Performance of the BioPlex 2200 HIV Ag-Ab assay for identifying acute HIV infection

Background: Assays that detect HIV antigen (Ag) and antibody (Ab) can be used to screen for HIV infection. Objectives: To compare the performance of the BioPlex 2200 HIV Ag-Ab assay and two other Ag/Ab combination assays for detection of acute HIV infection. Study Design: Samples were obtained from 24 individuals (18 from the US, 6 from South Africa); these individuals were classified as having acute infection based on the following criteria: positive qualitative RNA assay; two negative rapid tests; negative discriminatory test. The samples were tested with the BioPlex assay, the ARCHITECT HIV Ag/Ab Combo test, the Bio-Rad GS HIV Combo Ag-Ab EIA test, and a viral load assay. Results: Twelve (50.0%) of 24 samples had RNA detected only (>40 to 13,476 copies/mL). Ten (43.5%) samples had reactive results with all three Ag/Ab assays, one sample was reactive with the ARCHITECT and Bio-Rad assays, and one sample was reactive with the Bio-Rad and BioPlex assays. The 11 samples that were reactive with the BioPlex assay had viral loads from 83,010 to >750,000 copies/mL; 9/11 samples were classified as Ag positive/Ab negative by the BioPlex assay. Conclusions: Detection of acute HIV infection was similar for the BioPlex assay and two other Ag/Ab assays. All three tests were less sensitive than a qualitative RNA assay and only detected HIV Ag when the viral load was high. The BioPlex assay detected acute infection in about half of the cases, and identified most of those infections as Ag positive/Ab negative

Characterization of HIV seroconverters in a TDF/FTC PrEP study: HPTN 067/ADAPT

Background: HPTN 067/ADAPT evaluated tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) pre-exposure prophylaxis (PrEP) in women (South Africa) and men who have sex with men (Thailand, US). Participants received once-weekly directly observed TDF/FTC (DOT), and were then randomized to daily, time-driven, or event-driven PrEP. This report describes characterization of 12 HIV seroconversion events in this trial. Methods: HIV rapid testing was performed at study sites. Retrospective testing included: 4th generation assays; HIV RNA testing; Western blot; an HIV-1/2 discriminatory assay; resistance testing; and antiretroviral (ARV) drug testing. Results: Six of the 12 seroconverters received TDF/FTC in the DOT phase, but were not randomized (3 were acutely infected at enrollment; 2 were infected during the DOT phase; one was not randomized due to pregnancy). One of the six randomized participants had acute infection at randomization but was not diagnosed for 3–4 months because HIV rapid tests were non-reactive; continued daily PrEP use was associated with false-negative antibody tests and low HIV RNA levels. The five participants infected after randomization included four with low adherence to the PrEP regimen, and one who reported a 7-day period without dosing prior to infection. Three participants had TDF/FTC resistance (M184I, K65R), including two who received only four once-weekly TDF/FTC doses; most TDF/FTC mutations were detected by next generation sequencing only. Conclusions: In HPTN 067/ADAPT, participants who acquired HIV infection had infrequent PrEP dosing or low/suboptimal adherence. Sensitive assays improved detection of HIV infection and drug resistance. Drug resistance was observed with limited PrEP exposure

Patterns of HIV-1 drug resistance among HIV-infected patients receiving first-line antiretroviral therapy in Novosibirsk Region, Russia

ABSTRACT: Objectives: Antiretroviral (ARV) drugs have played a vital role in controlling the HIV-1 epidemic; however, some challenges remain. ARV drugs vary in their ability to control HIV infection, displaying differences in treatment-limiting factors and genetic barriers to resistance. The current report assesses the prevalence of HIV-1 drug resistance mutations (DRMs) among patients who failed first-line antiretroviral therapy (ART) and evaluates the genetic barrier of different regimens. Methods: The study cohort (n = 271) included HIV-infected individuals who visited the Novosibirsk, Russia, HIV/AIDS clinic in 2018–2022. All patients received first-line ART prior to virological failure. Sociodemographic and HIV-related data were collected from medical records and self-reported questionnaires. HIV-1 pol gene sequences were generated, and the presence of HIV-1 DRM was assessed. The genetic barrier to resistance was assessed by combining treatment regimen and adherence data. Results: Nonoptimal ART adherence was identified in 48.3% of patients and correlated with male sex, PWID, unemployment, and rural area residence. Most of the patients with high-level adherence were identified among those who were on TDF+3TC+DTG. HIV-1 DRMs were identified in 54.6% of the patients. The analysis of HIV-1 DRM, ART regimen, and adherence data classified TDF+3TC+DTG and TDF+3TC+LPV/r as treatment regimens with a high genetic barrier, whereas EFV-containing ART was classified as a regimen with a low genetic barrier. Conclusions: The current study delivers results on the efficacy of HIV-1 ART and treatment adherence in real-world practice settings. This report suggests that ART regimens with a high genetic barrier to resistance combined with improved treatment adherence may reduce the transmission of HIV-1 resistant variants

