Serum Hepatitis C Virus RNA Concentration Research Articles

Virological response after 6 week triple-drug regimens for hepatitis C: a proof-of-concept phase 2A cohort study

Direct-acting antiviral drugs have a high cure rate and favourable tolerability for patients with hepatitis C virus (HCV). Shorter courses could improve affordability and adherence. Sofosbuvir and ledipasvir with ribavirin have high efficacy when taken for 8 weeks but not for 6 weeks. We assessed whether the addition of a third direct-acting antiviral drug to sofosbuvir and ledipasvir would allow a shorter treatment duration. In this single-centre, open-label, phase 2A trial, we sequentially enrolled treatment-naive patients with HCV genotype 1 infection into three treatment groups: 12 weeks of sofosbuvir and ledipasvir; 6 weeks of sofosbuvir, ledipasvir, and GS-9669; or 6 weeks of sofosbuvir, ledipasvir, and GS-9451. Patients and investigators were not masked to treatment assignment. The primary endpoint was the propotion of patients with sustained viral response at 12 weeks after treatment completion (SVR12), assessed by serum HCV RNA concentrations lower than 43 IU/mL (the lower limit of quantification). We did an intention-to-treat analysis for the primary endpoint and adverse events. This study is registered with ClinicalTrials.gov, number NCT01805882. Between Jan 11, 2013, and Dec 17, 2013, we enrolled 60 patients, and sequentially assigned them into three groups of 20. We noted an SVR12 in all 20 patients (100%, 95% CI 83-100) allocated to sofosbuvir and ledipasvir for 12 weeks; in 19 (95%, 75-100) of the 20 patients allocated to sofosbuvir, ledipasvir, and GS-9669 for 6 weeks (one patient relapsed 2 weeks after completion of treatment); and in 19 (95%, 75-100%) of the 20 patients allocated to sofosbuvir, ledipasvir, and GS-9451 for 6 weeks (one patient was lost to follow-up after reaching sustained viral response at 4 weeks). Most adverse events were mild and no patients discontinued treatment. Two serious adverse events occurred (pain after a post-treatment liver biopsy and vertigo), both unrelated to study drugs. In this small proof-of-concept study, two different three-drug regimens that were given for 6 weeks resulted in high cure rates for HCV infection with excellent tolerability. Addition of a third potent direct-acting antiviral drug can reduce the duration of treatment required to achieve sustained viral response in patients with chronic HCV genotype 1 infection without cirrhosis. National Institute of Allergy and Infectious Diseases (NIAID), National Cancer Institute and Clinical Center Intramural Program, German Research Foundation, National Institutes of Health, Gilead Sciences.

Sustained eradication of hepatitis C virus by low-dose long-term interferon therapy in a renal transplant recipient with dual infection with hepatitis B and C viruses: a case report

IntroductionAccelerated liver function deterioration has been recognized in renal transplant recipients infected with hepatitis C virus (HCV). Although combination therapy with interferon plus ribavirin has been established as the standard treatment for patients with chronic HCV, the high risk of allograft rejection associated with interferon therapy has greatly discouraged the clinical use of this regimen. In Asia, where chronic hepatitis B virus (HBV) is prevalent, dual infection with HBV and HCV poses an even greater challenge for clinical hepatologists.Case presentationIn this article, we report the case of a 51-year-old Taiwanese man with dual infection with HBV and HCV prior to renal transplantation. Low-dose interferon (3 to 6 × 106 U/week) and ribavirin (100 mg/day to 200 mg/day) were prescribed following the reactivation of the man's HCV after renal transplantation. Additionally, lamivudine (100 mg/day) was administered concomitantly to prevent HBV reactivation. His initial serum HCV RNA concentration was 5.2 × 106 copies/mL (genotype 2a). After three and one-half years of antiviral therapy, his HCV was successfully eradicated without any episodes of allograft rejection. His serum HCV RNA remained negative six months after withdrawal from interferon and ribavirin treatment. His serum HBV DNA remained undetectable throughout the course of therapy.ConclusionLow-dose, long-term interferon therapy may achieve sustained eradication of HCV in the renal transplant recipient with dual infection with HBV and HCV.

