Low Hepatitis C Virus RNA Research Articles

Chronic Hepatitis C.

Infection with hepatitis C virus (HCV) accounts for 40% of cases of chronic liver disease in the United States and is now the most common indication for liver transplantation. Estimates suggest that 4 million people (1.8%) of the American population are or have been infected with HCV. Currently, the treatment of choice for patients with chronic HCV infection is recombinant interferon alfa with ribavirin. Pegylated interferons are a promising new development, and in combination with ribavirin, they will rapidly become the standard of care. The goals of therapy are to slow disease progression, improve hepatic histology, reduce infectivity, and reduce the risk of hepatocellular carcinoma. Sustained virologic response, which generally implies the absence of viremia for 6 months or more following completion of therapy, is increasingly being regarded as a cure, with evidence of slowing or even regression of fibrosis on follow-up liver biopsy. A number of factors have been shown to be predictive of a sustained response, including viral genotype other than 1, low serum HCV RNA levels, absence of cirrhosis, younger age, female gender, and shorter duration of infection. Disease severity as assessed by liver biopsy, comorbidities, and possible contraindications to therapy should be weighed in the decision to begin treatment. Counseling patients regarding transmission, natural history, and drug and alcohol abstinence also should be included in management. Close monitoring should be done during treatment for side effects of interferon, including depression and bone marrow suppression. Hemolytic anemia is the major side effect of ribavirin.

Hepatitis C virus genotypes in a non-cirrhotic Italian population with chronic hepatitis C: correlation with clinical, virological and histological parameters. Results of a prospective multicentre study.

To identify correlations between the distribution of hepatitis C virus (HCV) genotypes and demographic, pathological and virological parameters of HCV-infected patients, we prospectively recruited 650 patients with biopsy-proven chronic hepatitis C without histological aspects of cirrhosis; none had been treated with antiviral therapy. Data regarding gender, age, mode of HCV transmission, alanine aminotransferase (ALT) and HCV RNA levels, immunoglobulin M (IgM) anticore values, liver histology and histological activity were obtained from each patient and correlated on multivariate analysis with infecting HCV genotype. Fifty-five per cent of the patients were infected with HCV genotype 1, 20% with HCV genotype 2, 18% with HCV genotype 3 and 7% with HCV genotype 4. Non-transfusional HCV transmission, low ALT levels, IgM anticore reactivity and a low histological grading score were independent variables associated with HCV genotype 1. Older age, female gender, post-transfusional transmission and a high histological grading score were related to HCV genotype 2, whilst younger age, history of current/previous drug abuse, high ALT values, low IgM anticore reactivity and high viraemic levels were associated with HCV genotype 3. History of illicit use of intravenous drugs and low HCV RNA levels were the only independent variables correlated with HCV genotype 4. Genotype 1 remains predominant in Italy but the prevalence of HCV genotypes is changing in relation to age and mode of transmission: Italian patients with HCV genotype 3 are younger and exhibit higher levels of ALT and HCV RNA than patients with other genotypes.

Changes in hepatitis C virus RNA viremia concentrations in long-term renal transplant patients after introduction of mycophenolate mofetil.

Mycophenolate mofetil (MMF) is a potent immunosuppressive agent and might inhibit chronic rejection, at least in primates. The prevalence of chronic hepatitis C virus (HCV) infection is high in renal transplant (RT) patients. To date, it has not been demonstrated whether MMF has any effect upon HCV viremia. Fourteen long-term HCV(+) RT patients with chronic allograft dysfunction whose maintenance immunosuppression was based on cyclosporine, were given MMF therapy either in place of azathioprine (n=11) or in addition to baseline therapy (n=3). HCV viremia levels were measured by the Amplicor HCV-Monitor RT-PCR assay (Roche Diagnostic Systems) on two separate occasions before the introduction of MMF, and 1 year after changing to MMF or at the last follow-up visit. MMF therapy was associated with a significant rise in HCV viremia, i.e., 5.8+/-0.5 vs. 5.2+/-0.7 log copies/ml (P=0.01), although there were no significant changes in liver enzymes. The increase in HCV viremia was not related to HCV genotypes either. At the patient level, HCV RNA concentrations changed in only seven patients (group B), i.e. >1 log copies/ml, whereas it remained stable in the others (group A). Before conversion, the only significant difference between group A and B was the level of HCV RNA, i.e., 5.5+/-0.4 log copies/ml in group A and 4.9+/-0.7 log copies/ml in group B (P=0.05). Our study suggests that MMF should be used with caution in stable HCV RT patients whose maintenance immunosuppressive therapy is based on cyclosporine, at least in the case of patients with a low HCV RNA titer.

