Rapid Immunoassay Improves HIV Detection

By LabMedica International staff writers
Posted on 12 Sep 2011
An improved human immunosuppressive virus (HIV) rapid test platform is designed to deliver test results in 10 minutes and detect the virus earlier in the course of infection.

The test is based on the OraQuick HIV rapid test platform, which detects antibodies to HIV-1 and HIV-2 in 20 minutes, and approved for use with finger prick blood or venipuncture whole blood or plasma.

The principle of the test is based on complexing a combination of HIV peptides and recombinant antigens with anti-HIV antibodies and then capturing the complex labeled with colloidal gold at the test line. Scientists evaluated the new test in 24 commercial seroconversion panels and a worldwide serologic panel representing 15 diverse genotypes. Sensitivity was evaluated by using 169 samples derived from patients infected with HIV-2. Specificity was evaluated in 300 plasma and 500 whole-blood specimens.

Results from the tests were compared with those from a third-generation enzyme immunoassay (EIA). The rapid HIV test detected seroconversion within an average of 1.13 days of 24 third-generation EIA panels, which detects seroconversion 15 days before the Western blot. The prototype assay (OraSure Technologies, Inc., Bethlehem, PA, USA) was 100% concordant when tested in 169 HIV-2 samples. In addition, the new test was also in accord with the EIA when tested with 15 worldwide serologic panel specimens detecting all major genotypes. The test was moreover 100% specific in 300 plasma and 500 whole-blood specimens. The improved sensitivity and short testing time of 10 minutes of this test should further improve the utility of rapid HIV testing, especially in high incidence populations.

Ron Ticho, senior vice president of corporate communications at OraSure, said, "We will need to establish performance in larger-scale clinical trials in order to support US Food and Drug Administration (FDA; Silver Spring, MD, USA) approval. A key component of the regulatory approvals will also be obtaining a certificate of laboratory improvement amendment (CLIA) waiver, which will allow the test to be used outside of laboratory settings, such as in doctor’s offices and clinics.” The findings were presented at the National HIV Prevention Conference, held in Atlanta, GA, USA, during August 14-17, 2011.

Related Links:

OraSure Technologies
US Food and Drug Administration



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