Development of an enzyme immunoassay using recombinant expressed antigen to detect hepatitis delta virus antibodies.
Two generic enzyme immunoassays (EIAs) were developed for detection of anti-hepatitis delta virus antibodies (anti-HD) and compared with a commercially available radioimmunoassay. Both generic assays were configured as blocking assays and used hepatitis delta antigen (HDAg) derived from infected chimpanzee liver (EIA-1) or from Escherichia coli transformed with a plasmid containing an insert from within an open reading frame encoding HDAg (EIA-2). Absolute sensitivity was ascertained by endpoint titration, which demonstrated essentially identical endpoints for EIA-1 and EIA-2. The absolute sensitivities of the EIAs were approximately four times greater than that of the radioimmunoassay. Specificity and sensitivity were ascertained by testing a panel of 176 serum specimens by each assay. The specimens were selected to represent a panel composed of sera from individuals with or without markers of viral hepatitis as follows: (i) serologically confirmed by exclusion as posttransfusion non-A, non-B hepatitis; (ii) acute or chronic hepatitis B virus infection, positive for hepatitis B surface antigen; (iii) resolved hepatitis B virus infection, positive for anti-hepatitis B surface antigen; (iv) acute hepatitis A virus infection, positive for anti-hepatitis A virus immunoglobulin M; and (v) normal human sera. All three assays for anti-HD gave similar specificity and sensitivity values. In conclusion, the recombinant expressed HDAg can replace antigen derived from infected liver tissue as a diagnostic reagent used to configure an EIA for detection of anti-HD. Furthermore, the results suggest that the expressed antigen contains the important immunodominant epitope(s).
Puig
J
J
Fundacion Gaspar de Portola, Barcelona, Spain.
Fields
H A
HA
D000914:Antibodies, Viral / Q000302:isolation & purification*; D000956:Antigens, Viral; D001667:Binding, Competitive; D005069:Evaluation Studies as Topic; D003699:Hepatitis D / Q000175:diagnosis / Q000276:immunology; D003698:Hepatitis Delta Virus / Q000276:immunology*; D006801:Humans; D007124:Immunoenzyme Techniques; D011863:Radioimmunoassay; D011994:Recombinant Proteins / Q000276:immunology
D000914:Antibodies, Viral; D000956:Antigens, Viral; D011994:Recombinant Proteins