Study of Hepatitis C Virus Detection Assays

Evaluation of an anti-HCV chemiluminescence assay: Enhancing diagnostic accuracy and reducing false positives in hepatitis C screening

OBJECTIVES

Detection of antibodies is recommended for the diagnosis and effective treatment of hepatitis C. This study evaluated the performance of a new chemiluminescence assay for detecting hepatitis C virus (HCV) antibodies and compared it with previous assays using a comprehensive set of routine and borderline samples.

METHODS

A total of 2,216 serum samples were included in this study, comprising of 2,121 routine clinical samples and 95 borderline cases (COI range: 0.9-5.0). We compared the Anti-HCV-2 assay's (Mindray Diagnostics, Shenzhen, China) performance with the Anti-HCV-1 assay, assessing key parameters including sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Precision was tested using replicate samples, and accuracy was validated through confirmatory RIBA (Mikrogen GmbH, Neuried, Germany) and Elecsys Anti-HCV assays (Roche Diagnostics, Mannheim, Germany). Interference testing was conducted to assess the assay's robustness against common substances found in clinical samples.

RESULTS

The Anti-HCV-2 assay demonstrated high sensitivity (98.2 %), specificity (99.1 %), and accuracy (98.7 %) in routine clinical samples. For borderline cases, the accuracy of Anti-HCV-2 was significantly higher (96.84 %) compared to Anti-HCV-1 (3.16 %). Precision testing showed a coefficient of variation (CV) of <2 %, indicating excellent reproducibility. Anti-interference testing confirmed that the Anti-HCV-2 assay performed consistently across samples with common interferences, such as hemolysis and lipemia.

CONCLUSION

The Anti-HCV-2 assay outperforms the Anti-HCV-1 assay in terms of accuracy, reproducibility, and reliability, especially in the range of borderline, making it a valuable tool for routine HCV screening.

Disposable and sensitive electrochemical magneto-immunosensor for point-of-care HCV diagnostics: Targeting HCVcAg, the active viremia biomarker, in patient samples

Early detection of hepatitis C virus (HCV) infection is crucial for eliminating this silent killer, especially in resource-limited settings. HCV core antigen (HCVcAg) represents a promising alternative to the current "gold standard" HCV RNA assays as an active viremia biomarker. Herein, a highly sensitive electrochemical magneto-immunosensor for the HCVcAg was developed. The biosensing strategy involved capturing HCVcAg using antibody-coated magnetic beads, followed by a sandwich immunoassay before electrochemical detection on disposable screen-printed electrodes. To achieve signal amplification and consequent enhanced sensitivity, the antigen-antibody reaction was detected with a biotinylated polyclonal antibody subsequently labelled with a streptavidin poly horseradish peroxidase conjugate followed by amperometric detection via a hydroquinone/hydrogen peroxide system. The developed biosensor exhibited a cathodic current variation directly proportional to the HCVcAg concentration over a wide range (0.1-500 ng/mL), with a detection limit of 10 pg/mL. Moreover, it successfully discriminated healthy control human plasma samples from HCVcAg-spiked samples, showed no interference from endogenous plasma constituents or cross-reactivity with other viruses tested, and possessed excellent percentage recoveries of HCVcAg (≥92.83%), demonstrating high specificity. The proposed bioplatform remained stable for at least ten days and showed excellent clinical performance in detecting HCVcAg across a cohort of thirty-six plasma and serum samples from active hepatitis C cases, and healthy individuals, with results matching those previously obtained using clinically validated qPCR and serological testing. In summary, this biosensor provides a simple, rapid and economic alternative to other available techniques such as ELISA and qPCR for early diagnosis of HCV infection.

Prevalence of hepatitis C virus antibodies and associated risks among residents in long-term assisted living facilities and shelters in Latvia

Aim of the study

This was a retrospective study which aimed to analyse two-year (October 1, 2020 to October 31, 2022) data collected by HIV Prevention Point employees during their routine work and to update hepatitis C virus (HCV) prevalence among residents of long-term assisted living facilities (LTALF) and shelters in Latvia. Key objectives included investigating risk factors associated with HCV infection and analysing demographic characteristics contributing to prevalence.

Material and methods

Retrospective analysis of the screening involved 46 LTALF and 6 shelters, randomly selected from Latvia's social service providers register where HCV rapid plasma immunochromatographic antibody tests were used, as well as demographic and risk-related questions asked to participants. Data were recorded, transferred to Google Sheets, and statistically analysed using SPSS software.

Results

Out of 2838 tests in LTALF and 349 in shelters, HCV prevalence was 4.2% and 12.0%, respectively. Risk factors such as intravenous narcotic use, incarceration, and unprotected sex were significantly associated with HCV prevalence in both populations. Males had higher prevalence rates than females, particularly in LTALF.

Conclusions

The study revealed an HCV prevalence in LTALF almost twice that of the general population and four times higher in shelters. Those denying prior incarceration or intravenous narcotic use still exhibited higher prevalence rates. Significant risk factors included intravenous narcotic use, prior incarceration and unprotected sex. The findings highlight the need for targeted interventions in these high-risk populations and emphasize the importance of tailored prevention, screening, and treatment strategies. The urgency of addressing elevated prevalence rates in LTALF and shelters is underscored, calling for immediate and targeted public health interventions.