Serum HCV-RNA levels in patients with chronic hepatitis C: Correlation with histological features.

Liver disease in chronic hepatitis C virus (HCV) infection ranges from minimal lesion to liver cirrhosis and sometimes eventually evolving hepatocellular carcinoma. Whether and how HCV determines the different clinical and histological manifestation of the disease is not fully understood. It has not been clearly elucidated whether the extent of liver injury induced by HCV is influenced mainly by direct cytopathic damage or by an immune-mediated response against HCV-infected hepatocytes. The aim of this study is to verify whether the amount of virus in individual patient's serum could be related to the severity of liver injury. This study was carried out in the Gastroenterology and Hepatology Teaching Hospital, Medical City, Baghdad. Serum levels of HCV-RNA were measured in 27 patients with chronic HCV using b-DNA assay. Core liver biopsies of the patients were evaluated according to Ishak histological activity index system. The serum HCV RNA concentrations in the patients ranged from 3.2×10(3) to 1.2×10(7)copies/ml. In all patients no correlation was observed between the variable levels of viraemia and the age of the patients. Furthermore no correlations were observed between the serum HCV RNA concentrations and the biochemical liver function test levels: Total serum bilirubin, AST, ALT, and alkaline phosphatase. Histologically; patients were categorized into four subgroups: four patients (14.8%) had minimal activity, 17 patients (63%) had mild activity, and six patients (22.2%) had moderate activity. No significant correlation was found between viraemic levels and these histological findings or their individual components: Interface hepatitis, confluent necrosis, intralobular liver cell necrosis and portal inflammation. According to the stage of the fibrosis, the patients were categorized into seven subgroups: one patient (3.7%) with stage zero, seven patients with stage one (25.9%), four patients with stage two (14.9%), eight patients with stage three (29.6%), three patients with stage four (11.1%), two patients with stage five (7.4%), and two patients in cirrhotic stage six (7.4%). There was no correlation between the serum HCV RNA concentration and the stage of fibrosis. Hepatic steatosis was observed in 16/27 patients. It was mild in nine patients, moderate in five patients, and severe in two patients. Correlation has not been observed between the serum HCV RNA viraemic level and the severity of steatosis. Serum HCV-RNA level does not determine the degree of hepatic injury precisely and liver biopsy is necessary to accurately evaluate the extent of liver damage.

Occult hepatitis C: How convincing are the current data?

Occult hepatitis C: How convincing are the current data?

Early virologic response after peginterferon alpha‐2a plus ribavirin or peginterferon alpha‐2b plus ribavirin treatment in patients with chronic hepatitis C*

Patients infected with hepatitis C virus (HCV) genotype 1 and with serum HCV RNA concentrations over 800 000 IU/mL have relatively low rates of virologic response to pegylated interferons. The 2 forms of pegylated interferon have different pharmacokinetic profiles, and pilot studies comparing them have yielded varying results. We compared the virologic response to 12 weeks of treatment with peginterferon alpha-2a plus ribavirin vs peginterferon alpha-2b plus ribavirin in 380 patients who were infected with HCV genotype 1 and had high viral loads. We observed no between-group differences in viral load reduction over time and no differences in the percentage of patients treated with peginterferon alpha-2a or peginterferon alpha-2b plus ribavirin who achieved early virologic response (EVR), defined as >/=2-log reduction in HCV RNA concentration or undetectable HCV RNA at 12 weeks (66%vs 63%). Serum levels of interferon were more frequently below the level of quantitation in patients treated with peginterferon alpha-2b plus ribavirin (58-68%) than in those treated with peginterferon alpha-2a plus ribavirin (1-2%). Patients treated with peginterferon alpha-2b plus ribavirin had higher rates of discontinuation for safety reasons (6%vs 1%). In conclusion, a substantial percentage of patients infected with HCV genotype 1 and high viral load can achieve EVR when treated with peginterferon and ribavirin. The 2 pegylated interferons showed comparable anti-HCV activity during the first 12 weeks of treatment when combined with the same doses of ribavirin (1000-1200 mg/day), but discontinuations for safety reasons were higher in the patients treated with peginterferon alpha-2b plus ribavirin.