Low Levels of Hepatitis C Virus RNA in Serum, Plasma, and Peripheral Blood Mononuclear Cells of Injecting Drug Users During Long Antibody-Undetectable Periods Before Seroconversion

Screening of antibodies to hepatitis C virus (HCV) is widely used for monitoring the prevalence of HCV infections and to assess HCV infectivity. Among HCV-infected individuals in the general population, the interval between the detection of HCV RNA and the development of HCV antibodies is usually 5 to 6 weeks, but in rare cases, seroconversion may be prolonged up to 6 to 9 months. In this study, we tested for the presence of HCV RNA during the antibody-undetectable period of 19 drug-injecting HCV seroconverters to gain insight into the antibody-negative carrier status in this population. HCV seroconversion status was determined by testing the first and last serum samples obtained from each subject, using third-generation antibody screening and confirmation assays. Serial samples were tested for HCV-specific antibodies to establish the moment of seroconversion and HCV RNA by single reverse transcriptase-polymerase chain reaction (RT-PCR) and branched DNA assay (bDNA) in serum. Plasma and peripheral blood mononuclear cells (PBMCs) were independently collected and tested for HCV RNA. HCV RNA-positivity was confirmed by Southern blot hybridization and sequencing of serial samples. The 19 HCV seroconverters had a mean follow-up of 5 years (range, 1 to 8 years). Of the 19, 4 were human immunodeficiency virus (HIV)-infected before HCV seroconversion. HCV RNA was detected in serum before seroconversion in 12 (63.2%) of the 19 HCV seroconverters, independent of HIV status. In 7 of these 12, the antibody-undetectable period was relatively short (2 to 10 months). The other 5, who were all HIV-negative before HCV seroconversion, had intermittent low levels of HCV RNA before seroconversion for a period of more than 12 months, with a mean of 40.8 months (range, 13 to 94 months). In all 5 individuals, independent repeats of the experiments confirmed the presence of HCV RNA in serum, and in 3 of these individuals, HCV-positivity was confirmed in independently collected plasma and PBMC samples. Low levels of HCV RNA may be present during prolonged antibody-undetectable periods before seroconversion in a number of injecting drug users. Independent of HIV status, their immune system appears to be unable to respond to these low HCV RNA levels and was sometimes only activated after reinfections with distinct HCV genotypes. These results indicate that primary HCV infection may not always elicit the rapid emergence of HCV antibodies and suggests that persistent low levels of HCV RNA (regardless of the genotype) may not elicit at all or delay antibody responses for prolonged periods of time.

Low Levels of Hepatitis C Virus RNA in Serum, Plasma, and Peripheral Blood Mononuclear Cells of Injecting Drug Users During Long Antibody-Undetectable Periods Before Seroconversion

