No abstract available.
Hepatitis C/*diagnosis ; Hepatitis C Antibodies/*blood ; Humans ; Immunoenzyme Techniques ; RNA, Viral/*blood ; Viremia/*diagnosis

BACKGROUND: Anti-hepatitis C virus antibody (anti-HCV) assays are recommended for screening HCV-infected persons. The VIDAS Anti-HCV Assay (bioMérieux, France), based on the enzyme-linked fluorescence test principle, was recently introduced in Korea. We evaluated the clinical performance of the VIDAS assay. METHODS: One hundred HCV-positive and 1,002 HCV-negative blood samples confirmed by Architect anti-HCV (Abbott Laboratories, USA) and COBAS TaqMan HCV real-time PCR (Roche Diagnostics, USA) or the Procleix Ultrio Plus Assay (Gen-Probe Incorporated, USA) were obtained from the Human Serum Bank (HSB) and tested by VIDAS. In case of discrepant results, we conducted a recombinant immunoblot assay (RIBA). RESULTS: The agreement rates for known HCV-positive and HCV-negative samples between the VIDAS assay and the HSB testing were 100% (95% confidence interval [CI]: 96.4-100%) and 99.5% (95% CI: 98.8-99.8%), respectively. One of the five discrepant samples was positive for Core 2+ and NS3-2 2+ reactivity, two samples were negative, and the other two were indeterminate regarding NS4 2+ reactivity in RIBA. We observed a significant but weak positive correlation between the titers of VIDAS and Architect assays (r=0.315, P<0.001). CONCLUSIONS: The VIDAS anti-HCV assay, developed on the VIDAS automated immunoassay platform based on the ready-to-use, single-sample test concept may be useful in small-to-medium-sized laboratories. It showed good agreement with Architect anti-HCV and COBAS PCR assays and is therefore useful for detection of HCV infection. Weakly test-positive (ambiguous) samples require additional testing by another anti-HCV, RIBA, or HCV RNA assay.
Automation ; Hepatitis C/*diagnosis ; Hepatitis C Antibodies/*blood ; Humans ; *Immunoassay ; Immunoblotting ; Reagent Kits, Diagnostic ; Sensitivity and Specificity

Hepatitis C ; diagnosis ; Hepatitis C Antibodies ; blood ; Humans ; Serologic Tests ; Viral Envelope Proteins ; immunology

BACKGROUNDTo study the antibody against hepatitis C virus first envelope (HCV-E1) protein in the sera from patients with HCV and to evaluate the application of HCV-E1 antigen in detection of HCV antibody.

METHODSPurified E1 engineering protein was used as antigen to develop an ELISA for detecting E1 antibody in 80 national reference sera, 821 blood donors' sera and l20 sera from clinical patients with hepatitis.

RESULTSAnti-HCV E1 was positive in 70% (28/40) and negative in 100% (40/40) of 80 national reference sera, and 1.9% (16/821) was positive in blood of the sera donors' and 68% (492/720) positive in sera of patients with hepatitis. Most anti-HCV E1 positive sera were positive for core, NS 3 and NS 5A, but only a few sera were positive for E1 antigen. Of the sera from 218 clinical patients, 813 blood donors and 848 normal people that were anti-HCV negative tested by commercial anti HCV ELISA kit, 1.4%, 1.1% and 0.9% were anti-HCV E1 positive, respectively. Investigation of seroconversion on three patients showed that anti-E1 was first detectable.

CONCLUSIONSDetection of anti-HCV E1 by engineered E1 protein is sensitive and specific. The prevalence and early presence of E1 antibody in HCV infected patients reflect the active status of the disease to a certain extent. Detection of the antibody is useful in clinical diagnosis.

Enzyme-Linked Immunosorbent Assay ; Hepatitis C ; diagnosis ; Hepatitis C Antibodies ; blood ; Humans ; Viral Structural Proteins ; immunology

Enzyme-Linked Immunosorbent Assay ; Hepacivirus ; genetics ; Hepatitis C ; diagnosis ; drug therapy ; Hepatitis C Antibodies ; blood ; Humans

Hepacivirus ; classification ; genetics ; Hepatitis C ; diagnosis ; Hepatitis C Antibodies ; blood ; Humans ; RNA, Viral ; blood ; Viral Core Proteins ; blood