Therapy for treatment-refractory chronic hepatitis C virus genotype 1b infection: A retrospective analysis

Background: The most effective current therapy for hepatitis C virus (HCV) infection is the combination of pegylated interferon (peg-IFN) plus ribavirin (RBV). Objective: The aim of this retrospective analysis was to determine the rateof response to this therapy, and the factors affecting outcome, in patients with treatment-refractory chronic HCV genotype l b. Methods: The records of patients with chronic HCV infection and HCV geno-type1b who failed (nonresponse or relapse) previous treatment with standard interferon (IFN) + RSV were retrospectively analyzed for demographic data, virologic load, liver histology, biochemistry, treatment-related adverse effects (AEs), and the effects of dose reduction during treatment with peg-IFN + RBV for 48 weeks. Early virologic response (EVR) was defined as ≥2-log (copies/mL) decrease from baseline in serum HCV RNA concentration or the absence of detectable serum HCV RNA at treatment week 12. End-of-treatment response (ETR) was defined as the absence of detectable serum HCV RNA at treatment week 48. Sustained virologic response (SVR) was defined as the absence of detectable serum HCV RNA 24 weeks after treatment was discontinued. Factors affecting treatment outcome were determined using correlation analyses. Results: Data from the files of 17 patients (12 men, 5 women; mean [SD] age, 48 [2] years) were analyzed. EVR was achieved in 7 patients; however, viral breakthrough occurred in 2 of these patients during the treatment period, and 5 of these patients discontinued treatment because of severe treatment-related AEs (depression [1 patient] and neutropenia [4]). Seven patients achieved ETR, but HCV infection relapsed during the follow-up period. Three (18%) patients achieved SVR. Data concerning previous patterns of response to IFN + RBV therapy were available in 10 patients. Of these, 3 of 6 patients who had experienced relapse with the previous treatment achieved SVR with peg-IFN + RBV; neither of the 2 patients with nonresponse to the previous treatment achieved SVR. Major determinants of failure to reach SVR in these patients included previous nonresponder pattern, noncompliance with the therapy, and advanced-stage liver fibrosis. Tolerability was similar to that with the previous treatment. Conclusions: In this study in patients with chronic HCV genotype lb infectionand a history of relapse or nonresponse to standard IFN + RSV treatment, treatment with peg-IFN + RBV achieved an SVR rate of 18%. Further research is needed to determine the role of peg-IFN + RBV in the re-treatment of HCV infection.

The Clinical Utility of Using Catrimox-14-Treated Whole Blood in Detecting Hepatitis C Virus RNA

Measuring hepatitis C virus (HCV) RNA in serum or plasma may underestimate the true HCV burden. Extracting viral RNA from whole blood (WB) with a cationic surfactant (Catrimox-14) has resulted in HCV RNA concentrations up to 1000-fold higher than from serum or plasma in some studies, but not others. We compared the Catrimox-14 WB assay with a standard serum assay. Seventy-two chronic HCV patients received 48 weeks of standard or pegylated interferon alpha-2b and ribavirin therapy. Catrimox-14-treated WB and corresponding serum samples were obtained at baseline and weeks 12, 24, 48 and 72. HCV RNA concentrations from WB and serum were quantified by a previously validated RT-PCR assay. Overall mean (+/- SD) baseline serum log10 HCV RNA concentration was 6.5 ((+/- 0.58) copies/ml. Out of 72 patients, 33 had no detectable virus at 72 weeks. Neither assay detected virus in these patients at 12 weeks and neither WB nor serum assays detected virus at end-of-treatment in the 10 patients who subsequently relapsed at 72 weeks. HCV RNA concentrations from WB and serum assays were linearly correlated (R2 = 0.73; P < 0.001), although mean serum HCV RNA concentrations were 0.5 log10, copies/ml higher in serum than in WB [6.0 (+/- 0.82) vs 5.5 ((+/- 0.84), respectively, P = 0.12]. Catrimox-14-treated WB assays detect changes in HCV RNA, but do not offer clinical advantage over a conventional serum RT-PCR based assay.

Effects of HAART on hepatitis C, hepatitis G, and TT virus in multiply coinfected HIV-positive patients with haemophilia.

