HIV-1 Assay Research Articles

A-353 Lay User testing of Rapid Multiplexed HIV/TP test

Abstract Background Palladium Diagnostics had developed a rapid, multiplexed POC assay for Syphilis and HIV for fingerstick whole blood. To increase potential patient engagement and simplify sample collection it was decided to expand the sample type from fingerstick whole blood to saliva without changing the test time or performance. Additionally, the test was designed to have a lower carbon footprint by using a bioplastic (environmentally friendly foam) for structural components rather than injection molded parts as are commonly used in other assays. The assay was run both by professional users in a lab setting and lay users in the field. Methods A flow through rapid assay was produced and tested both by professional users in a lab setting using library sample and by lay users in a field setting using self collected samples. Results The results are shown in table 1, the assay performance was broadly similar for both whole blood and saliva, however the saliva dataset was much smaller for the professional use setting. The human factor analysis from the lay user field studies showed that they preferred the saliva collection procedure however for a small subset of subjects it proved difficult to collect sufficient sample for testing. For subjects who were able to collect adequate sample the results corresponded well between the device and lab-based ELISA. Conclusions The lay user experience validated test design and function and proved the usability in the field.

Comparison of short-read and long-read next-generation sequencing technologies for determining HIV-1 drug resistance.

Accurate HIV-1 genome sequencing is necessary to identify drug resistance mutations (DRMs) in people with HIV-1 (PWH). Next-generation-sequencing (NGS) allows the detection of minor variants and is now available in many laboratories. Our study aimed to compare two NGS approaches, a "short read" sequencing protocol using DeepChek® Whole Genome HIV-1 Assay on Illumina, and a "long read" sequencing protocol of HIV-1 pol and env single-molecule real-time sequencing (SMRT) on Pacific Biosciences (PacBio). We analyzed 16 plasma samples and 13 cellular samples from PWH. HIV-1 whole genome was amplified into five amplicons using DeepChek® Whole Genome HIV-1 Assay and sequenced on an iSeq. 100. In parallel, HIV-1 pol and env genes were separately amplified and sequenced using PacBio SMRT system with the circular consensus sequencing mode on a Sequel IIe. Concordance rates for determining DRMs with both approaches varied depending on the HIV-1 region, with higher concordance in the integrase region compared to the reverse transcriptase and protease regions. DeepChek® Whole Genome HIV-1 Assay exhibited better sensitivity in HIV-1 RNA sequencing of plasmas with lower viral loads. In cell HIV-1 DNA sequencing, the DeepChek® Whole Genome HIV-1 Assay performed better in pol and env sequencing but detected more APOBEC-induced DRMs, which can represent defective proviruses. Our findings indicate that both DeepChek® Whole Genome HIV-1 Assay and PacBio SMRT sequencing exhibit good performance for subtype determination, detection, and quantification of DRMs of the HIV-1 genome. However, some discrepancies were found in cellular samples, highlighting the challenges of interpreting HIV-1 DNA DRMs.

A multiplexed real‐time PCR assay for simultaneous quantification of human immunodeficiency virus and Hepatitis B virus for low‐and‐middle‐ income countries

Due to shared routes of transmission, including sexual contact and vertical transmission, HIV-HBV co-infection is common, particularly in sub-Saharan Africa. Measurement of viral load (VL), for both HIV and HBV, plays a critical role for determining their infectious phase and monitoring response to antiviral therapy. Implementation of viral load testing in clinical settings is a significant challenge in resource-limited countries, notably because of cost and availability issues. We designed HIV and HBV primers for conserved regions of the HIV and HBV genomes that were specifically adapted to viral strains circulating in West Africa that are HIV-1 subtype CRF02AG and HBV genotype E. We first validated two monoplex qPCR assays for individual quantification and, then developed a multiplex qPCR for simultaneous quantification of both viruses. HIV RNA and HBV DNA amplification was performed in a single tube using a one-step reverse transcription-PCR reaction with primers and probes targeting both viruses. Performance characteristics such as the quantification range, sensitivity, and specificity of this multiplex qPCR assay were compared to reference qPCR tests for both HIV and HBV viral load quantification. The multiplex assay was validated using clinical samples from co- or mono-infected patients and gave comparable viral load quantification to the HIV and HBV reference test respectively. The multiplex qPCR demonstrated an overall sensitivity of 71.25 % [68.16–74.3] for HBV and 82 % [78.09–85.90] for HIV and an overall specificity of 100 % [94.95–100] for both viruses. Although the overall sensitivities of the HIV and HBV assays were lower than the commercial comparator assays, the sensitivity in the clinical decision range of >1000 copies/mL for HIV was 80 % [71.26–88.73] and >1000 IU/mL for HBV was 100 % [95.51–100] which indicates the test results can be used to guide treatment decisions. This in-house developed multiplex qPCR assay represents a useful diagnostic tool as it can be performed on affordable "open" real-time PCR platforms currently used for HIV or SARS-Cov-2 infection surveillance in Mali.