AbstractScreening of antibodies to hepatitis C virus (HCV) is widely used for monitoring the prevalence of HCV infections and to assess HCV infectivity. Among HCV-infected individuals in the general population, the interval between the detection of HCV RNA and the development of HCV antibodies is usually 5 to 6 weeks, but in rare cases, seroconversion may be prolonged up to 6 to 9 months. In this study, we tested for the presence of HCV RNA during the antibody-undetectable period of 19 drug-injecting HCV seroconverters to gain insight into the antibody-negative carrier status in this population. HCV seroconversion status was determined by testing the first and last serum samples obtained from each subject, using third-generation antibody screening and confirmation assays. Serial samples were tested for HCV-specific antibodies to establish the moment of seroconversion and HCV RNA by single reverse transcriptase-polymerase chain reaction (RT-PCR) and branched DNA assay (bDNA) in serum. Plasma and peripheral blood mononuclear cells (PBMCs) were independently collected and tested for HCV RNA. HCV RNA-positivity was confirmed by Southern blot hybridization and sequencing of serial samples. The 19 HCV seroconverters had a mean follow-up of 5 years (range, 1 to 8 years). Of the 19, 4 were human immunodeficiency virus (HIV)-infected before HCV seroconversion. HCV RNA was detected in serum before seroconversion in 12 (63.2%) of the 19 HCV seroconverters, independent of HIV status. In 7 of these 12, the antibody-undetectable period was relatively short (2 to 10 months). The other 5, who were all HIV-negative before HCV seroconversion, had intermittent low levels of HCV RNA before seroconversion for a period of more than 12 months, with a mean of 40.8 months (range, 13 to 94 months). In all 5 individuals, independent repeats of the experiments confirmed the presence of HCV RNA in serum, and in 3 of these individuals, HCV-positivity was confirmed in independently collected plasma and PBMC samples. Low levels of HCV RNA may be present during prolonged antibody-undetectable periods before seroconversion in a number of injecting drug users. Independent of HIV status, their immune system appears to be unable to respond to these low HCV RNA levels and was sometimes only activated after reinfections with distinct HCV genotypes. These results indicate that primary HCV infection may not always elicit the rapid emergence of HCV antibodies and suggests that persistent low levels of HCV RNA (regardless of the genotype) may not elicit at all or delay antibody responses for prolonged periods of time.

Discordance between serum alanine aminotransferase (ALT) and virologic response to IFN-alpha2b in chronic hepatitis C patients with high and low pretreatment serum hepatitis C virus RNA titers.

Although serum alanine aminotransferase (ALT) and hepatitis C virus (HCV) RNA concentrations are primary markers used to assess the clinical benefit of interferon (IFN) therapy in patients with chronic HCV infection, discrepancies between these two variables exist. In this study, 103 patients with chronic hepatitis C were treated with 3 MIU IFN-alpha2b three times weekly for 24 weeks, followed by 24 weeks of observation. ALT and virologic responses were compared in patients with high pretreatment HCV RNA titers (defined as pretreatment HCV RNA concentrations at or above the 75th percentile of the distribution or >5,000,000 copies/ml) and low pretreatment HCV RNA titers (defined as pretreatment concentrations below the 75th percentile or < or =5,000,000 copies/ml). Analysis of the virologic response for the high-titer and low-titer groups demonstrated a significantly greater HCV RNA sustained response in the low-titer group (21%) compared with the high-titer group (7%) (p < 0.05). In contrast, the ALT sustained response was not significantly different between the low-titer group (21%) and the high-titer group (18%). Analysis of the correspondence between biochemical and virologic responses showed that only 38% of patients with high pretreatment HCV RNA titers had both a sustained ALT response and a sustained loss of HCV RNA compared with 75% of patients with low pretreatment HCV RNA titers. The level of agreement between the ALT and HCV RNA responses was greater for the low-titer group compared with the high-titer group (kappa = .6848 and kappa = .4966, respectively). Our results indicate that chronic HCV patients with high pretreatment HCV RNA titers showed greater discordance between sustained ALT and HCV RNA responses compared with patients with low pretreatment HCV RNA titers and that measurement of HCV RNA should be included in the assessment of response to IFN therapy in chronic hepatitis C patients.

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.

Interferon treatment for hepatitis C virus infection in patients on haemodialysis.

This study examined the efficacy and tolerability of interferon alpha-2b (IFN) in the treatment of chronic hepatitis C virus (HCV) infection in patients on maintenance haemodialysis. A 24-month prospective cohort study was performed in 11 HCV RNA-positive haemodialysis patients, who were treated with IFN at 3 MU thrice weekly for 6 months. Serial biochemical and virological monitors included serum alanine aminotransferase levels, and HCV RNA by both qualitative PCR assay and quantitative bDNA assay. HCV genotypes were determined by PCR and nucleotide sequencing. Ten patients had baseline liver biopsy. HCV genotypes 1b and 2b were identified in 10 and one patients respectively. Six (55%) patients had biochemical and/or histological features of chronic active hepatitis before treatment. All 11 patients became HCV RNA-negative by PCR, with normalization of deranged aminotransferase levels, within 2-8 weeks of IFN therapy. HCV RNA reappeared in eight (73%) patients 2-8 weeks after the cessation of IFN, while biochemical relapse occurred in six (55%) patients. Sustained eradication of HCV was achieved in three (27%) patients. Sustained responders were characterized by pretreatment HCV RNA level < 3.5 x 10(5) Eq/ml as determined by the bDNA assay, and less severe histological abnormalities ('Total score' 1.7 +/- 1.2 compared to 5.4 +/- 2.2 in relapsers, P < 0.05). HCV RNA levels were similar before and after IFN treatment in non-responders and relapsers. Persistent malaise and poor appetite were noted in eight (73%) patients during IFN therapy. Other side-effects of IFN included the exacerbation of anaemia, induction of resistance to erythropoietin, weight loss, and reduced serum albumin level. Eradication of chronic HCV infection with IFN can be achieved in 27% of haemodialysis patients. Predictors of sustained response include low baseline HCV RNA level and mild liver pathology. Virological relapse can occur despite normal liver biochemistry. Exacerbation of anaemia, erythropoietin resistance, and malnutrition constitute the side-effects of IFN that deserve special attention in uraemic subjects.

