Acute hepatitis C virus infection

The metabolic fingerprint of chronic hepatitis C progression: Metabolome shifts and cutting-edge diagnostic options

Hepatitis C virus infection causes chronic diseases such as cirrhosis and hepatocellular carcinoma. Metabolomics research has been shown to be linked to pathophysiologic pathways in liver illnesses. The aim of this study was to investigate the serum metabolic profile of patients with chronic hepatitis C (CHC) infection and to identify underlying mechanisms as well as potential biomarkers associated with the disease. Nuclear magnetic resonance (NMR) was used to evaluate the sera of 83 patients with CHC virus and 52 healthy control volunteers (NMR). Then, multivariate statistical analysis was used to find distinguishing metabolites between the two groups. Sixteen out of 40 metabolites including include 3-HB, betaine, carnitine, creatinine, fucose, glutamine, glycerol, isopropanol, lysine, mannose, methanol, methionine, ornithine, proline, serine, and valine-were shown to be significantly different between the CHC and normal control (NC) groups (variable importance in projection >1 and p < 0.05). All the metabolic perturbations in this disease are associated with pathways of Glycine, serine, and threonine metabolism, glycerolipid metabolism, arginine and proline metabolism, aminoacyl-tRNA biosynthesis, cysteine and methionine metabolism, alanine, aspartate, and glutamate metabolism. Multivariate statistical analysis constructed using these expressed metabolites showed CHC patients can be discriminated from NCs with high sensitivity (90%) and specificity (99%). The metabolomics approach may expand the diagnostic armamentarium for patients with CHC while contributing to a comprehensive understanding of disease mechanisms.

MicroRNA-122 Regulation of HCV Infections: Insights from Studies of miR-122-Independent Replication

Despite the advancement in antiviral therapy, Hepatitis C remains a global health challenge and one of the leading causes of hepatitis related deaths worldwide. Hepatitis C virus, the causative agent, is a positive strand RNA virus that requires a liver specific microRNA called miR-122 for its replication. Unconventional to the canonical role of miRNAs in translation suppression by binding to 3'Untranslated Region (UTR) of messenger RNAs, miR-122 binds to two sites on the 5'UTR of viral genome and promotes viral propagation. In this review, we describe the unique relationship between the liver specific microRNA and HCV, the current knowledge on the mechanisms by which the virus uses miR-122 to promote the virus life cycle, and how miR-122 impacts viral tropism and pathogenesis. We will also discuss the use of anti-miR-122 therapy and its impact on viral evolution of miR-122-independent replication. This review further provides insight into how viruses manipulate host factors at the initial stage of infection to establish a successful infection.

Rapid Diagnostics for Hepatitis B and C Viruses in Low- and Middle-Income Countries

The global health challenge posed by hepatitis B virus (HBV) and hepatitis C virus (HCV) persists, especially in low-and-middle-income countries (LMICs), where underdiagnosis of these viral infections remains a barrier to the elimination target of 2030. HBV and HCV infections are responsible for most liver-related mortality worldwide. Infected individuals are often unaware of their condition and as a result, continue to transmit these viruses. Although conventional diagnostic tests exist, in LMIC they are largely inaccessible due to high costs or a lack of trained personnel, resulting in poor linkage to care and increased infections. Timely and accurate diagnosis is needed to achieve elimination of hepatitis B and C by the year 2030 as set out by the World Health Organization Global Health Sector Strategy. In this review rapid diagnostic tests allowing for quick and cost-effective screening and diagnosis of HBV and HCV, are discussed, as are their features, including suitability, reliability, and applicability in LMIC, particularly those within Africa.

