Identification of Acute HIV-1 Infection by Hologic Aptima HIV-1 RNA Qualitative Assay

Laboratory diagnosis of HIV: a contemporary overview in the Australian context

Over the past decade there have been technical advances in human immunodeficiency virus (HIV) assays and updates to testing regulations that have substantially changed the landscape of laboratory testing for HIV. In addition, there have been significant changes in the epidemiology of HIV in Australia in the context of highly effective contemporary biomedical treatment and prevention strategies. Here, we provide an update on contemporary issues for the laboratory detection and confirmation of HIV in Australia. These include (1) the impact of early treatment and biological prevention strategies on the serological and virological detection of HIV; (2) the updated national HIV laboratory case definition and its interaction with testing regulations, public health and clinical guidelines; and (3) novel strategies for the laboratory detection of HIV, including the incorporation of HIV nucleic acid amplification tests (NAATs) into testing algorithms. These developments present an opportunity to develop a nationally consistent contemporary HIV testing algorithm that would result in optimisation and standardisation of HIV testing in Australia.

Practical approach to method verification in plasma and validation in cerebrospinal fluid under accreditation using a flexible scope in molecular virology: setting up the HIV, HBV and HCV Aptima™ Quant Dx assays

Background Our laboratory obtained the ISO 15189 accreditation for the plasmatic HIV-1, HBV and HCV viral load (VL) using the m2000 RealTime™ system, which was recently changed for the platform Panther®. Here, we discuss a strategy for performing method validation/verification very quickly. Methods We performed the mandatory (repeatability, internal quality assessment [IQA], measurement uncertainty [MU]) and optional technical verifications for CE/IVD assays using the flexible scope range A. We also performed the mandatory assays for the validation of HIV-1 VL in the cerebrospinal fluid (CSF) using the flexible scope range B. The change was checked by following up on the turnaround time (TAT). Results The coefficient of variation (CV%) for repeatability and IQA complied with the limit of 0.25 log. The MU results ranged from 0.04 to 0.25 log copies or IU/mL. The comparisons of methods showed excellent correlations (R2 = 0.96 for the three parameters) but a delayed centrifugation on HCV VL showed variations of up to 2 log IU/mL. An excellent linearity for HIV-1 in the CSF was obtained from 1.5 to 5 log copies/mL with R2 = 0.99. The TAT increased (84%-98%) in routine usage. Conclusions The three Aptima assays are well suited for routine laboratory use and can be integrated within less than 2 weeks in accordance with flexible scope range A. Our data allows us to confidently perform HIV-1 VL in CSF following flexible scope range B. Finally, we provide an organizational guide for flexible scope management in molecular virology within a short time frame.

Risk assessment and identification of HIV infection among men who have sex with men: a cross-sectional study in Southwest China

OBJECTIVES

The HIV epidemic is around 7%-20% among men who have sex with men (MSM) in Southwest China. The low HIV-testing rate highlights the need for tools to identify high-risk MSM in resource-limited regions. Our aim was, therefore, to evaluate the HIV RISK Assessment Tool for HIV prediction and to characterise the primary infection among MSM in Southwest China.

DESIGN

A cross-sectional survey was conducted in Guizhou province between January and December 2018. Participants were recruited from gay communities, among whom the HIV RISK Assessment Tool was evaluated. Logistic regression was used to analyse items associated with HIV and the area under the curve (AUC) of the receiver operating curve was calculated to quantify discrimination performance.

PARTICIPANTS

1330 MSM participants, of which 83 (6.2%) tested as HIV positive.

RESULTS

A higher composite score of the tool (adjusted OR (aOR) 9.33, 95% CI 4.57 to 19.05) was independently associated with HIV infection. Items positively associated with HIV infection included having 2-5 same sex partners (aOR 2.43, 95% CI 1.28 to 4.64), always (aOR 5.93, 95% CI 1.59 to 22.13) or sometimes (aOR 4.25, 95% CI 2.09 to 8.64) having unprotected anal intercourse, taking both insertive and receptive sex roles (aOR 4.95, 95% CI 2.57 to 9.53) or only the receptive sex role (aOR 2.26, 95% CI 1.21 to 4.24). The tool showed an optimal discrimination ability (AUC=0.827), with a specificity of 0.747 and sensitivity of 0.785. Five MSM were identified with primary infection and had similar sexual risk behaviors as HIV-positive participants.

