Hepatitis C Virus Ag Research Articles

Comparison of a dual antibody and antigen HCV immunoassay to standard of care algorithmic testing.

The Centers for Disease Control and Prevention (CDC) guidelines for hepatitis C virus (HCV) testing, although effective, may miss crucial diagnostic opportunities. The goal of this study was to assess the utility of an antibody (Ab) and antigen (Ag) combination immunoassay as an alternative to traditional HCV screening. Remnant specimens from 1,341 patients with concurrent third-generation serologic (Roche anti-HCV-II) and nucleic acid amplification testing (NAAT) were assessed using the HCV Duo Ab/Ag immunoassay (Roche). Patient demographics, risk factors, and standard of care (SOC) laboratory results from the medical records were recorded. Overall, 99.0% (197/199) of the HCV Duo Ab+/Ag+specimens accurately identified active infections as confirmed by NAAT, and 99.9% (670/671) Ab-/Ag- samples corresponded to those without HCV infections. Individually, the HCV Duo Ab component demonstrated a 95.6% positive percent agreement (PPA) (95% CI = 93.8-96.9) and 99.1% negative percent agreement (NPA) (98.8-99.6) compared with SOC anti-HCV II Ab assay. The HCV Duo Ag had a 73.5% PPA (67.9-78.4) and 99.8% NPA (99.3-100) with NAAT. Among RNA+ specimens, 73.4% (197/267) were HCV Duo Ag+, and 265/267 (99.3%) were successfully detected on the HCV Duo Ab component. Notably, 5/7 (71.4%) Ab-/RNA +specimens were detected by HCV Duo, which would have been missed by traditional algorithmic testing. Fourth generation HCV Duo Ab/Ag assay demonstrated comparable performance to SOC testing and shortens the diagnostic window but does not eliminate the need for NAAT in all patients. Ab/Ag testing identified several Ab-/RNA+ cases, a subgroup often undiagnosed by current algorithmic testing, demonstrating promise for improved diagnostic efficiency and accuracy in HCV detection.IMPORTANCEThis study highlights the potential of a combined hepatitis C virus (HCV) Duo antibody (Ab) and antigen (Ag) immunoassay to improve early detection of HCV infections. Traditional Ab-only screening methods recommended by the Centers for Disease Control and Prevention may miss early-stage infections. The HCV Duo assay showed high accuracy, detecting nearly all active infections confirmed by nucleic acid amplification testing. Dual detection of HCV Ab and Ag shortens the diagnostic window, enabling intervention and treatment in a single visit, which is crucial for improving patient outcomes and reducing HCV transmission, especially in areas with limited access to confirmatory molecular testing.

Diagnostic performance of hepatitis C core antigen assay to identify active infections: A systematic review and meta-analysis.

Hepatitis C virus (HCV) core antigen (HCVcAg) assay is an alternative for diagnosing HCV infection in a single step. This meta-analysis aimed to evaluate the Abbott ARCHITECT HCV Ag assay's diagnostic performance (validity and utility) for diagnosing active hepatitis C. PubMed, EMBASE, Scopus, Web of Science, and Cochrane Library were searched until 10 January 2023. The protocol was registered at the prospective international register of systematic reviews (PROSPERO: CRD42022337191). Abbott ARCHITECT HCV Ag assay was the test for evaluation, and nucleic acid amplification tests with a cut-off ≤50IU/mL were the gold standard. Statistical analysis was performed using STATA with the MIDAS module and random-effects models. The bivariate analysis was conducted on 46 studies (18,116 samples). The pooled sensitivity was 0.96 (95% CI=0.94-0.97), specificity 0.99 (95% CI=0.99-1.00), positive likelihood ratio 141.81 (95% CI=72.39-277.79), and negative likelihood ratio 0.04 (95% CI=0.03-0.06). The area under the summary receiver operating characteristic curve was 1.00 (95% CI=0.34-1.00). For active hepatitis C prevalence values of 0.1%-15%, the probability that a positive test was a true positive was 12%-96%, respectively, indicating that a confirmatory test should be necessary, particularly with a prevalence ≤5%. However, the probability that a negative test was a false negative was close to zero, indicating the absence of HCV infection. The validity (accuracy) of the Abbott ARCHITECT HCV Ag assay for screening active HCV infection in serum/plasma samples was excellent. Although the HCVcAg assay showed limited diagnostic utility in low prevalence settings (≤1%), it might help diagnose hepatitis C in high prevalence scenarios (≥5%).