The Study of Performance of a Nanoribbon Biosensor, Sensitized with Aptamers and Antibodies, upon Detection of Core Antigen of Hepatitis C Virus

The development of highly sensitive diagnostic systems for the early revelation of diseases in humans is one of the most important tasks of modern biomedical research, and the detection of the core antigen of the hepatitis C virus (HCVcoreAg)-a protein marker of the hepatitis C virus-is just the case. Our study is aimed at testing the performance of the nanoribbon biosensor in the case of the use of two different types of molecular probes: the antibodies and the aptamers against HCVcoreAg. The nanoribbon sensor chips employed are based on "silicon-on-insulator structures" (SOI-NR). Two different HCVcoreAg preparations are tested: recombinant β-galactosidase-conjugated HCVcoreAg ("Virogen", Watertown, MA, USA) and recombinant HCVcoreAg ("Vector-Best", Novosibirsk, Russia). Upon the detection of either type of antigen preparation, the lowest concentration of the antigen detectable in buffer with pH 5.1 was found to be approximately equal, amounting to ~10-15 M. This value was similar upon the use of either type of molecular probes.

Comparison of double antigen sandwich and indirect enzyme-linked immunosorbent assay for the diagnosis of hepatitis C virus antibodies

BACKGROUND

The aim of this study is to compare double-antigen sandwich enzyme-linked immunosorbent assay (ELISA) and indirect ELISA in the diagnosis of hepatitis C virus（HCV）infection.

METHODS AND MATERIALS

A total of 176 samples from the Tumor Hospital Affiliated to Xin Jiang Medical University were utilized to comparison. All serum samples were tested using double-antigen sandwich ELISA and indirect ELISA. Cohen's kappa statistics were used to assess the agreement between the two assays, and multivariate analysis was used to evaluate risk factors for the discordance between the double-antigen ELISA and indirect ELISA.

RESULTS

The positivities of indirect ELISA (Beijing Wantai), double-antigen sandwich ELISA (Beijing Wantai), and indirect ELISA (Beijing Jinhao) were 74.43%, 68.75%, and 73.30%, respectively. The agreement between the indirect ELISA (Beijing Wantai) and double-antigen sandwich ELISA (Beijing Wantai) was high (κ = 0.829;P < .001), and the agreement between the double-antigen sandwich ELISA (Beijing Wantai) and indirect ELISA (Beijing Jinhao) was high (κ = 0.847;P < .001). Variables associated with discordant results between the double-antigen sandwich and indirect ELISA in multivariate analysis were as follows: female (OR:1.462; P < .05), age (<35 years old; OR:3.667; P < .05), and cancer (suffer from malignant tumor; OR:3.621; P < .05).

CONCLUSION

In detection of HCV, high agreement was found between the double-antigen sandwich ELISA and indirect ELISA. Female, younger age, and suffer from malignant tumor were significant risk factors for the discordance. Based on double-antigen sandwich ELISA has distinct methodological advantages over indirect ELISA. It is recommended for the diagnosis of HCV infection.

Evaluation of a Novel Enzyme-Linked Immuno Assay Model to Detect E2 Antigen and Antibodies Against Core, NS3, NS4, and NS5 Antigens of Hepatitis C Virus

Background: The serological measurement of the anti‐hepatitis C virus antibody is a widely used tool in the first-line diagnosis of HCV infection. Therefore, increasing the testing criteria of these tests is of crucial importance for screening HCV infection. Objectives: The current study aimed to optimize a novel enzyme-linked immuno assay model to detect E2 antigen with or without sample pretreatment in combination with antibodies against core, NS3, NS4, and NS5 antigens of the hepatitis C virus and to compare the performances of these assays with indirect antigen (Ag), biotin/HRP labeled Antigen Sandwich and methods of enzyme-linked immunosorbent assay (ELISA) for their ability to detect HCV. Methods: A total of 107 positive and 415 negative controls from volunteer whole blood donors in Blood Transfusion Organization and 204 blood samples from patients under hemodialysis treatment in Tehran and Bandar Abbas hemodialysis centers are investigated. Six different methods of ELISA test were used to detect anti-HCV antibodies and/or HCV antigens in serum samples. Results: Regarding sensitivity, specificity, and accuracy, E2 Antigen detection alone or combined with antibody detection have the highest accuracy value (99% and 98%, respectively) compared to other methods for antibodies detection. The results of the combined Ag/Ab ELISA test were closer to the results of real-time PCR. Conclusions: This new approach to the detection of antigen and antigen/antibody has better performance criteria concerning the serologic detection of HCV, especially in HD patients who might experience a longer window period.

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.

Clinical diagnostic performance of light-initiated chemiluminescent assay compared with the Architect chemiluminescence immunoassay for detection of HCV antibody

BACKGROUND

Hepatitis C virus antibody (anti-HCV) test had been approved as a preliminary screening test for HCV infection. Light-initiated chemiluminescent assay (LiCA) was a homogenous method. We aimed to assess the clinical diagnostic performance of LiCA and compare it with that of chemiluminescence immunoassay (CLIA) which was widely used in clinical laboratories.

METHODS

A total of 10 772 patients from the Peking University Third Hospital were enrolled. The serum samples were detected on the ChIVD LiCA500 and Abbott Architect i2000SR platforms. Recombinant immunoblot assay (RIBA) and HCV RNA assay were used for confirmation.

RESULTS

The negative agreement rate between ChIVD LiCA anti-HCV assay and Abbott Architect anti-HCV assay was 99.91%, the positive agreement rate was 37.31%, the total agreement rate was 98.74%, and the kappa coefficient (κ) was 0.519. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ChIVD LiCA anti-HCV assay were 96.39%, 99.95%, 89.58%, and 99.97%, respectively, which were superior to those of Abbott Architect anti-HCV assay (93.98%, 99.25%, 51.90%, and 99.95%, respectively).

CONCLUSION

ChIVD LiCA anti-HCV assay was a highly sensitive, specific homogenous method with good diagnostic performance, and was applicable for the routine screening of HCV infection in clinical laboratories.