“Evaluation of ELITE InGenius® integrative system for detection, quantification and monitoring of HIV-1 RNA in Cerebrospinal Fluid.”

IntroductionHuman Immunodeficiency virus (HIV) is effectively suppressed in the blood by the Antiretroviral Therapy in people living with HIV, but in rare cases can be present in some tissues and body fluids. In recent years, integrated systems were validated for detecting HIV-1 in plasma or serum. but not in cerebrospinal fluid (CSF). We evaluated the performance of ELITE InGenius® in comparison with the cobas® in this area. MethodsTo test the diagnostic accuracy of the HIV-1 ELITe MGB® kit on CSF samples, we tested CSF samples previously characterised with the cobras® HIV1 test. Archived CSF samples were also spiked with serial dilutions of the 4th WHO International Standard for HIV-1 NAT and assays and tested to assess the repeatability and reproducibility of the ELITechGroup assay. ResultsThe HIV-1 ELITe MGB® Kit confirmed all the HIV-1 negative CSF samples from patients HIV positive in plasma and from non-HIV1 patients. All the CSF samples that were HIV-1 positive by the cobas®, were confirmed positive by the ELITe InGenius®. Concordance across the methods was also observed when processing the CSF dilutions spiked at medium-low titre, mimicking HIV-1 low-load infections. ConclusionsThe two systems were equivalent in the detection and quantification of HIV-1 RNA in CSF samples.

Evaluation of the analytical and clinical performance of the Abbott Alinity m instrument for the quantification of HIV-1 RNA plasma viral load in a reference laboratory in Rio de Janeiro, Brazil.

We sought to evaluate the analytical performance of the Alinity m system (Abbott Molecular) and to compare the clinical performance of HIV-1 assays on the Alinity m and m2000 RealTime platforms (Abbott Molecular). The sensitivity, precision, and accuracy of the Alinity m instrument were determined using a panel of standard samples (n = 46). The carryover effect was assessed by analyzing HIV-negative clinical samples (n = 20). Clinical performance of the Alinity m and m2000 RealTime platforms was compared using surplus HIV-positive patient plasma samples (n = 39). The Alinity m HIV-1 assay demonstrated 100% sensitivity, a high precision (coefficient of variation (s/x̄) × 100 ≤1.5% [SD ≤ 0.05] logarithm to base 10 [log10] copies/mL), and partial accuracy over the quantification range. Analysis of clinical samples suggested that the Alinity m HIV-1 assay does not cause carryover effect and produced a mean bias of 0.209 log10 copies/mL (95% CI, 0.153-0.265) compared with the m2000 RealTime System. The Alinity m instrument's performance correlated to that of the m2000 RealTime platform and showed excellent sensitivity, precision, and accuracy, despite producing overquantification not clinically relevant for disease management. Furthermore, use of the Alinity m platform can reduce turnaround time.

An Evaluation of the Performance, Patient Acceptability, and Feasibility of a Point-of-Care HIV-Syphilis Assay in an Urban Emergency Department.

