RealTime HIV-1 Research Articles

Epidemiological and virological characteristics of people living with HIV on antiretroviral treatment for more than 6 months in virological failure in Brazzaville, Republic of Congo

Introduction. Virological failure is one of the main causes of failing to treat, and better management of HIV infection requires understanding and controlling the factors that contribute to this phenomenon. The main objective was to characterize the patients of the active file of the Brazzaville Outpatient Treatment Center in virological failure to identify predictive factors leading to virological failure. Methods. Conducted between June and December 2020, this was a cross-sectional study. Patients enrolled were HIV-1-infected patients from the Brazzaville Outpatient Treatment Center receiving a potent combination therapy for at least 6 months but experiencing virological failure. Viral load was measured using the automated Abbott Real-time HIV-1 m2000rt System. Sociodemographic and clinical data were collected from a computerized patient record software called Santia. For the identification of the independent predictors of virological failure, statistical analysis was performed. Results. A total of 109 patients with virological failure were recruited. The median age of the patients was 45 years (interquartile range: 37–52 years) and women were more represented (74%). More than half of the patients had World Health Organization stage IV HIV and the median duration of antiretroviral treatment was 96 months. The most followed treatment regimen was AZT+3TC+EFV (or nevirapine) with 48%, while the median viral load was 12985 copies ml−1. Conclusion. In our study, we did not identify any sociodemographic or clinical variables predictive of virological failure. However, we felt that it would be desirable to carry out a study with temporal follow-up and the possibility of sequencing in order to identify the different circulating genotypes and resistance mutations.

Comparison of the Performance of Commercially Available Quantitative Viral Load Assays Using Clinical Samples from Patients from Regions Where Distinct HIV-1 Subtypes Co-Circulate: Potential Implications for Patient Management.

HIV RNA plasma viral load (VL) is the standard surrogate marker to monitor response to antiretroviral treatment (ART). We compared the linearity, repeatability, and concordance of six commercially available HIV RNA VL platforms using clinical samples from patients from Brazilian sites where different HIV-1 subtypes co-circulate. A total of 150 plasma samples from each city were collected in Curitiba, Southern Brazil (subtype C), São Paulo (subtype B), and Santos (BF recombinants), Southeast Brazil. Platforms were VERSANT® Siemens HIV RNA 1.0 (kPCR); VERSANT® Siemens HIV-1 RNA 3.0 (bDNA); Abbott Real-Time HIV-1; NucliSens EasyQ® HIV-1 v2.0 Biomerieux; COBAS® TaqMan®, Roche; and artus HIV Virus-1 RT-PCR, QIAGEN. OptiQuant HIV-1 RNA quantification panel was used to compare VL linearity, using samples containing 50, 500,5,000, 50,000, 500,000, and 5,000,000 HIV copies/mL. HIV RNA panels with subtypes A, B, C, D, F, G, H, circulating recombinant form (CRF)1, and CRF2 were utilized. A high degree of linearity and repeatability was demonstrated for all platforms. When compared with a subtype B reference sample, 17 of 54 (31.48%) samples diverged by more than 0.5 log10 copies/mL. Except for the Roche platform, all platforms underestimated subtype C VLs. A total of 743 (82.6%) valid results were obtained with samples from São Paulo, 707 (78.6%) from Santos, and 673 (74.8%) from Curitiba (São Paulo vs. Santos, p = .03; São Paulo vs. Curitiba, p = .00006; Santos vs. Curitiba, p = .06). The number of discordant samples between different methodologies when VL was undetectable in one method and detectable in the other ranged from 1.25% (Abbot vs. Siemens) to 44.8% (Abbott vs. Biomerieux). Finding samples with undetectable VL in one method and a high VL in another might have important individual and public health consequences. Standardization of VL measurements, particularly for non-B subtypes infections, especially subtype C, is necessary to maximize the individual and public health benefits of ART globally.

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.