Performance of the BioPlex 2200 HIV Ag-Ab assay for identifying acute HIV infection.

BackgroundAssays that detect HIV antigen (Ag) and antibody (Ab) can be used to screen for HIV infection.ObjectivesTo compare the performance of the BioPlex 2200 HIV Ag-Ab assay and two other Ag/Ab combination assays for detection of acute HIV infection.Study designSamples were obtained from 24 individuals (18 from the US, 6 from South Africa); these individuals were classified as having acute infection based on the following criteria: positive qualitative RNA assay; two negative rapid tests; negative discriminatory test. The samples were tested with the BioPlex assay, the ARCHITECT HIV Ag/Ab Combo test, the Bio-Rad GS HIV Combo Ag-Ab EIA test, and a viral load assay.ResultsTwelve (50.0%) of 24 samples had RNA detected only ( > 40 to 13,476 copies/mL). Ten (43.5%) samples had reactive results with all three Ag/Ab assays, one sample was reactive with the ARCHITECT and Bio-Rad assays, and one sample was reactive with the Bio-Rad and BioPlex assays. The 11 samples that were reactive with the BioPlex assay had viral loads from 83,010 to >750,000 copies/mL; 9/11 samples were classified as Ag positive/Ab negative by the BioPlex assay.ConclusionsDetection of acute HIV infection was similar for the BioPlex assay and two other Ag/Ab assays. All three tests were less sensitive than a qualitative RNA assay and only detected HIV Ag when the viral load was high. The BioPlex assay detected acute infection in about half of the cases, and identified most of those infections as Ag positive/Ab negative

Значение химических и физических свойств пластмасс при аллопластике

BACKGROUND:South Africa has one of the highest rates of HIV-1 (HIV) infection world-wide, with the highest rates among young women. We analyzed the molecular epidemiology and evolutionary history of HIV in young women attending high school in rural South Africa. METHODS:Samples were obtained from the HPTN 068 randomized controlled trial, which evaluated the effect of cash transfers for school attendance on HIV incidence in women aged 13-20 years (Mpumalanga province, 2011-2015). Plasma samples from HIV-infected participants were analyzed using the ViroSeq HIV-1 Genotyping assay. Phylogenetic analysis was performed using 200 pol gene study sequences and 2,294 subtype C reference sequences from South Africa. Transmission clusters were identified using Cluster Picker and HIV-TRACE, and were characterized using demographic and other epidemiological data. Phylodynamic analyses were performed using the BEAST software. RESULTS:The study enrolled 2,533 young women who were followed through their expected high school graduation date (main study); some participants had a post-study assessment (follow-up study). Two-hundred-twelve of 2,533 enrolled young women had HIV infection. HIV pol sequences were obtained for 94% (n = 201/212) of the HIV-infected participants. All but one of the sequences were HIV-1 subtype C; the non-C subtype sequence was excluded from further analysis. Median pairwise genetic distance between the subtype C sequences was 6.4% (IQR: 5.6-7.2). Overall, 26% of study sequences fell into 21 phylogenetic clusters with 2-6 women per cluster. Thirteen (62%) clusters included women who were HIV-infected at enrollment. Clustering was not associated with study arm, demographic or other epidemiological factors. The estimated date of origin of HIV subtype C in the study population was 1958 (95% highest posterior density [HPD]: 1931-1980), and the median estimated substitution rate among study pol sequences was 1.98x10-3 (95% HPD: 1.15x10-3-2.81x10-3) per site per year. CONCLUSIONS:Phylogenetic analysis suggests that multiple HIV subtype C sublineages circulate among school age girls in South Africa. There were no substantive differences in the molecular epidemiology of HIV between control and intervention arms in the HPTN 068 trial