Point-of-care (POC) tests for sexually transmitted infections (STIs) permit delivery of results during the patient's emergency department (ED) encounter. We evaluated performance, patient acceptability, and feasibility of a new duplex POC test, Chembio Dual Path Platform HIV-Syphilis Assay, in an urban ED setting. Convenience sampling approach prioritizing those considered at increased risk for an STI and/or with a history of HIV. For the performance evaluation, participants were tested for HIV/syphilis with the Chembio POC assay and the reference laboratory tests; sensitivity and specificity were determined. For the patient acceptability evaluation, participants completed pre- and post-user surveys. For the feasibility evaluation, ED clinical technicians completed a survey evaluating their perceptions regarding feasibility of use of this POC test. A total of 327 patients were consented and enrolled. The diagnostic sensitivity and specificity of the Chembio POC assay for HIV were 96.5% (95% confidence interval [CI], 90.1%-99.3%) and 99.6% (95% CI, 97.7%-100.0%), respectively, and for syphilis, the values were 93.9% (95% CI, 85.0%-98.3%) and 99.6% (95% CI, 97.9%-100.0%), respectively. Regarding patient acceptability, 87% trusted the result, and 93% reported that they were more likely to seek treatment if they received a positive STI test result in the ED rather than after the ED visit. Regarding feasibility, 90% of the technicians reported that they would recommend using the test in EDs. The Chembio Dual Path Platform HIV-Syphilis POC Assay had excellent performance characteristics when evaluated in an ED population, as well as high perceived acceptability from patients, and feasibility for ED use from clinical technicians. The test may have utility for HIV-syphilis screening among high-risk ED patients.

Dolutegravir + Lamivudine vs. Dolutegravir + Tenofovir Disoproxil Fumarate/Emtricitabine: Very-Low-Level HIV-1 Replication through 144 Weeks in the GEMINI-1 and GEMINI-2 Studies.

In GEMINI-1/-2, dolutegravir + lamivudine was non-inferior to dolutegravir + tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) in achieving viral suppression (viral load [VL] < 50 copies/mL) in treatment-naive adults. Abbott's RealTime HIV-1 assay provides quantitative VL (40-10,000,000 copies/mL) and qualitative target detected or target not detected (TND) for VL < 40 copies/mL. This post hoc analysis assessed very-low-level viremia and "blips" through Week 144. Proportions with VL < 40 copies/mL and TND are presented overall and by baseline VL and CD4+ cell count. "Blips" (single VL ≥ 50 to <200 copies/mL with adjacent values < 50 copies/mL) were assessed from Day 1 after VL suppression and from Weeks 48 through to 144. Proportions with TND increased through Week 48 and were similar between groups at all visits (Week 144: dolutegravir + lamivudine, 451/716 [63%]; dolutegravir + TDF/FTC, 465/717 [65%]). By observed analysis, TND rates were similar between groups across baseline subgroups. Through Week 144, proportions with ≥1 "blip" were generally comparable for dolutegravir + lamivudine vs. dolutegravir + TDF/FTC from Day 1 (15% vs. 20%) and from Week 48 (7% vs. 11%). Through 144 weeks, the proportions with TND or "blips" were similar between dolutegravir + lamivudine and the three-drug comparator, reinforcing the efficacy and durability of dolutegravir + lamivudine.

Evaluation of the accuracy of the Asanté assay as a point-of-care rapid test for HIV-1 recent infections using serum bank specimens from blood donors in South Africa, July 2018 - August 2021.

