AEGiS-13IAC: HIV-screening with the COBAS CORE automated analyser: Combined testing for anti-HIV and HIVAg in one determination.

13th International AIDS Conference

Durban, South Africa - July 9-July 14, 2000

HIV-screening with the COBAS CORE automated analyser: Combined testing for anti-HIV and HIVAg in one determination.

Int Conf AIDS 2000 Jul 9-14; 13:(abstract no. MoOrA112)

Schmitt U, Andres H, Faatz E
U. Schmitt, Roche Diagnostics GmbH, Nonnenwald 2, 82377 Penzberg, Germany, Tel.: 49-8856-603309, Fax: 49-8856-603131, E-mail: urban.schmitt@roche.com

BACKGROUND: Even with the best anti-HIV diagnostic assays the early detection of HIV infection is on average 5 to 7 days later than the detection by HIVAg-assays, but performing HIV-screening with HIVAg assays in addition to anti-HIV assays is very expensive and time consuming. We have combined both types of assay in one determination in order to shorten the diagnostic window phase of HIV-screening at reasonable costs.

METHODS: The assay is a combination of a double antigen sandwich assay (antibody detection module) comprising antigens from the env region of HIV-1, HIV-2, HIV-1 Sub O and from the pol region of HIV-1 and a monoclonal antibody sandwich assay (antigen detection module) of four anti-p24 monoclonal antibodies. The anti-HIV/HIVAg combined assay was applied to the Roche COBAS CORE System by using recombinant antigens and anti-p24 Mabs at the solid phase, as well as and Digoxigenin labelled anti-p24 Mabs and peroxidase labelled antigens and anti-Digoxigenin.

RESULTS: This assay (COBAS CORE HIV combi, Roche Diagnostics GmbH) is earlier in the detection of seroconversion by on average 6 days compared to the best anti-HIV screening assays. It displays a very good antigen detection with less than 15 pg p24 (DuPont standard) and an excellent antibody detection with samples of different subtypes of HIV 1 (group M and O). It also shows a good HIV-2 antibody detection and some reactivity with HIV2 p26 antigen. Specificity tested with 610 samples of blood donors and 478 samples of hospitalised patients was found to be > 99.8%.

CONCLUSION: The COBAS CORE HIV combi is a HIV screening assay with combined anti-HIV and HIVAg detection showing very good sensitivity during seroconversion with good specificity on a full automated system.

Keywords: AEGIS, HIV Infections, HIV-2, HIV-1, HIV Seropositivity, AIDS Serodiagnosis, Mass Screening, Sensitivity and Specificity, Blood Donors, Research Design, Immunoenzyme Techniques, Laboratory Techniques and Procedures, Neutralization Tests, Blotting, Western, Human
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MoOrA112