepatitis C patients with baseline liver stiffness (LSM) by FibroScan and hyaluronic acid measurements were identified retrospectively. The patients were grouped by baseline LSM: < 10kPa, 10–16.9kPa, and 17-75kPa. Primary outcomes were all-cause mortality and liver-related mortality, analyzed using cox regression and competing risk regression models, respectively.

Results

Median follow-up was 46.1 months. Prevalence of cirrhosis at baseline was 107/591 (18.1%). Median LSM was 6.8kPa (IQR 5.3–11.6) and divided into groups, 404/591 (68.4%) had a LSM < 10kPa, 100/591 (16.9%) had a LSM between 10–16.9kPa and 87/591 (14.7%) had a LSM between 17-75kPa. There were 69 deaths, 27 from liver-related disease. 26 patients developed cirrhosis and 30 developed complications of cirrhosis. The mortality rate in the 17-75kPa group was 9.7/100 person-years, compared to 2.2/100 person-years and 1.1/100 person-years in the 10–16.9kPa and <10kPa groups (p<0.005). Liver-related mortality increased 10-fold for each group (p<0.005). Cirrhotic complications occurred almost exclusively in the 17-75kPa group, with an incidence of 10.3/100 person-years, compared to 1.8/100 person-years and 0.2/100 person-years in the 10–16.9kPa and <10kPa groups (p<0.005). Median hyaluronic acid in the 17-75kPa group was approximately 200ng/mL. Patients with a LSM 17-75kPa had significantly higher risks of death, liver-related death, and complications to cirrhosis if their hyaluronic acid measurement was more than or equal to 200ng/mL at baseline, with hazard ratios of 3.25 (95% CI 1.48–7.25), 7.7 (95% CI 2.32–28), and 3.2 (95% CI 1.35–7.39), respectively.

Conclusions

The combination of LSM and circulating hyaluronic acid measurements significantly improved prognostic ability, relative to LSM alone. Combined static and dynamic markers of liver fibrosis could provide superior risk prediction.

Should surveillance for liver cancer be modified in hepatitis C patients after treatment-related cirrhosis regression?

Surveillance of hepatocellular carcinoma (HCC) with abdominal ultrasound (US) is recommended for patients with advanced liver fibrosis because of hepatitis C virus (HCV) infections who achieve a sustained virological response (SVR) to antiviral therapy. HCC, in fact, may still develop following SVR as a consequence of long-standing carcinogenic activity of either HCV or hepatic fibrosis, whereas HCC risk in non-viraemic patients may also be driven by cofactors like alcohol abuse or diabetes. This explains the debate on whether surveillance for HCC should be continued in patients with documented cirrhosis regression following a SVR too. While regression of cirrhosis was documented to occur in a majority of patients with compensated cirrhosis 5 years after an SVR to interferon, it should be noted that this clinical benefit could be the consequence of treating a selected population with well-compensated liver disease who in fact were interferon able. This may not be the case for most real-life patients with advanced cirrhosis receiving direct antivirals, in whom liver fibrosis may have reached a point of no-return thus potentially preventing the recovery of a normal liver architecture following SVR. Both invasive and non-invasive tools have suboptimal diagnostic accuracy for fibrosis regression in non-viraemic patients, and this prompts to follow international societies' recommendation to perform surveillance in patients with advanced liver fibrosis achieving a SVR, independently on liver histology outcome.

Development of an In-House TaqMan Real Time RT-PCR Assay to Quantify Hepatitis C Virus RNA in Serum and Peripheral Blood Mononuclear Cells in Patients With Chronic Hepatitis C Virus Infection

BACKGROUND

Viral load measurements are commonly used to monitor HCV infection in patients with chronic diseases or determining the number of HCV-genomes in serum samples of patients after sustained virological response. However, in some patients, HCV viral load in serum samples is too low to be detected by PCR, especially after treatment.

OBJECTIVES

The aim of this study was to develop a highly specific, sensitive, and reproducible in-house quantitative PCR using specific primers and probe cited in highly conservative region of HCV genome that allows simultaneous detection of HCV genotypes 1 - 4.

MATERIALS AND METHODS

In this study, three sets of primer pairs and a TaqMan probe for amplification and detection of selected region within 5'-non-coding (5'NCR) of four HCV genotypes were used. Using plasmid containing 5'NCR region of HCV, standard curve, threshold, and threshold cycle (CT) values were determined. Real-time and nested PCR were performed on HCV genotypes 1 - 4 extracted from plasma and peripheral blood mononuclear cells (PBMCs) samples collected from patients with chronic HCV infection.

RESULTS

The lower limit detection of this in-house HCV real-time RT-PCR was determined as 100 RNA copies/mL. Inter- and intra-assay coefficient of variation (CV) of this in-house HCV real-time RT-PCR ranged from 0.9% to 1.8% and 1.76% to 3.94%, respectively. The viral load of the genotyped samples ranged from 2.0 × 10(6) ± 0.31 to 2.7 × 10(5) ± 0.46 copies/mL in serum samples and 5 × 10(2) ± 0.36 to 4.0 × 10(3) ± 0.51 copies/10(6) cells/mL of PBMCs.

CONCLUSIONS

The quite sensitive in-house TaqMan real time RT-PCR assay was able to detect and quantify all four main HCV genotypes prevailing around all geographical regions of Iran.

Peginterferon alfa-2a and peginterferon alfa-2b combined with ribavirin in patients with genotype 1 chronic hepatitis C: results of a prospective single-centre study

PURPOSE

This prospective, randomized, single-centre study compared peginterferons alfa-2a and alfa-2b, combined with ribavirin, in treating patients infected with hepatitis C virus (HCV) genotype 1.

MATERIAL/METHODS

Hundred-and-one patients received 48 weeks of open-label treatment with peginterferon alfa-2a (180 μg/week) and 111 patients received peginterferon alfa-2b (1.5 μg/kg/week). All patients received the same dose of ribavirin 1000/1200 mg/day, depending on weight. The primary efficacy endpoint was sustained virologic response (SVR), defined as undetectable HCV RNA (<50 IU/mL) 24 weeks after the end of treatment.

RESULTS

Early virologic response (EVR), defined as at least 2 log₁₀ IU/mL reduction of viral load at 12 weeks, was more common in patients treated with peginterferon alfa-2a (88% vs. 74.8%; p=0.04). However, the difference in SVR was not statistically significant (49.5% vs. 44.1%; p=0.43).

CONCLUSIONS

Peginterferon alfa-2a treated patients were also more likely to be HCV RNA negative at the end of treatment (67.3% vs. 57.7%), but this difference did not reach statistical significance. Multivariate logistic regression analysis found that SVR was associated with low fibrosis stage (F1-2 by Scheuer; p=0.001) and low serum HCV RNA level (<400,000 IU/L; p=0.023). While both forms of peginterferon showed similar efficacy as measured by SVR, use of peginterferon alfa-2b could lower the number of patients receiving unnecessary treatment beyond 12 weeks.

