A novel antigen detection immunoassay for field diagnosis of hepatitis C virus infection.

Abstract

The limitations of dominant methods-based on the detection of anti-HCV antibodies or HCV viremia currently used for the diagnosis of HCV infection enhance efforts to have a rapid, simple, sensitive, and specific alternative diagnostic approach to detect viral antigens. A highly reactive IgG antibody was raised to HCV-NS4 recombinant antigen. The produced antibody showed no cross-reactivity with the other HCV structural and nonstructural recombinant antigens (C1 + 2, C3 + 4, E2/NS1, NS3, NS5). The well established ELISA technique was adapted to detect the new target HCV-NS4 antigen in serum samples. Extremely high agreement was found between the results of ELISA and qualitative detection of HCV-RNA, using a RT-PCR test as a gold standard for the diagnosis of HCV infection. Based on these encouraging results, a novel enzyme immunoassay; dot-ELISA was developed for rapid (approximately 5 min) and simple qualitative detection of the target HCV antigen in serum. The developed method detected the HCV target antigen in 95% of serum samples from HCV infected individuals, with a specificity of 97% using sera of noninfected individuals in comparison with PCR test. The antigen detection method showed high predictive values of positive (99%) and negative (90%). Moreover, the dot-ELISA could detect the HCV target antigen in sera negative for anti-HCV Abs, but positive for HCV-RNA, and in sera of HCV infected individuals with low viremia, as well as those with high viremia, using quantitative RT-PCR. Accordingly, the developed highly sensitive and specific HCV antigen detection method could be applied for mass screening of HCV infection.

• Authors: Abdelfattah M Attallah, Hisham Ismail, Ashraf A Tabll, Gamal E Shiha, Ibrahim El-Dosoky
• Journal: Journal of immunoassay & immunochemistry (J Immunoassay Immunochem) Vol. 24 Issue 4 Pg. 395-407 ( 2003) ISSN: 1532-1819 [Print] England
• PMID: 14677657 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Hepatitis C Antibodies
• Hepatitis C Antigens
• Immunoglobulin G
• NS4 protein, hepatitis C virus
• RNA, Viral
• Recombinant Proteins
• Viral Nonstructural Proteins

Topics

• Adolescent
• Adult
• Diagnosis, Differential
• Egypt (epidemiology)
• Enzyme-Linked Immunosorbent Assay (methods)
• Hepatitis C (diagnosis, epidemiology)
• Hepatitis C Antibodies (immunology)
• Hepatitis C Antigens (analysis, blood, immunology)
• Humans
• Immunoglobulin G (immunology)
• Male
• Mass Screening (methods)
• Middle Aged
• Polymerase Chain Reaction
• RNA, Viral (blood)
• Recombinant Proteins (analysis)
• Sensitivity and Specificity
• Viral Nonstructural Proteins (analysis, blood, immunology)