Article

Detection of acute HIV infection: A field evaluation of the determine® HIV-1/2 Ag/Ab combo test

Departments of Epidemiology, University of North Carolina, Chapel Hill 27599, USA.
The Journal of Infectious Diseases (Impact Factor: 6). 12/2011; 205(4):528-34. DOI: 10.1093/infdis/jir789
Source: PubMed

ABSTRACT

Most human immunodeficiency virus (HIV) point-of-care tests detect antibodies (Ab) but not p24 antigen (Ag) or RNA. In the absence of antibodies, p24 antigen and RNA typically indicate acute HIV infection. We conducted a field evaluation of the Determine® HIV-1/2 Ag/Ab Combo rapid test (Combo RT).
The antigen portion of the Combo RT (for acute HIV infection) was compared with a Roche Monitor HIV RNA polymerase chain reaction assay. The antibody portion of Combo RT (for established HIV infection) was compared with rapid test algorithms. Participants were enrolled at a sexually transmitted infection clinic and HIV testing and counseling center in Lilongwe, Malawi. Rapid testing was conducted with parallel testing in the clinic and serial testing in the center. The Combo RT was performed in clinic participants with negative or discordant antibody results and in all center participants.
Of the participants 838 were HIV negative, 163 had established HIV infection, and 8 had acute HIV infection. For detecting acute HIV infection, the antigen portion had a sensitivity of 0.000 and a specificity of 0.983. For detecting established HIV infection, the antibody portion had a sensitivity of 0.994 and a specificity of 0.992.
Combo RT displayed excellent performance for detecting established HIV infection and poor performance for detecting acute HIV infection. In this setting, Combo RT is no more useful than current algorithms.

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Available from: Nora E Rosenberg, Apr 02, 2014
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    • "Our data show a median time of 7 days between the first Ag-reactive and the first Ab-reactive Determine Combo result in 22 seroconverters, similar to the 5–9 days reported by the manufacturer in studies outside the US. [6] These results for Ag reactivity, which contradict published studies [9] [12] [13] [16] in which acute infections were not detected by the Ag component of the Determine Combo, might be due to differences in the test after the manufacturer's modifications. The sensitivity of any assay for detecting p24 during acute HIV-1 infections must overcome the challenge of the formation of Ag/Ab immune-complexes in early stages of seroconversion. "

    Full-text · Dataset · Aug 2013
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    • "Our data show a median time of 7 days between the first Ag-reactive and the first Ab-reactive Determine Combo result in 22 seroconverters, similar to the 5–9 days reported by the manufacturer in studies outside the US. [6] These results for Ag reactivity, which contradict published studies [9] [12] [13] [16] in which acute infections were not detected by the Ag component of the Determine Combo, might be due to differences in the test after the manufacturer's modifications. The sensitivity of any assay for detecting p24 during acute HIV-1 infections must overcome the challenge of the formation of Ag/Ab immune-complexes in early stages of seroconversion. "
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    ABSTRACT: FDA-approved HIV Antigen/Antibody combo (4th generation) immunoassays (IAs) can identify HIV-1 infections before the Western blot (WB) becomes positive. In the US, increased detection of acute HIV infections has been facilitated by using 4th generation IAs, but there is no FDA-approved 4th generation rapid test (RT). The Alere Determine™ HIV-1/2 Ag/Ab Combo (Determine Combo) RT detects and distinguishes HIV p24 Antigen (Ag) from Antibody (Ab) to HIV-1+HIV-2 and thus has the potential to improve diagnosis of acute HIV infection. To evaluate the ability of Determine Combo RT to detect acute/early HIV-1 infections and HIV-2 antibody in well-characterized plasma specimens. In HIV-1 seroconverters from the US, Determine Combo reactivity was evaluated by performing the 50% cumulative frequency analysis and by comparing with 3rd and 4th generation IAs' reactivity. HIV-2 plasma specimens from Ivory Coast were tested with Determine Combo. The 50% cumulative frequency analysis in 17 seroconverters placed Determine Combo (Ag+/Ab-, Ag+Ab+, Ag-/Ab+) and Ab-component reactivity at 15.5 and 7 days before WB positivity, respectively. In 26 seroconverters, Determine Combo was reactive in 99.0% and 92.5% of 3rd and 4th generation IAs-reactive specimens, respectively. All HIV-2 plasma specimens were Ab-reactive/Ag-non-reactive by Determine Combo. Based on previous results with the same seroconversion panels, combined Ag/Ab reactivity of the Determine Combo appears between FDA-approved 4th and 3rd generation laboratory IAs. These data indicate that this RT could detect HIV-1 infection earlier than other RTs and it performs well in HIV-2 specimens.
    Full-text · Article · Aug 2013 · Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology
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