Axsym hiv 1 2 go

Microparticle EIA anti-HIV-1/2 (AxSYM HIV-1/2 gO, Abbott) was confirmed with Western Blot (MP Diagnostics).

Blood samples were tested for HIV antibodies by AxSYM HIV-1/2 gO (Abbott) and confirmed by Western Blot (MP Diagnostics). Recent HIV infection was detected by the LAg assay (Sedia™ Biosciences Corporation) (Duong et al., 2015 (link)). HIV-RNA was quantified in HIV positive samples in TRIP using Artus HI Virus-1 RG RT–PCR (Qiagen). HIV-RNA at HIV clinics was measured using Cobas Taqman HIV, PCR RNA, branched DNA 3.0, and Versant HIV-1 RNA 1.0 kPCR.

Until 1996, HIV diagnosis was established by enzyme immunoassay with confirmation by immunoblot assay. After 1997, HIV polymerase chain reaction (PCR) was used to confirm the diagnosis in patients with reactive serologic tests.
Initial serologic testing for HIV 1 and 2 was performed using a micro-particle enzyme immunoassay (MEIA; AxSYM HIV 1/2 gO, Abbott Laboratories, Abbott Park, USA). If serology was reactive, specimens were confirmed using the Chiron RIBA HIV-1/HIV-2 strip immunoblot assay.
For the purpose of this report, we used the CDC definition of AIDS [16 ]. Opportunistic infections are defined by microbiological confirmation (by stain for Pneumocystis jirovecii, culture for M. tuberculosis, atypical mycobacteria, and fungi).
Molecular testing included HIV PCR, which uses three sets of four primers from envelope, polymerase, reverse transcriptase, and core protein genes. Viral load was measured with the branched DNA method (VER SANT HIV-1 RNA 3.0 Assay, [bDNA], Bayer Diagnostics, Berkeley, CA, USA). Results were reported in a range from 50 to >500,000 copies/ml. CD4+ count and percentage was obtained by standard flow cytometric methods.

Blood samples were tested by a microparticle anti-HIV-1/2 EIA (AxSYM HIV-1/2 gO, Abbott) and confirmed by Western Blot (WB) (MP Diagnostics). Specimens that were initially reactive (S/CO, ≥1.0) or initially gray zone reactive (0.9 ≤ S/CO < 1.0) in AxSYM HIV-1/2 gO were retested in duplicate. Results on WB p31 band reactivity were recorded. P31 can be detected approximately 100 days after infection and could be used as an indicator of recency among individuals with positive WB (Fiebig stage V: WB+/p31−) [19 (link),20 (link)].
WB-confirmed samples were further tested by LAg (Figure 1). Samples with ODn less than two during the screening mode were subjected to confirmatory evaluation and tested in triplicate. If the median of the three ODn values was then ≤ 1.5, the seroconversion was classified as recent (LAg+). The ODn cutoff of 1.5 corresponds to a mean duration of recent infection of 130 days [14 (link)].
HIV RNA was quantified in positive specimens obtained from participants of the first round of ARISTOTLE using Artus HI Virus-1 RG RT-PCR (Qiagen).
Available data on HIV-1 subtypes and circulating recombinant forms (CRF) were retrieved from an existing database as described in [21 (link)].