Comparison of serum hepatitis C virus (HCV) RNA and core antigen levels in patients coinfected with human immunodeficiency virus and HCV and treated with interferon plus ribavirin

Design of a novel rapid immunoassay for simultaneous detection of hepatitis C virus core antigen and antibodies

HCV is a potential cause of viral hepatitis, which leads to blood-borne chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Anti-HCV antibody detection assays detect HCV infection after approximately 70 days. HCV core antigen can be detected much earlier than anti-HCV antibodies. However, it disappears soon after the appearance of anti-HCV antibodies. Thus, there is a need for a rapid assay for simultaneous detection of HCV core antigen and anti-HCV antibodies for early diagnosis of HCV infection. A rapid diagnostic assay (HCV Ag-Ab Combo) for simultaneous detection of HCV core antigen and anti-HCV antibodies for early diagnosis of HCV infection was developed. HCV Ag-Ab Combo was evaluated in order to determine its potential for detection of HCV infection earlier than anti-HCV antibody detection assays. We compared the sensitivity of the newly developed assay with anti-HCV antibody detection assays (ELISA [HCV Ab ELISA] and rapid test [HCV Ab Rapid]) and HCV core antigen/anti-HCV antibody detection ELISA (HCV Ag-Ab ELISA). This study included 11 samples that were found positive in HCV RNA detection and HCV Ag-Ab ELISA but negative in HCV antibody detection assays (HCV Ab ELISA and rapid), 10 samples that were found positive in HCV Ag-Ab ELISA and HCV Ab ELISA but negative in HCV Ab Rapid, 69 samples that were found positive in HCV Ag-Ab ELISA, HCV Ab ELISA, and HCV Ab Rapid, and 509 samples that were found negative in HCV Ag-Ab ELISA, HCV Ab ELISA, and HCV Ab Rapid. Three seroconversion panels, PHV 913, PHV 911 (M) and PHV904-00-1.0, and a HCV RNA genotype qualification panel (2400-0182) acquired from Seracare Life Sciences (USA) were also tested. HCV Ag-Ab Combo showed a combined sensitivity and specificity of 100% when tested with 90 samples that were positive for HCV by HCV Ag-Ab ELISA and 509 HCV-negative samples. Its positive predictive value (PPV) and negative predictive value (NPV) were found to be 100%. It detected HCV infection approximately 7 to 12 days earlier than the HCV Ab detection assays, and its performance was not affected when testing different genotypes of HCV. HCV Ag-Ab Combo did not detect HCV infection as early as HCV RNA or HCV Ag-Ab ELISA. HCV Ag-Ab Combo provided a significant improvement for the early detection of HCV infection during the preseroconversion phase when compared with anti-HCV antibody detection assays. It could be a useful screening assay, and an alternative to HCV RNA detection or HCV Ag-Ab ELISA when nucleic acid technologies cannot be implemented.

HIV-1 Nef interacts with HCV Core, recruits TRAF2, TRAF5 and TRAF6, and stimulates HIV-1 replication in macrophages

Tumor necrosis factor receptor-associated factor (TRAF) signaling plays a central role in many biological activities, such as the regulation of immune and inflammatory responses and control of apoptosis, which are key events in the pathogenesis of the human immunodeficiency virus (HIV)-1 and the hepatitis C virus (HCV) infections. Here we show that TRAF2, TRAF5 and TRAF6 interact with the HIV-1 Nef protein, an immunomodulatory viral protein expressed and released by cells infected by the virus. We also found that TRAF2 and TRAF5 interact with the HCV Core protein. Interestingly, we observed that HIV-1 Nef interacts with HCV Core. The activation of TRAF (2, 5, 6) - mediated by HIV-1 Nef and HCV Core - enhanced the activation of the nuclear factor-kappa B (NF-κB) and increased HIV-1 replication in monocyte- derived macrophages (MDMs). The knockdown of TRAF2, TRAF5 and TRAF6 resulted in decreased NF-κB activation and reduced HIV-1 replication in MDMs. Our results reveal a mechanism by which the activation of the TRAF pathway by HIV-1 Nef and HCV Core favors the replication of HIV-1 in macrophages and could be a critical factor for optimal replication of HIV-1 in macrophages of HIV-HCV-coinfected patients.