FERROPTOSIS IN CD4+ AND CD8+ T-CELLS IN THE SETTINGS OF HIV INFECTION

Introduction: Elevation of intracellular iron concentration triggers ferroptosis. Understanding the regulation and pathophysiological mechanisms of this process in HIV infection may contribute to antiretroviral therapy (cART) monitoring. Aim: To perform a correlation analysis of the intracellular labile-bound iron pool (LIP) in CD4+ and CD8+ T cells in association with CD4+, CD8+ T cells absolute count (AC) and CD4/CD8 index in HIV+ individuals on continuous cART with sustained viral suppression. Material and methods: Peripheral blood samples (Li heparin, n=34) were collected in the course of the routine immune monitoring of HIV+ individuals at four time points during 24 months. Plasma HIV viral load (VL) was determined with the Abbott Real-Time HIV-1 test (sensitivity 40 copies/ml). AC and percentage of CD4+ and CD8+ T cells were determined by direct flow cytometry (Multitest, BD Trucount, FACS Canto II). The intracellular content of LIP in CD4 and CD8 T cells (LIP CD4, LIP CD8) was measured at the beginning of the study, using acetoxymethyl ester and subsequent incubation with a chelator (Deferiprone). LIP was quantified according to the mean fluorescence intensity (MFI) (FACSCanto II, Diva 6.1.2). Results: In the settings of a higher LIP CD4 , high LIP CD8 correlated with increased CD8AC (Rho=0.70, p&lt;0.05) up to 11 (min. 6, max. 15) months after LIP measurement., and decreased CD4/CD8 ratio correlated inversely with LIP CD8 in all consecutive measurements (Rho= -0.71, p&lt;0.01 for all), Importantly, high LIP CD8 correlated with a lower CD4AC (Rho=-0.65, p&lt;0.05) up to five (min.1, max.8) months after LIP measurement. Conclusion: The increased concentration of intracellular LIP in CD8 cells in HIV+cART individuals could indicate viral activity in the settings of undetectable HIV VL, directly associated with ongoing cell ferroptosis.

M-PIMA™ HIV1/2 VL: A suitable tool for HIV-1 and HIV-2 viral load quantification in West Africa

Point-of-Care for HIV viral RNA quantification seems to be a complementary strategy to the existing conventional systems. This study evaluated the performance of the m-PIMA™ HIV1/2 Viral Load for the quantification of both HIV-1 and HIV-2 RNA viral load. A total of 555 HIV-1 and 90 HIV-2 samples previously tested by Abbott RealTime HIV-1 (Abbott, Chicago, USA) and Generic HIV-2® Charge virale (Biocentric, France) were tested using the m-PIMA™ HIV1/2 Viral Load at the HIV National Reference lab in Senegal. For HIV-1, Pearson correlation and Bland-Altman plots showed a coefficient r = 0.97 and a bias of −0.11 log10 copies/ml (95% confidence interval [CI]: −0.086 to −0.133 log10 copies/ml) for the m-PIMA™ HIV1/2 Viral Load, respectively. Sensitivity and specificity at 3 log10 copies/ml (threshold of virological failure) were 93.6% (95%[CI]: 91.5% to 95.6%) and 99.1% (95%[CI]: 98.3% to 99.9%), respectively. For HIV-2, a correlation of r = 0.95 was also noted with a bias of − 0.229 log10 copies/ml (95%[CI]: −0.161 to −0.297 log10 copies/ml). Sensitivity and specificity at 3 log10 copies/ml were 97.6% (95%[CI]: 94.3% to 100%) and 93.9% (95%[CI]: 88.9% to 98.8%), respectively. These results confirmed that m-PIMA™ HIV1/2 VL could be a good alternative for HIV-1 and HIV-2 viral load testing in decentralized settings in Senegal.

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.

High risk of virologic failure among HIV-infected children and adolescents routinely followed-up in Littoral region of Cameroon.

Virological response to antiretroviral therapy (ART) remains a challenge for HIV-infected children and adolescents due to non-optimization of pediatric ART for resource-limited settings. In this study, we aimed to investigate factors associated with virologic failure (VF) in HIV-infected-children and adolescents on ART in Cameroon. A prospective patient-based cohort study was conducted among HIV-infected children (0-9 years) and adolescents (10-19 years) followed-up between November 2018 and October 2019 in 38 healthcare centers located in the Littoral region of Cameroon. The 1st viral load (VL) was assessed after 6 months of ART initiation and the 2nd VL between 3 and 6 six months later in patients with VL ≥1000 copies/ml in accordance with the national algorithm using Abbott Real-Time HIV-1 Viral Load Assay. Multivariate analyses were performed to identify the determinants of higher risk of VF. Of 1,029 HIV-infected children and adolescents (393 children and 636 adolescents), 801 (77.8%) cumulatively presented with VL <1000 copies/mL within 12 months on ART. Adolescents were more likely to have VF than children (24.5% vs 18.3%, OR: 1.39; 95%CI: 1.00-1.93; p = 0.047). Patients followed-up in decentralized care units were significantly more likely to have VF compared to those attending the accredited treatment centers (26.1% vs 16.6%, OR: 1.88, 95%CI: 1.37-2.58; p<0.001). Our findings show a high rate of VL suppression (VLS, 77.8%) among HIV-infected children and adolescents, albeit lower than the established target of 90%. Being adolescent and patients followed in the decentralized care units are high risk factors for VF, thereby necessitating routine therapeutic education of patients and guardians in resource limited countries to improve VLS.

