Quantitative detection of human immunodeficiency virus (HIV) antigen by the Enzymun-Test: comparison with alternative assays and nucleic acid sequence-based amplification of HIV type 1 RNA.
A new modular automated enzyme immunoassay (EIA) (Enzymun-Test HIV Ag: Boehringer Mannheim) for quantitative human immunodeficiency virus (HIV) antigen detection was evaluated by testing a panel of 1,506 serum samples, including seroconversions, dilution series, follow-up samples from patients under antiretroviral therapy, single serum specimens from HIV-seropositive individuals in different stages of infection, potentially cross-reactive samples, and sera from HIV-negative hospitalized patients. The Abbott HIV type 1 (HIV-1) antigen monoclonal antibody assay served as the reference assay, and nucleic acid sequence-based amplification (Organon Teknika) for quantitative amplification of HIV-1 RNA was used for follow-up of patients under antiretroviral chemotherapy. The Boehringer Mannheim and Abbott EIAs showed concordant results for the early detection of HIV antigen in all the seroconversion panels. The follow-up samples from 29 HIV-infected individuals under antiretroviral therapy gave divergent results between both antigen tests. For the detection of HIV antigen in single serum samples from HIV-infected patients in different stages of HIV infection, a higher number of positive samples was detected with the Abbott HIV-1 antigen monoclonal antibody assay in samples from patients in stages II and III of HIV infection. The Enzymun-Test detected three or more positive samples than did the Abbott assay among the samples of patients with AIDS. The concordance on a sample-to-sample basis between the Boehringer Mannheim and Abbott EIAs was 98.6%. The sensitivity of the Enzymun-Test in comparison to the reference assay was 97.2%; the specificity was 98.8%. Although no close correlation could be found between the amount of viral RNA in serum detected by nucleic acid sequence-based amplification and the concentration of HIV antigen, a high HIV-1 RNA copy number was mostly associated with high levels of HIV antigen. In conclusion, the Enzymun-Test permits accurate HIV antigen detection and offers, in contrast to previous assays, the possibility of completely automated detection.
Weber
B
B
Institut für Medizinische Virologie, Zentrum der Hygiene, Universitätskliniken Frankfurt am Main, Germany.
Melchior
W
W
Preiser
W
W
Hess
G
G
Wahl
M
M
Braner
J
J
Doerr
H W
HW
D015492:AIDS Serodiagnosis / Q000379:methods / Q000706:statistics & numerical data; D000911:Antibodies, Monoclonal; D000998:Antiviral Agents / Q000627:therapeutic use; D005069:Evaluation Studies as Topic; D005189:False Positive Reactions; D005784:Gene Amplification; D015488:HIV Antigens / Q000032:analysis*; D015658:HIV Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000821:virology; D006679:HIV Seropositivity / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000706:statistics & numerical data; D012367:RNA, Viral / Q000235:genetics*; D012680:Sensitivity and Specificity; D014773:Virology / Q000379:methods* / Q000706:statistics & numerical data
D000911:Antibodies, Monoclonal; D000998:Antiviral Agents; D015488:HIV Antigens; D012367:RNA, Viral