Utility of a commercial quantitative hepatitis C virus core antigen assay in a diagnostic laboratory setting

In this study, the utility and impact of hepatitis C virus (HCV) core antigen (Cag) detection via a commercial assay have been evaluated in diagnostic laboratory conditions. In a total of 272 samples from 226 individuals, HCV RNA was detected in 81.3% and anti-HCV antibody prevalence was 86.4%. HCV Cag reactivity was identified in 59.9% of the samples and in 75.8% with detectable RNA. The sensitivity and specificity of HCV Cag assay have been calculated as 75.8% and 95.1%, respectively, and agreement between HCV RNA and HCV Cag was moderate (κ = 0.554). HCV Cag and RNA levels were highly correlated (r = 0.915 and 0.937). A viral load threshold of 10(3) IU/mL has been recognized, above which the correlation with RNA became statistically significant and sensitivity increased to 90.9%. Detection and quantification of HCV core antigen have been observed as a strong alternative to nucleic acid testing for HCV monitorization.

Analytical evaluation of HCV core antigen and interest for HCV screening in haemodialysis patients

BACKGROUND

It is important to diagnose a hepatitis C virus infection in the acute phase in order to reduce the incidence of this infection in high-risk populations like haemodialysis patients. But detection systems for serum HCV antibodies are insensitive in the acute phase because of the long serological window. Previous studies showed that the HCV core antigen (HCV Ag) may be an alternative to HCV RNA in this context.

OBJECTIVES

To evaluate the performances of the new Abbott ARCHITECT((R)) HCV Ag test and its usefulness in screening for HCV infections in haemodialysis patients.

STUDY DESIGN

The serum HCV Ag titre was compared to the HCV RNA viral load in 98 samples from HCV-infected patients to determine the correlation between the two markers and the influence of genotype. We screened 2752 patients from 37 French haemodialysis units who tested negative for HCV antibodies using the HCV Ag and RNA assays.

RESULTS

The HCV Ag titre was correlated with the HCV RNA (Spearman test coefficient 0.9041, p<0.0001) and all genotypes and subtypes were detected. The HCV Ag and HCV RNA results agreed well for haemodialysis patients. Diagnostic specificity of HCV Ag was high (99.2%) considering HCV RNA as the reference. The two seronegative patients (of 2752) who were HCV RNA positive were also HCV Ag positive.

CONCLUSIONS

The ARCHITECT HCV Ag test is a reliable, highly specific assay for screening acute HCV infections in haemodialysis units. It is a robust alternative to HCV RNA testing.

Antiviral treatment for chronic hepatitis C in patients with human immunodeficiency virus

BACKGROUND

Antiviral treatment for chronic hepatitis C may be less effective if patients are co-infected with human immunodeficiency virus (HIV).

OBJECTIVES

To assess the benefits and harms of antiviral treatment for chronic hepatitis C in patients with HIV.

SEARCH STRATEGY

Trials were identified through manual and electronic searches in The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded. The last search was May 2009.

SELECTION CRITERIA

Randomised trials comparing at least 12 weeks of any anti-HCV treatment versus another treatment regimen or no treatment. Included patients had chronic hepatitis C and stable HIV irrespective of previous antiviral therapy.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of risk of bias were done in duplicate. Analysis was by intention-to-treat.

MAIN RESULTS

Fourteen trials were included. None of the included 2269 patients were previously treated for chronic hepatitis C. Peginterferon (either 2a, 180 microgram, or 2b, 1.5 microgram/kg, once weekly) plus ribavirin was more effective in achieving end of treatment and sustained virological response compared with interferon plus ribavirin (5 trials, 1340 patients) or peginterferon (2 trials, 714 patients). The benefit of peginterferon plus ribavirin was seen irrespective of HCV genotype although patients with genotype 1 or 4 had lower response rates (27%) than patients with genotype 2 or 3 (56%). The remaining trials compared different treatment regimens in patients who were treatment naive or had no virological response after three months of treatment, but overall they had not enough power to show any effect of increasing the dose of interferon or adding both amantadine or ribavirin. The overall mortality was 23/2111 patients with no significant differences between treatment regimens. Treatment increased the risk of adverse events including anaemia and flu-like symptoms, and several serious adverse events occurred including fatal lactic acidosis, liver failure, and suicide due to depression.