Durability of the response to peginterferon-α2b and ribavirin in patients with chronic hepatitis C: a cohort study in the routine clinical setting

OBJECTIVES

To evaluate whether, in chronic hepatitis C-positive naive patients recruited in the routine clinical setting and treated with pegylated-interferon-α2b (Peg-IFN) and ribavirin (RBV), the sustained virologic response (SVR) is durable over the long term and whether it is associated with a decrease in liver complications and incidence of glucose abnormalities.

PATIENTS AND METHODS

This was a prospective long-term follow-up study of 182 naive patients enrolled in 2001-2002 and treated with Peg-IFN and RBV and followed up to December 2010, with clinical, biochemical, and virological evaluations every 6-12 months.

RESULTS

None of the 115 (63.2%) sustained responders showed late viremic relapse during the follow-up. SVR was better defined at 24 weeks (16/16 relapsers, 100%) than at 12 weeks after the end of therapy (14/16 relapsers, 87.5%). On multivariable analysis, viral genotype (odds ratio 0.16, 95% confidence interval 0.07-0.36, P=0.0001) and a greater than 20% RBV reduction (odds ratio 5.21, 95% confidence interval 1.54-17.67, P=0.008) predicted long-term response (LTR) independently. The incidence of cirrhosis was significantly higher among nonresponders (21.3%) compared with long-term responders (0.9%, P≤0.0001), but the risk of developing glucose abnormalities was not significantly reduced in long-term responders (hazard ratio 1.36, P=0.363). Hepatocellular carcinoma occurred only in three cases.

CONCLUSION

SVR achieved in patients treated in the routine clinical setting with Peg-IFN and RBV is durable over the long term and LTR significantly reduces the risk of progression to cirrhosis; however, in a population with mild liver fibrosis, the clinical impact of LTR on the risk of glucose abnormalities seems negligible.

Sequence analysis of hepatitis C virus from patients with relapse after a sustained virological response: relapse or reinfection?

BACKGROUND

A sustained virological response (SVR) is the major end point of therapy for chronic hepatitis C virus (HCV) infection. Late relapse of infection is rare and poorly characterized. Three of 103 patients with a SVR treated at the National Institutes of Health had late relapse. We evaluated HCV RNA sequences in serum and liver tissue to distinguish relapse from reinfection.

METHODS

Per patient, 10-22 clones of amplified 5' untranslated region were evaluated in pretreatment and relapse serum specimens and in liver biopsy specimens obtained during SVR. Genotypes and sequence diversity were evaluated. Four patients whose infection relapsed before they reached a SVR (ie, the early relapse group) were used as a comparison.

RESULTS

Results of tests for detection of serum HCV RNA in all patients with late relapse were repeatedly negative during the first 24 weeks after therapy but became positive 8, 75, and 78 months after SVR. Reinfection risk factors were absent in 2 of 3 patients. In all patients with early or late relapse, apart from minor variations, the original HCV sequence was present before treatment and after relapse. All liver biopsy specimens from patients with late relapse were HCV RNA positive at SVR, with sequences nearly identical to those of specimens obtained at other time points.

CONCLUSIONS

Sequence comparisons suggest that reappearance of HCV RNA years after a SVR can be from relapse of the initial viral infection rather than reinfection from a different virus.

Durability of a sustained virological response, late clinical sequelae, and long-term changes in aspartate aminotransferase to the platelet ratio index after successful treatment with peginterferon/ribavirin for chronic hepatitis C: a prospective study

OBJECTIVES

Previous studies, mostly retrospective using conventional interferon, have suggested a favorable prognosis for patients with chronic hepatitis C and a sustained virological response (SVR). However, long-term outcome, including changes in the degree of hepatic fibrosis, of SVR patients in the era of pegylated interferon (PegIFN) remains underdefined. We prospectively evaluated the long-term virological, clinical, and biochemical outcomes, including aspartate aminotransferase-to-platelet ratio index (APRI), in chronic hepatitis C patients with an SVR.

PATIENTS AND METHODS

We included 145 consecutive, treatment-naive chronic hepatitis C patients (mean age 47.3±9.1 years; 87 men; 42.1% genotype 1; 36.6% genotype 2/3) who achieved an SVR after combination therapy with PegIFN-α/ribavirin.

RESULTS

The mean follow-up time was 68.8±35 months. The overall incidence of hepatocellular carcinoma (HCC) and liver-related death was 1.4 and 0.7%, respectively. Among nine (7.6%) patients with pretreatment cirrhosis, two (22.2%) developed HCC and one of them (11.1%) died. No patient had conclusive evidence of late virological relapse. All patients retained normal liver biochemistry, except for five of 145 (3.5%), who had persistently elevated transaminase levels, all of whom were diagnosed with new liver disease. APRI values improved significantly with treatment (0.95±1.09 vs. 0.66±0.64, P<0.001) and continued to improve after a mean of 61.4±45.5 months from an SVR in patients (n=54; 37.2%) with significant (Metavir ≥F2) pretreatment fibrosis (1.13±0.66 vs. 0.67±0.45, P<0.001).

CONCLUSION

The long-term outcome, including APRI, of chronic hepatitis C patients treated successfully with PegIFN/ribavirin and followed for a mean of 5.7 years is favorable. However, a high risk of progression to HCC and liver-related death remains for patients with pretreatment cirrhosis, in our setting, as high as 22.2 and 11.1%, respectively.

Durability of sustained virologic response in chronic hepatitis C

BACKGROUND/AIMS

The aim of this study is to investigate the rate of sustained virologic response (SVR) in chronic hepatitis C patients receiving antiviral treatment.

METHODS

The files of patients with chronic hepatitis C treated with interferon±ribavirin between 1995 and 2009 were reviewed retrospectively. Six months after the end of treatment, patients with negative hepatitis C virus (HCV)-RNA (<50 IU/mL, as determined by the polymerase chain reaction method) were enrolled in the study.

RESULTS

The mean age of 196 patients (89 males) was 46.13±11.10 years (range, 17 to 73 years). In biopsies, the mean stage was 1.50±0.94; histological activity index was 7.18±2.43. In total, 139 patients received pegylated interferon (IFN)+ribavirin, 21 patients received classical IFN+ribavirin, and 36 patients received IFN alone. The HCV genotypes of 138 patients were checked: 77.5% were genotype 1b, and 22.5% were other genotypes. After achievement of SVR, the median follow-up period was 33.5 months (range, 6 to 112 months), and in this period relapse was only detected in two patients (1.02%) at 18 and 48 months after treatment.

CONCLUSIONS

In total, 98.9% of patients with SVR in chronic hepatitis C demonstrated truly durable responses over the long-term follow-up period of 3 years; relapsed patients had intermittent or low-grade viremia.