Performance of the automated COBAS AMPLICOR ™ system for the detection of hepatitis C virus RNA

Background: The COBAS AMPLICOR ™ (CA) instrument for the amplification and detection steps of the AMPLICOR ™ molecular diagnostic assays has recently been introduced. The system contains a single thermal cycler with two independently controlled heating/cooling blocks, a pipettor, a magnetic particle washer, a photometer and an incubator. Objective: The performance of the CA instrument was evaluated in a routine diagnostic laboratory for the detection of hepatitis C virus (HCV) RNA. The new system was compared with the corresponding microwell plate assay (AMPLICOR HCV Test). Study design: Routine clinical sera (350) from hemodialysis patients and patients with chronic HCV infection and interferon therapy were studied. If discrepant results were obtained, both assays were repeated (specimen preparation, amplification and detection); in addition, the HCV copy number was determined with the AMPLICOR HCV MONITOR ™ Test. Results: There was a correlation between the CA HCV Test and the AMPLICOR HCV Test in 341 of 350 specimens (97%). After resolution of 9 discrepant results, the CA HCV Test gave a sensitivity of 97.8% and a specificity of 99.4%. The most common reason for discrepant results was a low HCV RNA copy number. Conclusion: The CA system was found to be a labor-saving, fast and reliable instrument for the amplification and detection steps of a RT-PCR molecular assay for detection of HCV RNA.

Pretreatment serum hepatitis C virus RNA levels and hepatitis C virus genotype are the main and independent prognostic factors of sustained response to interferon alfa therapy in chronic hepatitis C

The aim of the study was to determine the respective influence of pretreatment serum hepatitis C virus (HCV) RNA levels and HCV genotype on the response to interferon (IFN) alfa in patients with chronic hepatitis C. We retrospectively studied 141 patients with chronic hepatitis C included in two consecutive controlled trials of IFN alfa. A sustained response was observed in 28, a response followed by relapse in 43, and no response in 70 patients. Pretreatment serum HCV RNA quantitation with the branched DNA (bDNA) assay and HCV genotyping with reverse hybridization assay (LiPA) were performed in all patients. Seventy-four percent of the patients had detectable serum HCV RNA (43%, 77% and 84%) in the three groups of patients with sustained response, relapse, and no response, respectively (P = .005). Mean serum HCV RNA level were 1.4 +/- 6 x 10(6), 4.8 +/- 6 x 10(6), and 3.9 +/- 5 x 10(6) genomes/mL in patients with sustained response, response and relapse, and no response, respectively (P < .01). Genotype 1b was found in 7%, 47%, and 46% of the patients in the three response groups, respectively. By univariate analysis, age, source, and duration of HCV infection, serum HCV RNA levels, and HCV genotypes were significantly different in the three response groups. By multivariate analysis, the only independent factors associated with sustained response were low serum HCV RNA levels and HCV genotype other than 1b. Pretreatment serum HCV RNA levels and HCV genotype are the main and independent factors associated with sustained response to IFN therapy.

