Urine Tenofovir Levels Measured Using a Novel Immunoassay Predict Human Immunodeficiency Virus Protection

Point-of-care urine tenofovir test predicts future HIV preexposure prophylaxis discontinuation among young users

BACKGROUND

Young men who have sex with men and transgender women (YMSM/TGW) have disproportionately high HIV incidence and lower preexposure prophylaxis (PrEP) adherence. Point-of-care (POC) urine tenofovir (TFV) rapid assay (UTRA) testing permits real-time monitoring for nonadherence within clinical settings. We performed UTRA testing among PrEP users to examine the relationship between low PrEP adherence and future PrEP discontinuation, and the accuracy of POC testing compared to gold-standard liquid chromatography tandem mass spectrometry (LC/MS/MS).

METHODS

YMSM/TGW participants ( n  = 100) were recruited during a daily PrEP visit. Logistic regression models analyzed the relationship between the primary predictor of urine POC assay results (cutoff 1,500 ng/ml) and the primary outcome of PrEP discontinuation, defined as no PrEP follow-up or prescription within 120 days.

RESULTS

Overall, 19% of participants had low urine TFV and 21% discontinued PrEP, while 11% of participants self-reported low PrEP adherence (<4 pills per week), which was only 43% sensitive/84% specific in predicting low TFV levels and was not associated with PrEP discontinuation. Low urine TFV level predicted PrEP discontinuation [adjusted odds ratio (AOR) 6.1; 95% confidence interval (CI): 1.4-11; P  = 0.005] and was 71% sensitive/90% specific for discontinuation after 120 days. Compared to LC/MS/MS, UTRA testing had a 98% positive and 100% negative predictive value.

CONCLUSIONS

In a sample of YMSM/TGW on daily PrEP, POC UTRA testing predicted PrEP discontinuation more accurately than self-reported adherence, with high predictive values compared to LC/MS/MS. UTRA testing may be a clinical tool for directing preventive interventions towards those likelier to discontinue PrEP despite ongoing HIV vulnerability.

Impact of a point-of-care urine tenofovir assay on adherence to HIV pre-exposure prophylaxis among women in Kenya: a randomised pilot trial

BACKGROUND

Adherence challenges with oral tenofovir-based pre-exposure prophylaxis (PrEP) are common. We developed a point-of-care assay to objectively assess tenofovir in urine and conducted a pilot trial examining the impact of counselling informed by use of this urine assay on long-term PrEP adherence.

METHODS

This randomised trial enrolled women not in serodiscordant partnerships 3 months after PrEP initiation at the Kenya Medical Research Institute to compare standard-of-care adherence counselling versus counselling informed by the urine assay (urine-test counselling group) every 3 months for 12 months. In the standard of care group, urine samples were stored and tested at study end without participant feedback. Here we report the adherence primary outcome of hair concentrations of tenofovir at 12 months as a long-term metric (undetectable levels defined long-term non-adherence), as well as urine concentrations of tenofovir at each visit as a short-term adherence metric and acceptability of the assay assessed by quantitative surveys. Data were analysed by randomisation group. This completed trial was registered with ClinicalTrials.gov (NCT03935464).

FINDINGS

From March 17, 2021 to Jan 18, 2022 we enrolled 49 women in the urine-test counselling group and 51 in the standard of care group; retention was 86 (86%) of 100. Nine (21%) of 42 in the urine-test counselling group had hair samples at 12 months with tenofovir concentrations below the limit of quantification compared with 15 (37%) of 41 in the standard of care group. The relative odds of long-term non-adherence in the standard of care group compared with urine-test counselling were 3·53 (95% CI 1·03-12·03; p=0·044). Pre-intervention, urine tenofovir was detectable in 65% in the urine-test counselling group and 71% in the standard of care group (p=0·68). At 12 months, 31 (72%) of 43 in the intervention group had detectable urine tenofovir compared with 19 (45%) of 42 in the standard of care group (p=0·0015). 40 (93%) of 43 participants liked the test very much and only one disliked the test. One participant in the standard of care group was withdrawn at the 6-month visit due to HIV seroconversion.

INTERPRETATION

A low-cost urine tenofovir assay to inform PrEP counselling resulted in improvement in both short-term and long-term metrics of adherence. This urine tenofovir assay could help to improve long-term PrEP adherence.

FUNDING

National Institute of Allergy and Infectious Diseases and National Institutes of Health.