Economic Evaluation of Boceprevir for the Treatment of Patients with Genotype 1 Chronic Hepatitis C Virus Infection in Hungary

Background: Recent international, randomized, placebo-controlled clinical trials (SPRINT-2; RESPOND-2) demonstrated that the triple combination of peginterferon (PEG), ribavirin (RBV) and boceprevir (BOC) was more efficacious than the standard dual therapy of PEG and RBV in treatment of patients chronically infected with genotype 1 hepatitis C virus (HCV) infection. The objective of this study was to evaluate the cost-effectiveness of triple therapy in both treatment-naive and treatment-experienced patients in Hungary. Methods: A Markov model was developed to evaluate the long-term clinical benefits and the costeffectiveness of the triple therapy from the Hungarian payer perspective. Model states were fibrosis (F0-F4, defined using METAVIR fibrosis scores), decompensated cirrhosis (DC), hepatocellular carcinoma (HCC), liver transplantation (LT), and liver-related deaths (LD). Efficacy was estimated from SPRINT-2 and RESPOND-2 studies. Disease progression rates and health state utilities used in the model were obtained from published studies. Estimates of probability of liver transplantation and cost were based on an analysis of the Hungarian Sick Fund database. All cost and benefits were discounted at 5% per year. Results: Compared to dual therapy, triple therapy was projected to increase the life expectancy by 0.98 and 2.42 life years and increase the quality-adjusted life years (QALY) by 0.59 and 1.13 in treatment-naive and treatment-experienced patients, respectively. The corresponding incremental cost-effectiveness ratios were HUF7,747,962 (€26,717) and HUF5,888,240 (€20,304) per QALY. The lifetime incidence of severe liver disease events (DC, HCC, LT, LD) were projected to decrease by 45% and 61% in treatment-naïve and treatment-experienced patients treated with triple therapy groups in comparison with PEG-RBV treatment. Conclusion: The addition of boceprevir to standard therapy for the treatment of patients with genotype 1 chronic HCV infection in Hungary is projected to be cost-effective using a commonly used willingness to pay threshold of HUF 8.46 million (3 times gross domestic product per capita).

Long-term outcome of chronic hepatitis C after sustained virological response to interferon-based therapy

BACKGROUND

Although the short-term benefits of a sustained virological response (SVR) to interferon-based therapies of chronic hepatitis C (CHC) are well known, the long-term consequences of SVR are less clear.

AIM

To assess changes in markers of disease activity and fibrosis in patients followed up to 23 years post-SVR.

METHODS

The first 103 SVR patients (from 1984 to 2003) at the National Institutes of Health Clinical Center were evaluated. Serum markers before treatment and at the last visit were compared. Evaluations after 2007 included transient elastography (TE).

RESULTS

Of 103 patients, three subsequently relapsed 0.7, 6.3 and 6.5 years post therapy. The remaining 100 patients (56 men, mean age 56 years) maintained SVR at final follow-up. No patients developed hepatic decompensation, but one with pre-treatment cirrhosis died 12 years post SVR of hepatocellular carcinoma. In comparison to pre-treatment values, markers improved at follow-up, including mean ALT (152-27 U/L), AST (87-24 U/L), alkaline phosphatase (78-69 U/L), IgG (1463-1113 mg/dL), platelet count (209 000-239 000/μL) and AST to platelet count ratio index (APRI: 1.31-0.33). TE was performed in 69 patients and was normal (<7.0 kPA) in 60%, moderately elevated (7.1-13.8) in 31% and cirrhotic range (>13.8) in 9%. TE and platelet counts at follow-up correlated with fibrosis on pre-treatment liver biopsy (P < 0.001).

CONCLUSIONS

In 97% of patients with CHC, SVR is durable without evidence of disease progression, although some degree of hepatic fibrosis may persist and patients with pre-treatment cirrhosis are at continuing low risk for hepatocellular carcinoma.

Efficacy and tolerability of telaprevir for chronic hepatitis virus C genotype 1 infection: a meta-analysis

Background

Chronic hepatitis C virus (HCV) infection is one of the leading causes of hepatic cirrhosis and hepatocellular carcinoma, and HCV genotype 1 is the most prevalent genotype and is resistant to current standard therapy. We performed this meta-analysis to evaluate the efficacy and safety of telaprevir-based therapy for chronic HCV genotype 1 infection.

Methods

We included randomized controlled trials with no year or language restriction. All data were analyzed using a random-effects model by Review Manager v5.0. The primary outcome was the proportion of patients achieving sustained virologic response (SVR), and the secondary outcomes were HCV relapse rate, incidence of severe adverse events (SAEs), and discontinuation due to adverse events.

Results

The proportion of achieving SVR was significantly higher in the telaprevir group (odds ratio [OR] = 3.40 [1.92, 6.00], P<0.0001; I² = 87%) regardless of a patients’ previous treatment status. It was also significantly higher in the 24-week and 48-week treatment groups (OR = 4.52 [2.08, 9.81], P<0.001; I² = 85%, and OR = 4.05 [1.56, 10.56], P = 0.004; I² = 92%, respectively), while it was comparable in the 12-week treatment group (OR = 1.32 [0.63, 2.75], P = 0.46; I² = 35%). In addition, the HCV relapse rate was significantly reduced in the telaprevir group (OR = 0.28 [0.16, 0.49], P<0.001; I² = 76%). However, the incidence of SAE (OR = 1.56 [1.15, 2.10], P = 0.004; I² = 0%) and study discontinuation due to adverse events (OR = 2.24 [1.43, 3.50], P<0.001; I² = 37%) were significantly higher in the telaprevir group.

Conclusion

Despite its higher incidence of SAEs and discontinuation due to adverse events, telaprevir-based therapy can increase the proportion of achieving SVR in both previously treated and untreated chronic HCV-1 infected patients.

Occult infection with hepatitis C virus: friend or foe?

Hepatitis C virus (HCV) infection is a global pandemic associated with a growing disease burden due to cirrhosis and the consequent morbidity and mortality. Transmission is largely via blood-to-blood contact. Following primary infection, a minority of individuals clear the infection predominantly via cellular immune mechanisms, whereas the majority become chronically infected. Recent data suggest that a third outcome may also be possible, termed 'occult' infection in which subjects who are known, or suspected to have previously been infected with HCV, no longer have viral RNA in their serum at levels detectable by sensitive commercial assays, but do have virus detected by ultra-sensitive techniques. Occult infection has also been detected in peripheral blood mononuclear cells, which may indicate an extra-hepatic reservoir of the virus. Although the clinical significance of occult infection remains unknown, most authors have raised concerns of recrudescent infection. Here we critically review the published literature, suggest further avenues of investigation and propose that occult infection may be beneficial to the host by maintaining immunological memory to protect against reinfection.

Sustained HCV clearance by interferon-based therapy reduces hepatocellular carcinoma in hepatitis B and C dually-infected patients

BACKGROUND

Recent studies have indicated that interferon (IFN) or pegylated interferon (PEG-IFN) plus ribavirin therapy can achieve sustained virological response (SVR) against HCV equally in dual HBV-HCV infection and in HCV monoinfection. Whether these therapies can reduce hepatocellular carcinoma (HCC) development in dual HBV-HCV infection remains unclear.

METHODS

A total of 135 dually-infected patients with active hepatitis C receiving IFN or PEG-IFN plus ribavirin therapy were enrolled. The cumulative incidence of HCC was compared to that in 1,470 HCV-monoinfected patients.