Hepatitis C transmission in young people who inject drugs: Insights using a dynamic model informed by state public health surveillance

Increasing injection of heroin and prescription opioids have led to increases in the incidence of hepatitis C virus (HCV) infections in US young adults since the early 2000s. How best to interrupt transmission and decrease HCV prevalence in young people who inject drugs (PWID) is uncertain. We developed an age-stratified ordinary differential equation HCV transmission model of PWID aged 15-64, which we fit to Michigan HCV surveillance data among young PWID aged 15-29. We used Latin hypercube sampling to fit to data under 10,000 plausible model parameterizations. We used the best-fitting 10% of simulations to predict the potential impact of primary (reducing injection initiation), secondary (increasing cessation, reducing injection partners, or reducing injection drug use relapse), and tertiary (HCV treatment) interventions (over the period 2017-2030) on acute and chronic HCV cases by the year 2030. Treating 3 per 100 current and former PWID per year could reduce chronic HCV by 27.3% (range: 18.7-30.3%) and acute HCV by 23.6% (range: 6.7-29.5%) by 2030 among PWID aged 15-29 if 90% are cured (i.e. achieved sustained virologic response [SVR] to treatment). Reducing the number of syringe sharing partners per year by 10% was predicted to reduce chronic HCV by 15.7% (range: 9.4-23.8%) and acute cases by 21.4% (range: 14.2-32.3%) among PWID aged 15-29 by 2030. In simulations of combinations of interventions, reducing injection initiation, syringe sharing, and relapse rates each by 10% while increasing cessation rates by 10% predicted a 27.7% (range: 18.0-39.7%) reduction in chronic HCV and a 38.4% (range: 28.3-53.3%) reduction in acute HCV. Our results highlight the need for HCV treatment among both current and former PWID and the scale up of both primary and secondary interventions to concurrently reduce HCV prevalence and incidence in Michigan.

Assessing hepatitis C spontaneous clearance and understanding associated factors-A systematic review and meta-analysis

New advances in the treatment of hepatitis C provide high levels of sustained viral response but their expense limits availability in publicly funded health systems. The aim of this review was to estimate the proportion of patients who will spontaneously clear HCV, to identify factors that are associated with clearance and to support better targeting of directly acting antivirals. We searched Ovid EMBASE, Ovid MEDLINE and PubMed from 1 January 1994 to 30 June 2015 for studies reporting hepatitis C spontaneous clearance and/or demographic, clinical and behavioural factors associated with clearance. We undertook meta-analyses to estimate the odds of clearance for each predictor. Forty-three studies met the inclusion criteria, representing 20 110 individuals, and 6 of these studies included sufficient data to estimate spontaneous clearance. The proportion achieving clearance within 3, 6, 12 and 24 months following infection were, respectively, 19.8% (95% CI: 2.6%-47.5%), 27.9% (95% CI: 17.2%-41.8%), 36.1% (95% CI: 23.5%-50.9%) and 37.1% (95% CI: 23.7%-52.8%). Individuals who had not spontaneously cleared by 12 months were unlikely to do so. The likelihood of spontaneous clearance was lower in males and individuals with HIV co-infection, the absence of HBV co-infection, asymptomatic infection, black or nonindigenous race, nongenotype 1 infection, older age and alcohol or drug problems. This study suggests that patients continue to spontaneously clear HCV for at least 12 months following initial infection. However, injecting drug users are comparatively less likely to achieve clearance; thus, they should be considered a priority for early treatment given the continuing risks that these individuals pose for onwards transmission.

Influence of camel milk on the hepatitis C virus burden of infected patients

Hepatitis C virus (HCV) infection represents a world health problem and no protective vaccine or effective drug currently exists. For economic reasons, many patients use traditional medicines to control the infection. In Egypt, camel milk is one of the traditional medicines widely consumed by patients infected with HCV. The present study aimed to evaluate the efficacy of camel milk in the treatment of patients infected with HCV. Whole camel milk from a local farm was administered to patients for 4 months (250 ml/day/patient). Patient sera were collected prior to and following camel milk drinking, and three markers were set-up for sera-evaluation. The three markers indicating the effect of camel milk on HCV infection were: Liver function assays [alanine aminotransferase (ALT) and aspartate aminotransferase (AST)]; a viral load assay; and anti-HCV antibodies profile and isotyping against synthetic HCV epitopes. Camel milk demonstrated the ability to improve general fatigue, health and liver function (ALT and AST levels); ALT was reduced in ~88% of patients and AST was reduced in all patients subsequent to drinking camel milk for four months. The majority of patients responded positively to camel milk treatment; RNA viral load decreased in 13 out of the 17 patients (76.47%) and one patient exhibited undetected viremia following camel milk treatment. The anti-HCV antibodies profile and isotyping were significantly decreased (P<0.05) in immunoglobulin (Ig)G1 following treatment in 70-76% of patients. However, the treatment was ineffective in 23.53% of patients who experienced no reduction in RNA viral load following treatment with camel milk. In conclusion, whole camel milk treatment demonstrated efficacy in vivo; the viral load in the majority of patient sera was reduced and the IgG isotype profile was converted to Th1 immunity.

