Evaluation of a new enzyme immunoassay for hepatitis C virus (HCV) core antigen with clinical sensitivity approximating that of genomic amplification of HCV RNA.
The aim of this study was to analyze the clinical performance of a new enzyme immunoassay (EIA) for hepatitis C virus (HCV) core antigen in comparison with the reverse transcription polymerase chain reaction (RT-PCR). A total of 310 patients with acute or chronic hepatitis C, and 132 HCV-negative controls were studied. Chemiluminescence EIA with monoclonal anti-HCV core antigen was used, and qualitative and quantitative commercial RT-PCRs and an in-house nested RT-PCR were performed. Compared with nested RT-PCR, the core antigen assay showed 97% sensitivity and 100% specificity in 75 patients with chronic hepatitis C and 132 controls. HCV core antigen was positive in 16 (94%) of 17 patients with acute hepatitis C at initial consultation. In 3 persons prospectively followed, core antigen was detected in the first available (1-3 weeks) post-transfusion sample. In 167 anti-HCV-positive individuals, 129 (77%) were viremic; core antigen was detected in 126 (98%) compared with 129 (100%) for nested RT-PCR and 121 (94%) for the commercial RT-PCR. In 48 patients with chronic hepatitis C treated with interferon alfa, the concentration of core antigen before treatment was significantly (P <.002) lower in patients with sustained response than in nonresponders. All responders had a sustained loss of core antigen, whereas all nonresponders remained core antigen positive. The concentrations of HCV core antigen and HCV RNA correlated significantly (n = 48, r =.627, P <.001). In conclusion, the HCV core antigen assay is useful for the diagnosis of acute and chronic hepatitis C, and for predicting and monitoring the effect of interferon alfa treatment.
Second Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan. etanaka@hsp.md.shinshu-u.ac.jp
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E
Tanaka
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C
Ohue
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Aoyagi
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Yamaguchi
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Yagi
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Kiyosawa
H J
HJ
Alter
D000208:Acute Disease; D000328:Adult; D000368:Aged; D005260:Female; D016174:Hepacivirus / Q000276:immunology*; D018936:Hepatitis C Antigens / Q000097:blood*; D019698:Hepatitis C, Chronic / Q000175:diagnosis / Q000188:drug therapy; D006801:Humans; D007124:Immunoenzyme Techniques; D016898:Interferon-alpha / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D065227:Transfusion Reaction; D014758:Viral Core Proteins / Q000097:blood*
D018936:Hepatitis C Antigens; D016898:Interferon-alpha; D012367:RNA, Viral; D014758:Viral Core Proteins; C069130:nucleocapsid protein, Hepatitis C virus