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.
Tanaka
E
E
Second Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan. etanaka@hsp.md.shinshu-u.ac.jp
Ohue
C
C
Aoyagi
K
K
Yamaguchi
K
K
Yagi
S
S
Kiyosawa
K
K
Alter
H J
HJ
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