RESULTS

Based on the Cox proportional hazards model, dual infection was an independent factor for HCC development in all 1,605 chronic hepatitis C patients with or without positive hepatitis B surface antigen receiving IFN or PEG-IFN plus ribavirin (hazard ratio (HR)=1.864, 95% CI 1.052-3.303; P=0.033). In dually-infected patients, HCC developed in 4 of 96 with HCV SVR and 11 of 39 without HCV SVR (P < 0.001) after a median follow-up of 4.6 years. Age (HR=1.175, 95% CI 1.070-1.291; P=0.001) and non-HCV-SVR (HR=7.874, 95% CI 2.375-26.32; P=0.001) were independent factors for HCC development. Subgroup analysis showed that HCC occurrence was lower in patients with HCV SVR and HBV DNA levels < 2,000 IU/ml at the end of treatment or follow-up compared to those with HCV SVR and HBV DNA levels ≥ 2,000 IU/ml (P=0.034) and those without HCV SVR (P<0.001).

CONCLUSIONS

Sustained HCV clearance by IFN or PEG-IFN plus ribavirin therapy may significantly reduce HCC in HBV-HCV dually-infected patients, whereas persistence or reactivation of HBV decreases the benefit of HCV SVR.

Durability of sustained response shown in paediatric patients with chronic hepatitis C who were treated with interferon alfa-2b plus ribavirin

Long-term studies in adults indicate that sustained virologic response (SVR) after combination treatment for chronic hepatitis C (CHC) predicts long-term clearance. Although peginterferon plus ribavirin is now standard care for children with CHC, long-term follow-up studies are not yet available. This study evaluated durability of virologic response over 5 years in children previously treated with interferon alfa-2b plus ribavirin (IFN/R). Ninety-seven of 147 children with CHC, who were treated with IFN/R and completed the 6-month follow-up in two previous clinical trials, participated in this long-term follow-up study. All were assessed annually for up to 5 years; patients with SVR were assessed for durability of virologic response. Children with SVR (n = 56) and those with detectable hepatitis C virus (HCV) RNA 24-week post-treatment (n = 41) were followed for a median of 284 weeks. Overall, 70% (68/97) of patients completed the 5-year follow-up. One patient with genotype 1a CHC had SVR and relapsed at year 1 of follow-up with the same genotype. Kaplan-Meier estimate for sustained response at 5 years was 98% (95% CI: 95%, 100%). Six patients with low-positive HCV RNA levels (n = 4) or missing HCV RNA at the 24-week follow-up visit (n = 2) in the initial treatment studies had virologic response during this long-term follow-up study. Linear growth rate was impaired during treatment with rapid increases in the immediate 6 months post-treatment. Mean height percentile at the end of the 5-year follow-up was slightly less than the mean pretreatment height percentile. Five patients experienced serious adverse events; none related to study drug exposure. SVR after IFN/R predicts long-term clearance of HCV in paediatric patients; growth normalized in the majority of children during the long-term follow-up. Similar long-term results could be expected after peginterferon alfa-2b plus ribavirin treatment.

The impact of antiviral therapy and the influence of metabolic cofactors on the outcome of chronic HCV infection

NATURAL HISTORY OF HCV RELATED CHRONIC HEPATITIS IS INFLUENCED AND MODIFIED BY MANY FACTORS: virus features, coinfections and host characteristics. In particular, a peculiar genetic background of the host by conditioning the occurrence of intracellular metabolic derangements (i.e., insulin resistance) might contribute to accelerate the rate of progression to cirrhosis and eventually the occurrence of hepatocellular carcinoma (HCC) and death. Likely, direct interplays between virus genotype and host genetic background might be hypothesized at this level. Morbidity and mortality in cirrhosis is primarily associated with complications of liver cirrhosis (ascites, hepatic encephalopathy, jaundice, and gastroesophageal bleeding) and HCC occurrence. Therefore the main goal of therapy is to clear viral infection and decrease liver necro-inflammation that directly relates to development of cirrhosis and HCC. Among patients treated with Interferon-based therapy, those with sustained viral response showed a significant reduction of progression to cirrhosis and development of HCC. However, a residual risk of hepatocellular carcinoma still remains indicating the need for careful follow-up using ultrasonography every six months in cirrhotic patients, even in those showing persistently normal ALT and undetectable HCV RNA levels after antiviral therapy.

Effects of a sustained virologic response on outcomes of patients with chronic hepatitis C

For patients with chronic hepatitis C virus infection, the goal of antiviral therapy is to achieve a sustained virologic response (SVR). We review the durability of the SVR and its effects on liver-related mortality, hepatic decompensation, and the development of hepatocellular carcinoma. We performed a systematic review of the effects of the SVR on liver-related hepatic outcomes and found the SVR to be durable (range, 98.4%-100%). An SVR reduced liver-related mortality among patients with chronic hepatitis C (3.3- to 25-fold), the incidence of hepatocellular carcinoma (1.7- to 4.2-fold), and hepatic decompensation (2.7- to 17.4-fold). An SVR can lead to regression of fibrosis and cirrhosis, and has been associated with a reduced rate of hepatic decompensation, a reduced risk for hepatocellular carcinoma, and reduced liver-related mortality.

HIV infection and the liver: the importance of HCV-HIV coinfection and drug-induced liver injury

Hepatitis C virus-Human immunodeficiency virus (HCV-HIV) coinfections are identified in up to 30% of patients infected with HIV and in 8% of patients infected with HCV. Now that progression of HIV and deaths due to AIDS can be prevented by highly active antiretroviral therapy (HAART), it is clear that HCV coinfection is associated with accelerated progression to cirrhosis and increased liver-related morbidity and mortality. Antiviral therapy with pegylated interferon and ribavirin for HCV in HCV-HIV coinfected patients is less successful than in patients with HCV monoinfection, and HAART can cause drug-induced liver injury. Multiple barriers limit the number of HCV-HIV coinfected patients who receive antiviral therapy for HCV, and the role of orthotopic liver transplantation (OLT) in HIV monoinfected and HCV-HIV coinfected patients remains controversial. Clinical trials of HCV-specific protease or polymerase inhibitors combined with pegylated interferon and ribavirin are needed urgently in coinfected patients, both before and after OLT.

Long-term outcome of chronic hepatitis C patients with sustained virological response to peginterferon plus ribavirin

AIM: To assess the clinical, biochemical and virological long-term outcome in chronic hepatitis C (CHC) patients with a sustained virological response (SVR) after peginterferon (PEG-IFN) plus ribavirin combination therapy.

METHODS: One hundred and fifty three patients with a SVR after treatment with PEG-IFN plus ribavirin were included in a 5-year follow-up study in a single Spanish center, based on standard clinical practice. Clinical anamnesis, biochemical analysis, hepatitis C virus RNA and alpha-fetoprotein measurement, ultrasonography and transient elastography were performed annually.

RESULTS: The mean follow-up period of the 153 patients was 76 ± 13 mo after they obtained a SVR. Five patients (3.26%) presented with cirrhosis before treatment and 116 (75.8%) had genotype 1. No patient showed evidence of hepatic decompensation. One patient (0.65%) developed a hepatocellular carcinoma at month 30 after achieving SVR. There were no virological relapses during this follow-up period. Persistently elevated alanine aminotransferase was found in only one patient (0.65%). At the end of the 5-year follow-up, the mean value of transient elastography was 7 ± 4.3 kPa (F1). There were no deaths and no other tumors.