HCV Core-antigen Assay as an Effective Alternative to HCV RNA Quantification in Patients With Hepatitis C.

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. 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]. 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). 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.

Diagnostic Performance of the HCV Core Antigen Test To Identify Hepatitis C in HIV-Infected Patients: a Systematic Review and Meta-Analysis.

The standard algorithm for diagnosing hepatitis C virus (HCV) infection has two steps, an HCV antibody test for screening and a nucleic acid amplification test (NAAT) for confirmation. However, the HCV core antigen (HCVcAg) detection assay is an alternative for one-step diagnosis. We aimed to evaluate the diagnostic performance of the Abbott ARCHITECT HCV Ag assay to detect active hepatitis C in serum/plasma in people living with HIV/AIDS (PLWHA), through a systematic review and meta-analysis. PubMed, EMBASE, Scopus, Web of Science, and the Cochrane Library were searched until 20 September 2022 (PROSPERO, CRD42022348351). We included studies evaluating Abbott ARCHITECT HCV Ag assay (index assay) versus NAATs (reference test) in PLWHA coinfected with HCV who did not receive antiviral treatment for HCV. Meta-analysis was performed with the MIDAS module using Stata and random-effects models. The QUADAS-2 tool evaluated the risk of bias. The bivariate analysis was conducted on 11 studies with 2,407 samples. Pooled sensitivity was 0.95 (95% CI = 0.92 to 0.97), specificity 0.97 (95% CI = 0.93 to 0.99), positive likelihood ratio 37.76 (95% CI = 12.84 to 111.02), and negative likelihood ratio 0.06 (95% CI = 0.04 to 0.09). The area under the curve was 0.97 (95% CI = 0.20 to 1.00). For low prevalence (≤5%), the posttest probability that an individual with a positive test was a true positive ranged from 4% to 67%, whereas, at high prevalence (≥10%), the posttest probability was between 81% and 87%, indicating that a confirmatory test should be necessary, particularly with prevalence values of ≤1%. Regardless of prevalence, the probability that an individual with a negative test was a false negative was close to zero, indicating that the individual was not infected with HCV. In conclusion, the accuracy of the Abbott ARCHITECT HCV Ag assay was very good for HCV screening in serum/plasma samples from PLWHA. The clinical utility to confirm HCV infection was acceptable in high-prevalence settings (≥10%) but poor in low-prevalence settings (≤1%). Furthermore, it was excellent in excluding active HCV infection.

Multicenter performance evaluation of the Elecsys HCV Duo immunoassay.

The diagnostic accuracy of the Elecsys® HCV Duo antigen-antibody combination immunoassay (Roche Diagnostics GmbH) was evaluated for the detection of hepatitis C virus (HCV) infection, versus commercially available comparators. This multicenter study (August 2020-March 2021) assessed the specificity of the Elecsys HCV Duo immunoassay and comparator assays in blood donor and routine clinical laboratory samples; sensitivity was determined in confirmed HCV-positive samples and seroconversion panels. The Elecsys HCV Duo immunoassay was compared with the Monolisa HCV Ag-Ab ULTRA V2, Murex HCV Ag/Ab Combination and ARCHITECT HCV Ag assays, as well as nucleic acid testing (NAT). The antibody (anti-HCV) module of the Elecsys HCV Duo immunoassay was compared with the Elecsys Anti-HCV II, Alinity s Anti-HCV, ARCHITECT Anti-HCV and RIBA HCV 3.0 SIA assays. The specificity of the Elecsys HCV Duo immunoassay was 99.94% (95% confidence interval [CI], 99.89-99.97) and 99.92% (95% CI, 99.71-99.99) in blood donor (n=20,634) and routine clinical laboratory samples (n=2531), respectively. The specificity of the Elecsys HCV Duo immunoassay was similar or better than comparator assays. The sensitivity of the Elecsys HCV Duo immunoassay in confirmed HCV-positive samples (n=257) was 99.6%. In seroconversion panels, the Elecsys HCV Duo immunoassay detected infections earlier (2.2-21.9 days) than all but one of the comparator assays and detected HCV 1.8 days later than NAT. The Elecsys HCV Duo immunoassay shows high diagnostic accuracy, reduces the diagnostic window, and could be used when NAT is not possible.

