A novel antigen detection immunoassay for field diagnosis of hepatitis C virus infection.
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.
Attallah
Abdelfattah M
AM
R&D Department, Biotechnology Research Center, New Damietta City, Egypt. amattallah@hotmail.com
Ismail
Hisham
H
Tabll
Ashraf A
AA
Shiha
Gamal E
GE
El-Dosoky
Ibrahim
I
D000293:Adolescent; D000328:Adult; D003937:Diagnosis, Differential; D004534:Egypt / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006526:Hepatitis C / Q000175:diagnosis* / Q000453:epidemiology; D018937:Hepatitis C Antibodies / Q000276:immunology*; D018936:Hepatitis C Antigens / Q000032:analysis* / Q000097:blood / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000097:blood; D011994:Recombinant Proteins / Q000032:analysis; D012680:Sensitivity and Specificity; D017361:Viral Nonstructural Proteins / Q000032:analysis* / Q000097:blood / Q000276:immunology
D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens; D007074:Immunoglobulin G; C093542:NS4 protein, hepatitis C virus; D012367:RNA, Viral; D011994:Recombinant Proteins; D017361:Viral Nonstructural Proteins