Point-of-care urine tenofovir monitoring of adherence to drive interventions for HIV treatment and prevention

INTRODUCTION

Although effective antiretroviral and pre-exposure prophylaxis/PrEP regimens are available globally, adherence challenges persist. Objective measures of adherence can both measure adherence accurately and can be used to drive interventions. The first point-of-care pharmacologic adherence measure, urine tenofovir testing using a lateral flow assay, is now available.

AREAS COVERED

This review examines the ability of pharmacologic metrics of adherence to predict HIV and PrEP clinical outcomes and the past use of pharmacologic metrics of adherence as tools to drive adherence interventions. The success of preliminary studies using point-of-care adherence metrics to guide interventions is then discussed.

EXPERT OPINION

Large randomized clinical trials are now needed to test the impact of point-of-care adherence interventions on HIV and PrEP clinical outcomes, given promising results of the pilot studies summarized here. Hybrid implementation-effectiveness studies will be needed to examine optimal approaches to incorporating point-of-care testing into routine clinical care delivery, including in guiding resistance testing, adherence counseling, and delivery of other evidence-based adherence interventions. Given the ability of point-of-care tenofovir testing to be implemented in settings where viral load testing is not available, and at more frequent intervals due to its low cost, urine-based tenofovir assays have the potential to be highly scalable in diverse clinical settings.

Adherence determination using urine-tenofovir point-of-care testing and pharmacy refill records: A cross-sectional study

Pharmacy refill records (PRR), are an accessible strategy for estimating adherence in low- and middle-income countries (LMICs). However, the low-cost urine-tenofovir point-of-care test opens up the possibility of an objective metric of adherence that is scalable to LMICs. This study compared adherence to tenofovir-based regimens using urine-tenofovir point-of-care (POC) test with pharmacy refill records in a Nigerian population of HIV-positive persons. This was a cross-sectional study among 94 HIV-positive adults, which was conducted from June to August 2021, in a large outpatient clinic in Lagos, Nigeria. Adherence to pharmacy appointments was automatically calculated using a computerized pharmacy appointment system (FileMaker Pro™). Urine drops on the urine-tenofovir POC test strip developed 2 lines for a negative test (tenofovir absent) and one line for a positive test. Fisher's exact test was used to examine the association between pharmacy refill record and urine-tenofovir point-of-care test. Logistic regression was performed to predict viral suppression (<1000 copies/mL, based on WHO recommendations) using both methods of adherence determination. A Receiver Operating Characteristic (ROC) curve of the association between specificity and sensitivity was generated to evaluate the predictive value of adherence determined using pharmacy-refill record and urine-tenofovir point-of-care test in forecasting viral suppression. The statistical significance level was set at 0.05. Fisher's exact test showed no statistically significant difference in adherence using urine-tenofovir point-of-care test or pharmacy refill record. The logistic regression model showed that an increase in pharmacy-refill record of ≥ 95% was associated with viral suppression (P = .019). From the ROC curve, the sensitivity was same at 95.5% for both methods, but the specificity of the urine-tenofovir point-of-care test was greater (96.6% vs 95.5%) than pharmacy refill record (P = .837). Urine-tenofovir point-of-care test provided equivalent adherence data to pharmacy refill data.

Diagnostic accuracy of a point-of-care urine tenofovir assay, and associations with HIV viraemia and drug resistance among people receiving dolutegravir and efavirenz-based antiretroviral therapy

INTRODUCTION

Novel point-of-care assays which measure urine tenofovir (TFV) concentrations may have a role in improving adherence monitoring for people living with HIV (PLHIV) receiving antiretroviral therapy (ART). However, further studies of their diagnostic accuracy, and whether results are associated with viraemia and drug resistance, are needed to guide their use, particularly in the context of the global dolutegravir rollout.

METHODS

We conducted a cross-sectional evaluation among PLHIV receiving first-line ART containing tenofovir disoproxil fumarate at enrolment into a randomized trial in two South African public sector clinics. We calculated the diagnostic accuracy of the Abbott point-of-care immunoassay to detect urine TFV compared to liquid chromatography-tandem mass spectrometry (LC-MS/MS). We evaluated the association between point-of-care urine TFV results and self-reported adherence, viraemia ≥1000 copies/ml and HIV drug resistance, among people receiving either efavirenz or dolutegravir-based ART.