Image_3_Spatiotemporal dynamics of HIV-1 CRF63_02A6 sub-epidemic.JPEG

HIV-1 epidemic in Russia is one of the fastest growing in the world reaching 1.14 million people living with HIV-1 (PLWH) in 2021. Since mid-1990s, the HIV-1 epidemic in Russia has started to grow substantially due to the multiple HIV-1 outbreaks among persons who inject drugs (PWID) leading to expansion of the HIV-1 sub-subtype A6 (former Soviet Union (FSU) subtype A). In 2006, a local HIV-1 sub-epidemic caused by the distribution of novel genetic lineage CRF63_02A6 was identified in Siberia. In this study, we used a comprehensive dataset of CRF63_02A6 pol gene sequences to investigate the spatiotemporal dynamic of the HIV-1 CRF63_02A6 sub-epidemic. This study includes all the available CRF63_02A6 HIV-1 pol gene sequences from Los Alamos National Laboratory (LANL) HIV Sequence Database. The HIV-1 subtypes of those sequences were conferred using phylogenetic analysis, and two automated HIV-1 subtyping tools Stanford HIVdb Program and COMET. Ancestral state reconstruction and origin date were estimated using Nextstrain. Evolutionary rate and phylodynamic analysis were estimated using BEAST v 1.10.4. CRF63_02A6 was assigned for 872 pol gene sequences using phylogenetic analysis approach. Predominant number (n = 832; 95.4%) of those sequences were from Russia; the remaining 40 (4.6%) sequences were from countries of Central Asia. Out of 872 CRF63_02A6 sequences, the corresponding genetic variant was assigned for 75.7 and 79.8% of sequences by Stanford and COMET subtyping tools, respectively. Dated phylogenetic analysis of the CRF63_02A6 sequences showed that the virus most likely originated in Novosibirsk, Russia, in 2005. Over the last two decades CRF63_02A6 has been widely distributed across Russia and has been sporadically detected in countries of Central Asia. Introduction of new genetic variant into mature sub-subtype A6 and CRF02_AGFSU epidemics could promote the increase of viral genetic diversity and emergence of new recombinant forms. Further HIV-1 studies are needed due to a continuing rapid virus distribution. Also, the implementation of HIV-1 prevention programs is required to reduce HIV-1 transmission. This study also highlights the discrepancies in HIV-1 subtyping approaches. The reference lists of HIV-1 sequences implemented in widely used HIV-1 automated subtyping tools need to be updated to provide reliable results.</p

HPTN 068 study cohort flowchart.

<p>The figure provides an overview of the study cohort, including the number of samples tested and the number of HIV genotyping results obtained in each participant group: infected at enrollment, infected during the main study (between enrollment and their expected graduation date), or infected during the follow-up study (after their expected graduation date). Abbreviations: mL: milliliter. Footnote for Fig 1: ^aFour participants were excluded due to unknown HIV status.</p

Transmission clusters from approximately maximum-likelihood phylogenetic tree.

<p>Phylogenetic clusters were detected in the approximately maximum-likelihood phylogenetic tree (FastTree) at a 4.5% genetic distance threshold. Each row represents one of the twenty-one phylogenetic clusters. Symbols representing participants in clusters are colored in red (intervention) or blue (control). Symbols represent the timing of participants’ first positive HIV test (enrollment, main study, follow-up study). Data from participants are shown on the x-axis (calendar time) according to the date of their first HIV-positive visit in the study. Drug resistant viruses are denoted with an asterisk.</p

GMRF Bayesian Skyride plot of HIV subtype C.

<p>The GMRF Bayesian Skyride plot was reconstructed from the 200 <i>pol</i> gene sequences. Bold black line indicates the median effective population size through time; blue shaded area represents the 95% highest posterior density (HPD) interval. The vertical dotted lines represent the estimated date of origin (1958) of HIV subtype C, and lower and upper 95% HPD intervals (1931–1980).</p