Prevalence of Hepatitis C Virus Infection and Its Risk Factors among Patients Attending Rwanda Military Hospital, Rwanda

In Rwanda, the prevalence of viral hepatitis (HCV) is poorly understood. The current study investigated the prevalence and risk factors of HCV infection in Rwanda. A total of 324 patients attending Rwanda Military Hospital were randomly selected and a questionnaire was administered to determine the risk factors. Blood was collected and screened for anti-HCV antibodies and seropositive samples were subjected to polymerase chain reaction method. Hematology abnormalities in the HCV infected patients were also investigated. Anti-HCV antibody and active HCV infection were found in 16.0% and 9.6% of total participants, respectively. Prevalence was highest (28.4%; 19/67) among participants above 55 years and least (2.4%; 3/123) among younger participants (18-35 years). There was a significant (P = 0.031) relationship between place of residence and HCV infection with residents of Southern Province having significantly higher prevalence. The hematological abnormalities observed in the HCV infected patients included leukopenia (48.4%; 15/52), neutropenia (6.5%; 2/52), and thrombocytopenia (25.8%; 8/52). The HCV infection was significantly higher in the older population (>55 years) and exposure to injection from traditional practitioners was identified as a significant (P = 0.036) risk factor of infection. Further studies to determine the factors causing the high prevalence of HCV in Rwanda are recommended.

The core of hepatitis C virus pathogenesis

Capsid proteins form protective shells around viral genomes and mediate viral entry. However, many capsid proteins have additional and important roles for virus infection and in modulating cellular response to infection, with important consequences on pathogenesis. Infection by the Hepatitis C virus (HCV) can lead to liver steatosis, cirrhosis, and hepatocellular carcinoma. Herein, we focus on the role in pathogenesis of Core, the capsid protein of the HCV.

The Combination Therapy with Peg-interferon Alfa and Ribavirin for Chronic Hepatitis C in Korea as an Initial Treatment

Objectives The combination therapy with peginterferon and ribavirin has been used to treat chronic hepatitis C for several years in Korea but there is a few report about the results of the treatment. We evaluated safety and efficacy of the combination therapy with Peg-interferon and ribavirin and analyzed factors that may affect treatment. Methods Total 72 untreated chronic hepatitis C patients were administered pegylated interferon alfa-2a (180µg/week) or alfa-2b (1.5µg/kg/week) and ribavirin (800 mg/day in genotype 2, 1000-1200 mg/day in genotype 1). Duration of the treatment was 24 weeks in genotype 2 and 48 weeks in genotype 1. Response of the treatment was evaluated by rapid virologic response (RVR), early virologic response (EVR), end treatment virologic response (ETR), sustained virologic response (SVR) and adverse event. Results The RVR, EVR, ETR, SVR were 61.8%, 82.5%, 88.9% and 80.5% retrospectively. The SVR of genotype 1 was 63.4% and non-genotype 1 was 96.7%. Genotype (Odds ratio: 14.92) was an independent predictor of the SVR. Leukocytopenia, flu-like symptoms, itching, rash and anemia were common adverse events of the combination therapy and if then we reduced dose and there was one case of cessation. Conclusions The combination therapy with Peg-interferon and ribavirin shows efficacy to the Korean patients with chronic hepatitis C as an initial treatment. Genotypes 2 and 3 were more likely to have a sustained virologic response.

Immediate vs. delayed treatment in patients with acute hepatitis C based on IL28B polymorphism: a model-based analysis

BACKGROUND & AIMS

Timing of treatment initiation in acute hepatitis C (AHC) patients is unclear. Spontaneous viral clearance argues for a "watch-and-wait" strategy. However, early initiation of treatment could increase the sustained virological response (SVR) rate. We compared three different HCV treatment initiation strategies in patients with AHC according to presence of clinical symptoms and IL28B polymorphism: (1) within 2 months after transmission (immediate initiation), (2) at 3 months (early initiation), and (3) at 4/5 months (delayed initiation).