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.

The plasma separation card as a novel solution for enhancing central laboratory capability for HIV-1 viral load monitoring in limited-access settings.

Measurement of HIV-1 viral load (VL) is essential for monitoring antiretroviral treatment (ART) efficacy. The preferred specimen type for VL is plasma, but in remote settings where collection and preservation of plasma many not be possible, dried blood spots (DBS) are often used instead. A new specimen collection matrix, the cobas plasma separation card (PSC, Roche Diagnostics Solutions), enables specimen preparation from a finger prick or venous blood, using a multi-layer absorption and filtration design that results in a specimen similar to dried plasma. We sought to confirm the correlation between VL results obtained using PSC prepared from venous blood to those from plasma or DBS, as well as PSC prepared with capillary blood from a finger prick. PSC, DBS and plasma were prepared with blood from HIV-1 infected persons attending a primary care clinic in Kampala, Uganda. VL in PSC and plasma was measured using cobas HIV-1 (Roche Diagnostics), while VL in DBS was measured with RealTime HIV-1 (Abbott Diagnostics). The correlation between VL from plasma and PSC made from capillary or venous blood was high (regression coefficient of determination r2 between 0.87 and 0.91), and there was good agreement based on mean bias (-0.14 to 0.24 log10 copies/mL) and classification of VL above or below 1000 copies/mL (91.4% agreement). In contrast, VL from DBS was lower than plasma or PSC (mean bias 0.51 to 0.63 log10 copies/mL) and not as well correlated (r2 0.78 to 0.81, 75.1-80.5% agreement). These results confirm the utility of PSC as an alternative specimen type for HIV-1 viral load measurement in areas where preparation and optimal storage or shipment of plasma is an obstacle to provision of treatment and care of HIV-1 infected people.

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.

Comparison of Two Molecular Tests, Roche COBAS&amp;lt;sup&amp;gt;®&amp;lt;/sup&amp;gt;AmpliPrep/COBAS&amp;lt;sup&amp;gt;®&amp;lt;/sup&amp;gt;TaqMan&amp;lt;sup&amp;gt;®&amp;lt;/sup&amp;gt; and Abbott-RealTime in the HIV-1 Early Infants Diagnosis

<i>Background: </i>Prompt diagnosis and treatment of infants born to parents living with HIV is essential to reduce infant mortality. The availability of several high-throughput automated molecular tests is necessary to increase the services of early diagnosis tests in infants, especially in countries with limited resources such as Senegal. <i>Objective: </i>The objective of this study was to compare two automated molecular tests, Roche COBAS^®AmpliPrep/COBAS^® TaqMan^®HIV-1 Qualitative and Abbott RealTime HIV-1 Qualitative in the early diagnosis of HIV-1 infection in children born to HIV-positive mothers in Senegal. Methods: The study was conducted exclusively at the molecular biology laboratory of the armed forces AIDS programme at the Ouakam Military Hospital, Dakar, Senegal, between September 2020 and December 2021. It involved 136 children aged between 1 and 18 months born to HIV-1 infected mothers. The samples were taken from blood obtained from the baby's heel, dried on blotting paper (DBS) and sent to the molecular biology laboratory. They were then stored at room temperature before being tested for the study. After these samples were analysed on both molecular techniques, the Abbott Qualitative results were compared to diagnostic tests performed with Roche COBAS^®AmpliPrep/COBAS^®TaqMan^®HIV-1 Qualitative, which is the reference molecular technique. R Studio software version 099.902, 2016 was used to calculate specificity and sensitivity and Kappa coefficient. For statistical tests, they are considered significant when the P-value is less than 5%. <i>Results:</i> Out of a total of 136 samples tested, the overall positive and negative concordance was 94.84%, 79.41% and 93.58% respectively. The concordance coefficient, Cohen's Kappa coefficient, was also analysed. It gave a value of 0.853 (95% CI: [74.7-95.8]). A discrepancy was found between the two tests. Seven samples, which had previously tested positive on Roche Cobas, tested negative on Abbott Qualitative. <i>Conclusion: </i>The result showed a comparable performance characterized by very good negative, positive and global concordances and also, a very high Cohen's Kappa coefficient κ. The present study showed that the two molecular tests are comparable and that the Abbott Qualitative is a practical alternative for the diagnosis of HIV in infants.