RESULTS

Between August 2020 and March 2022, we enrolled 124 participants. The median age was 39 (IQR 34-45) years, 55% were women, 74 (59.7%) were receiving efavirenz and 50 (40.3%) dolutegravir. The sensitivity and specificity of the immunoassay to detect urine TFV ≥1500 ng/ml compared to LC-MS/MS were 96.1% (95% CI 90.0-98.8) and 95.2% (75.3-100.0), respectively. Urine TFV results were associated with short (p<0.001) and medium-term (p = 0.036) self-reported adherence. Overall, 44/124 (35.5%) had viraemia, which was associated with undetectable TFV in those receiving efavirenz (OR 6.01, 1.27-39.0, p = 0.014) and dolutegravir (OR 25.7, 4.20-294.8, p<0.001). However, in those with viraemia while receiving efavirenz, 8/27 (29.6%) had undetectable urine TFV, compared to 11/17 (64.7%) of those receiving dolutegravir. Drug resistance was detected in 23/27 (85.2%) of those receiving efavirenz and only 1/16 (6.3%) of those receiving dolutegravir. There was no association between urine TFV results and drug resistance.

CONCLUSIONS

Among PLHIV receiving ART, a rapid urine TFV immunoassay can be used to accurately monitor urine TFV levels compared to the gold standard of LC-MS/MS. Undetectable point-of-care urine TFV results were associated with viraemia, particularly among people receiving dolutegravir.

TRIAL REGISTRATION

Pan-African Clinical Trials Registry: PACTR202001785886049.

Urine tenofovir-monitoring predicts HIV viremia in patients treated with high genetic-barrier regimens

OBJECTIVE

Access to viral load measurements is constrained in resource-limited settings. A lateral flow urine tenofovir (TFV) rapid assay (UTRA) for patients whose regimens include TFV offers an affordable approach to frequent adherence monitoring.

DESIGN

We conducted a cross-sectional study of patients to assess the utility of UTRA to predict virologic failure, defined as a viral load greater than 400 copies/ml.

METHODS

We assessed urine TFV among 113 participants at increased risk of viral failure (who had previous viral failure on this regimen or had previously been ≥30 days out of care), comparing low genetic-barrier efavirenz (EFV) regimens (n = 60) to dolutegravir (DTG)-boosted or ritonavir-boosted protease inhibitor (PI/r)-based high genetic-barrier regimens (n = 53). Dried blood spots (DBS) for TFV-diphosphate and plasma for TFV concentrations were collected, with drug resistance assessed if viral failure present.

RESULTS

Among 113 participants, 17 of 53 received DTG or PI/r had viral failure at the cross-sectional visit, with 11 (64.7%) demonstrating an undetectable urine TFV; the negative-predictive value (NPV) of undetectable UTRA for viral failure was 85% (34/40); none of the 16 sequenced had dual class drug resistance. In those treated with EFV regimens the sensitivity was lower, as only 1 (4.8%) of 21 with viral failure had an undetectable UTRA (P < 0.001).

CONCLUSIONS

Urine tenofovir-testing had a high negative-predictive value for viral failure in patients treated with DTG or ritonavir-boosted protease inhibitor regimens, where viral failure was largely explained by poor drug adherence. Frequent monitoring with inexpensive lateral flow urine TFV testing should be investigated prospectively in between viral load visits to improve viral load suppression on DTG-based first-line therapy in resource-limited settings.

Women's experience receiving drug feedback and adherence counseling in MTN-025/HOPE - an HIV Prevention open-label trial of the Dapivirine Vaginal Ring

In the Phase IIIB MTN-025/HOPE open label extension trial, participants were offered the dapivirine vaginal ring as HIV prophylaxis, and those who accepted the ring received semi real-time individual adherence feedback, based on residual drug level (RDL) from returned rings, during Motivational Interviewing-based counseling. Counseling messages, based on the best knowledge at the time, framed RDL results in terms of ring use and HIV protection, from no use /no protection (0 RDL) to high use /high protection (3 RDL). At six HOPE sites, in-depth-Interviews (IDIs) about RDL were conducted with 64 participants who had received at least one RDL result. We found mixed interpretations of what the RDL meant and strong emotional reactions with a focus on the external validation of the level itself. Counseling was critical to help participants process their reactions to the RDL and make decisions accordingly (i.e., persistence, adherence improvement, and/or switching to another HIV prevention method). Providing drug adherence feedback was complex to implement yet proved useful as a component of a multi-pronged adherence support strategy.

