title: Evaluation of a total hepatitis C virus (HCV) core antigen assay for the detection of antigenaemia in anti-HCV positive individuals.
abstract: 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.
authors.affiliation: Department of Pathology and Laboratory Medicine, Section of Microbiology, University of Parma, Parma, Italy. micromed@ipruniv.cce.unipr.it
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Valcavi
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Medici
authors.forename: Francesca
authors.initials: F
authors.lastname: Casula
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Arcangeletti
authors.forename: Flora
authors.initials: F
authors.lastname: De Conto
authors.forename: Federica
authors.initials: F
authors.lastname: Pinardi
authors.forename: Adriana
authors.initials: A
authors.lastname: Calderaro
authors.forename: Carlo
authors.initials: C
authors.lastname: Chezzi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Dettori
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay; D016174:Hepacivirus / Q000276:immunology / Q000302:isolation & purification*; D006526:Hepatitis C / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D018937:Hepatitis C Antibodies / Q000097:blood*; D018936:Hepatitis C Antigens / Q000097:blood; D006801:Humans; D015151:Immunoblotting; D012367:RNA, Viral / Q000097:blood; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D014758:Viral Core Proteins / Q000097:blood*; D014766:Viremia / Q000175:diagnosis
chemical_list: D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens; D012367:RNA, Viral; D014758:Viral Core Proteins; C069130:nucleocapsid protein, Hepatitis C virus