CONCLUSION: The long-term outcome of 153 CHC patients with SVR to PEG-IFN plus ribavirin was good. No evidence of a virological relapse was seen. One patient (0.65%) developed a hepatocellular carcinoma.

Evolution of interferon-based therapy for chronic hepatitis C

Since 1986, interferon-alfa (IFN-α) monotherapy has been administered for patients with chronic hepatitis C (CHC). However, sustained response rate is only about 8% to 9%. Subsequent introduction of ribavirin in combination with IFN-α was a major breakthrough in the treatment of CHC. Sustained virological responses (SVRs) rate is about 30% in hepatitis C virus genotype 1 (HCV-1) patients, and is about 65% in HCV-2 or -3 patients. After 2000, pegylated interferon (PegIFN) much improved the rates of SVR. Presently, PegIFN-α-ribavirin combination therapy has been current standard of care for patients infected with HCV. In patients with HCV-1, treatment for 48 weeks is optimal, but 24 weeks of treatment is sufficient in HCV-2 or -3 infected patients. Clinical factors have been identified as predictors for the efficacy of the IFN-based therapy. The baseline factor most strongly predictive of an SVR is the presence of HCV-2 or -3 infections. Rapid virological response (RVR) is the single best predictor of an SVR to PegIFN-ribavirin therapy. If patients can't achieve a RVR but achieve a complete early virological response (cEVR), treatment with current standard of care can provide more than 90% SVR rate. HCV-1 patients who do not achieve an EVR should discontinue the therapy. Recent advances of protease inhibitor may contribute the development of a novel triple combination therapy.

Long-term effects of antiviral therapy in patients with chronic hepatitis C

Chronic hepatitis C is a major cause of chronic liver disease globally, and the natural history of progression may lead to cirrhosis with liver failure, hepatocellular carcinoma, and premature liver-related death. Emerging data demonstrates that interferon-based therapy, particularly among those achieving a sustained virologic response (SVR), is associated with long-term persistence of SVR, improved fibrosis and inflammation scores, reduced incidence of hepatocellular carcinoma, and prolonged life expectancy. This reduction in the rate of progression has also been demonstrated in patients with chronic hepatitis C and cirrhosis in some but not all studies. The majority of these results are reported with standard interferon therapy, and long-term results of peginterferon plus ribavirin therapy with a higher likelihood of SVR should have a yet greater impact on the population of treated patients. The impact on slowing progression is greatest in patients with an SVR, less in relapsers, and equivocal in nonresponders. Thus, the natural history of chronic hepatitis C after completion of antiviral therapy is favorable with achievement of an SVR, although further data are needed to determine the likely incremental impact of peginterferon plus ribavirin, late long-term effects of therapy, and the benefit of treatment in patients with advanced hepatic fibrosis.

Telaprevir: a new hope in the treatment of chronic hepatitis C?

More than 180 million people worldwide have chronic hepatitis C (CHC) virus infection, a major cause of liver cirrhosis and its life-threatening complications including liver failure, portal hypertension, and hepatocellular carcinoma. With the current standard of care of pegylated interferon-alpha and ribavirin (PEG-IFN-alpha/RBV), the chances of sustained viral clearance or "cure" are only 40%-50% for genotype 1 infection, which is the most common genotype in western populations. Consequently, there has been a drive to develop new agents specifically targeting essential components of the viral life cycle, such as the hepatitis C virus (HCV) NS3/4A serine protease. Perhaps the most advanced HCV protease inhibitor in clinical development is telaprevir, which has been shown to improve treatment outcomes when combined with PEG-IFN-alpha/RBV in genotype 1 infection, and is currently undergoing phase 3 study. In this review, we summarize the pharmacology, pharmacokinetics, and results of phase 1 and 2 clinical trials of telaprevir, and discuss the likely role of this agent in the future management of CHC.

Twelve weeks posttreatment follow-up is as relevant as 24 weeks to determine the sustained virologic response in patients with hepatitis C virus receiving pegylated interferon and ribavirin

A sustained virologic response (SVR) in patients with chronic hepatitis C receiving pegylated interferon (PEG-IFN) plus ribavirin is defined as undetectable serum HCV-RNA at 24 weeks (W+24) posttreatment follow-up. Viral load outcome in patients with virological relapse (VR) has not been explored. This study evaluated whether the assessment of serum HCV-RNA 12 weeks (W+12) after the end of treatment was as relevant as W+24 to evaluate SVR in 573 patients who received combination PEG-IFN and ribavirin and had a virological response at the end of treatment. Serum HCV-RNA was measured, using a new assay based on transcription-mediated amplification (TMA) with a lowest detection limit of 5-10 IU/mL, at W+12 and W+24 after the end of treatment. VR was defined as reappearance of detectable HCV-RNA at W+24 posttreatment follow-up. The positive predictive value (PPV) of undetectable serum HCV-RNA at W+12 was evaluated to identify patients with SVR, and the viral load outcome was measured in relapse patients. At the W+24 posttreatment follow-up, 408 (71%) patients had an SVR, 181 (71.2%) were treated with PEG-IFNalpha-2a and ribavirin, and 227 (71.1%) were treated with PEG-IFNalpha-2b and ribavirin. At W+12, serum HCV-RNA was undetectable in 409 patients, and 408 patients were SVR (PPV 99.7%, 95% confidence interval 99.1-100). In relapse patients, serum HCV-RNA levels were 5.623 +/- 0.748, 4.979 +/- 0.870, and 5.216 +/- 0.758 log(10) IU/mL at baseline, W+12, and W+24, respectively.

CONCLUSION

Our results show that the assessment of serum HCV-RNA 12 weeks after the end of treatment, using the highly sensitive TMA assay (PPV 99.7%), is as relevant as after 24 weeks to predict SVR and make decisions on the management of treated patients, suggesting a new definition for SVR.

Reduction of liver stiffness by interferon treatment in the patients with chronic hepatitis C

AIM

To assess the regression of liver fibrosis after interferon (IFN) treatment in patients with chronic hepatitis C, liver stiffness (LS) was measured repeatedly and the factors associated with reduction of LS were assessed.

METHODS

LS was measured by transient elastography before treatment, at end of treatment (EOT), and 1 year and 2 years after EOT in 145 patients with chronic hepatitis C treated by IFN with or without ribavirin.

RESULTS

In the patients with sustained virological response (SVR) (n = 93) and relapsers (n = 28), LS significantly decreased at EOT (median, 5.4 [interquartile range, 4.0-8.6] kilopascals [kPa], P < 0.0001 and 6.8 [4.5-8.9] kPa, P = 0.0023) and 1 year after EOT (5.3 [4.2-7.0] kPa, P < 0.0001 and 6.8 [4.5-9.3] kPa, P = 0.0204) compared with baseline (8.0 [5.0-11.9] kPa and 10.6 [7.0-16.6] kPa). In SVR patients, LS significantly decreased 2 years after EOT (5.3 [4.1-6.3] kPa) compared with baseline (P < 0.0001) and LS at EOT (P = 0.0034). Two points or greater reduction of deduced stage at last LS measurement was observed in 78% of SVR patients, 59% of relapsers and 15% of patients with non-virological response whose pretreatment deduced stages were F3-F4. Fibrosis stage, hyaluronic acid levels, duration of treatment, response to treatment and alanine aminotransferase levels were associated with a 2-point or greater decrease of deduced fibrosis stage.