Point-of-care (POC) rapid recency testing can be used as a cost-effective tool to identify recently infected individuals (i.e. infected within the last 12 months) in near-real time, support epidemic control and identify hotspots for transmission as part of recent infection surveillance. To evaluate the performance of the Asanté (HIV-1) rapid recency assay as a POC rapid test among blood donors in South Africa (SA). The study was a cross-sectional and validity study of the Asanté HIV-1 Rapid Recency Assay performed on 715 consecutively archived plasma donor specimens from the SA National Blood Services to determine their recency and established HIV infection status. ELISA and rapid assays for HIV antibody detection were used as the reference-testing standard for confirming an infection, while the Maxim HIV-1 limiting antigen (LAg) avidity assay was used as a reference for comparing HIV recency status. Validity tests (sensitivity, specificity, negative and positive predictive values) and Cohen-Kappa tests of the agreement were conducted to compare the Asanté HIV-1 rapid recency assay results with the reference tests. Of the 715 studied blood samples, 63.1% (n=451/715) were confirmed to be HIV-positive based on the reference standard. The sensitivity and specificity of the Asanté HIV-1 rapid recency assay in diagnosing established HIV infection compared to the ELISA were 98.4% (95% CI 96.7 - 99.3) and 99.6% (95% CI 97.6 - 100), respectively. Compared with HIV rapid assay, the sensitivity and specificity of the Asanté HIV-1 rapid recency assay was 98.7% (95% CI 97.0 - 99.4) and 99.2% (95% CI 97.1 - 100), respectively. Of the 451 HIV-positive blood samples, 43% were confirmed as recent HIV infections by the Maxim HIV-1 LAg avidity assay. There was high agreement between the Asanté HIV-1 rapid recency assay and the Maxim HIV-1 LAg avidity assay (94.1%, k=0.879, p<0.0001). The sensitivity and specificity of the Asante HIV-1 assay was 89.4% (95% CI 84.0 - 93.0) and 97.7% (95% CI 94.8 - 99.0), respectively. The Asanté HIV-1 rapid recency assay test results demonstrated high accuracy (>90%) compared with the HIV ELISA and rapid assays for determining established infection and the Maxim HIV-1 LAg avidity assay for classifying recent HIV-1 infections. The assay's sensitivity for established infections was below the World Health Organization criteria (<99%) for POC devices. The Asanté HIV-1 rapid recency assay can be used to distinguish between recent and long-term infections, but may not be considered a POC test for determining HIV infection.

Loss to Follow-up and Death Among Individuals With Newly Diagnosed Human Immunodeficiency Virus Receiving Dolutegravir-Based First-Line Antiretroviral Treatment in Eastern Ethiopia: Implications for 95% United Nations Targets.

Loss to follow-up (LTFU) and death are unfavorable outcomes of human immunodeficiency virus (HIV) treatment. This study aimed to identify the predictors of LTFU and death among individuals with newly diagnosed HIV receiving dolutegravir (DTG)-based first-line antiretroviral treatment (ART) in eastern Ethiopia. A multisite prospective cohort study was carried out between October 2020 and July 2022. New case patients who started ART were enrolled consecutively and then followed up for the next 6 months. A structured questionnaire and checklists were used to collect data. HIV viral load was determined using the Abbott RealTime HIV-1 assay. Bivariable and multivariable logistic regression models were used to identify baseline factors associated with the outcomes. A total of 235 people with newly diagnosed HIV were enrolled; 16.6% (95% confidence interval, 12.3%-21.9%) were lost to follow-up, and 5.9% (3.5%-9.8%) died within 6 months of follow-up. Baseline World Health Organization clinical stage I (adjusted odds ratio, 3.93 [95% confidence interval, 1.34-11.57]), low viral load (3.67 [1.09-12.36]), and body weight (1.04 [1.01-1.07]) were predictors of LTFU, whereas nonfunctional status (10.02 [1.9-51.3]) was the only factor associated with death. LTFU and death rates among patients with DTG were relatively high, accounting for roughly a quarter of the attrition of people with newly diagnosed HIV from ART care and services. Thus, targeted interventions are required to reduce LTFU and death among individuals with HIV on ART. Further investigation is necessary to evaluate the long-term effects of DTG-based regimens on LTFU and its impact on HIV mortality rates, and qualitative research, specifically tracing LTFU, is recommended.