AUTHORS' CONCLUSIONS

Peginterferon plus ribavirin may be considered a treatment for patients with chronic hepatitis C and stable HIV who have not received treatment for hepatitis C as the intervention may clear the blood of HCV RNA. Supporting evidence comes mainly from the analysis of this non-validated surrogate outcome assessed in comparisons against other antiviral treatments. There is no evidence on treatment of patients who have relapsed or did not respond to previous therapy. Careful monitoring of adverse events is warranted.

Simultaneous detection of anti-HCV antibody and HCV core antigen

HCV infection is usually diagnosed by means of an enzyme immune assay for the detection of antibody against HCV. The window period between infection and seroconversion remains a dramatic problem in the transfusional and diagnostic setting. In this chapter, we report (i) procedures for assays using two different approaches designed to reduce the window period and (ii) performance in terms of specificity and sensitivity in the detection of both antibody and antigen, and we compare their efficacy with that of commercial assays.

Kinetics of hepatitis C viral RNA and HCV-antigen during dialysis sessions: evidence for differential viral load reduction on dialysis

Hepatitis C infection is a common problem in dialysis units. The prevalence ranges from 3% to more than 50%. Several reports have described a variable reduction of HCV-RNA during hemodialysis treatment sessions. But so far nothing is known about the HCV antigenemia or the kinetics of the reduction of HCV-RNA and HCV antigenemia during these sessions. HCV-RNA was monitored using the VERSANT HCV bDNA assay 3.0 (Bayer Healthcare Diagnostics, Leverkusen, Germany) or the HCV-Monitor TaqMan (Roche Diagnostics). HCV antigenemia was tested by using Ortho-trac-C assay (Ortho Clinical Diagnostics, Neckargemünd, Germany). Kinetics of HCV-RNA were available in 15 dialysis sessions measured by bDNA assay and in 5 dialysis sessions measured by rt-PCR. Quantitative HCV-antigenemia was available in fourteen dialysis sessions. Not only HCV-RNA but as expected also the HCV-antigenemia fell during the dialysis session. However, while the average reduction of HCV-antigen appears steady and linear, the level of HCV-RNA seems to be stable during the first 3 hr of dialysis, and decreases rapidly during the last 2 hr. The results seem to be independent of the HCV-RNA detection method. The different kinetics of HCV RNA and HCV antigen load suggest that there are different mechanisms responsible for the reduction of the HCV antigen and HCV-RNA, respectively. Reduction of viral load during dialysis session indicates a potential benefit of dialysis in case of HCV associated antiviral therapy.

A Decline in Hepatitis B virus Surface Antigen (HBsAg) Predicts Clearance, but does not Correlate with Quantitative HBeAg or HBV DNA Levels

Background

The elimination of hepatitis B virus surface antigen (HBsAg) is the final goal of hepatitis B treatment, but is rarely achieved. As quantitative assays for HBsAg recently became available, we have investigated whether quantitative HBsAg measurements can substitute for hepatitis B virus (HBV) DNA quantification in treatment monitoring.

Methods

Within this study, 23 liver transplant patients and 18 heart transplant recipients were retrospectively analysed. Patients had been treated with famciclovir and/or lamivudine, in addition some had also received adefovir in cases of lamivudine resistance. Quantitative HBsAg and hepatitis B virus e antigen (HBeAg) levels were determined with the ArchitectTM assay. HBV DNA levels were determined with different assays available at given time points.

Results

We did not find a significant correlation between either HBsAg or HBeAg and HBV DNA levels – both in treated and untreated patients. More importantly, there was no significant concordance between an increase or decrease of HBsAg or HBeAg with HBV DNA. However, the curve and decline of quantitative HBsAg enabled prediction of eventual viral clearance. Eight patients showed a 2 log10 drop of HBsAg levels and eight patients demonstrated a reduction of HBsAg levels below 100 IU/ml; five patients fulfilled both criteria. Three of those five cleared HBsAg and became positive for antibodies against HBsAg.

Conclusions

Quantitative HBsAg and HBeAg cannot substitute for HBV DNA quantification during the assessment of antiviral therapy; however, the decline of HBsAg does predict eventual HBsAg clearance. A 2 log10 drop to below 100 IU/ml is associated with a high likelihood of HBsAg clearance.