Clinical utility of HCV core antigen detection and quantification in the diagnosis and management of patients with chronic hepatitis C receiving an all-oral, interferon-free regimen (original) (raw)
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Journal of gastrointestinal and liver diseases : JGLD, 2014
The study aimed to evaluate the clinical utility of the chemiluminescent HCV core Ag test compared to viral load assessment in the management of patients with chronic hepatitis C. A retrospective study was performed at a tertiary-care infectious diseases hospital on samples collected from anti-HCV positive patients. Seventy-six samples were tested with the Architect HCV core Antigen kit and Cobas AmpliPrep/Cobas Taqman HCV kit. The HCV Ag test accuracy was estimated using data from all the HCV RNA tested samples received between January 2011 and December 2012. The HCV Ag test showed a good correlation between the logarithmic values of HCV RNA and HCV Ag (R=0.98), with a 100% specificity and PPV, but with reduced sensitivity for viral loads lower than 1,000 UI/mL. In a model using data from 2,478 HCV RNA tested samples and a cut-off of the Ag assay corresponding to 1,000 UI/mL HCV RNA, the Ag test would have a sensitivity of 82.4%, a NPV of 80.9% and a high specificity and PPV (100%)...
Viral Hepatitis Journal
Objectives: Recently, with the use of direct-acting antivirals (DAA) for treating chronic hepatitis C (CHC), the success rate has exceeded 90%. The implementation of these strong therapies has reduced the role of monitoring therapy with hepatitis C virus (HCV)-RNA tests. The current study compares the HCV-core antigen test (HCV-Ag) with HCV-RNA in terms of correlation, effectiveness and cost in patients who started DAA and to evaluate the usability of HCV-Ag as a routine laboratory test. Materials and Methods: This study includes 76 patients with CHC. Patients with positive HCV-RNA, over 18 years old and who will initiate DAA are included. HCV-Ag level was studied in all samples by using ARCHITECT core antigen measurement Abbott method. HCV-RNA and anti-HCV levels compared with HCV-Ag levels. Results: Of the 76 patients, 44 (57%) were males, 48 (63%) were treatment experienced and 21 (27%) were cirrhotic. All patients were started with DAAs. When compared before and after treatment, HCV-RNA level, HCV-Ag level was found to be significantly different (p<0.001). Before treatment, HCV-RNA and HCV-Ag levels were found to be positive correlations (correlation coefficient: 0.419). Conclusion: The use of DAAs in HCV therapy has eliminated the need for response-guided therapy. It has been demonstrated in the study that HCV-Ag measurement is very successful and cost effective in detecting viremic patients and evaluating virological response, which are the two most important factors in the management of CHC.
in Vivo, 2023
Background/Aim: Hepatitis C virus (HCV) core antigen (Ag) test has been increasingly applied as an effective alternative to conventional molecular tests allowing rapid and affordable diagnosis, which is of paramount relevance to achieve global elimination of HCV infection. Materials and Methods: ARCHITECT ® HCV Ag test was evaluated in comparison with HCV RNA quantification test (CAP/CTM) to calculate its sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and to determine their correlation level. Its performance, according to low and high viral load values and in different treatment stages [during treatment (T), at the end of the therapeutic protocol (EOT) and when sustained virological response (SVR) was evaluated]. Results: In total, 145 samples were included. Considering CAP/CTM, the sensitivity, specificity, PPV and NPV of the HCV-Ag test were 88.9%, 99.1%, 97.0% and 96.4%, respectively, and the correlation among tests was high (r=0.890), with only five discordant results. A decrease in sensitivity was found for low viral load values (<1,000 IU/ml), but the opposite was verified for high viral concentrations (≥1,000 IU/ml). A good agreement was verified for the T and EOT groups (k=0.789 and k=0.638) and an excellent agreement in the SVR group (k=1.000). Conclusion: HCV-Ag seems to be an effective alternative that can be routinely combined with other faster and more accessible tests (e.g., HCV antibody tests) for the identification of new HCV infections in suspected patients, eventually reserving the molecular techniques for samples with discordant results.
Journal of Clinical Virology, 2013
Background: An early drop of HCV-RNA levels is useful in assessing response to antiviral treatment in chronic hepatitis C; the first recommended time point is 4 weeks after the start of therapy. Objectives: We evaluated retrospectively HCV-RNA and HCVAg levels at different time points to assess the clinical value of an early monitoring. Study design: Thirty-five patients with chronic hepatitis C infected by genotype 1b and consecutively enrolled in an open-label study on PegIFN plus Ribavirin and/or ketoprofene were tested for HCV-RNA (real-time PCR) and HCVAg (ARCHITECT) at baseline and after 1 and 2 days and 1, 2, 4 and 12 weeks after the start of treatment. Treatment response was assessed according to the EASL consensus criteria. Results: In the 17 sustained responders (SR) the median log decrease of HCV-RNA and HCVAg at the different time points was 0.40 and 0.37; 1.36 and 0.84; 1.47 and 0.97; 2.34 and 1.86; 2.51 and 2.32; 3.28 and 2.61, respectively. The best time point to predict SR was 2 weeks after the start of therapy, with a sensitivity, specificity and overall accuracy of 76.9%, 86.7% and 82.1% for HCV-RNA and 81.8%, 75.0% and 76.8% for HCVAg, respectively. Discussion: An early monitoring is at least equally effective than standard monitoring in predicting response to hepatitis C therapy. The similarity of HCV-RNA and HCVAg kinetics suggests that HCVAg may be useful in the early phases as a trigger to evaluate HCV-RNA levels at earlier time points for a personalized approach to therapy monitoring.