Clinical performance evaluation of HCV and HIV-1 assays on the fully automated molecular system Alinity m

The demand for molecular virology testing continues to grow in clinical laboratories worldwide. The Alinity m system is a fully automated, continuous, random-access molecular diagnostic analyzer that was designed to streamline the laboratory workflow. In this study, we assessed the clinical performance characteristics of the Alinity m HCV and HIV-1 assays to detect and quantify these two bloodborne pathogens in 71 serum and plasma specimens. The overall qualitative agreement between the Alinity m and Abbott m2000 was 100 % for HCV and 94.4 % for HIV-1. Our data demonstrated a weak bias across the quantitative range of the Abbott m2000 and Alinity m HCV and HIV-1 assays, indicating a strong correlation on viral loads between them. Taken together, the Alinity m HCV and HIV-1 assays had comparable results to their current predecessors, the Abbott RealTime HCV and HIV-1 assays.

Virological Non-Suppression among Newly Diagnosed HIV-Positive Individuals on Dolutegravir-Based Antiretroviral Treatment in Eastern Ethiopia: Follow-Up Study.

There have been limited studies linking baseline factors, including the viral load (VL) test, with virological non-suppression since the introduction of dolutegravir (DTG)-based regimens as first-line antiretroviral treatment (ART) in Ethiopia. This study aimed to identify baseline factors associated with virological non-suppression between October 2020 and July 2022. A follow-up study was conducted in eastern Ethiopia among newly diagnosed people living with HIV (PLHIV). A questionnaire and a checklist were used to collect the data. Five milliliters of venous blood were obtained at baseline and six months to determine the VL. A VL test was performed using the Abbott RealTime HIV-1 assay. To determine predictors of virological non-suppression, bivariate and multivariate logistic regression analyses were used. There were 235 PLHIV enrolled, 70.6% of whom were female, with a mean age of 33.9 years. Of the 161 retained on ART, virological non-suppression was 8.7% at six months. Baseline predictors of virological non-suppression were age ≤ 30 years, a history of substance use, and a VL greater than 4-log10 copies/mL. In this cohort, virological non-suppression was found to be optimal but still lagged slightly behind the third 95%-target. Thus, targeted interventions, the introduction of baseline VL testing to improve treatment outcomes, and fostering the attainment of UNAIDS 95-95-95 targets are recommended. Furthermore, broader research is recommended to explore the reasons for virological non-suppression in the study area.

Serological Evidence of HIV/HBV Co-infection among HIV-infected patients in Onitsha, Anambra State, Nigeria

Research suggests that HIV-infected individuals who have also been co-infected with HBV face a greater risk of HIV progression. Hepatitis B and HIV infections pose serious public health challenges in sub-Saharan Africa. This study examined the possible HBV co-infection with the socio-demographic traits of HIV-infected individuals attending the HIV clinic at a referral specialist mission hospital in Onitsha, Anambra State, Nigeria. Two hundred and twenty (220) HIV-infected individuals gave consent to participate in the study. Between March 2022 and October 2022, blood samples (about 5ml) were aseptically collected during routine investigations into sterile EDTA bottles, and plasma samples were obtained by centrifugation. These samples were tested for HBsAg using a Monolisa HBsAg ULTRA kit (Bio-Rad, USA). CD4 counts were measured using the Partec CyFlow. Plasma viral loads (PVL) were also determined using the Abbott Real-Time HIV-1 Assay US protocol. HIV/HBV co-infection was 40.9%. The results showed that most (39.7%) study participants co-infected with HBV had a CD4 cell count of 350 cells/µl. The virological assay revealed that the highest HBsAg seroprevalence was detected in the study participants whose viral loads were between 40 and 1000µl (61.9%). The majority of the study participants were female HIV patients (74.5%), while those co-infected with HBV were mainly male patients (48.2%). HIV-positive individuals aged 18-30 (53.3%) were mostly affected. None of the socio-demographic variables tested was significantly associated with HBV in HIV-infected patients in Onitsha, Anambra State, Nigeria. This study showed a high HIV/HBV co-infection in Onitsha, Anambra State, Nigeria.

Current HIV/SIV Reservoir Assays for Preclinical and Clinical Applications: Recommendations from the Experts 2022 NIAID Workshop Summary.