Community-based screening by Anti-HCV reflex HCV Ag test and accessible post-screening care toward elimination of hepatitis C in two hyperendemic townships

Hyperendemic townships of hepatitis C virus (HCV) infection should devote extra efforts to eliminate HCV. We aimed to evaluate efficacy of the screening and linkage to care in two HCV hyperendemic townships. Village-to-village HCV screening using anti-HCV reflex HCV Ag test was conducted in two HCV hyperendemic rural townships (Lioujiao and Yijhu). All residents aged 30 years or older were invited. Those patients detected as infected were referred to nearby hospitals or clinics in Lioujiao and to an accessible outreach hepatology clinic in Yijhu. The populations of Lioujiao and Yijhu townships at time of survey were 18,389 and 14,787 with 6086 (33.1%) and 4604 (31.1%) having ever been previously screened, and 1517 and 1071 responded to this screening respectively. Their crude screening coverage rates were 41.5% and 38.5%, and adjusted screening coverage rates were 54.3% and 94.6% respectively. The prevalence rates of anti-HCV and HCV Ag were 17.9% and 11.9% in Lioujiao, and 9.2% and 5.6% in Yijhu respectively, with their rates of antigenemia (HCV Ag/anti-HCV) being 62.1% and 60.6% respectively. Numbers needed to test (NNT) to find a candidate for anti-viral treatment were 9 and 18. For linkage to care, treatment rate by referral (Lioujiao) was slightly lower than by accessible outreach hepatology clinic (Yijhu) (84.9% vs. 93.3%, p=0.093). Overall successful sustained virological response rate at week 12 was 98.2% (161/164) in outreach hepatology clinic. Since NNT was low, it was worthwhile conducting intensive screening in these hyperendemic townships. For high treatment rate, accessible outreach hepatology clinic is feasible especially in areas without adequate medical resources.

Performance Evaluation of In Vitro Screening and Diagnostic Kits for Hepatitis C Virus Infection.

AimA reliable kit with high sensitivity and specificity is indispensable for diagnosing hepatitis C virus (HCV) infection. Detection kits for anti-HCV antibodies (anti-HCV) are used for screening, and quantification kits for HCV RNA and HCV antigen (Ag) are used for the definite diagnosis of HCV infection or the evaluation of the pathological condition of and therapeutic effects in patients with chronic hepatitis C. Several kits are currently available for these purposes and are provided for clinical use in Japan. In this study, we aimed to evaluate the performance of these kits.MethodsWe used International Standards for HCV RNA and HCV Ag and a regional reference panel to evaluate the performance of thirteen anti-HCV, five HCV RNA, and two HCV Ag kits.ResultsAll specimens in the regional reference panel were diagnosed correctly by all anti-HCV kits, although the distributions of the quantified values varied, and the ratios of titer classification were not identical across kits. All HCV RNA kits quantified the International Standard with minimum deviation and diagnosed the specimens of the reference panel correctly. The quantified values of the International Standard by two HCV Ag kits were inconsistent. HCV Ag titers of some specimens were underestimated owing to the amino acid polymorphisms in comparison with HCV RNA titers.ConclusionsThe evaluation with International Standards and the regional reference panel was useful for assessing the quality of screening and diagnostic kits for HCV infection, and such quality control is essential for the clinical usage of these kits.

Performance of HCV Antigen Testing for the Diagnosis and Monitoring of Antiviral Treatment: A Systematic Review and Meta-Analysis.