METHODS

We calculated spontaneous HCV clearance probability based on the symptomatic (sAHC) and asymptomatic (aAHC) nature of disease and C/C or non-C/C genotype. We used different SVR probabilities according to delay between transmission and treatment. We estimated the probability of developing chronic hepatitis C (CHC).

RESULTS

The probability of developing CHC was lower for immediate treatment initiation (7.1% in C/C and 7.3% in non-C/C patients with sAHC; 6.6% in C/C and 7.1% in non-C/C patients with aAHC) than for delayed initiation (13.5% in C/C and 18.0% in non-C/C patients with sAHC; 14.6% in C/C and 18.5% in non-C/C patients with aAHC) regardless of the presence of symptoms or IL28B genotype.

CONCLUSIONS

In patients such as health care workers, in whom HCV is detected ≤ 2 months following transmission, treatment should be immediately initiated regardless of clinical symptoms and IL28B polymorphism. In those in whom HCV is detected>2 months after transmission, treatment 4/5 months after may be preferable because of a higher rate of spontaneous HCV clearance after 2 months and a poor HCV treatment efficacy's differential between months 3 and 4/5.

Divergent quasispecies evolution in de novo hepatitis C virus infection associated with bone marrow transplantation

Quasispecies is a remarkable characteristic of hepatitis C virus (HCV) and has profound roles in HCV biology and clinical practice. The understanding of HCV quasispecies behavior, in particular in acute HCV infection, is valuable for vaccine development and therapeutic interference. However, acute HCV infection is seldom encountered in clinic practice due to its silent onset. In the present study, we reported a unique case of de novo HCV infection associated with the transplantation of bone marrow from a HCV-positive donor. HCV quasispecies diversity was determined in both the donor and the recipient over a 4-year follow-up, accompanied with simultaneous measurement of HCV neutralizing antibody. Detailed genetic and phylogenetic analyses revealed a divergent quasispecies evolution, which was not related to dynamic changes of HCV neutralizing antibody. Instead, our data suggested an essential role of the fitness adaptation of founder viral population in driving such an evolutionary pattern.

The impact of illicit drug use on spontaneous hepatitis C clearance: experience from a large cohort population study

BACKGROUND AND AIMS

Acute hepatitis C infection usually ends in chronic infection, while in a minority of patients it is spontaneously cleared. The current population-based study is performed on a large cohort in Golestan province of Iran to examine the demographic correlates of Spontaneous Hepatitis C Clearance.

METHODS

Serum samples used in this study had been stored in biorepository of Golestan Cohort Study. These samples were evaluated for anti hepatitis C Virus by third generation Enzyme-linked immunosorbent assay (ELISA). Subjects who tested positive were then invited and tested by Recombinant Immunoblot Assay (RIBA) and Ribonucleic Acid Polymerase Chain Reaction test (PCR). If tested positive for RIBA, subjects were recalled and the two tests were re-done after 6 months. Those subjects who again tested positive for RIBA but negative for PCR were marked as cases of spontaneous clearance.

RESULTS

49,338 serum samples were evaluated. The prevalence of Chronic Hepatitis C Virus (CHCV) infection based on PCR results was 0.31%. Among those who had acquired hepatitis C, the rate of SC was 38%. In multivariate analysis, illicit drug use both Injecting Use (OR = 3.271, 95% CI: 1.784-6.000, p-value<0.001) and Non-Injecting Use (OR = 1.901, 95% CI: 1.068-3.386, p-value = 0.029) were significant correlates of CHCV infection versus SC.

CONCLUSIONS

Illicit drug use whether intravenous or non-intravenous is the only significant correlate of CHCV, for which several underlying mechanisms can be postulated including repeated contacts with hepatitis C antigen.

