Application of a new enzyme‐linked immunosorbent assay for detection of total hepatitis C virus core antigen in blood donors

Cano, Horacio; Candela, M. J.; Lozano, Marı́a Luisa; Vicente, Vicente

doi:10.1046/j.1365-3148.2003.00452.x

Cited by 25 publications

(23 citation statements)

References 27 publications

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“…HCV core antigen was detected in the vast majority (94.7%) of specimens containing HCV-RNA. Our results are not surprising considering previous findings [Cano et al, 2003;Laperche et al, 2003;Lunel et al, 2003]. The limit of detection of the trak-C assay in IU/mL of HCV-RNA using the WHO 96/ 793 standard has been reported to be approximately 10,000 .…”

Section: Discussionsupporting

confidence: 83%

Evaluation of a total hepatitis C virus (HCV) core antigen assay for the detection of antigenaemia in anti‐HCV positive individuals

Valcavi

Medici

Casula

et al. 2004

Journal of Medical Virology

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A new, sensitive enzyme immunoassay has been developed for detecting and quantifying total hepatitis C virus (HCV) core antigen in anti-HCV positive or negative sera ("trak-C", Ortho Clinical Diagnostics, Raritan, NJ). The purpose of this study was to evaluate the performance of trak-C as an additional laboratory diagnostic marker of viraemia. The performance was compared to HCV-RNA detection in the "screening" of sera from a large heterogeneous population of hospitalised patients and outpatients. Six hundred and eighteen anti-HCV negative sera, 405 anti-HCV positive/HCV-RNA negative sera, 604 anti-HCV positive/HCV-RNA positive sera and 67 anti-HCV negative sera containing antigens or antibodies potentially interfering with the performance of the assay were analysed. Supplemental HCV antibody testing was performed using a commercial strip immunoblot assay. HCV-RNA was investigated using a qualitative commercial assay. A quantitative commercial RT-PCR was used for the analysis of selected samples. Sensitivity and specificity values were 94.7 and 100%, respectively. The latter was also confirmed when anti-HCV negative samples containing potentially interfering antigens/antibodies were examined. Sensitivity below 100% was probably due to an antigenaemia below the detection limit of trak-C. Besides, because 65.6% of HCV-RNA positive/trak-C negative samples presented specific antibodies against all four RIBA antigens, the hypothesis was raised that, in some cases, the dissociation step efficiency could be sub-optimal. In conclusion, trak-C seems suitable for identifying HCV infection on large based populations. It is a rapid to perform, reliable and specific assay that can be adapted to any laboratory setting.

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Section: Discussionsupporting

confidence: 83%

Evaluation of a total hepatitis C virus (HCV) core antigen assay for the detection of antigenaemia in anti‐HCV positive individuals

Valcavi

Medici

Casula

et al. 2004

Journal of Medical Virology

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“…To the best of our knowledge, five studies evaluated the usefulness of HCV core antigen as a marker of active/ongoing HCV infection in the therapynaïve patients [Cano et al, 2003;Agha et al, 2004;Krajden et al, 2004;Netski et al, 2004;Valcavi et al, 2004]. These studies reported on HCV RNA positive samples from 114 to 348 and showed the OTCA to be 86.9-97.4% as sensitive as NAT.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of a total core antigen assay for the diagnosis of hepatitis C virus infection in hemodialysis patients

et al. 2005

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Hemodialysis patients are recognized as a group at high risk of infection with hepatitis C virus (HCV). Therefore, such a population should be screened routinely for the presence of HCV viremia. Since nucleic acid techniques remain expensive and largely unavailable in many laboratories in the developing world, the present study assesses the clinical usefulness of the HCV core antigen enzyme immunoassay for the diagnosis of HCV infection in dialysis patients. One hundred seventy-five dialysis patients were screened for the presence of anti-HCV antibodies and HCV RNA in the serum. One hundred twenty-eight serum samples were collected from the 76 patients who were anti-HCV antibody- and/or HCV RNA-positive. These were evaluated for total HCV core antigen. Of these samples, 55 had sufficient volume to be further tested to quantify HCV RNA by reverse transcription polymerase chain reaction (RT-PCR). Genotyping of the HCV strains showed that the majority belonged to genotype 1b (77%). The HCV core antigen assay showed a sensitivity and specificity of 84% and 89%, respectively. The use of core antigen assay has enabled the early detection of three patients who developed an acute hepatitis C infection during the period of study. A correlation study was undertaken between the quantitative values of viral load, expressed as pg/ml of HCV core antigen in serum, and viral RNA in UI/ml. A significant correlation was observed (Pearson's correlation coefficient: 0.552; P<0.001). In conclusion, detection of HCV core antigen in serum is an inexpensive, reliable, and highly specific assay that can be useful in most laboratory settings to diagnose HCV infection, and especially in laboratories where nucleic acid technologies are not yet available.