Since the first HIV-cured person was reported in 2009, a strong interest in developing highly sensitive HIV and SIV reservoir assays has emerged. In particular, the question arose about the comparative value of state-of-the-art assays to measure and characterize the HIV reservoir, and how these assays can be applied to accurately detect changes in the reservoir during efforts to develop a cure for HIV infection. Second, it is important to consider the impact on the outcome of clinical trials if these relatively new HIV reservoir assays are incorporated into clinical trial endpoints and/or used for clinical decision-making. To understand the advantages and limitations and the regulatory implications of HIV reservoir assays, the National Institute of Allergy and Infectious Diseases (NIAID) sponsored and convened a meeting on September 16, 2022, to discuss the state of knowledge concerning these questions and best practices for selecting HIV reservoir assays for a particular research question or clinical trial protocol.

Co-infection of Hepatitis C among HIV-infected patients: A cross-sectional study from A University Teaching hospital in Anambra State, Nigeria

Hepatitis C virus co-infection (HCV) with HIV is regarded as a significant public health risk despite being less frequent than hepatitis B co-infection with HIV. This observation results from HIV's impact on the HCV life cycle and, ultimately, the hepatic system. In this study, potential HCV co-infection was examined in connection to the socio-demographic characteristics of HIV-positive patients attending an HIV clinic at a University Teaching Hospital in Awka, Anambra State, Nigeria. Between September 2021 and June 2022, 255 HIV patients who consented to participate in the study had their HCV levels checked using the anti-HCV antibody ELISA kit (DIA.PRO, Italy). Using the Partec CyFlow, CD4 counts were calculated. During routine investigations, blood samples (approximately 5ml) were aseptically collected into sterile EDTA vials, and plasma samples were obtained by centrifugation. With the aid of Abbott Real-Time HIV-1 Assay US methodology, plasma viral loads (PVL) were also calculated. A total of 11 (4.3%) HIV-positive people were also confirmed to have HCV infection, with women making up the majority (4.8%). Most of those affected were between the ages of 31 and 40 (6.8%). With marital status, HCV co-infection was found more amongst married patients, with a rate of 4.8%. The prevalence of HIV/HCV co-infection was higher (4.8%) in those with CD4 cell counts under &gt;350 cells per ml than others. Most patients (3.1%) did not have their viral RNA detected (TND). Self-employed infected persons and those with secondary school educational backgrounds had the highest HIV/HCV prevalence rate of 6.6% and 7.6%, respectively. The study's findings show no statistically significant relationships between the patients' socio-demographic traits and HCV. Also, HCV co-infection prevalence was significantly low in the study participants.

A protocol for feasibility of plasma based GeneXpert platform and Dried Blood Spot (DBS) based Abbott platform for HIV-1 viral load testing among the people living with HIV attending ART centers in India.

HIV-1 Viral load (VL) measures efficiency of the antiretroviral therapy (ART) after treatment initiation and helps to diagnose virological failures at an early stage. Current VL assays require sophisticated laboratory facilities. As well as there are other challenges pertaining to insufficient laboratory access, cold-chain management and sample transportation. Hence the number of HIV-1 VL testing laboratories is inadequate in the resource limited settings. The revised national tuberculosis elimination programme (NTEP) in India has developed a vast network of point of care (PoC) testing facilities for diagnosis of tuberculosis and several GeneXpert platforms are functional under this programme. Both the GeneXpert HIV-1 assay and HIV-1 Abbott real time assay are comparable and GeneXpert HIV-1 assay can be used as PoC for HIV-1 Viral load testing. Also, the dried blood spot (DBS) as a sample type has been considered as a good option for HIV-1 VL testing in hard to reach areas. This protocol is therefore developed to assess the feasibility of integrating HIV-1 VL testing among people living with HIV (PLHIV) attending ART centres using the two public health models under the current programme: 1. HIV-1 VL testing using GeneXpert platform and plasma as a sample type, and 2. HIV-1 VL testing using Abbott m2000 platform and DBS as a sample type. This ethically approved feasibility study will be implemented at two moderate to high burden ART centres where VL testing facility is not available in the town. Under Model-1, arrangements will be made to carry out VL testing on the adjacent GeneXpert facility and under Model-2, DBS will be prepared on site and couriered to identified viral load testing laboratories. In order to assess the feasibility, data will be collected on pretested questionnaire pertaining to number of samples tested for VL testing, number of samples tested for tuberculosis (TB) diagnosis and the turnaround time (TAT). In-depth interviews will be conducted among the service providers at ART centre and different laboratories for addressing any issues regarding the model implementation. The proportion of PLHIV tested for VL at ART centres, total TAT for both models including TAT for sample transportation, sample testing and receipt of results as well as proportion of sample rejections and reasons for the same, correlation coefficient between DBS based and plasma based VL testing will be estimated using various statistical tools. If found promising, these public health approaches will be helpful for the policy makers and program implementation in scaling up HIV-1 viral load testing within India.