Background and Aims Active hepatitis C virus (HCV) infection is based on the detection of HCV RNA that it is effective but presents high cost and the need to hire trained personnel. This systematic review and meta-analysis is aimed at evaluating the diagnostic accuracy of HCV Ag testing to identify HCV cases and to monitor antiviral treatment including DAA treatment. Methods The studies were identified through a search in PubMed, Lilacs, and Scopus from 1990 through March 31, 2020. Cohort, cross-sectional, and randomized controlled trials were included. Two independent reviewers extracted data and assessed quality using an adapted Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Our primary outcome was to determine the accuracy of HCV Ag detection for the diagnosis, which we estimated using random-effects meta-analysis. Results Of 3,062 articles identified, 54 met our eligibility criteria. The studies described cohorts from 20 countries, including 14,286 individuals with chronic HCV individuals. Studies for ECLIA technology demonstrated highest quality compared to studies that used ELISA. The pooled sensitivity and specificity (95% CI) for HCV Ag detection of active HCV infection were 98.82% (95%CI = 98.04%; 99.30%) and 98.95% (95%CI = 97.84%; 99.49%), respectively. High concordance was found between HCV Ag testing and HCV RNA detection 89.7% and 95% to evaluate antiviral treatment. Conclusions According to our findings, HCV Ag testing could be useful to identify HCV active cases in low-resource areas. For antiviral treatment, HCV Ag testing will be useful at the end of treatment.

Seroprevalence of hepatitis C virus antigen in patients with chronic liver disease and hepatocellular carcinoma at 12th week of treatment: a cross-sectional study.

epidemiological data suggests that more than 50% of hepatitis C virus (HCV) patients fail treatment. The objective of the study was to highlight the seroprevalence of hepatitis C virus antigen (HCV Ag) at the 12th week of treatment. during a cross-sectional study, participants with chronic liver disease and hepatocellular carcinoma (HCC) were recruited between December 2020 and March 2022 at the Yaoundé General Hospital (HGY) and the University Teaching Hospital of Yaounde (UTHY). Five millilitres of blood samples were taken from each consenting participant and then a qualitative search for HCV Ag by Enzyme-Linked Immuno Assay (ELISA) was performed. Analysis of the results was performed using SPSS Version 25.0 software. out of the 192 participants selected for the study, only 92 (47,9%) participants were at 12 weeks of treatment, including 69 (75%) participants positive for the hepatitis C virus antibody (HCV Ab) by RDT. Of these participants, 44 (47.8%) participants were positive for HCV Ag by ELISA, respectively 19/37 (51.3%), 14/19 (73.6%), 11/13 (84.6%) with chronic hepatitis (HC), Cirrhosis, and HCC (P<0.0001). our results showed a high prevalence of HCV Ag in patients at their 12th week of treatment which predicts treatment failure and calls for public policy to develop new management strategies to prevent HCV treatment failure in our context.

Evaluation of Hepatitis C Virus Core Antigen Assay in a Resource-Limited Setting in Pakistan.

The diagnosis of Hepatitis C virus (HCV) infection can be challenging due to its cost and a lack of access to centralized testing. There is an urgent need to develop simplified HCV testing algorithms. The aim of this study was to evaluate the performance characteristics of a Hepatitis C core antigen (HCVcAg) assay in a decentralized, resource-limited setting. This is a descriptive cross-sectional study from a highly endemic area of Karachi, Pakistan. Between October 2019 and July 2020, subjects aged 12 years and above who screened positive for HCV antibodies were simultaneously tested for HCV RNA (Xpert HCV Viral Load, GeneXpert® IV, Cepheid, France) and HCVcAg (ARCHITECT HCV Ag assay, Abbott® Diagnostics) to confirm active HCV infection. An Abbott ARCHITECT® i1000SR Immunoassay Analyser was installed at a local district hospital as a point-of-care (POC) facility for HCVcAg testing, while samples for HCV RNA were tested in a central lab. Two hundred individuals (mean age 46.4 ± 14.5 years, 71.5% females), who screened positive for HCV antibody, were included in the study. HCV RNA was detected in 128 (64.0%) while HCVcAg was reactive in 119 (59.5%) cases. Performance of the Immunoassay Analyser was excellent with a higher throughput and quicker readout value compared to the GeneXpert System. The sensitivity and specificity of HCVcAg (≥10 fmol/L) at HCV RNA thresholds of ≥12 was 99.1% (95% CI: 95–100%) and 87.6% (95%CI: 78.4–94%). A strong agreement was observed between the HCVcAg assay and HCV RNA. The ARCHITECT HCV Ag assay showed high sensitivity and specificity compared to HCV RNA in a decentralized, resource-limited setting. It can therefore be used as a confirmatory test in HCV elimination programs, particularly for low-income countries such as Pakistan.