In multiply coinfected human immunodeficiency virus (HIV)-positive patients, we investigated the effects of high-activity antiretroviral therapy (HAART) using HIV protease inhibitors on three other viruses: hepatitis C virus (HCV), hepatitis G virus (HGV), and TT virus (TTV). Viral concentrations were measured serially by polymerase chain reaction methods in five patients with quadruple infection (HIV, HCV, HGV, and TTV) and in two patients with triple infection (HIV, HCV, and HGV) before and during HAART. In addition, CD4+ cell counts and serum alanine aminotransferase (ALT) levels were measured serially. Generally we observed no difference in serum HCV RNA, HGV RNA, or TTV DNA concentrations between samples obtained before and after initiation of HAART, whereas HIV RNA concentration decreased and CD4 counts increased in most patients. However, two patients had markedly decreased concentrations of HCV RNA and HGV RNA, respectively, more than 12 months after beginning HAART. Normalization of serum ALT levels was observed in a patient with decline of HCV RNA concentrations. No interactions were observed among these four viruses. HAART had no apparent direct effects on HCV, HGV, or TTV. Further studies will be required to elucidate whether the restoration of immune status through suppression of HIV replication by HAART may affect HCV or HGV RNA concentrations.

Effects of storage and type of blood collection tubes on hepatitis C virus level in whole blood samples.

In this study, we compared serum hepatitis C virus (HCV) RNA concentrations with HCV RNA concentrations in whole blood collection tubes, including two different types of EDTA tubes and nucleic acid stabilization tubes (NASTs). We also investigated the impact of a processing delay on HCV RNA concentration in these tubes. In NASTs, the mean HCV RNA concentration was comparable to the mean serum HCV RNA concentration at "date zero." In EDTA tubes, mean baseline HCV RNA concentrations were higher. Storage at room temperature up to 96 h did not result in a decline of HCV RNA concentration in any of the whole blood collection tubes. In NASTs, HCV RNA concentrations remained stable during the whole study period, whereas a significant increase of HCV RNA was observed in both types of EDTA tubes at 96 h compared to date zero. We concluded that HCV RNA remains stable in NASTs at room temperature for at least 96 h, allowing greater flexibility in sample collection and transport.

Assessment of hepatitis C virus RNA and genotype from 6807 patients with chronic hepatitis C in the United States.

Hepatitis C virus (HCV) RNA status and HCV genotype have become important tools in the diagnosis and monitoring of therapy in chronic HCV infection. To establish a database with respect to HCV genotype and serum HCV RNA concentrations in chronic hepatitis C patients in the United States, we analysed 6807 chronic hepatitis C patients who had HCV RNA and HCV genotype tests conducted at a central laboratory. The HCV RNA concentration cut-off for the lower 25th percentile of this population (low titre) was 0.9 x 106 copies ml-1. The median HCV RNA concentration was 3.5 x 106 copies ml-1 and the cut-off for the upper 25th percentile (high titre) was 5 x 106 copies ml-1. Male patients had a median HCV RNA concentration of 3.9 x 106 copies ml-1, which was significantly higher than the median HCV RNA level for females (2.75 x 106 copies ml-1; P < 0.001). HCV genotype 1 was detected in 73% of patients; genotype 2 in 14%; genotype 3 in 8%; mixed genotype in 4%; and genotypes 4, 5 and 6 with a frequency of < 1%. Patients from the Northeast, Southeast and Midwest had significantly (P < 0.001) more infections with genotype 1 than patients from the Western and Southern regions. African-American patients were more likely to be infected with genotype 1 when compared with Caucasian, Hispanic or Asian Pacific Islanders (P < 0.001). Patients infected with HCV genotype 1 and mixed HCV genotypes had significantly higher serum HCV RNA concentrations when compared with HCV genotypes 2 and 3 (P < 0.001 for all comparisons).