Clinical performance evaluation of the Aptima viral assays for the quantitation of HIV-1, HCV, and HBV in plasma samples

The clinical performance of the Aptima® HIV-1 Quant Dx, Aptima HCV Quant Dx, and Aptima HBV Quant Dx were evaluated and compared to the Roche cobas HIV-1, HCV, and HBV assays performed on the Roche cobas 6800 system. The Aptima Quant assays exhibited an overall percent agreement of 99.4% for HBV, 98.3% for HCV, and 85.14% for HIV-1. The average log difference between the Aptima and Roche assays was below 0.2 IU (or copies)/mL and the quantitative correlation's (R-squared value (R2)) was between 0.95 and 0.97. The Aptima viral assays demonstrated a high level of quantitative correlation with the Roche cobas assays for HCV, HBV, and HIV-1.

Antiviral activity of tenofovir alafenamide (TAF) against HIV-1 clinical isolates harboring K65R.

Tenofovir alafenamide (TAF) is a prodrug of the nucleoside reverse transcriptase (RT) inhibitor tenofovir (TFV). Compared to the earlier TFV prodrug, TFV disoproxil fumarate (TDF), TAF achieves more than fourfold-higher intracellular levels of its active metabolite TFV diphosphate (TFV-DP) in clinical studies, while achieving a significant reduction of TFV systemic exposure. Resistance to TFV has been well established, with the K65R mutation inRTas the signature mutation.Here we evaluated the in vitro activity of TAF and TDF in patient-derived HIV-1 isolates harboring the K65R mutation.Clinical isolates containing K65R were cloned into the pXXLAI construct (n = 42). In vitro phenotypic susceptibility of the constructs to TAF and TDF was evaluated in an MT-2 cell HIV assay and in viral breakthrough assays modeling physiological concentrations of TAF and TDF.TAF and TDF susceptibility were highly correlated in K65R-containing mutants, ranging from 2.7- to 3.0-fold (K65R alone) and 1.2- to 27.6-fold (K65R+ other RT mutations) relative to wild-type. In viral breakthrough assays mimicking differences in physiological concentrations, TAF inhibited breakthrough of 40 of 42 clinical isolates, while the TDF equivalent only inhibited 32 of 42 isolates tested.TAF displayed a higher barrier to resistance than TDF in this panel of K65R-containing clinical isolates.

Molecular confirmation of HIV-1 and HIV-2 coinfections among initially serologically dually-reactive samples from patients living in West Africa.

This study aimed to confirm the co-infection with HIV-1 and HIV-2, among West African patients using in-house HIV type/group enzyme-immuno assays and molecular diagnosis. A cross-sectional survey was conducted from April 2016 to October 2017 in the biggest HIV clinics of Côte d'Ivoire and Burkina Faso. A first serological confirmation was done in the referral laboratory using an in-house, indirect immuno-enzymatic essay allowing the qualitative detection of both HIV-1 and HIV-2 antibodies. In order to separately detect anti-HIV-1 and anti-HIV-2 antibodies, a type/group specific enzyme-immuno assay (HIV-GSEIA) was used. To confirm the co-infections, HIV-1 and HIV-2 DNA-qualitative PCR assays were performed. A total of 91 patients were enrolled in the study and provided blood sample for HIV type confirmatory testing including 13 (14.3%) HIV-2 mono-reactive and 78 (85.7%) HIV-1/HIV-2 dually-reactive based on the HIV testing National Algorithms. The first serological ELISA confirmatory test performed showed that 80 (78.9%) of the 91 participants were dually-reactive. The HIV-GSEIA performed on these 80 serum samples retrieve one 61 HIV-1/HIV-2 dually-reactive samples. HIV-1 and HIV-2 DNA PCR were performed on 54 of the 61 HIV-1/HIV-2 dually-reactive samples and 46 out of 61 (75.4%) samples were found HIV-1/HIV-2 coinfected. The contribution of type/group specific enzyme-immuno assay to accurately identify HIV-1/HIV-2 coinfections remain suboptimal, emphasizing the need for molecular diagnosis platforms in West Africa, to avail HIV DNA PCR test for the confirmation of HIV-1/HIV-2 co-infections.