Village-to-village screening for hepatitis B and C using quantitative HBsAg and anti-HCV testing with reflex HCV core antigen tests in the remote communities of a resource-rich setting: a population-based prospective cohort study

ObjectivesCommunity-based screening for hepatitis B virus (HBV) and hepatitis C virus (HCV) is essential for hepatitis elimination. This study attempted to increase screening accessibility and efficacy by using alternative tools.DesignPopulation-based...

Architect HCV Ag assay is an efficient alternative tool to RNA qRT-PCR quantification for assessing viral load in HCV infection

Objective To evaluate the performance characteristics of the automated Architect hepatitis C virus (HCV) core Ag assay versus HCV RNA by PCR among Egyptian patients and to assess its use for valuable clinical workup. Background HCV diagnosis by conventional anti-HCV assays has high rate of false positivity, false negativity, and a limited sensitivity for detection. Although HCV RNA assays are a reliable method for HCV diagnosis, they need technical skills and may also have false-positive results because of contamination. Moreover, the test is time consuming and more expensive. In contrast, the HCV core antigen test detects circulating HCV core antigen and identifies individuals who are actively infected with HCV. A commercialized test (the Architect HCV core antigen test) is supposed to have a sensitivity to detect ∼0.06 pg/ml and consequently a significant increase in sensitivity over the previous assay and a stronger correlation with HCV RNA testing. Patients and methods A descriptive, cross-sectional study was conducted on 60 HCV antibody-positive patients attending the outpatient clinic of Tropical Medicine Department, Al-Hussein University Hospital, Cairo, Egypt. The patients were classified into four groups based on the level of HCV viremia: group A included five patients with PCR below detection limit (12 IU/ml), group B included 39 patients with low viremia (&lt;100 000 IU/ml), group C included 13 patients with moderate viremia (100 000–10 000 000 IU/ml), and group D included three patients with high viremia (&gt;10 000 000 IU/ml). Each case was subjected to thorough clinical evaluation, HCV RNA quantification by Abbott Real Time HCV assay, and HCV Ag quantification by Architect HCV core antigen test. Results HCV Ag was found to be negative only in five of 55 HCV RNA-positive patients who had low level of viremia. The levels of HCV Ag showed a good correlation with those from the HCV RNA quantification (r=0.913, P≤0.001). Regarding HCV core antigen/HCV RNA ratio, it was not fixed for all patients. In most of them, each 1 pg/ml core Ag was equal to ∼10 000 IU/ml of RNA. Conclusion The Architect HCV Ag assay could be used as an alternative tool to HCV RNA PCR quantification in assessing viral load in HCV infection, and it has the advantages of lower cost, easy testing, and rapid reporting.

Real-world utility of HCV core antigen as an alternative to HCV RNA testing: Implications for viral load and genotype.