CONCLUSION

IFN treatment reduced LS in SVR patients and relapsers. Significant reduction of LS is associated with milder fibrosis stage, lower hyaluronic acid levels, longer IFN treatment, virological response of SVR or relapse and higher alanine aminotransferase levels.

Long-term effectiveness and cost-effectiveness of antiviral treatment in hepatitis C

We systematically reviewed the evidence for long-term effectiveness and cost-effectiveness of antiviral treatment in patients with chronic hepatitis C. We performed a systematic literature search on the long-term effectiveness and cost-effectiveness of AVT in hepatitis C (1990-March 2007), and included health technology assessment (HTA) reports, systematic reviews, long-term clinical trials, economic studies conducted alongside clinical trials and decision-analytic modelling studies. All costs were converted to 2005euro. Antiviral therapy with peginterferon plus ribavirin in treatment-naïve patients with chronic hepatitis C was the most effective (3.6-4.7 life years gained [LYG]) treatment and was reasonably cost-effective (cost-saving to 84 700euro/quality adjusted life years [QALY]) when compared to interferon plus ribavirin. Some results also suggest cost-effectiveness (below 8400euro/(QALY) of re-treatment in nonresponders/relapsers. Results for patients with persistently normal alanine aminotransferase (ALT) levels or with special co-morbidities (e.g. HIV) or risk profiles were rare. We conclude that antiviral therapy may prolong life, improve long-term health-related quality-of-life and be reasonably cost-effective in treatment-naïve patients with chronic hepatitis C as well as in former relapsers/nonresponders. Further research is needed in patients with specific co-morbidities or risk profiles.

Profile of hepatitis A infection with atypical manifestations in children

We assessed the clinical course and biochemical profile of symptomatic children with viral hepatitis A who had atypical manifestations. Of 229 children with hepatitis A, atypical manifestations were found in 32 (14%) subjects. Prolonged cholestasis (n = 14), acute liver failure (9), relapse (9), ascites (8), and hematological problems (8) were the common presentations. Liver histology was suggestive of chronic liver disease in six children with protracted jaundice. Patients with atypical presentations were older (7.7 [1.6] years vs. 6.5 [2.6] years; p=0.012) and had higher total serum bilirubin (13.7 [8.1] mg/dL vs. 7.2 [4.0] mg/dL; p=<0.001) than those with typical presentation. Approximately 15% of children with acute hepatitis A infection have atypical presentation which is associated with increase in morbidity.

Progress towards improving antiviral therapy for hepatitis C with hepatitis C virus polymerase inhibitors. Part I: Nucleoside analogues

BACKGROUND

With an increasing worldwide burden of liver failure and liver cancer from chronic hepatitis C virus (HCV) infection, discovery and development efforts for new antiviral medicines for HCV are expanding rapidly. Two HCV protease inhibitors (PIs), telaprevir (VX950) and boceprevir (SCH503034), are now furthest along in clinical development, with Phase II data suggesting a potential treatment advance with triple combination regimens comprising a protease inhibitor, pegylated interferon and ribavirin. However, the current data suggest that such regimens will fail to produce sustained virologic responses in > or = 30 - 40% of patients, and tolerance of interferon/ribavirin treatment regimens is often problematic; hence, there is a need for continued development of new anti-HCV agents to further optimize treatment efficacy and safety. The HCV polymerase (HCV Pol) is an attractive target for antiviral therapy because the gene sequences encoding HCV Pol are relatively conserved across the six main HCV genotypes and the emergence of viral resistance is expected to be relatively slow for pharmaceutical agents, such as nucleoside analogues, that are targeted to the active (catalytic) site of HCV Pol.

METHODS

This review (Part I) of HCV Pol inhibitors focuses on the scientific rationale and recent development progress for nucleoside-type HCV Pol inhibitors; a subsequent review (Part II) will assess progress with non-nucleosidic HCV Pol inhibitors.

RESULTS/CONCLUSIONS

Early clinical data for several nucleosides targeted to HCV Pol indicate marked antiviral effects and a likelihood of relatively slow HCV resistance, consistent with the profile of nucleosidic inhibitors of HIV and hepatitis B virus infection and supporting potentially important roles for nucleoside agents in optimizing combination therapies for HCV infection. Optimally effective future anti-HCV therapies are likely to be based on multi-class treatment regimens combining polymerase and PIs, together with pegylated interferon and ribavirin or pharmaceutical agents from other mechanistic classes.

Benefits and risks of nucleoside analog therapy for hepatitis B

Five oral agents have been approved for the treatment of chronic hepatitis B, ranging in virological potency, clinical efficacy, barrier to resistance, and side-effect profile. The degree of histological, biochemical, and serological improvement with therapy generally corresponds to the degree of suppression of serum hepatitis B virus (HBV) DNA achieved with therapy. Conversely, for agents with a low barrier to resistance, the profundity of HBV DNA suppression in individual patients correlates inversely with the likelihood of resistance. The durability of hepatitis B e antigen (HBeAg) responses after a consolidation period of an additional 6-12 months of therapy is approximately 80% in western populations, lower in Asian populations. Loss of hepatitis B surface antigen (HBsAg) during a year of oral-agent therapy is limited, except with the most potent agents, but extending therapy for a second year and beyond can yield frequencies of HBsAg responses close to those reported in trials of interferon-based therapy. The oral agents are approved for 1-2 years of therapy, but treatment is continued indefinitely in the majority of patients (except for the approximately 20% of patients who are HBeAg-reactive who achieve a durable HBeAg response). HBeAg responses and virological/biochemical benefit continue to be maintained and to increase with continued therapy beyond the first year. Data continue to accumulate supporting the link between long-term HBV DNA suppression and reduction in hepatic fibrosis, hepatic decompensation, and liver-related mortality. All the benefits of a single year of injectable peginterferon therapy can be achieved with the newer, low-resistance oral agents continued beyond the first year, without interferon side effects. Future studies are needed to develop drug regimens that are even more effective in achieving clinical endpoints, that are not hampered by resistance, and that are more confined in treatment duration but are more durable.