To evaluate the clinical feasibility of the antibody titer against a chimeric polypeptide (named Core 518), in which a domain of Core and NS3 of hepatitis C virus (HCV) was fused, ELISA was performed in a total of 76 serum samples. Each serum was serially diluted using two-fold dilution method with distilled water into 10 concentrations. They were all positive for second generation anti-HCV assay (HCV EIA II; Abbott Laboratories). Genotyping RT-PCR, quantitative competitive RT-PCR, and RIBA (Lucky Confirm; LG Biotech) were also assayed. Anti-Core 518 antibody was detected in x 12800 or higher dilutions of sera from 35 of 43 chronic hepatitis C (81.4%) and nine of 16 hepatocellular carcinoma sera (56.3%), one of four cirrhosis (25%), 0 of four acute hepatitis C, and one of nine healthy isolated anti-HCV-positive subjects (p=0.0000). The anti-Core 518 antibody titers were well correlated with the presence of HCV RNA in serum (p=0.002). The anti-Core 518 antibody titers decreased significantly in nine of ten responders to IFN-alpha treatment. Monitoring anti-Core 518 titers may be helpful not only for differentiating the status of HCV infection among patients with various type C viral liver diseases, but also for predicting responses to IFN-alpha treatment.
Adult ; Aged ; Female ; Genotype ; Hepatitis C/immunology* ; Hepatitis C/drug therapy* ; Hepatitis C/diagnosis ; Hepatitis C/blood ; Hepatitis C Antibodies/immunology* ; Hepatitis C Antibodies/blood ; Hepatitis C Antigens/immunology* ; Hepatitis C-Like Viruses/immunology* ; Hepatitis C-Like Viruses/genetics ; Human ; Immunoblotting ; Interferon Alfa-2a/therapeutic use* ; Male ; Middle Age ; RNA, Viral/blood ; Recombinant Fusion Proteins/immunology ; Viral Core Proteins/immunology* ; Viral Nonstructural Proteins/immunology*

Clinical Laboratory Techniques ; Enzyme-Linked Immunosorbent Assay ; Hepatitis C ; diagnosis ; Hepatitis C Antibodies ; blood ; Humans ; RNA, Viral ; blood

INTRODUCTIONDried blood spot (DBS) collection is an appealing alternative to whole blood or plasma sampling, as it has technical and economic advantages over the latter.

MATERIALS AND METHODSA prospective cross-sectional study was conducted at a Malaysian tertiary referral hospital from November 2009 to March 2010. One hundred and fifty paired specimens of DBS and plasma were analysed by the standard assays for HIV Ag/Ab, HBsAg, anti-HBS and anti-HCV, separately (total 600 paired specimens). DBS sample titres were then compared to the results of plasma testing, which was used as the gold standard.

RESULTSFor the HIV Ag/Ab assay with a cut-off point of 0.35 Relative Light Units (RLUs), the sensitivity and specificity were both 100%. For the HBsAg assay, the sensitivity was 96.5% and the specificity was 97.8%, with a cut-off point of 1.72 RLUs. Sensitivity for the anti-HBs test was 74.2% and the specificity was 86.9%, using a cut-off point of 0.635 RLUs. For the anti-HCV assay, the sensitivity was 97.3% and the specificity was 100%, with a cut-off point of 0.10 RLUs.

CONCLUSIONDBS is an ideal choice to be used as a screening tool for the detection of HIV, Hepatitis B and Hepatitis C virus infections. However, different cut-off values need to be used for the validation of test positivity in DBS samples because the small amount of blood in the DBS specimens leads to lower assay titres.

Cross-Sectional Studies ; Dried Blood Spot Testing ; HIV Antibodies ; blood ; immunology ; HIV Antigens ; blood ; immunology ; HIV Infections ; diagnosis ; Hepacivirus ; isolation & purification ; Hepatitis B ; diagnosis ; Hepatitis B Antibodies ; blood ; immunology ; Hepatitis B Surface Antigens ; blood ; immunology ; Hepatitis C ; diagnosis ; Hepatitis C Antibodies ; blood ; immunology ; Hepatitis C Antigens ; blood ; immunology ; Humans ; Malaysia ; Plasma ; virology ; Prospective Studies ; Referral and Consultation ; Sensitivity and Specificity ; Specimen Handling

BACKGROUND/AIMS: Hepatitis C virus (HCV) RNA testing can be performed using qualitative or quantitative assays, and it is still unclear which is more useful as a primary test in patients positive for anti-HCV. The present study evaluated the usefulness of anti-HCV signal-to-cutoff ratio (S/CO ratio) for predicting HCV RNA results. METHODS: Patients on whom a qualitative HCV RNA test was performed due to a positive anti-HCV enzyme immunoassay were enrolled. Patients were divided into viremia and no-viremia groups according to HCV RNA results. Receiver-operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic accuracy of anti-HCV S/CO for a diagnosis of viremia. RESULTS: In total, 487 patients were enrolled. HCV RNA was positive in 301 subjects (61.8%). Age, serum ALT level, and anti-HCV S/CO ratio were significantly different between the viremia and no-viremia groups. By ROC curve analysis, anti-HCV S/CO ratio (area, 0.989; 95% confidence interval, 0.981 to 0.998) accurately predicted the presence of viremia, with a cutoff value of 10.9 (sensitivity, 94.4%; specificity, 97.3%). CONCLUSIONS: Anti-HCV S/CO ratio was found to be highly accurate at predicting HCV viremia. The anti-HCV S/CO ratio can be used to determine whether a quantitative or qualitative HCV RNA test should be used to confirm HCV viremia in patients with a positive anti-HCV by the following criteria: if the anti-HCV S/CO ratio is <10.9, a qualitative HCV RNA test can be used, and if the anti-HCV S/CO ratio is > or =10.9 a quantitative HCV RNA test can be performed.
Adult ; Aged ; Female ; Hepatitis C/*diagnosis ; Hepatitis C Antibodies/*blood ; Humans ; Immunoenzyme Techniques ; Male ; Middle Aged ; RNA, Viral/*blood ; Viremia/*diagnosis