Following positive serology, the gold standard confirmatory test of hepatitis C virus (HCV) infection is detection of HCV RNA by PCR. We assessed the utility of HCV core antigen testing to identify active infection among those positive for anti-HCV antibodies, when introduced to routine testing. We identified serum samples that were tested at a single laboratory in Scotland from June 2011to December 2017. Serum samples testing positive for HCV antibodies (HCV Ab positive) followed by reflex HCV core antigen (Ag) testing during the study period were identified. Those patients for whom a PCR test was requested on the baseline sample were also identified. For this group, the sensitivity and specificity of HCV Ag as a diagnostic tool were assessed using HCV PCR as gold standard. In our cohort of 744 patients, we demonstrated a sensitivity of 82.1% (95% CI 77.1%-86.2%) and a specificity of 99.8% (95% CI 98.6%-100%). Genotype 3 was associated with increased odds of a false-negative result (OR=3.59, 95% CI: 1.32-9.71), and reduced odds of a false negative were associated with older age (odds ratio (OR)=0.92, 95% CI: 0.88-0.97 per year) and viral load (OR=0.10, 95% CI: 0.05-0.21 per log10 IU/ml). While the implementation of HCV core antigen testing for diagnosis could lead to significant cost savings in national screening programmes, our data suggest that a significant proportion of HCV-infected individuals may be missed. These findings have implications for HCV diagnosis and determination of viral clearance after treatment, particularly in low- and middle-income regions, where genotype 3 is prevalent.

HCV Core Antigen as an alternative test to Quantitative HCV RNA for assessment of SVR in Chronic HCV infected patients treated with Direct Acting Antiviral agents

Abstract Background and aims Widespread use of direct-acting antiviral (DAA) agents to treat patients with hepatitis C virus (HCV) infection has reduced the need for monitoring of HCV-RNA levels, because viral kinetics do not predict sustained virologic response (SVR) to these drugs. However, the performance of cheaper tests, such as the assay to quantify HCV core antigen (HCV Ag), has not been determined. This study was aimed at investigating the accuracy of the HCV Ag test in predicting which patients receiving DAAs will achieve SVR at week 12 (SVR12). Methods We performed a prospective study on 90 patients, chronically infected with HCV, receiving DAAs therapy from different NCCVH centers in Cairo during the period from August 2017 to June 2018. We collected blood samples and measured the levels of HCV core Ag and HCV-RNA at baseline and 12 weeks after end of treatment. We compared the ability of these assays to predict which patients would have SVR12. Results The median baseline level of HCV-RNA was 1688529.6 ± 994697.3 IU/ml (range, 312700 IU/ml to 3491100 IU/ml) and HCV Ag was 179.2 ± 83.5 pg/ml (range, 33.5 pg/ml to 315.6 pg/ml). HCV Ag became undetectable in 92.2% 12 weeks after the end of treatment. HCV-RNA became undetectable in 87.8% at the end of treatment (P&amp;lt;.0001). 79 out of 90 patients (87.8%) achieved an SVR12; the test for HCV Ag identified 63.6% of these patients. Conclusions Tests that measure HCV Ag monitor efficacy of DAA therapy for HCV infection as well as assays that measure HCV-RNA, and hence could be recommended for clinical practice.

Can hepatitis C virus core antigen replace quantitative RNA in the assessment of a sustained virologic response?

BackgroundThe widespread use of direct-acting antivirals (DAAs) in the treatment of hepatitis C virus (HCV) infection has reduced the need for monitoring HCV-RNA levels because viral kinetics do not predict a sustained virologic response (SVR). However, the performance of cheaper tests, such as the assay to quantify hepatitis C virus core antigen (HCV Ag), has not been determined. Our aim was to assess the accuracy of the HCV core Ag test in predicting the achievement of SVR and its predictive value as a monitoring test in the course of treatment.Patients and methodsThis prospective study was carried out on 90 patients, chronically infected with HCV, who received DAA therapy. Blood samples were collected and the levels of HCV core Ag and HCV-RNA were measured at baseline and at 12 weeks after the end of treatment. We compared the ability of these assays to predict which patients would achieve SVR12.ResultsThe baseline level of HCV-RNA was 1 688 529.6±994 697.3 IU/ml (range: 312 700–3 491 100 IU/ml) and HCV core Ag was 179.2±83.5 pg/ml (range: 33.5–315.6 pg/ml). HCV Ag became undetectable in 92.2% 12 weeks after the end of treatment, whereas HCV-RNA became undetectable in 87.8% at the end of treatment (P<0001). Seventy-nine out of 90 (87.8%) patients achieved SVR12; the test for HCV Ag identified 63.6% of these patients.ConclusionMeasurement of HCV core Ag can monitor the efficacy of DAA therapy for HCV infection. Thus, it can be applied in clinical practice.