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“…surement of HCV RNA viral load (2,12,20). This test has also been shown to be appropriate for screening for HCV infection in blood donors (3). The ability of this assay to identify viremic subjects in the general population has never been evaluated prospectively.…”

Section: Discussionmentioning

confidence: 99%

Usefulness of the Hepatitis C Virus Core Antigen Assay for Screening of a Population Undergoing Routine Medical Checkup

et al. 2005

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We studied the usefulness of the recently designed Trak-C assay for the detection and quantification of the hepatitis C virus (HCV) core antigen (Ag) for the screening of HCV infection in 4,201 subjects selected from 74,150 consecutive volunteers undergoing routine medical checkups. Subjects were selected for screening because they had risk factors (group II, n ‫؍‬ 321) and/or elevated alanine transaminase activity (group I, n ‫؍‬ 3847). Initially, the anti-HCV antibody assay and the Trak-C assay were performed on each patient. Subsequently, the Trak-C assay was performed only when the anti-HCV enzyme immune assay (EIA) was positive. Positive samples were further evaluated for anti-HCV antibodies by a third-generation strip immunoblot assay and for HCV RNA. Four samples (1.2%) from group II and 113 (2.9%) from group I were anti-HCV EIA positive. We also tested 33 subjects who previously tested positive for anti-HCV in our medical center. Among the 150 anti-HCV EIA-positive samples, the HCV core Ag result was in accord with the HCV RNA result in 146 cases (97.3%). When the EIA result was positive, the HCV core Ag concentration and the HCV RNA load were correlated (r 2 ‫؍‬ 0.78; P < 0.001). Four samples with low viral loads were Trak-C negative but HCV RNA positive. Among the 2,395 anti-HCV EIA-negative serum samples collected during the first part of the study, 17 (0.7%) were found to contain very low levels of HCV core Ag (<8.5 pg/ml, the cutoff value being 1.5 pg/ml). All these samples were HCV RNA negative and considered to be false positives. This was confirmed by HCV core Ag neutralization analysis. The HCV core Ag assay is a useful method in the screening strategy of HCV infection and provides a reliable means of distinguishing between current and cleared HCV infections that is well correlated with HCV RNA testing.The method currently recommended for identifying subjects with hepatitis C virus (HCV) infection is an enzyme immune assay (EIA) for the detection of anti-HCV antibodies (16). However, this assay sometimes generates false-positive or false-negative results. Furthermore, it is not always possible to distinguish between current and past cleared infections. Thus, supplementary tests are required. The strip immunoblot assay, a more specific anti-HCV serological test, is useful to distinguish true-positive from false-positive EIA results. Positive results from nucleic acid testing (NAT) for HCV RNA indicate active HCV infection (1). Assays that detect the HCV core antigen (Ag) have been developed to diagnose current HCV infection. The first such assay developed was a qualitative assay, conceived for screening blood donations. This assay increased viral safety by significantly reducing the length of the window preceding seroconversion (4, 13). A second test was subsequently developed for the detection and quantification of total HCV core antigen (Trak-C; Ortho-Clinical Diagnostics, Raritan, N.J.). This assay, incorporating an immune complex dissociation step, was designed for blood donation screening (3...

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Application of a new enzyme‐linked immunosorbent assay for detection of total hepatitis C virus core antigen in blood donors

Cited by 25 publications

References 27 publications

Evaluation of a total hepatitis C virus (HCV) core antigen assay for the detection of antigenaemia in anti‐HCV positive individuals

Evaluation of a total hepatitis C virus (HCV) core antigen assay for the detection of antigenaemia in anti‐HCV positive individuals

Evaluation of a total core antigen assay for the diagnosis of hepatitis C virus infection in hemodialysis patients

Usefulness of the Hepatitis C Virus Core Antigen Assay for Screening of a Population Undergoing Routine Medical Checkup

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