The changes in quantitative HCV RNA titers during interferon alpha 2B therapy in patients with chronic hepatitis C infection

Monitoring response during a randomised controlled trial of escalating interferon dose for chronic hepatitis C infection: predictive value of quantitative and qualitative HCV RNA assays

BACKGROUND

In chronic hepatitis C infection, raising the interferon dose in initial non-responders may increase the generally poor sustained response rates. Monitoring virological response is essential in this kind of individual patient based approach. Quantitative HCV RNA assays are increasingly used for this purpose. However, their additional value as compared to strictly qualitative HCV RNA assays should be evaluated before they are implemented as a routine measurement, since these assays are more expensive and time consuming than qualitative assays.

OBJECTIVES

Goals of this study were (1) to test the hypothesis that increasing interferon dose in initial non-responders results in permanent viral clearance in more patients and (2) evaluation of the predictive value of quantitative versus qualitative HCV RNA assays before and during treatment.

STUDY DESIGN

63 patients were treated in a randomised controlled trial of escalating interferon dose. In the standard treatment group patients received 6 MU alpha-2a thrice weekly for 3 months followed by 3 MU thrice weekly for 3 months. In the experimental group interferon dose was escalated at 6 weeks to 9 MU if HCV RNA was still detectable at 4 weeks. Predictors of response were analyzed at various time points before and during treatment and the predictive value of quantitative HCV RNA measurements was compared to that of qualitative HCV RNA assays.

RESULTS

No significant difference in sustained response rate was found between the treatment groups at the end of follow-up. At baseline, the strongest independent predictor for a sustained response was a viral load level below 10(6) copies/ml and age younger than 40 years. During treatment a negative HCV RNA status at week 4 was the strongest predictor of a sustained response. Viral load levels during treatment did not independently predict a sustained response.

CONCLUSIONS

While on treatment, qualitative HCV RNA assays should be used to monitor response.

Effects of immunosuppression and organ transplantation on the natural history and immunopathogenesis of hepatitis C virus infection

The hepatitis C virus (HCV) is recognized as the leading cause for parenterally transmitted hepatitis. It is characterized by a high propensity to chronicity. Several efforts have been directed towards understanding the natural history of chronic HCV infection and the immunopathogenic pathways involved in mediating liver injury in the non-immunosuppressed and immunosuppressed states. In the non-immunosuppressed setting, liver damage seems to be largely immune mediated. In contrast, in the non-immunosuppressed state, there are several other factors that may modify the natural course of the infection and play a role in mediating liver injury. In this review we will address the natural history, virological and immunological aspects of HCV infection. Also, the role played by immunosuppression and organ transplantation in modifying the course of the infection and the pathogenesis of liver injury will be discussed.

Viral hepatitis A, B, and C

Mankind probably has known viral hepatitis for many centuries; however, the major and most dramatic developments in our knowledge of these diseases have taken place during the second half of the 20th century. During this relatively short period of time, the infectious nature of hepatitis A, B, and C has been proven, leading to their identification and description. The advent of serologic markers has provided the means for establishing the diagnosis. Epidemiologic studies have provided important information that led to exciting achievements in detection and prevention of transmission. Molecular biology studies and cell culture techniques have established our knowledge of the viral genomes, and led to the development of specific vaccines for hepatitis A and B. Anti-viral therapy has been developed and aggressive combination therapy has emerged as a promising strategy for chronic hepatitis B and C. This article reviews some of the main fields of progress and achievement related to viral hepatitis A, B, and C in the 20th century.

Diagnostic tests for hepatitis C

Two categories of virological assays are in practice used for the diagnosis and management of hepatitis C virus (HCV) infection, including serological and molecular biology-based assays. Serological assays include: screening tests based on enzyme immunoassays (EIAs); supplemental "analytical" assays based on immunoblot testing; and serological assays detecting genotype-specific antibodies for the serological determination of HCV genotype, so-called "serotyping" assays. Molecular assays include: qualitative assays, detecting HCV RNA in body fluids; quantitative assays measuring HCV viral load, a parameter that estimates the level of HCV replication in the liver; and tests analyzing the sequence of HCV genomes (genotyping assays).

Analysis of the viability of freezer stored serum samples for hepatitis C virus RNA analysis by the SUPERQUANT method: results of a 16 year retrospective study

Prior to the discovery of the hepatitis C virus (HCV), virological analysis of serum from patients with non-A non-B hepatitis was not possible. Since the finding that HCV is the causative agent of most non-A non-B hepatitis, several reliable methodologies have been developed that allow for quantification of HCV RNA. To determine the viability of stored serum samples for HCV RNA analysis. 256 samples were examined for HCV RNA using a multi-cycle RT-PCR assay. All samples were stored unopened in a -70 degree C freezer until the time of testing. Collection years ranged from 1981 to 1995. To examine the integrity of stored serum samples, the distribution of quantitative HCV RNA values for each year was compared: year-to-year; and, to the distribution of HCV RNA concentrations from 1510 chronic HCV patients determined by the same assay in 1996 and 1997. Pairwise year-to-year analysis revealed that samples collected prior-to-and-including 1991 had significantly lower HCV RNA concentrations as compared to samples collected after 1991 (P < 0.001). Likewise, comparison of the stored samples to the 1510 fresh samples demonstrated that samples collected prior-to-and-including 1991 had significantly lower HCV RNA concentrations as compared to samples collected after 1991 (P < 0.001). The results demonstrate a method for determination of the integrity of stored serum samples from chronic HCV patients. The mechanism of RNA degradation is unknown but it is most likely to be due to poor sample collection procedures in place prior to 1991.

Viral hepatitis

Viral hepatitis is still one of the most common causes of acute and chronic liver disease worldwide. Major advances have been made in our knowledge of these diseases, many during the past year. Molecular biology and clinical studies have improved our understanding of the mechanisms of antiviral drugs, as well as viral resistance to therapy. The risks of hepatitis A in patients with chronic liver disease have been confirmed, and the efficacy of hepatitis A vaccines in these patients has been proven. Aggressive combination therapy has emerged as a promising strategy for chronic hepatitis B and C, and techniques for immune prophylaxis for hepatitis B are being improved. Liver transplantation has become routine for end-stage hepatitis B virus liver disease, and new strategies to prevent and treat recurrence are being explored. This review discusses the recent advances in our knowledge of hepatitis viruses A through G, focusing on the literature of the past year.