Seronegative hepatitis C virus infection in Polish blood donors-Virological characteristics of index donations and follow-up observations.

Nucleic acid testing (NAT) was implemented in Poland in 1999 for screening of plasma for fractionation and for all blood donors in 2002. To analyze seronegative NAT‐positive samples representing hepatitis C virus (HCV) window‐period (WP) in the years 2000 to 2016 and to determine infection outcome. We analyzed results of 17 502 739 donations screened in minipools (6‐48) or individually. Index samples underwent viral load (VL) quantification, genotyping and Ag, and anti‐HCV re‐testing using chemiluminescence (CMIA), electrochemiluminescence (ECLIA), and fourth‐generation enzyme‐linked immunosorbent assay (IV EIA) assays. HCV‐seronegative infections were identified in 126 donations (7.2/mln donations; 95% confidential intervals, 6.0‐8.6). Frequency of NAT yields was decreasing over time. Of the initial 126 seronegative index cases 106 were retested: 32.1% were reactive in IV EIA, 11.3% in ECLIA, and 1.9% in CMIA. The lowest VL correlated with absent anti‐HCV and HCV Ag, while VL was highest when the antigen was detectable and then it decreased when anti‐HCV appeared at a level detectable by sensitive third generation tests while retesting. The proportion of genotype 1 was 38.9% in samples positive only for HCV RNA and 71.4% in samples that were anti‐HCV reactive in re‐testing. In parallel, genotype 3 frequency was 50% in the former group and 21% in the latter. NAT is an effective measure to limit HCV transmission by transfusion and IV EIA seems to have higher clinical sensitivity than ECLIA. Samples representing likely successive phases of early HCV infection were characterized by different genotype distribution probably due to very early elimination of genotype 3.

Community screening for hepatitis C virus infection in a low-prevalence population

BackgroundAge cohort screening for hepatitis C virus (HCV) might be an effective strategy if the majority of undiagnosed cases are concentrated in a particular age group. The objective of this study was to determine HCV prevalence in different age cohorts of the general population in the Central European part of Russia and second, to assess feasibility of HCV antigen testing for community screening programs.MethodsSera from 2027 volunteers were tested for anti-HCV (Architect Anti-HCV, Abbott Laboratories). All anti-HCV reactive samples were confirmed in an immunoblot and tested for HCV Ag (ARCHITECT HCV Ag, Abbott Laboratories), HCV RNA and HCV viral load.ResultsOut of 31 individuals with anti-HCV reactive result, 22 (71%) were confirmed by immunoblot, six were false positives and three were indeterminate. Active infection was observed in 73% of anti-HCV confirmed positives. Five out of 16 individuals had low HCV-RNA levels (< 10,000 IU/mL) and one of those had a very low level (594 IU/mL). Agreement between HCV Ag and HCV RNA was 100%. Total anti-HCV and active HCV infection rates were 1.09% (22/2027) and 0.79% (16/2027), respectively. The peak rates were observed in people 60 years or older (anti-HCV: 2.84% [95% CI: 1.66–4.74%], 13/319; HCV RNA/HCV Ag: 2.23% [95% CI: 1.20–4.00%], 10/319).ConclusionsOverall HCV prevalence is low, except in people 60 years or older. The latter should be considered as a target group for HCV screening. The high agreement between HCV RNA and HCV Ag suggests the utility of HCV Ag testing to confirm active infection in screening programs.