Antiviral effect of human recombinant interleukin-12 in patients infected with hepatitis C virus

The heterogeneity of hepatitis C virus (HCV) is due to the continuous and high replication rate, the low fidelity of the RNA-dependent RNA polymerase, and the immune surveillance of the host. Interleukin-12 (IL-12) plays a central role in mounting an effective cellular immune response directed towards elimination of intracellular pathogens. The effect of IL-12 on hepatitis C viremia and the HCV quasispecies population is unknown. In this study, 12 patients (9 males, 3 females; mean age: 44 +/- 11 years), all virological non-responders to previous IFN-alpha treatment, received recombinant human IL-12 s.c. once weekly for 10 weeks stratified to three dose schedules (0.03 microg/kg, 0.1 microg/kg, and 0.5 microg/kg body weight, respectively). Fourteen IFN-alpha non-responders and 14 untreated patients served as age- and sex-matched controls. Serum HCV RNA concentrations and HCV quasispecies distribution were measured serially by quantitative reverse transcription - polymerase chain reaction and single strand conformation polymorphism analysis of the hypervariable region of the second envelope gene, respectively. Serum ALT and median HCV RNA levels before treatment (52.7 +/- 21.7 U/L; 2.6 x 10(6) copies/mL) showed no significant changes during IL-12 treatment (57.3 +/- 58.8 U/L and 3.2 x 10(6) copies/mL, 50.3 +/- 46.2 U/L and 3.1 x 10(6) copies/mL, and 46.8 +/- 35.3 U/L and 3.9 x 10(6) copies/mL at weeks 1, 4, and 10, respectively). Similar results were observed in 14 IFN-alpha non-responders and 14 untreated patients. However, changes in HCV quasispecies occurred in 10/12 (83%) and 9/14 (64%) patients treated with interleukin-12 and interferon-alpha, respectively, but only in 3/14 (21%) untreated subjects (P < 0.003 and P < 0.03). These results imply that interleukin-12 exerts only limited antiviral activity against certain HCV quasispecies in vivo.

Antiviral effect of human recombinant interleukin-12 in patients infected with hepatitis C virusPresented in part: 49th American Association for the Study of Liver Diseases meeting, Chicago, IL, 6–10 November 1998 (abstract # 1239)

The heterogeneity of hepatitis C virus (HCV) is due to the continuous and high replication rate, the low fidelity of the RNA-dependent RNA polymerase, and the immune surveillance of the host. Interleukin-12 (IL-12) plays a central role in mounting an effective cellular immune response directed towards elimination of intracellular pathogens. The effect of IL-12 on hepatitis C viremia and the HCV quasispecies population is unknown. In this study, 12 patients (9 males, 3 females; mean age: 44 ± 11 years), all virological non-responders to previous IFN-α treatment, received recombinant human IL-12 s.c. once weekly for 10 weeks stratified to three dose schedules (0.03 μg/kg, 0.1 μg/kg, and 0.5 μg/kg body weight, respectively). Fourteen IFN-α non-responders and 14 untreated patients served as age- and sex-matched controls. Serum HCV RNA concentrations and HCV quasispecies distribution were measured serially by quantitative reverse transcription - polymerase chain reaction and single strand conformation polymorphism analysis of the hypervariable region of the second envelope gene, respectively. Serum ALT and median HCV RNA levels before treatment (52.7 ± 21.7 U/L; 2.6 × 106 copies/mL) showed no significant changes during IL-12 treatment (57.3 ± 58.8 U/L and 3.2 × 106 copies/mL, 50.3 ± 46.2 U/L and 3.1 × 106 copies/mL, and 46.8 ± 35.3 U/L and 3.9 × 106 copies/mL at weeks 1, 4, and 10, respectively). Similar results were observed in 14 IFN-α non-responders and 14 untreated patients. However, changes in HCV quasispecies occurred in 10/12 (83%) and 9/14 (64%) patients treated with interleukin-12 and interferon-α, respectively, but only in 3/14 (21%) untreated subjects (P < 0.003 and P < 0.03). These results imply that interleukin-12 exerts only limited antiviral activity against certain HCV quasispecies in vivo. J. Med. Virol. 60:264–268, 2000. © 2000 Wiley-Liss, Inc.

Genetic heterogeneity of hypervariable region 1 of the hepatitis C virus (HCV) genome and sensitivity of HCV to alpha interferon therapy.