Comparative sensitivity of automated (Abbott M2000) and manual plasma HIV-1 RNA PCR assays for the detection of persistent viremia after long-term antiretroviral therapy

BackgroundThe ability of automated, FDA-cleared plasma HIV-1 RNA assays to detect low-level viremia, compared to manual, highly sensitive research-only methods, is not well-defined. We therefore tested paired plasma samples from people with HIV-1 (PWH) on long-term antiretroviral therapy (ART) with both the Abbott M2000 RealTime HIV-1 Viral Load assay (Abbott) and a quantitative reverse transcriptase (RT)-initiated PCR assay that has a reported 95% detection limit of 1 HIV-1 RNA copy/ml (single copy assay, SCA). MethodsPlasma samples from 309 participants in the AIDS Clinical Trials Group study A5321 were tested by both Abbott and SCA. Participants were mostly men (82%). All were on stable ART for a median of 7 years with HIV-1 RNA <40 copies/mL by Abbott. Pooled plasma from each donor was divided and tested. Abbott results were reported as target detected <40 copies/mL but not quantifiable (target detected <40) or target not detected (TND), and SCA results were classified as HIV-1 RNA detected or not detected. ResultsBy Abbott, 17% (51/309) of sample results were target detected <40, whereas 83% (258/309) were TND. Of the samples that were target detected <40 by Abbott, 73% (37/51) had HIV-1 RNA detected by SCA. By contrast, 43% of samples that were TND by Abbott (110/258) had HIV-1 RNA detected by SCA (p < 0.001). ConclusionPlasma samples from PWH with HIV-1 RNA detected but <40 copies/ml by the automated Abbott M2000 assay are likely (73% of 51 samples) to have HIV-1 RNA detected by an optimized manual assay with single copy sensitivity. An Abbott HIV-1 RNA result of target not detected did not exclude low-level viremia: 43% of 258 samples had HIV-1 RNA detected by the single copy assay. These findings indicate that the Abbott M2000 assay cannot exclude the persistence of viremia on ART and thus may have less utility, compared to a manual single copy assay, for assessing the impact of experimental interventions designed to eliminate low-level viremia as a step towards achieving ART-free HIV-1 remission.

Comparison of the performance of Aptima HIV-1 Quant Dx Assay with Abbott RealTime HIV Assay for viral load monitoring using plasma and Dried Blood Spots collected in Kenya.

HIV-1 viral Load (VL) testing is recommended for the monitoring of antiretroviral treatment. Dried Blood Spots (DBS) are an effective sample type in resource limited settings, where safe phlebotomy and reliable shipping are hard to guarantee. In HIV high burden countries, high throughput assays can improve access to testing services. The Hologic Aptima HIV-1 Quant Dx Assay (Aptima Assay) is a high throughput assay that runs on the CE-IVD approved Panther platform. The objectives of this study were to assess the performance characteristics of Aptima for VL monitoring using plasma and venous DBS specimens and to determine the stability of HIV-1 RNA in DBS. This was a cross-sectional study of 2227 HIV infected adults visiting health facilities in Nairobi and Busia, Kenya. Each provided a venous blood sample; plasma was prepared from 1312 samples while paired DBS samples and plasma were prepared from the remaining 915 samples. The agreement between the Aptima assay and the Abbott RealTime HIV-1 Assay (Abbott RT) was analysed by comparing the HIV-1 VL in both assays at the medical decision point of 1000 copies/mL. To assess stability of HIV-1 RNA in DBS, VL in DBS spotted on day 0 were compared with that from the same DBS card after 21 days of storage at room temperature. Overall, 436 plasma samples had quantifiable results in both Aptima and Abbott RT. The agreement between the two assays at 1000 copies/mL was 97.48% with a Pearson's correlation coefficient (r) of 0.9589 and gave a mean bias of 0.33 log copies/mL on Bland-Altman analysis. For fresh DBS, the agreement in both assays was 94.64% at 1000 copies/mL, with an r of 0.8692 and a mean bias of 0.35 log copies/mL. The overall agreement between DBS tested in Aptima on day 0 versus day 21 was 95.71%, with a mean bias of -0.154. The Aptima HIV-1 Quant Dx assay is an accurate test for VL monitoring of HIV-1 using DBS and plasma sample types in Kenya.