Drug Resistance, Rather than Low Tenofovir Levels in Blood or Urine, Is Associated with Tenofovir, Emtricitabine, and Efavirenz Failure in Resource-Limited Settings

The high cost of viral load (VL) testing limits its use for antiretroviral therapy (ART) adherence support. A low-cost lateral flow urine tenofovir (TFV) rapid assay predicts pre-exposure prophylaxis breakthroughs, but has not yet been investigated in HIV treatment. We therefore evaluated its utility in a pilot cross-sectional study of TFV-containing ART recipients at an increased risk of virologic failure (VF). Participants who had a treatment interruption ≥30 days or had ≥1 episode of viremia (VL ≥400 copies/mL) in the previous year were recruited from a public health setting in Cape Town, South Africa. Self-reported adherence data were collected, the urine TFV assay performed, and concurrent TFV-diphosphate analyzed in dried blood spots. VL testing was done concurrently and, if viremic, genotypic HIV drug resistance testing was performed. Of 48 participants, 18 (37.5%) had VL (>400 copies/mL) at the time of the study, including 16 of 39 receiving efavirenz (EFV), 2 of 6 receiving protease inhibitors, and 0 of 3 receiving dolutegravir. Resistance testing succeeded in 17/18, of which 14 had significant mutations compromising ≥2 agents of the current EFV-based regimen. Of these 14, all had detected urine TFV. Urine TFV was undetectable in two out of three without regimen-relevant resistance; p = .02. In participants on EFV-based regimens returning to care, VF was largely due to viral resistance, where detectable urine TFV had 100% sensitivity (14/14 participants) in predicting resistance. Conversely, when undetectable, the urine-based assay could be used to preclude participants with poor adherence from undergoing costly HIV drug resistance testing.

Novel population-level proxy measures for suboptimal HIV preexposure prophylaxis initiation and persistence in the USA

OBJECTIVE

In the United States (USA), HIV preexposure prophylaxis (PrEP) use is suboptimal. Population-level metrics on PrEP use are limited and focus on prescriptions issued rather than how much prescriptions are picked up. We introduce PrEP reversals, defined as when patients fail to pick up PrEP prescriptions at the pharmacy point-of-sale, as a proxy for PrEP initiation and persistence.

DESIGN

We analysed PrEP pharmacy claims and HIV diagnoses from a Symphony Health Solutions dataset across all US states from 1 October 2015 to 30 September 2019.

METHODS

We calculated the percentage of individuals who were newly prescribed PrEP and who reversed (i.e. patient did not pick up an insurance-approved prescription and pharmacy withdrew the claim), delayed (reversed and then picked up within 90 days), very delayed (reversed and then picked up between 90 and 365 days) or abandoned (not picked up within 365 days), and subsequent HIV diagnosis within 365 days.

RESULTS

Of 59 219 individuals newly prescribed PrEP, 19% reversed their index prescription. Among those, 21% delayed initiation and 8% had very delayed initiation. Seventy-one percent of patients who reversed their initial prescription abandoned it, 6% of whom were diagnosed with HIV---three times higher than those who persisted on PrEP.

CONCLUSION

Nearly one in five patients newlyprescribed PrEP reversed initial prescriptions, leading to delayed medication access, being lost to PrEP care, and dramatically higher HIV risk. Reversals could be used for real-time nationwide PrEP population-based initiation and persistence tracking, and for identifying patients that might otherwise be lost to care.

Simplifying TREAtment and Monitoring for HIV (STREAM HIV): protocol for a randomised controlled trial of point-of-care urine tenofovir and viral load testing to improve HIV outcomes

INTRODUCTION

Substantial improvements in viral suppression among people living with HIV (PLHIV) are needed to end the HIV epidemic, requiring extensive scale-up of low-cost HIV monitoring services. Point-of-care (POC) tests for monitoring antiretroviral therapy (ART) adherence and viral load (VL) may be efficient and effective tools for real-time clinical decision making. We aim to evaluate the effects of a combined intervention of POC ART adherence and VL testing compared with standard-of-care on ART adherence, viral suppression and retention at 6 and 18 months post-ART initiation among PLHIV.