It takes more than a machine: A pilot feasibility study of point-of-care HIV-1 viral load testing at a lower-level health center in rural western Uganda.

Barriers continue to limit access to viral load (VL) monitoring across sub-Saharan Africa adversely impacting control of the HIV epidemic. The objective of this study was to determine whether the systems and processes required to realize the potential of rapid molecular technology are available at a prototypical lower-level (i.e., level III) health center in rural Uganda. In this open-label pilot study, participants underwent parallel VL testing at both the central laboratory (i.e., standard of care) and on-site using the GeneXpert HIV-1 assay. The primary outcome was the number of VL tests completed each clinic day. Secondary outcomes included the number of days from sample collection to receipt of result at clinic and the number of days from sample collection to patient receipt of the result. From August 2020 to July 2021, we enrolled a total of 242 participants. The median number of daily tests performed on the Xpert platform was 4, (IQR = 2-7). Time from sample collection to result was 51 days (IQR = 45-62) for samples sent to the central laboratory and 0 days (IQR = 0-0.25) for the Xpert assay conducted at the health center. However, few participants elected to receive results by one of the expedited options, which contributed to similar time-to-patient between testing approaches (89 versus 84 days, p = 0.07). Implementation of a rapid, near point-of-care VL assay at a lower-level health center in rural Uganda appears feasible, but interventions to promote rapid clinical response and influence patient preferences about result receipt require further study. Trial registration: ClinicalTrials.gov Identifier: NCT04517825, Registered 18 August 2020. Available at: https://clinicaltrials.gov/ct2/show/NCT04517825.

Evaluation of the performance of a novel HIV-1 viral load assay for HIV quantification in China.

Our objective was to assess the HIV-1 quantification performance of the Livzon HIV-1 viral load (VL) assay and the Roche Cobas HIV-1 assay to evaluate an HIV-1 VL testing reagent for application in China. We compared the Livzon and Roche Cobas HIV-1 VL assays using ethylenediaminetetraacetic acid plasma samples collected between May 2021 and November 2021 from patients with HIV-1 and healthy controls. We used Cohen's κ coefficient to measure agreement of qualitative values and Pearson's correlation coefficient (r) values and the coefficient of determination (R2 ) to determine the linear relationship between the two assays. We performed a Bland-Altman analysis to assess VL quantification agreement. In total, 11 plasma samples from patients with hepatitis B virus (HBV) or hepatitis C virus (HCV) and nine samples from healthy controls were undetectable on both assays. Overall agreement was seen in 419 of 500 specimens (91.40%), with a κ value of 0.59. Pearson's correlation coefficient between the two assays was 0.970. Using the Bland-Altman method, 95.14% (352/370) of paired VLs fell within the 95% confidence limits of agreement (-0.51 to 0.95 log10 copies/mL). Higher VLs had a better correlation and a smaller mean difference between the two assays. Pearson's correlation coefficient for the samples of subtype CRF01_AE, CRF07_BC, and CRF55_01B was 0.950, 0.935, and 0.952, respectively. The Livzon HIV-1 VL assay exhibits good precision and linearity and a high correlation with the Roche Cobas HIV-1 assay. The Livzon HIV-1 VL assay has salient advantages in terms of the lyophilized powder reagent, which gives the assay greater stability and sensitivity and can be readily used in low-resource areas.