Evaluation of SAMBA II: A Qualitative and Semiquantitative HIV Point-of-Care Nucleic Acid Test.

Point-of-care (POC) nucleic acid tests (NATs) have potential to diagnose acute HIV infection and monitor persons taking pre-exposure prophylaxis or antiretroviral therapy (ART). POC NATs have not yet been evaluated in the US. From June 2018-March 2019, we conducted a cross-sectional evaluation of the Simple Amplification-Based Assay version II (SAMBA II) POC NAT. People with HIV (PWH) and persons testing for HIV were tested with the SAMBA II qualitative (Qual) whole blood (WB) test. From April-September 2019, the Qual test was used on persons who were ART-naive, and SAMBA II Semi-quantitative (Semi-Q) WB was used with ART-experienced PWH. Both were performed on unprocessed venipuncture (VP) and, when indicated by protocol, fingerstick (FS) WB and plasma. SAMBA results were compared with Abbott RealTime HIV-1 polymerase chain reaction results on plasma. We calculated sensitivity, specificity, and concordance between tests. SAMBA was used in 330 visits among 280 participants: 202 (61.2%) visits from PWH, and 128 (38.8%) from HIV-negative persons. Qual test sensitivity with ART-naive participants was 91.4% [32/35, 95% confidence interval (CI): 77.6% to 97.0%] using VP WB and 100% (27/27, 95% CI: 87.5% to 100%) using FS WB. Specificity was 100% using both specimen types. Concordance between the gold standard and Semi-Q at 1000 copies/mL among PWH on ART was 97.7% (86/88, 95% CI: 92.1% to 99.4%) and 100% (30/30, 95% CI: 88.7% to 100%) using VP and FS WB, respectively. The SAMBA II POC NATs showed high sensitivity, specificity, and concordance with the gold standard assay, indicating its potential use in diagnostics and monitoring. Future work will evaluate POC NAT implementation in the US.

Performance of Xpert HIV-1 viral load test in Senegal: a country of high circulation of CRF02_AG

Introductionthe introduction of the point-of-care in HIV-1 viral load quantification appears to be a complementary strategy to the existing conventional system of the acceleration plan for the achievement of the three 90s in Senegal. The objective of this study was to evaluate the performance of the Xpert® HIV-1 viral load in the context of circulation of non-B, non-C subtypes.Methodstwo hundred samples, were tested on Xpert® HIV-1 Viral Load using 1 ml of plasma in comparison to 600 μl on Abbott Real-time HIV-1 assay. The difference between viral load values was considered significant for Dlog <0.5 log copies/ml.Resultsa good correlation (r=0.985) was noted and confirmed using passing-bablok regression (slope 1.048; 95% CI: 1.036 to 1.069) for 188 samples with samples. A mean difference of 0.0075 log10 copies/ml for a 95% confidence interval (CI) of 0.002 log10 copies/ml to 0.013 log10 copies/ml was obtained. Sensitivity and specificity were respectively 93.6% and 93.5% at the threshold of 1.6 log10 copies/ml and 100% and 99% at the threshold of 3.0 log10 copies/ml.Conclusionthese results show that Xpert® HIV-1 Viral Load has excellent performance. In Senegal, and can be used for HIV viral load monitoring.

