Cost-Effectiveness of HCV Core Antigen versus PCR for Monitoring Treatment Response in DAAS-Treated Egyptian Patients

PCR is currently the non-debatable proof for diagnosis of HCV infection as well as conclusion of treatment outcomes. HCV core antigen (HCVcAg) testing is a neglected, less expensive and less time consuming test that's presumed to achieve the same aims. The aim of this study is to find the cost-effectiveness of HCV core antigen testing in the monitoring of treatment response as an alternative to the gold-standard PCR test

Clinical Utility of a New Automated Hepatitis C Virus Core Antigen Assay for Prediction of Treatment Response in Patients with Chronic Hepatitis C

Hepatitis C virus core antigen (HCV Ag) is a recently developed marker of hepatitis C virus (HCV) infection. We investigated the clinical utility of the new HCV Ag assay for prediction of treatment response in HCV infection. We analyzed serum from 92 patients with HCV infection who had been treated with pegylated interferon and ribavirin. HCV Ag levels were determined at baseline in all enrolled patients and at week 4 in 15 patients. Baseline HCV Ag levels showed good correlations with HCV RNA (r = 0.79, P < 0.001). Mean HCV Ag levels at baseline were significantly lower in patients with a sustained virologic response (SVR) than in those with a non SVR (relapse plus non responder) based on HCV RNA analysis (2.8 log10fmol/L vs. 3.27 log10fmol/L, P = 0.023). Monitoring of the viral kinetics by determination of HCV RNA and HCV Ag levels resulted in similarly shaped curves. Patients with undetectable HCV Ag levels at week 4 had a 92.3% probability of achieving SVR based on HCV RNA assay results. The HCV Ag assay may be used as a supplement for predicting treatment response in HCV infection, but not as an alternative to the HCV RNA assay.

Early predictive efficacy of core antigen on antiviral outcomes in genotype 1 hepatitis C virus infected patients

Response-guided therapy is of limited use in developing countries because hepatitis C virus RNA detection by sensitive molecular methods is time- and labor-consuming and expen- sive. We evaluated early predictive efficacy of serum hepatitis C virus core antigen kinetics on sustained virologic response in patients with genotype 1 hepatitis C virus during pegylated interferon plus ribavirin treatment. For 478 patients recruited, hepatitis C virus RNAs were detected at baseline, and at weeks 4, 12, 24, 48, and 72 using Cobas TaqMan. Architect hepatitis C virus core antigen was performed at baseline, and weeks 4 and 12. Predictive values of hepatitis C virus core antigen on sustained virologic response were compared to hepatitis C virus RNA. In the first 12 weeks after treatment initiation the dynamic patterns of serum hepatitis C virus core antigen and hepatitis C virus RNA levels were similar in sustained virologic response, relapse, and null response patients groups. Although areas under the receiver operating characteristics curves of hepatitis C virus core antigen were lower than those of hepatitis C virus RNA at the same time points, modeling analysis showed that undetectable hepatitis C virus core antigen (rapid virological response based on hepatitis C virus core antigen) had similar positive predictive value on sustained virologic response to hepatitis C virus RNA at week 4 (90.4% vs 93.3%), and hepatitis C virus core antigen decrease greater than 1 log10 IU/mL (early virological response based on hepatitis C virus core antigen) had similar negative predictive value to hepatitis C virus RNA at week 12 (94.1% vs 95.Z%). Analysis on the validation group demonstrated a positive predictivevalue of 97.5% in rapid virological response based on hepatitis C virus core antigen and a negative predictive value of 100% in early virological response based on hepatitis C virus core antigen. In conclusion, hepatitis C virus core antigen is comparable to hepatitis C virus RNA in predicting sustained virologic response of chronic genotype 1 hepatitis C virus infected patients, and can be used to guide anti-hepatitis C virus treatment, especially in resource-limited areas.