Distinguishing acute from chronic hepatitis C virus (HCV) infection based on antibody reactivities to specific HCV structural and nonstructural proteins

Currently available serological assays for detection of antibodies to hepatitis C virus (HCV) cannot reliably discriminate acute from chronic HCV infection. We developed a multiplexed, flow-cytometric microsphere immunoassay to measure anti-HCV-IgG reactivities to the core, NS3, NS4, and NS5 HCV recombinant proteins and applied it to 99 serum samples from 24 anti-HCV seroconverters and 141 anti-HCV-IgG and HCV RNA-positive plasma specimens from chronically infected people. Differences in the geometric means or means of signal/cutoff ratios between the two sample sets were statistically significant for all the antigens tested. A multivariate logistic regression model correctly classified the samples in two groups, with a cross-validation accuracy of 90.8% for the acute group and 97.2% for the chronic group. The immunoassay described has the potential to distinguish acute from chronic HCV infection.

Low accuracy of the national reporting system of acute hepatitis C infection in Taiwan, 1995-2004

BACKGROUND AND AIM

This study attempted to clarify accuracy of acute hepatitis C (AHC) and its clinical characteristics.

METHODS

We reviewed 632 reported cases from national surveillance data of the Taiwan Center for Disease Control between 1995 and 2004, and reclassified diagnoses. A definite case was defined as alanine aminotransferase (ALT) > 10 x the upper limit of normal (ULN) with seroconversion of anti-hepatitis C virus antibody (anti-HCV). A probable case was defined as (i) seroconversion of anti-HCV and/or elevated ALT levels; or (ii) anti-HCV(+) but titers increased (from < 40 S/CO to >or= 40 S/CO) and ALT > 10 x the ULN. A suspected case was defined as initial anti-HCV(+) and ALT level > 10 x the ULN and/or jaundice. Excluded cases were defined as ALT levels less than 10 x ULN with initial positive anti-HCV Ab.

RESULTS

A total of 310 (49%) cases were confirmed as AHC; these included 95 (15%) definite and 215 (34%) probable cases. Higher incidence rates and accuracy of AHC were demonstrated in the southern area significantly if compared with northern, eastern and central areas, respectively (all P < 0.05). On comparison between blood centers and hospitals, more AHC cases were found in Southern Taiwan than in other areas (157/73 vs 24/40, P < 0.001), younger mean age (33.3 +/- 11.1 vs 49.3 +/- 16.4, P < 0.001), lower ALT levels (263.1 +/- 200.9 vs 1264.2 +/- 706.8, P < 0.001) and male predominance (191/39 vs 46/18, P = 0.046).

CONCLUSIONS

This study showed our reporting system over-estimated the AHC diagnosis, which is also a common issue worldwide. Greater efforts are needed to establish appropriate reporting systems, as well as more supplemental methods to distinguish between prevalent and incident cases.

Prospective follow-up of patients with acute hepatitis C virus infection in Brazil

BACKGROUND

The natural outcome of infection with hepatitis C virus (HCV) varies substantially among individuals. However, little is known about host and viral factors associated with a self-limiting or chronic evolution of HCV infection.

METHODS

From 1 January 2001 through 31 December 2008, a consecutive series of 65 patients from Rio de Janeiro, Brazil, with a well-documented diagnosis of acute HCV infection, acquired via various routes, were enrolled in this study. Patients were prospectively followed up for a median of 40 months after the estimated date of HCV infection with serial measurements of serum alanine aminotransferase, HCV RNA, and anti-HCV antibodies. Spontaneous viral clearance (SVC) was defined as undetectable levels of HCV RNA in serum, in the absence of treatment, for 3 consecutive HCV polymerase chain reaction tests within the first 6 months of follow-up. Cox proportional hazards regression was used to identify host and viral predictors of SVC.

RESULTS

The cumulative rate of SVC was 44.6% (95% confidence interval, 32.3%-57.5%). Compared with chronic HCV evolution, patients with self-limiting disease had significantly lower peak levels of anti-HCV antibodies (median, 109.0 vs 86.7 optical density-to-cutoff ratio [od/co]; P<.02), experienced disease symptoms more frequently (69.4% vs 100%; P<.001), and had lower viral load at first clinical presentation (median, 4.3 vs 0.0 log copies; P=.01). In multivariate analyses, low peak anti-HCV level (<93.5 od/co) was the only independent predictor for SVC; the hazard ratio compared with high anti-HCV levels (> or =93.5 od/co) was 2.62 (95% confidence interval, 1.11-6.19; P=.03).