CONCLUSIONS

The HIV RISK Assessment Tool showed an overall good performance in predicting HIV risk among MSM in Guizhou province where the prevalence is still severe. This tool also demonstrated a potential to identify primary infection and is worth being promoted in resource-limited regions.

Decreased Seroreactivity in Individuals Initiating Antiretroviral Therapy during Acute HIV Infection

Antiretroviral therapy (ART) during acute HIV infection (AHI) interrupts viral dynamics and may delay the emergence of serological markers targeted by current HIV screening and confirmatory assays, thus creating challenges for correctly classifying HIV infection status. The performance of three HIV antigen/antibody combination (HIV Ag/Ab Combo) assays (the Bio-Rad GS, Abbott Architect, and Bio-Rad BioPlex 2200 assays) was evaluated with samples collected from RV254/South East Asia Research Collaboration in HIV 010 (RV254/SEARCH010) study (Bangkok, Thailand) participants at weeks 12 and 24 following the initiation of ART at Fiebig stage I (FI) (n = 23), FII (n = 39), or FIII/IV (n = 22). Supplemental, confirmatory testing was performed by the Geenius HIV 1/2 and HIV-1 Western blot assays (Bio-Rad). Samples from 30 untreated, HIV-1-infected individuals demonstrated robust HIV Ag/Ab Combo assay reactivity with well-developed HIV-1 Western blotting profiles by 24 weeks after infection. In contrast, 52.2% of samples from individuals initiating ART at FI, 7.7% of samples from individuals initiating ART at FII, and 4.5% of samples from individuals initiating ART at FIII/IV were nonreactive by the HIV Ag/Ab Combo assays, with 36.4 to 39.1% of samples having low signal-to-cutoff (S/CO) results by the Architect and BioPlex assays (S/CO < 10). Seroreversion from a reactive to a nonreactive status was observed in 10 individuals initiating ART at FII and 3 individuals initiating ART at FIII/IV. The Geenius and HIV-1 Western blot assay results were negative or indeterminate for 73.9% and 69.6% of individuals, respectively, treated at FI; 50.0% and 26.3% of individuals, respectively, treated at FII; and 54.5% and 40.9% of individuals, respectively, treated at FIII/IV. Virologic suppression of HIV-1 by ART during AHI impedes seroconversion to biomarkers of infection, limiting the utility of HIV Ag/Ab Combo and supplemental, confirmatory assays for infection status determination.

Distinct biomarker signatures in HIV acute infection associate with viral dynamics and reservoir size

Estimating the size of the viral reservoir is critical for HIV cure strategies. Biomarkers in peripheral circulation may give insights into the establishment of the viral reservoir in compartments not easily accessible. We therefore measured systemic levels of 84 soluble biomarkers belonging to a broad array of immune pathways in acute HIV infection in both antiretroviral therapy-naive (ART-naive) individuals as well as individuals who began ART upon early detection of HIV infection. These biomarkers were measured longitudinally during acute and chronic infection and their relationship to viral reservoir establishment and persistence was assessed. We observed several distinct biomarker pathways induced following HIV infection such as IFN-γ-signaled chemokines, proinflammatory markers, and TNF-α-family members. Levels of several of these factors directly correlated with contemporaneous viral loads and/or frequency of peripheral blood mononuclear cells harboring HIV DNA during acute HIV infection. MCP-1, MIP-3β, sTNFR-II, and IL-10 levels prior to ART associated with HIV DNA levels after 96 weeks of treatment, suggesting a link between early immune signaling events and the establishment and persistence of the viral reservoir during ART. Furthermore, they offer potentially novel tools for gaining insight into relative reservoir size in acutely infected individuals and the potential of associated risks of treatment interruption.