1163. HIV-1 NAAT Pitfalls in B-cell Lymphoblastic Leukemia Patients Following CAR-T Cell Therapy

BackgroundCAR-T Cell Therapy is approved for the treatment of pediatric patients with relapsed/refractory B-ALL. Lentiviral vector technology, highly modified from HIV-1, is used to induce stable, long-term transgene expression by integration into the host genome. This integration may interfere with HIV-1 NAAT producing false-positive results. MethodsA retrospective chart review of Pre-B ALL patients who underwent to CAR T cell therapy with KYMRIAH(tisagenlecleucel) at a single institution between January 2019 and May 2021 to assess for patients whose CAR-T infusion interfered with post-infusion HIV-1 testing. All patients had HIV NAAT pre and post CAR T-cell therapy (using platform, Roche COBAS AmpliPrep/Quantitative TaqMan HIV-1 T). Reactive HIV NAAT by Roche test were subsequently tested using different HIV-1 assay platforms to rule out or confirm HIV infection.ResultsWe report three cases in which interpretation of HIV-1 NAAT testing was complicated by CAR T cell therapy. Case 1: 1-year-old male with refractory infantile leukemia was found to have a reactive HIV NAAT post CAR-T in routine infectious screening prior to SCT. Case 2: 3-year-old refractory ALL planned for SCT who had a reactive HIV NAAT 9 months post CART. Fourth-generation HIV-1 testing (targeting the p24 antigen and anti-HIV-1 antibodies) was negative pre and post CART. Viral loads were also undetectable indicating false-positive post-CAR-T HIV-1 NAT test results. Case 3: 21-year-old sexually active female with relapsed B cell ALL. Post CAR-T HIV NAAT was reactive, and a quantitative viral load was positive at 176 copies/mm3 one day prior to start of stem cell transplant conditioning regimen. Aptima HIV testing is typically used as confirmatory test for CAR-T associated false positive HIV NAT cases, but surprisingly, the Aptima test was also reactive. Additional testing with Abbott m2000 Realtime HIV-1 assay and 4th generation p24 antigen-based testing were both negative. Table 1 Summary of reported patients with false-positive HIV-1 NAAT test results following CAR T cell therapy and Table 2, HIV platforms used for screening and diagnosis with interpretations following CAR T cell therapy.ConclusionClinicians need to be aware of potential false-positive HIV testing after CAR-T therapy. HIV testing platforms with targets not used in lentiviral vectors (4th generation test/P24, or Abbott test/integrase region) are highly recommended to avoid delays in subsequent therapy and unwanted stress for the patients, families, and cliniciansDisclosures All Authors: No reported disclosures

Evidence of HIV-1 Genital Shedding after One Year of Antiretroviral Therapy in Females Recently Diagnosed in Bamako, Mali.

Little is known about the dynamic of HIV-1 shedding and resistance profiles in the female genital reservoir after antiretroviral therapy (ART) initiation in resource-limited countries (RLCs), which is critical for evaluating the residual sexual HIV-1 transmission risk. The present study aimed to evaluate the efficacy of 1 year duration ART at blood and genital levels in females newly diagnosed for HIV-1 from three centers in Bamako, Mali. Seventy-eight consenting females were enrolled at the time of their HIV-1 infection diagnosis. HIV-1 RNA loads (Abbott Real-Time HIV-1 assay) were tested in blood and cervicovaginal fluids (CVF) before and 12 months after ART initiation. Primary and acquired resistances to ART were evaluated by ViroseqTM HIV-1 genotyping assay. The vaginal microbiota was analyzed using IonTorrentTM NGS technology (Thermo Fisher Scientific). Proportions of primary drug resistance mutations in blood and CVF were 13.4% and 25%, respectively. Discrepant profiles were observed in 25% of paired blood/CVF samples. The acquired resistance rate was 3.1% in blood. At month 12, undetectable HIV-1 RNA load was reached in 84.6% and 75% of blood and CVF samples, respectively. A vaginal dysbiosis was associated with HIV RNA shedding. Our findings emphasize the need of reinforcing education to improve retention in care system, as well as the necessity of regular virological monitoring before and during ART and of implementing vaginal dysbiosis diagnosis and treatment in RLCs.

Performance Analysis of Three Commercial Kits Designed for RNA Quantification of HIV-1 Group O Variants.

The genetic divergence of HIV-1 group O is high relative to pandemic group M, which could impact detection and quantification of plasma RNA. Recent commercial kits for RNA quantification seem to show good performances in HIV-1/O, but discrepancies are still observed. Here, we compare the performances of 3 commercial assays for the RNA quantification of HIV-1/O. We studied the RNA quantification of 117 clinical samples using Abbott RealTime HIV-1, Cepheid Xpert HIV-1 Viral Load, or Roche Cobas TaqMan HIV-1 v2. First, we conducted a qualitative description, and second, we focused on a quantitative analysis of the results above 40 cp/mL. The degree of agreement between methods and the strength of the correlation of viral load determination were estimated using Bland-Altman plot and Passing-Bablok regression with the Spearman coefficient, respectively. Our 2-by-2 analysis showed that the Abbott and Cepheid assays were very close in terms of correlation and dispersion of points, whereas Roche presented higher values in the highest range of quantification (>5 log10). The Cepheid assay combined better correlation with the consensus value and a lower dispersion of values, leading to an overall better performance of quantification. The quantification was still impacted by intragroup genetic diversity with, here, 1 strain (YBF26). Using a new approach to compare the performances of RNA quantification between more than 2 techniques, we demonstrated that Cepheid could be the most suitable assay for HIV-1/O quantification, although the results from all assays remained strain dependent.