Clinical, virologic, histologic, and biochemical outcomes after successful HCV therapy: a 5-year follow-up of 150 patients

One hundred fifty patients with sustained virologic response (SVR) after treatment of chronic hepatitis C were enrolled in a long-term clinical follow-up study; patients were followed for 5 years for liver-related outcomes and evidence of biochemical or virologic relapse. Patients with stage 2 or greater fibrosis on pretreatment biopsy were invited to undergo a long-term follow-up biopsy after their fourth year of follow-up. One hundred twenty-eight patients (85%) were followed through their fourth year, and long-term follow-up biopsies were obtained from 60 patients (40%). Forty-nine patients had paired pretreatment and long-term follow-up biopsies blindly rescored. Forty of these patients (82%) had a decrease in fibrosis score, and 45 (92%) had a decrease in combined inflammation score. Ten patients (20%) had normal or nearly normal livers on long-term follow-up biopsy. Two patients with pretreatment cirrhosis developed hepatocellular carcinoma (HCC), and one died. All the other patients with pretreatment cirrhosis or advanced fibrosis had improved fibrosis scores on long-term follow-up biopsy. No patient had conclusive evidence of virologic relapse. Three patients had persistently elevated alanine aminotransferase levels; two of these had new liver disease.

CONCLUSION

In a cohort of 150 patients with SVR followed for 5 years, the majority of patients had good outcomes. Serum virologic relapse was not seen, but two patients with pretreatment cirrhosis developed HCC, and one died. In a blind rescoring of 49 paired pretreatment and long-term follow-up biopsies, 82% improved fibrosis scores and 92% improved at least one component of inflammation. A minority of patients had normal or nearly normal liver tissue on long-term follow-up biopsy. Patients with cirrhosis pretreatment are at a low but real risk of HCC after SVR.

Clinical management of HIV/hepatitis C virus coinfection

PURPOSE

The purpose of this study was to review the current management of hepatitis C virus (HCV) in persons coinfected with HIV.

DATA SOURCES

Comprehensive review of current scientific literature derived from electronic databases, article bibliographies, and conference abstracts.

CONCLUSIONS

HCV treatment is feasible in the individual coinfected with HIV; however, therapy is complex and requires intensive monitoring and support to achieve the outcome of viral eradication. New strategies to improve HCV treatment rates, adherence to therapy, and virological response rates are needed in this patient population.

IMPLICATIONS FOR PRACTICE

Nurse practitioners are crucial to the management of the HIV/HCV-coinfected patient. This patient population requires detailed clinical monitoring, education, side effect management, and strategies to improve adherence to therapy.

Using high-throughput genomics to study hepatitis C: what determines the outcome of infection?

High-throughput genomic methods are now being used to study a wide variety of viral diseases, in an effort to understand how host responses to infection can lead either to efficient elimination of the pathogen or the development of severe disease. This article reviews how gene expression studies are addressing important clinical issues related to hepatitis C virus infection, in which some 15-25% of infected individuals are able to clear the virus without treatment, while the remainder progress to chronic liver disease that can lead to cirrhosis and death. Similar methods are also being used in an effort to identify the mechanisms underlying the failure of some hepatitis C patients to respond to interferon-alpha/ribavirin therapy. By providing a detailed picture of virus-host interactions, high-throughput genomics could potentially lead to the identification of novel cellular targets for the treatment of hepatitis C.

Interferons and their use in persistent viral infections

In 2007, the world celebrated the 50th anniversary of the discovery of interferon (IFN) by Isaacs and Lindenmann. Subsequently, the IFN-alpha gene was cloned, fully sequenced and IFN-alpha was produced in recombinant form. Recombinant IFN-alpha is now used as the basis for treatment of chronic hepatitis C virus infection and can also be used to treat certain forms of chronic hepatitis B virus infections. IFNs have also been used in other viral infections, although with less success. The antiviral mechanisms of IFNs are reviewed in this chapter as well as the utility of IFNs in the treatment of persistent viral infections.

Interpretation of positive transcription-mediated amplification test results from polymerase chain reaction-negative samples obtained after treatment of chronic hepatitis C

The Siemens VERSANT transcription-mediated amplification (TMA) assay is extremely sensitive for the detection of hepatitis C virus (HCV) RNA in serum. Eleven of 180 subjects in the Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial who achieved polymerase chain reaction (PCR)-defined sustained virological response (SVR) at week 72 also had TMA-positive results from the same blood draw; six were positive on repeat testing. We report the follow-up on these 11 patients, and the reproducibility of TMA test results from PCR-negative samples in relationship to antiviral treatment outcome. Peginterferon and ribavirin treatment was initiated in 1145 prior interferon nonresponders with advanced hepatic fibrosis. Treatment was continued for 48 weeks if patients had undetectable HCV RNA by PCR at treatment week 20. Frozen serum samples from weeks 12, 20, 24, 48, and 72 were subsequently tested by TMA. Nine of the 11 patients returned for testing (median, 30 months after the week 72 visit), and all had undetectable HCV RNA by TMA and PCR. Among 759 PCR-negative samples obtained during treatment that were tested twice by TMA, 17% overall exhibited consistently positive results, and 21% exhibited inconsistently positive results. SVR was more likely if TMA was consistently negative than if consistently or inconsistently positive. With continued treatment, patients with inconsistently positive TMA results were more likely to become TMA-negative than TMA-positive (P < 0.0001).

CONCLUSION

In PCR-negative samples, positive TMA results may indicate the presence of low levels of HCV RNA. However, because patients with positive TMA results may achieve SVR, management decisions during therapy should not be based on a single positive TMA test result.

Recurrence of HCV infection in a sustained responder after chemotherapy for non-Hodgkin's lymphoma: successful retreatment

It is known that sustained virological response (SVR) in patients with chronic hepatitis C is associated with sustained elimination of hepatitis C virus (HCV) and that late relapse after SVR in HCV patients is doubtful. A 47-year-old man with chronic hepatitis C genotype 3, achieved SVR after combination treatment with pegylated interferon and ribavirine for 6 months. Sixteen months later non-Hodgkin's lymphoma was diagnosed. After successful completion of chemotherapy for non-Hodgkin's lymphoma, he presented with HCV infection recurrence of the same genotype. Retreatment with the same schedule resulted in normalization of aminotransferases and disappearance of HCVRNA from the serum. This case suggests that recurrence of HCV infection in a sustained responder may be probable after immunosuppressive therapy. Prevention is currently impossible but retreatment may be successful.

Eradication of hepatitis C virus in patients successfully treated for chronic hepatitis C

BACKGROUND & AIMS

It is unclear whether hepatitis C virus (HCV) is eradicated in patients with chronic hepatitis C who achieved a sustained virologic response (SVR).

METHODS

In this long-term follow-up study, including chronic hepatitis C patients who achieved SVR after interferon-based therapy, the presence of residual HCV RNA in serum, liver, and peripheral blood mononuclear cells (PBMCs) was assessed, using transcription-mediated amplification (sensitivity, <9.6 IU/mL). The benefit of SVR on liver fibrosis was evaluated using the METAVIR score.

RESULTS

A total of 344 patients were followed up for a median duration of 3.27 years (range, 0.50-18 y; interquartile range [IQR], 1.68-5.35 y). A total of 114 patients had a posttreatment liver tissue (median, 0.50 y; range, 0-14 y; IQR, 0-3.5 y) and a total of 156 had one PBMC (median, 3.0 y; range, 0.50-18 y; IQR, 1.25-5.50 y). Serum HCV RNA remained undetectable (1300 samples), indicating that none of the patients had a relapse. HCV RNA was detectable in 2 of 114 (1.7%) liver specimens, and in none of 156 PBMC specimens. Histologic analysis of 126 paired pretreatment and posttreatment liver biopsy specimens (median, 0.50 y; range, 0-14 y; IQR, 0-3.5 y) showed that fibrosis stage was improved in 56%, stable in 32%, deteriorated in 12%. Regression of cirrhosis was observed in 9 of 14 (64%) (95% confidence interval, 39-89) patients. No cirrhosis decompensation was observed, and 3 patients developed hepatocellular carcinoma.