Hepatitis C core antigen highly correlated to HCV RNA

Hepatitis C virus core antigen (HCV-Ag) immunoassay has been proposed as a more cost and time efficient one-step alternative to the current two-step screening and diagnostic process. This study investigates the correlation between the HCV-Ag immunoassay and the current gold standard of Hepatitis C Virus (HCV) ribonucleic acid (RNA) molecular assay. Stored sera of 221 consecutive treatment-naive patients tested anti-HCV positive were selected to undergo both HCV-Ag immunoassay and HCV RNA molecular assay. Active infection status and HCV genotype were determined using both assays, and correlation was calculated using a logarithmic scale. Among 221 anti-HCV-positive sera, 197 were positive for both HCV Ag (≥3 fmol/L) and HCV RNA (>15 IU/mL), 22 were negative for both tests, while 2 were positive to HCV RNA only. The sensitivity and specificity for HCV Ag in predicting HCV RNA were 99% and 100%, respectively. Out of 199 patients (90%) tested positive for HCV viremia, 107 (56%) were of genotype 1, 77 (38.7%) of genotype 2 and 15 of other genotypes. Analysis of 221 anti-HCV-positive patient sera found a strong positive correlation between HCV RNA and HCV-Ag (r = 0.960, p < 0.001). Genotype 1 (log [HCV RNA] = 0.988 x log [HCV-Ag] + 2.768), with correlation coefficient 0.945, exhibited a stronger correlation than genotype 2 (log [HCV RNA] = 0.859 x log [HCV-Ag] + 2.859; r = 0.862). Given the strong positive correlation between HCV-Ag immunoassay and HCV RNA molecular assay in genotyping affected individuals, we propose that HCV-Ag immunoassay is a more cost and time efficient alternative to the current two-step diagnostic process.

THYROID DYSFUNCTION IN CHRONIC HEPATITIS C PATIENTS TREATED WITH PEG INTERFERON AND RIBAVIRIN

Introduction Hepatitis C virus (HCV)-RNA can be detected in the serum of most patients with chronic hepatitis C using the reverse transcription polymerase chain reaction. During therapy with interferon-a, levels of HCV-RNA tend to fall in parallel with serum aminotransferase activities. Generally, in patients whose serum aminotransferases reach normal levels, HCV-RNA becomes undetectable. When hepatitis relapses after interferon (IFN) is stopped, HCV-RNA promptly reappears in serum. Patients with a sustained response to interferon have persistently normal serum aminotransferases and undetectable HCV-RNA after stopping interferon. Hepatitis C viral antigen is detectable by immunostaining of liver in the majority of patients with chronic hepatitis C. The intensity of staining for HCV antigen (HCV Ag) before therapy may be a useful predictor of response to treatment. HCV Ag staining decreases with IFN therapy and may become undetectable in patients who respond with normalization of serum aminotransferases and loss of HCV-RNA from serum. Thus, HCV-RNA in serum and HCVAg in liver appear to be useful markers of HCV infection to follow during therapy with IFN-a. Low levels of these markers may indicate an increased likelihood of responding to IFN therapy. Their absence at the end of therapy does not necessarily predict that relapse of hepatitis will not occur. However, their prolonged absence, months or even years after stopping IFN, appears to be a feature of a sustained response to IFN.

Hepatitis C virus core antigen for screening organ donors and recipients

Organ donors and recipients are routinely screened for hepatitis C virus (HCV) infection, typically via anti-HCV detection. We analyze the utility of an alternative HCV core antigen (HCV-Ag) quantification system, the ARCHITECT HCV Ag Assay, in this setting. We simultaneously tested 315 samples from potential organ donors and recipients using two chemiluminescent microparticle immunoassays: ARCHITECT Anti-HCV and HCV Ag (Abbott, Germany). HCV-Ag was detected in 81 of the serum samples (25.71%) and anti-HCV in 87 (27.62%). Seventy-five of the HCV-Ag–positive samples were positive for anti-HCV (92.59%). Overall concordance between the two assays was 94.29%. Of the six HCV-Ag–positive/anti-HCV–negative patients, five had HCV-Ag values <32 fmol/L, and the sixth had a concentration of 477.50 fmol/L (viral load, 137,000 IU/mL). The HCV AG Assay detects HCV infections missed by the Anti-HCV Assay. Both markers should be used to screen for HCV infection in potential organ donors and recipients.