Hepatitis C virus (HCV) populations persist in vivo as a mixture of heterogeneous viruses called quasispecies. The relationship between the genetic heterogeneity of these variants and their responses to antiviral treatment remains to be elucidated. We have studied 26 virus strains to determine the influence of hypervariable region 1 (HVR-1) of the HCV genome on the effectiveness of alpha interferon (IFN-alpha) therapy. Following PCR amplification, we cloned and sequenced HVR-1. Pretreatment serum samples from 13 individuals with chronic hepatitis C whose virus was subsequently eradicated by treatment were compared with samples from 13 nonresponders matched according to the major factors known to influence the response, i.e., sex, genotype, and pretreatment serum HCV RNA concentration. The degree of virus variation was assessed by analyzing 20 clones per sample and by calculating nucleotide sequence entropy (complexity) and genetic distances (diversity). Types of mutational changes were also determined by calculating nonsynonymous substitutions per nonsynonymous site (K(a)) and synonymous substitutions per synonymous site (K(s)). The paired-comparison analysis of the nucleotide sequence entropy and genetic distance showed no statistical differences between responders and nonresponders. By contrast, nonsynonymous substitutions were more frequent than synonymous substitutions (P </= 0.05) in responders, but there was no significant difference in nonresponders. Nonsynonymous substitutions tended to be more frequent than synonymous substitutions in women (P = 0.06) but not in men. Nucleotide entropy and genetic distances were significantly related to serum RNA concentration (P </= 0.01). Our findings suggest that after controlling for the major determinants of interferon response, neither complexity nor diversity of the HVR-1 region is associated per se with virus eradication. Because a higher proportion of nonsynonymous substitutions than synonymous substitutions was found only in responders, host anti-HCV-specific immune response rather than viral factors may be playing an important role in the interferon response.

A randomized, double-blind, controlled trial of consensus interferon in the treatment of chinese patients with chronic hepatitis C

OBJECTIVE: Patients with chronic hepatitis C virus (HCV) infection have an increased risk of developing cirrhosis or hepatocellular carcinoma. Consensus interferon (CIFN) offers sustained clinical efficacy to patients studied in the Western countries. This randomized, double-blind, controlled trial in 75 Chinese patients with chronic hepatitis C compared treatment with CIFN or placebo to determine whether CIFN had efficacy and safety in Chinese patients similar to that in Western patients. METHODS: Patients were randomized to receive CIFN (3 μg or 9 μg ) or placebo given subcutaneously 3 times/wk for 24 wk, followed by 24 wk of observation. Efficacy was assessed by normalization of serum alanine transaminase (ALT) and clearance of serum HCV RNA concentrations to undetectable levels by reverse-transcription polymerase chain reaction. RESULTS: There was a greater benefit with CIFN 9 μg than with CIFN 3 μg or placebo. At the end of 24 wk of treatment, the ALT response was 64%, 38.5%, and 8.4% for the 9-μg, 3-μg, and placebo-treated groups, respectively. After an additional 24 wk of observation, sustained ALT responses were 44%, 23.1%, and 12.5% for the 9-μg, 3-μg, and placebo-treated groups, respectively. HCV RNA clearance at the end of treatment was 56%, 42.3%, and 4.2%; and after 24 wk of additional observation, 40%, 11.5%, and 0% for the 9-μg, 3-μg, and placebo-treated groups, respectively. There were no unexpected adverse reactions to CIFN. CONCLUSIONS: The results show that administration of CIFN subcutaneously at 9 μg 3 times a week is safe and can effectively reduce serum ALT and HCV RNA concentrations in Chinese patients with chronic hepatitis C.