CONCLUSIONS

In this large cohort of chronic hepatitis C patients, SVR was durable up to 18 years after treatment cessation, in addition to fibrosis stability/improvement (88%) and cirrhosis regression (64%). The presence of residual HCV RNA was observed only in liver tissue (1.7%). This result strongly suggests that SVR may be considered to show eradication of HCV infection.

Innate immune modulation by RNA viruses: emerging insights from functional genomics

By providing a global and integrated view of the host response to infection, functional genomic and systems-biology approaches are contributing to our understanding of RNA virus–host interactions. One area in which these approaches are being put to particularly good use is in shedding new light on the components of innate antiviral defence mechanisms and the viral strategies used to regulate or overcome them.

Genomic analyses have helped to reveal virus-specific differences in the way that viral recognition through pathogen-recognition receptors (PRRs) initiates intracellular signalling cascades. Whereas influenza virus appears to signal primarily through retinoic-acid-inducible gene I (RIG-I), West Nile virus signals through both RIG-I and melanoma differentiation-associated gene 5 (MDA5). Both viruses induce the expression of interferon (IFN)-regulatory factor 3 (IRF3) target genes and IFN-stimulated genes (ISGs).

Genomic analyses have provided a comprehensive view of the transcriptional programmes that are induced by Toll-like receptor (TLR) activation. One transcriptional profile is universally activated by all TLRs and a second profile is specific to TLR3 and TLR4. Nuclear factor-κB (NF-κB) is the key regulator of the universal response, which occurs early after TLR stimulation, and the IFN-stimulated response element (ISRE) is the key component of the TLR3/TLR4 response, which is induced after the NF-κB response.

Some highly virulent viruses, such as Ebola virus and rabies virus, are successful at inhibiting ISG expression, resulting in the marked suppression of genes in key innate antiviral pathways, including those mediated by IRF3. There seems to be a correlation between the antagonism of the IFN response and virulence.

Genomic analyses of the host response to the reconstructed 1918 pandemic influenza virus have revealed similarities and differences to contemporary influenza virus infection. Contemporary and 1918 influenza viruses each trigger an innate immune response that includes the expression of NF-κB and IRF3 target genes, and both viruses trigger a robust cytokine response that attracts immune-cell infiltration to infected tissues. Unlike contemporary virus strains, in which the early response to infection is resolved, the innate immune response triggered by the 1918 influenza virus is characterized by a strong and sustained induction that is associated with massive tissue damage and death.

Global gene-expression profiling has revealed that many effective, attenuated live-virus vaccines transiently induce a stronger type I IFN response than the cognate pathogen, and therefore implicates modulation of this response as an important strategy in rational vaccine design.

By providing a global view of the host response to infection, functional genomic approaches are proving useful in deciphering complex virus–host interactions. Here, the authors reveal how such approaches are being used to better understand viral triggering and regulation of host innate immune responses.

Although often encoding fewer than a dozen genes, RNA viruses can overcome host antiviral responses and wreak havoc on the cells they infect. Some manage to evade host antiviral defences, whereas others elicit an aberrant or disproportional immune response. Both scenarios can result in the disruption of intracellular signalling pathways and significant pathology in the host. Systems-biology approaches are increasingly being used to study the processes of viral triggering and regulation of host immune responses. By providing a global and integrated view of cellular events, these approaches are beginning to unravel some of the complexities of virus–host interactions and provide new insights into how RNA viruses cause disease.

Pegylated interferon 2a and 2b in combination with ribavirin for the treatment of chronic hepatitis C in HIV infected patients

Coinfection with hepatitis C virus (HCV) and HIV is an increasingly recognized clinical dilemma, particularly since the advent of highly active antiretroviral therapy. Several studies of this population have demonstrated both more rapid progression of liver disease and poorer overall prognosis compared to HCV monoinfected patients. Consensus guidelines, based primarily on the results of 4 major randomized trials, recommend treatment with peginterferon and ribavirin for 48 weeks in coinfected patients. However, this current standard of care is associated with lower response rates to therapy than those seen in monoinfected patients. Important predictors of response include HCV genotype, pretreatment HCV RNA level, and presence of rapid virologic response (RVR) and early virologic response (EVR). Use of weight-based ribavirin dosing appears to be safe and enhances the likelihood of sustained virologic response (SVR). Adverse effects most commonly encountered are anemia and weight loss. Mitochondrial toxicity can occur in the setting of concomitant nucleoside reverse transcriptase inhibitor use, especially didanosine, abacavir, and zidovudine, and these should be discontinued before initiation of ribavirin therapy. Discontinuation of therapy should be considered in patients failing to demonstrate EVR, though ongoing trials are investigating a potential role for maintenance therapy in these patients. Peginterferon combined with weight-based ribavirin is appropriate and safe for treatment of HCV in HIV - HCV coinfected patients. This review summarizes the data supporting these recommendations.

Pegylated interferon alpha-2b plus ribavirin for naive patients with HCV-related cirrhosis

BACKGROUND

Data on the efficacy of antiviral therapy in patients with HCV-related compensated cirrhosis are generally drawn from analyzing subgroups in larger trials.

AIMS

(1) To analyze the safety and efficacy of combination therapy in naive patients with HCV-related cirrhosis; (2) to evaluate the factors influencing the sustained virologic response (SVR) in cirrhotic patients by comparison with a group of noncirrhotic patients; (3) to analyze the outcome of cirrhotic patients either acquiring SVR and nonresponders to the antiviral therapy during the posttreatment follow-up.

METHODS

We consecutively enrolled 365 patients with biopsy-proven HCV-related chronic hepatitis meeting the inclusion criteria for pegylated interferon a-2b plus Ribavirin: 87 patients had compensated liver cirrhosis and 278 had histologic stages between 1 and 4 according to Ishak's classification.

RESULTS

The 2 groups were comparable for genotype, viral load, and alanine transferase at presentation. Cirrhotic patients were significantly older and had significantly higher body mass index, serum ferritin, and gamma-glutamyl transpeptidase. The rate of side effects was similar in the 2 groups, whereas the rate of SVR was significantly lower in cirrhotic (45.9%) than in noncirrhotic patients (65.8%). Logistic regression analysis showed that genotype 1 to 4 and high viral load were independent variables correlating with nonresponse in the sample as a whole. During follow-up, hepatocellular carcinoma developed in 5/38 (13.2%) cirrhotic patients not responding or relapsing after treatment. No cases of hepatocellular carcinoma were seen among cirrhotic or noncirrhotic patients with a SVR.

CONCLUSIONS

Cirrhotic patients with compensated disease have a reasonably good chance of virologic response and should be offered treatment, carefully monitoring any side-effects.