Liver International, 2005
Background: Hepatitis C virus (HCV) is an important etiologic agent for chronic liver diseases. Methods: The aim of this study was to evaluate the clinical usefulness of second-generation HCV core antigen assay by comparing the results of the assay with those of the COBAS AMPLICOR HCV MONITOR version 2.0 (COBAS v2.0). Results: HCV core antigen was detectable by this assay in 142/149 (95.3%) of serotype 1 (3821 AE 322 fmol/l; mean AE SD), in 56/58 (96.6%) of serotype 2 (2589 AE 449 fmol/l), and in 6/6 (100%) of serotypes 112 (1240 AE 548 fmol/l). The HCV core antigen levels measured by this assay correlated well with the HCV RNA levels by COBAS v2.0 (r 5 0.848, Po0.0001). In relation to the outcome of interferon monotherapy, the pretreatment HCV core antigen levels of sustained and non-sustained virological responders were 659 AE 189 and 4904 AE 376 fmol/l in serotype 1, 1993 AE 740 and 3145 AE 519 fmol/l in serotype 2. The cutoff values with the best accuracy for HCV core Ag levels to discriminate between sustained and non-sustained virological response were 699 fmol/l for serotype 1 and 292 fmol/l for serotype 2, respectively, by receiver operating characteristic curve analysis. Conclusion: This new assay was considered to be useful in evaluating the HCV levels in patients with chronic hepatitis C.
2015
Simplified, affordable tools to diagnose active hepatitis C virus (HCV) infection are needed to scale up treatment. This study evaluated the analytical performance of HCV core antigen (HCVcAg) detection in plasma and dried blood spot (DBS) samples. Paired plasma and venous DBS samples were prepared from remnant diagnostic samples. Plasma HCV RNA was quantified by AmpliPrep/COBAS Taqman (Roche) and HCVcAg measured by ARCHITECT HCV Ag (Abbott Diagnostics). Sensitivity and specificity for HCVcAg (>3 fmol/L) at two HCV RNA thresholds (≥15 IU/mL and ≥3,000 IU/mL) were calculated. Of 120 paired samples tested, 25 had non-quantifiable HCV RNA and 95 quantifiable HCV RNA. The median HCV RNA level in plasma was 5.6 log 10 IU/mL (IQR: 5.2, 6.2). The median HCVcAg level for plasma and DBS was 2.3 log 10 fmol/L (IQR: 0.1, 3.1) and 1.1 log 10 fmol/L (IQR: 0.0, 1.9), respectively. For diagnosing HCV RNA ≥3,000 IU/mL, the sensitivity and specificity of HCVcAg in plasma was 97.7% (95%CI: 91% to 100%) and 100% (95%CI: 87% to 100%), respectively. The sensitivity and specificity of HCVcAg in DBS was 88.6% (95%CI: 80% to 94%) and 97% (95%CI: 82% to 100%), respectively. The data from this study demonstrate a good sensitivity and specificity of HCVcAg in plasma when HCV RNA >3,000 IU/mL. The level of HCVcAg quantified in plasma was higher than that in DBS.
Quantitative Determination of Hepatitis C Core Antigen in Therapy Monitoring for Chronic Hepatitis C
Intervirology, 2011
The correlation and kinetics of hepatitis C virus (HCV) RNA and HCV core antigen levels in chronic hepatitis C patients treated with pegylated interferon + ribavirin were evaluated in order to envision a combined use of the two assays in therapy monitoring. HCV core antigen levels by a chemiluminescent immunoassay (Abbott ARCHITECT) and HCV-RNA levels by branched DNA (bDNA) or real-time PCR have been evaluated on plasma specimens from 32 patients treated for chronic hepatitis C. An early virological response (undetectable levels of HCV-RNA 4 weeks after start of treatment) was found in 10/23 subjects (43.5%) followed up for 5 months or more. The response was linked to the HCV genotype (20% in genotype 1B vs. 61.5% in other genotypes; p < 0.05). HCV RNA and HCV antigen showed a good correlation (r = 0.814); HCV antigen was still detectable in 3 samples with undetectable (<615 IU/ml) RNA by bDNA, while no differences in clinical sensitivity were recorded in comparison with real-...
Journal of Viral Hepatitis, 2005
Early virological response may predict outcome following treatment with peginterferon alpha-2a and ribavirin in patients chronically infected with hepatitis C virus (HCV). As total HCV core antigen may constitute an alternative direct marker to HCV RNA for assessing the levels of viraemia in such patients, we evaluated the correlation between HCV core antigen and HCV RNA, and whether HCV core antigen at baseline, 4 and 12 weeks after treatment could predict sustained virological response (SVR) to combined therapy, in comparison with HCV RNA. A total of 290 serum samples from 58 previously treatment naïve chronic HCV patients were examined for HCV core antigen and HCV-RNA by means of quantitative HCV RNA when receiving combination therapy for the first time. SVR was significantly associated with basal HCV core antigen but not with HCV RNA. There was a good correlation between HCV core antigen and HCV RNA (r 2 ¼ 0.781). The negative predictive value of HCV core antigen testing in predicting nonresponse at weeks 4 and 12 were 75 and 100%, and for undetectable or a 2-log drop in HCV RNA were 69.6 and 75% respectively. HCV core antigen detection is quick, and easy to perform alternative to HCV RNA, and could be used as a marker of HCV viraemia for monitoring the progress of therapy.