Histological Damage in Chronic Hepatitis C Is Not Related to the Extent of Infection in the Liver

It has not been completely elucidated whether the liver injury induced by the hepatitis C virus (HCV) is due to direct cytopathic damage or to an immune-mediated response against HCV-infected hepatocytes. In this work, we have determined the percentage of HCV-infected hepatocytes, the histological activity index, and the viremia levels in chronically HCV-infected patients with different grades of liver injury to investigate any possible correlation between them. For that purpose, liver biopsies from 27 patients with HCV chronic hepatitis were analyzed by in situ hybridization. This technique revealed that the percentage of infected hepatocytes ranged from 0.04% to 83.6%. Regarding the viremia levels, HCV RNA concentration ranged from 1.8 x 10(3) to 1.4 x 10(6) genome copies/ml. A significant correlation (r = 0.54; P = 0.003) between the percentage of infected hepatocytes and the viremia levels was found. In contrast, no correlation was observed between the percentage of HCV-infected hepatocytes or the viremia levels and the histological activity index. In conclusion, we have shown that the HCV viremia reflects the extent of the infection in the liver and that the liver injury in chronic HCV infection is not directly related to either the number of infected hepatocytes or the serum HCV RNA concentration.

Hepatitis C: natural history, diagnosis, and management.

The virology, epidemiology, clinical spectrum, diagnosis, and management of hepatitis C are reviewed. Hepatitis C infection is responsible for most cases of chronic viral hepatitis in the United States and is the major reason for liver transplantation. Hepatitis C virus (HCV) is divided into six major genotypes, with type 1 being the most prevalent in the United States. Direct percutaneous exposure is the main route of HCV transmission. Diagnosis of the infection is made by HCV antibody testing or direct detection of HCV RNA in serum. Liver biopsy is recommended for evaluating disease severity before treatment is started. The currently approved treatment for patients with chronic hepatitis C who have elevated liver transaminases and compensated liver disease consists of interferon alfa alone or in combination with ribavirin. Rates of sustained biochemical and virological responses in the range of 20-40% have been reported for a 12-month regimen of interferon alfa. Combination therapy with ribavirin improves these rates. Response rates are lower in patients with HCV genotype 1, a serum HCV RNA concentration higher than 1 million copies/mL, and cirrhosis. In patients who relapse after an initial response to interferon alfa, retreatment with interferon alfa plus ribavirin or with a higher dosage of interferon alfa is recommended. New agents under development for use against hepatitis C include viral enzyme inhibitors, ribozymes and antisense oligonucleotides, and immunomodulators. Further research is needed to optimize existing strategies for treating hepatitis C and to develop new, more effective therapies. Ultimately, combination therapies may hold the key.

Acute hepatitis C virus structural gene sequences as predictors of persistent viremia: hypervariable region 1 as a decoy.

We hypothesized that hepatitis C virus (HCV) persistence is related to the sequence variability of putative envelope genes. This hypothesis was tested by characterizing quasispecies in specimens collected every six months from a cohort of acutely HCV-infected subjects (mean duration of specimen collection, 72 months after seroconversion). We evaluated 5 individuals who spontaneously cleared viremia and 10 individuals with persistent viremia by cloning 33 1-kb amplicons that spanned E1 and the 5' half of E2, including hypervariable region 1 (HVR1). To assess the quasispecies complexity and to detect variants for sequencing, the first PCR-positive sample was examined by using a previously described method that combines heteroduplex analysis and analysis of single-stranded conformational polymorphisms. The ratio of nonsynonymous to synonymous substitutions (dN/dS) within each sample was evaluated as an indicator of relative selective pressure. Amino acid sequences were analyzed for signature patterns, glycosylation signals, and charge. Quasispecies complexity was higher and E1 dN/dS ratios (selective pressure) were lower in those with persistent viremia; the association with persistence was strengthened by the presence of a combination of both characteristics. In contrast, a trend toward higher HVR1 dN/dS ratios was detected among those with persistent viremia. We did not detect any such association for factors that may affect complexity such as serum HCV RNA concentration. HVR1 had a lower positive charge in subjects with persistent viremia, although no consistent motifs were detected. Our data suggest that HCV persistence is associated with a complex quasispecies and immune response to HVR1.

Characteristics of patients with chronic infection due to hepatitis C virus of mixed subtype: prevalence, viral RNA concentrations, and response to interferon therapy.

We studied 349 patients with chronic infection due to hepatitis C virus (HCV), including 83 with coagulopathy, 122 with community-acquired infection, 20 with chronic posttransfusion hepatitis C, and 124 for whom the transmission mode was unknown. The prevalence of mixed-subtype HCV infection was investigated in each group of patients. The serum HCV RNA concentration and the response to interferon (IFN) therapy were evaluated. HCV infection with mixed subtypes was more frequent in patients who had been at high risk for exposure to HCV, such as those with coagulopathy or community-acquired infection. HCV RNA concentrations were lower in patients infected with mixed subtypes, except for those with subtypes 1a and 1b. Ten of 11 patients with mixed subtypes (not including those with 1a and 1b) achieved complete clearance of HCV RNA with IFN therapy.