Pretreatment serum hepatitis C virus RNA levels and hepatitis C virus genotype are the main and independent prognostic factors of sustained response to interferon alfa therapy in chronic hepatitis C

The aim of the study was to determine the respective influence of pretreatment serum hepatitis C virus (HCV) RNA levels and HCV genotype on the response to interferon (IFN) alfa in patients with chronic hepatitis C. We retrospectively studied 141 patients with chronic hepatitis C included in two consecutive controlled trials of IFN alfa. A sustained response was observed in 28, a response followed by relapse in 43, and no response in 70 patients. Pretreatment serum HCV RNA quantitation with the branched DNA (bDNA) assay and HCV genotyping with reverse hybridization assay (LiPA) were performed in all patients. Seventy-four percent of the patients had detectable serum HCV RNA (43%, 77% and 84%) in the three groups of patients with sustained response, relapse, and no response, respectively ( P = .005). Mean serum HCV RNA level were 1.4 ± 6 x 10 6, 4.8 ± 6 x 10 6, and 3.9 ± 5 x 10 6 genomes/mL in patients with sustained response, response and relapse, and no response, respectively ( P < .01). Genotype lb was found in 7%, 47%, and 46% of the patients in the three response groups, respectively. By univariate analysis, age, source, and duration of HCV infection, serum HCV RNA levels, and HCV genotypes were significantly different in the three response groups. By multivariate analysis, the only independent factors associated with sustained response were low serum HCV RNA levels and HCV genotype other than lb. Pretreatment serum HCV RNA levels and HCV genotype are the main and independent factors associated with sustained response to IFN therapy.

Interferon therapy in chronic hepatitis C virus infection

Antiviral treatment of chronic hepatitis C with interferon is reviewed. Alpha-interferon, both recombinant alpha-2a, -2b and human lymphoblastoid interferon given at a dose of > or = 3MU t.i.w. for 6-12 months will result in normalisation of ALT levels (complete response) in some 50-60% of treated patients with chronic hepatitis C virus (HCV) infection. Approximately half of the complete responders to interferon will relapse within 6 months once treatment is withdrawn (non-sustained response). Longer treatment schedules (6 vs. 12 months) seem to diminish the relapse rate and increase the percentage of sustained response. In patients with sustained response to interferon treatment with continuously normal ALT levels > or = 6 months after treatment stop a concomitant eradication of the viraemia is usually seen, whereas a non-sustained or non-response to interferon usually will indicate a continuous viraemia. Factors predictive of a favourable response are low pretreatment HCV RNA levels in serum, genotypes other than type II according to Okamoto, short disease duration, female gender and less pronounced liver damage, whereas high serum HCV RNA levels, having genotype II and cirrhosis, are predictive of a less favourable response. Patients with a sustained response and eradication of the viraemia will also improve their liver inflammation with diminishing scores for portal inflammation, piecemeal necrosis, lobular inflammation and also fibrosis after treatment. For non-responders and non-sustained responders to interferon, ribavirin especially in combination with interferon will offer some hope for the future.

Serum hepatitis C virus RNA levels in chronic hepatitis C--importance for outcome of interferon alfa-2b treatment.

Sera from 39 out of 40 patients with chronic hepatitis C virus (HCV) infection who had been treated for 60 weeks with interferon alfa-2b proved initially HCV RNA positive by reversed transcriptase polymerase chain reaction (PCR). These patients were analysed for genotype and quantitatively for HCV RNA levels prior to treatment by using a competitive PCR method with colorimetric detection of the amplified products. HCV RNA levels were correlated to outcome of treatment, mode of acquisition, histology and HCV genotype. The median pretreatment HCV RNA level in sustained responders (n = 15) with eradication of the viremia and normalization of serum ALT levels lasting 24 weeks post treatment was significantly lower than that in the combined group of non-sustained responders (n = 9) and non-responders (n = 15), 2.52 x 10(5) vs 8.90 x 10(5) genome equivalents per ml serum, p < 0.0125, respectively. 10 out of 17 patients with HCV RNA levels lower than the median level (5.64 x 10(5) genome equivalents per ml serum) had a sustained response to interferon treatment versus only 5/22 with levels equal to or higher than the median level, p = 0.04. No significant pretreatment differences in median HCV RNA levels according to mode of acquisition, genotype, or liver histology prior to treatment were seen. It is concluded that a low pretreatment HCV RNA level seems to be indicative of a sustained response to interferon alfa-2b treatment, whereas a high level seems to be indicative of a non-sustained or non-response. In the individual patient, however, the levels varied widely irrespective of response category.