CONCLUSION

Our data suggest that low levels of anti-HCV antibodies during the acute phase of HCV infection are independently related to spontaneous viral clearance.

Early treatment improves outcomes in acute hepatitis C virus infection: a meta-analysis

Acute hepatitis C virus infection is associated with high rates of spontaneous clearance and variable rates of treatment-induced clearance. The benefit of early treatment versus awaiting spontaneous clearance is unknown, as is the optimal timing of treatment.We performed a MEDLINE and EMBASE search for the time period 1950 to October 2008. All English language abstracts using the search terms acute hepatitis C, hepatitis C and acute and hepatitis C and acute disease or acute infection were reviewed. Bibliographies were reviewed.Twenty-two studies including 1075 patients met the inclusion criteria. The sustained virologic response (SVR) rate for treated patients was 78%, significantly higher than 55.1% in untreated patients (OR = 3.08, 95% CI: 1.8-4.8 P value <0.0001). Mean time from diagnosis to spontaneous clearance was 9.7 weeks (SD 6.5). SVR rates varied inversely with time from acute HCV diagnosis. SVR rates for treatment within 12 weeks was 82.5% (95% CI: 75.6-89.3), significantly better than the clearance rates in untreated patients (P < 0.001). Response rates fell to 66.9% for treatment between 12 and 24 weeks, and decreased further to 62.5% for treatment beyond 24 weeks. Rates of viral clearance in treated patients with acute hepatitis C virus infection were significantly higher than that in untreated patients. Treatment rates were highest when treatment was initiated within 12 weeks of diagnosis. Based on these findings, we would advocate a 12 week period of observation for spontaneous clearance before treatment initiation. If no clearance has occurred by 12 weeks, treatment should be initiated.

Improving the diagnosis of acute hepatitis C virus infection with expanded viral load criteria

BACKGROUND

The diagnosis of acute hepatitis C virus (HCV) infection is imprecise because antibody testing does not differentiate between acute and chronic infection. Although virologic features, such as viral load fluctuations and low levels of viremia, have been noted to be characteristic of acute HCV infection, these parameters have not been used for diagnosis.

METHODS

We validated the use of these novel parameters (ie, viral load fluctuations >1 log and HCV RNA levels <100,000 IU/mL) in a cohort of acute HCV seroconverters. We then applied standard diagnostic criteria for acute HCV infection in a cohort of high-risk injection drug users entering prison with suspected acute HCV infection (n=37). We subsequently assessed whether these novel virologic parameters, measured serially over a 10-week period, could enhance the diagnosis of acute infection.

RESULTS

Low-level viremia and viral load fluctuations were highly prevalent in our cohort of acute seroconverters (81% and 86%, respectively), whereas low-level viremia occurred in only 13% of control patients with chronic infection. With use of standard criteria, 37 inmates received a diagnosis of acute HCV infection. Among the 35 patients with HCV RNA detectable at baseline, we found low-level viremia to be highly prevalent (n=27; 77%); among patients with a minimum of 2 HCV RNA samples, we demonstrated viral fluctuations in more than one-third (n=9; 36%).

CONCLUSIONS

The diagnosis of acute infection in HCV-seropositive patients is strengthened by the use of virologic parameters that are uncommon in chronic disease. Viral load fluctuations and low levels of HCV RNA should be incorporated into standard diagnostic criteria.

Immune suppression leading to hepatitis C virus re-emergence after sustained virological response

Sustained virological response SVR is defined as undetectable HCV RNA in plasma 6 months after therapy has been discontinued. Relapse or re-emergence of viremia after SVR is rare. We report two patients that relapsed when immune suppressive therapy was given within a few weeks of achieving SVR. Patient 1 received prednisone for bronchitis and patient 2 relapsed soon after immune suppression was started post renal transplantation. These data suggest that the early phase of SVR might be associated with incomplete protective immunity. They suggest that sterilizing immunity with complete elimination of virus is unlikely. The cases also caution against the use of immune suppressive therapy in the immediate aftermath of SVR.