Diagnostic performance of an immunoassay for simultaneous detection of HCV core antigen and antibodies among haemodialysis patients

Nosocomial transmission of HCV is a concern in haemodialysis (HD) units worldwide. Diagnosis of HCV infection among dialysis patients is currently based on the detection of anti HCV antibodies by ELISA, and is confirmed by HCV RNA. The average window period between HCV infection and seroconversion with new generations of HCV antibody tests remains approximately 70 days with more prolonged period among dialysis patients. In this study we assessed the diagnostic performance of an immunoassay designed for simultaneous detection of anti HCV antibodies and core antigen in one step in comparison to qualitative RT-PCR and anti HCV antibodies detection test among Egyptian haemodialysis patients. The studied patients were 39 chronic renal failure patients on maintenance haemodialysis. The results obtained in the present study revealed HCV infection of 56.4 percent. Combined Ag/Ab test detected 3 out of the 4 anti-HCV negative viraemic patients who were in the window period. The sensitivity, specificity and accuracy of the test were higher than that of anti HCV antibodies detection test (95.45 percent, 94.1 percent and 94.87 percent versus 81.8 percent, 88.23 percent and 84.6 percent) and they were raised to 100 percent on combining its positivity with liver enzymes elevation results. Therefore, this simple combined Ag/Ab test can be applied for early detection of HCV infection during window period among HD patients as an alternative to HCV RNA detection.

Evaluation of ARCHITECT HCV Core Antigen Assay / 대한진단검사의학회지

BACKGROUND: Hepatitis C virus (HCV) core antigen (Ag) levels are known to be well correlating with HCV RNA levels, and may be used as an alternative marker of HCV replication for monitoring the response to HCV treatment. However, the low sensitivity of HCV core Ag assay has been an obstacle for clinical use. In this study, recently developed ARCHITECT HCV Ag assay (Abbott Laboratories, USA) was evaluated for analytical performance and clinical usefulness. METHODS: A total of 109 sera from HCV infected patients including various genotypes of HCV (1b, 2, 2a/2c, 2b, and 3a) and 20 sera from healthy donors were used for evaluating the sensitivity, precision, and linearity of the HCV core Ag assay. The cross reactivity with HIV, hepatitis B virus and myeloma proteins (N=5, each) and correlation with HCV RNA PCR assay were also evaluated. RESULTS: The sensitivity of the HCV core Ag assay was 97.2% (106/109) and there were no false positive results and cross reactivity. The within-run, between-run and between-day CVs were 3.0%, 2.5% and 3.0%, respectively. The levels of HCV core antigen showed a good correlation with those of HCV RNA quantification (r=0.940). The HCV Ag assay showed an excellent linearity in the range from 0.63 to 17,114 fmol/L (r=0.999). CONCLUSIONS: The ARCHITECT HCV Ag assay was good in sensitivity, precision, and linearity and its results well correlated with HCV RNA levels. This assay could be used as a good marker of viral replication for monitoring the therapy response in chronically HCV infected patients.

Usefulness of Track-C (Total HCV Core Antigen) Assays in Anti-HCV Positive Patients / 대한진단검사의학회지

BACKGROUND: Virologic diagnosis of hepatitis C virus (HCV) infection is based on the use of sero-logic assays detecting specific anti-HCV antibodies, and then definitive diagnosis is made by detecting HCV RNA. Recently, newly developed Track-C (total HCV core antigen) test using an enzyme immunoassay (EIA) can detect and quantify total HCV core antigen in the peripheral blood of HCV-infected patients. In this study, the usefulness of Track-C test for the detection of HCV viremia was investigated by comparing the results with those of the HCV RNA test. METHODS: The study group consisted of 159 sera including 72 anti-HCV positive sera. The Track-C test was performed by enzyme immunoassay (Ortho Clinical Diagnostics, USA) with pretreatment for the dissociation of antigen-antibody complex. HCV RNA test was performed by HCV in house RT-nested PCR method. Results were calculated for the sensitivity, specificity and efficiency by comparing to each other. RESULTS: The efficiency between HCV RNA and Track-C was 77.4% for the 72 anti-HCV positivesera. Comparing with the results of HCV RNA, Track-C assay showed the sensitivity and specificity of 56.0% and 96.4%, respectively. Track-C assay demonstrated a relatively good linearity (R2=0.9836) and reproducibility (CV=4.4%) at high concentrations. CONCLUSIONS: Although the sensitivity of Track-C assay was not as high as that of HCV RT-PCR, a positive Track-C assay suggests the presence of HCV viremia, especially at higher concentrations. Track-C assay, therefore, may be used as a simple and supplementary test for HCV viremia and for follow-up monitoring.