Baseline level and early suppression of serum HCV RNA for predicting sustained complete response to alpha-interferon therapy.

The relationship between serum hepatitis C virus (HCV) RNA and the outcome of alpha-interferon (alpha-IFN) therapy in patients with chronic hepatitis C has important implications for therapeutic research and clinical care. Serum HCV RNA was tested for HCV genotype and quantified by a standardized reverse transcriptase-polymerase chain reaction assay as a measure of viral load in a cohort of 130 patients with chronic hepatitis C treated with alpha-IFN at a standard dose of 3 million units three times a week scheduled for 6 (n = 50) or 12 months (n = 76). Twenty-one of 126 evaluable patients (16.7%) developed a sustained complete response to alpha-IFN according to biochemical and virological criteria. The 3 pretreatment independent factors associated with a sustained complete response were a low baseline serum HCV RNA concentration, non-1 HCV genotype, and female sex. A multivariate logistic regression model, with pretreatment and month 1 variables, showed that a lower baseline serum HCV RNA concentration, female sex, and a greater suppression of RNA were the significant predictors of sustained complete response. The lowest baseline serum HCV RNA concentration was observed in patients with genotype 2 infection and the greatest decrease in HCV RNA from baseline to month 1 in those with genotype 3. The findings suggest that measuring HCV RNA in serum before and soon after beginning treatment can be helpful for selecting patients who are most likely to have a sustained complete response to standard schedule of alpha-IFN and for identifying patients in whom alternative strategies should be examined.

Treatment of chronic hepatitis C with consensus interferon: A multicenter, randomized, controlled trial

This multicenter, randomized, controlled, double-blind, phase III study in 704 patients with chronic hepatitis C infection compared treatment with consensus interferon (CIFN), a non-natural recombinant type-1 interferon, with a standard regimen of recombinant interferon alfa-2b (IFN-alpha2b). Patients were randomized to receive CIFN at doses of 3 microg or 9 microg, or 15 microg IFN-alpha2b (3 million units), subcutaneously three times weekly for 24 weeks, followed by 24 weeks of observation. Efficacy was assessed by normalization of serum alanine transaminase (ALT) concentration and decrease in serum hepatitis C virus (HCV) RNA concentration below the limit of detection by reverse- transcription polymerase chain reaction (RT-PCR) (100 copies/mL). The beneficial effect of CIFN was greater with the 9-microg dose than the 3- microg dose. The sustained ALT and HCV RNA response rates were 20.3% and 12.1%, respectively, in the 9-microg CIFN cohort and 19.6% and 11.3%, respectively, in the 15-microg IFN-alpha2b cohort. However, patients receiving 9 microg of CIFN had a greater reduction in serum HCV RNA concentrations compared with patients receiving 15 microg IFN- alpha2b over the course of treatment (P < .01). Similarly, analysis of patients infected with HCV genotype 1 showed a greater reduction in serum HCV RNA concentration over the course of treatment for the 9- microg CIFN group when compared with the 15-microg IFN-alpha2b group (P < .01). In addition, a greater percentage of patients infected with HCV genotype 1 treated with 9 microg CIFN had undetectable HCV RNA concentrations when compared with patients in the 15-microg IFN-alpha2b cohort at the end of treatment (24% vs. 15%; P = .04). Improvements in liver histology were noted in all three treatment groups; 52% to 55% of the patients in the three cohorts had at least a 2-unit improvement in the Knodell score at the end of the posttreatment period. The adverse- events profiles were characteristic of treatment with type-1 interferon, and the incidences of anti-interferon antibody formation did not significantly differ among the three treatment groups. These results show that administration of 9 microg CIFN three times weekly for 6 months is safe and is effective in reducing serum HCV RNA concentration. (Hepatology 1997 Sep;26(3):747-54)