Acute hepatitis C: a systematic review

INTRODUCTION

The annual incidence of acute hepatitis C virus (HCV) has fallen in recent years, primarily because of effective blood screening efforts and increased education on the dangers of needle sharing. However, hepatitis C infection is still relatively frequent in certain populations. Most patients infected with HCV are unaware of their exposure and remain asymptomatic during the initial stages of the infection, making early diagnosis during the acute phase (first 6 months after infection) unlikely. While some of those infections will have a spontaneous resolution, the majority will progress to chronic HCV. We scanned the literature for predictors of spontaneous resolution and treatment during the acute stage of HCV to identify factors that would assist in treatment decision making.

METHODS

A medical literature search through MEDLINE was conducted using the keyword "acute hepatitis C" with a variety of keywords focused on (a) epidemiology, (b) natural history and outcome, (c) diagnosis, (d) mode of transmission, and (e) treatment.

RESULTS

There are no reliable predictors for spontaneous resolution of HCV infection and a significant percentage of individuals exposed to HCV develop persistent infections that progress to chronic liver disease. An intriguing approach is to treat acute HCV and prevent the development of chronic hepatitis. Several clinical trials showed that treatment of hepatitis C infection during the acute phase is associated with high sustained virological response (SVR) rates ranging between 75% and 100%. Although there is a prevailing consensus that intervention during the acute phase is associated with improved viral eradication, relevant clinical questions have remained unanswered by clinical trials. Optimization of therapy for acute hepatitis C infection and identification of predictors of SVR represent a real challenge.

CONCLUSION

With more than 170 million chronic hepatitis C patients worldwide and an increase in the related morbidity and mortality projected for the next decade, an improvement in our ability to diagnose and treat patients with acute hepatitis C would have a significant impact on the prevalence of chronic hepatitis and its associated complications particularly in countries with a high endemic background of the infection.

Acute hepatitis C: Prospects and challenges

More than 170 million people worldwide have chronic hepatitis C. Acute hepatitis C is rarely diagnosed because it is commonly asymptomatic. Most infected patients are unaware of their condition until the symptoms of chronic infection manifest. Treatment of acute hepatitis C is something of a paradox because spontaneous resolution is possible and many patients do not have symptoms. However, several factors provide a rationale for treating patients who have acute hepatitis C. Compared with acute hepatitis C, chronic hepatitis C is associated with a worse prognosis, the need for more intensive treatment, longer treatment duration, and a decrease in successful treatment outcomes. Conversely, early intervention is associated with improved viral eradication, using a regimen that is better tolerated, less expensive, more convenient, and of shorter duration than the currently approved combination therapies for chronic hepatitis C.

Medical management of HIV-hepatitis C virus coinfection in injection drug users

Several million people inject drugs of abuse and, as a result, are coinfected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV). The treatment of this coinfected drug-abusing population is fraught with many problems such that clinicians and other health care providers have to determine whether patients should be treated first for drug addiction, for HIV/AIDS, or for HCV infection or simultaneously treated. These proceedings present the incidence and prevalence of coinfections with HIV and HCV in high-risk populations and discuss the underlying pathophysiology of coinfections and the problems and strategies of managing the treatment of coinfections among people who also inject illicit drugs. In addition, the expert panel recommended further research to determine the best possible treatment regimens applicable to injection drug users coinfected with HIV and HCV.

Oligonucleotide-Based Therapeutic Options against Hepatitis C Virus Infection

The hepatitis C virus (HCV) is the cause of a silent pandemic that, due to the chronic nature of the disease and the absence of curative therapy, continues to claim an ever-increasing number of lives. Current antiviral regimens have proven largely unsatisfactory for patients with HCV drug-resistant genotypes. It is therefore important to explore alternative therapeutic stratagems whose mode of action allows them to bypass viral resistance. Antisense oligonucleotides, ribozymes, small interfering RNAs, aptamers and deoxyribozymes constitute classes of oligonucleotide-based compounds designed to target highly conserved or functionally crucial regions contained within the HCV genome. The therapeutic expectation for such compounds is the elimination of HCV from infected individuals. Progress in oligonucleotide-based HCV antivirals towards clinical application depends on development of nucleotide designs that bolster efficacy while minimizing toxicity, improvement in liver-targeting delivery systems, and refinement of small-animal models for preclinical testing.