METHODS AND ANALYSIS

Simplifying TREAtment and Monitoring for HIV (STREAM HIV) is a two-arm, open-label, randomised controlled superiority trial of POC urine tenofovir (POC TFV) and VL monitoring in PLHIV. We aim to enrol 540 PLHIV initiating a first-line ART regimen at a public HIV clinic in South Africa. Participants will be randomised 1:1 to the intervention or control arm. Intervention arm participants will receive monthly POC TFV testing for the first 5 months and POC VL testing at months 6 and 12. Intervention arm participants will also receive reflex POC TFV testing if viraemic and reflex HIV drug resistance testing for those with viraemia and detectable TFV. Control arm participants will receive standard-of-care, including laboratory-based VL testing at months 6 and 12. Primary outcomes include ART adherence (TFV-diphosphate concentration) at 6 months and viral suppression and retention at 18 months. Secondary outcomes include viral suppression and retention at 6 months, TFV-diphosphate concentration at 18 months, cost and cost-effectiveness of the intervention and acceptability of the intervention among PLHIV and healthcare workers.

ETHICS AND DISSEMINATION

STREAM HIV has received ethical approval from the University of Washington Institutional Review Board (STUDY00007544), University of KwaZulu-Natal Biomedical Research Ethics Committee (BREC/00000833/2019) and Division of AIDS Regulatory Support Center (38509). Findings will be disseminated at international conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04341779.

Adherence to daily HIV pre-exposure prophylaxis in a large-scale implementation study in New South Wales, Australia

OBJECTIVES

To examine patterns of long-term pre-exposure prophylaxis (PrEP) adherence and its association with HIV seroconversion in NSW, Australia.

DESIGN

Population-based HIV PrEP implementation study.

METHODS

Expanded PrEP Implementation in Communities in New South Wales was an open-label study of daily oral PrEP which recruited participants from March 2016 to April 2018. Adherence was measured using dispensing records. PrEP discontinuation was defined as an at least 120-day period without PrEP coverage. Long-term adherence patterns were identified using group-based trajectory modelling.

RESULTS

Participants dispensed at least once (n = 9586) were almost all male (98.5%), identified as gay (91.3%), with a median age of 34 years (range: 18-86). Of the 6460 (67.4%) participants who had at least 9 months of follow-up since first dispensing, 1942 (30.1%) discontinued. Among these, 292 (15.0%) restarted later. Four distinct groups were identified ['Steep decline' in adherence (15.8%), 'Steady decline' (11.6%), 'Good adherence' (37.4%), and 'Excellent adherence' (35.2%)]. Older (P < 0.001) and gay-identified (P < 0.001) participants were more likely to have higher adherence, so were those living in postcodes with a higher proportion of gay-identified male residents (P < 0.001). Conversely, those who at baseline reported recent crystal methamphetamine use and had a recent diagnosis of sexually transmitted infection (STI) had lower adherence (P < 0.001). Overall HIV incidence was 0.94 per 1000 person-years (95% confidence interval: 0.49-1.81; n = 9) and was highest in the 'steep decline' group (5.45 per 1000 person-years; P = 0.001).

CONCLUSION

: About 15% of participants stopped PrEP during study follow-up and were at increased risk of HIV infection. They were more likely to be younger and report a recent STI or methamphetamine use prior to PrEP initiation.

An Overview on SARS-CoV-2 (COVID-19) and Other Human Coronaviruses and Their Detection Capability via Amplification Assay, Chemical Sensing, Biosensing, Immunosensing, and Clinical Assays

A novel coronavirus of zoonotic origin (SARS-CoV-2) has recently been recognized in patients with acute respiratory disease. COVID-19 causative agent is structurally and genetically similar to SARS and bat SARS-like coronaviruses. The drastic increase in the number of coronavirus and its genome sequence have given us an unprecedented opportunity to perform bioinformatics and genomics analysis on this class of viruses. Clinical tests like PCR and ELISA for rapid detection of this virus are urgently needed for early identification of infected patients. However, these techniques are expensive and not readily available for point-of-care (POC) applications. Currently, lack of any rapid, available, and reliable POC detection method gives rise to the progression of COVID-19 as a horrible global problem. To solve the negative features of clinical investigation, we provide a brief introduction of the general features of coronaviruses and describe various amplification assays, sensing, biosensing, immunosensing, and aptasensing for the determination of various groups of coronaviruses applied as a template for the detection of SARS-CoV-2. All sensing and biosensing techniques developed for the determination of various classes of coronaviruses are useful to recognize the newly immerged coronavirus, i.e., SARS-CoV-2. Also, the introduction of sensing and biosensing methods sheds light on the way of designing a proper screening system to detect the virus at the early stage of infection to tranquilize the speed and vastity of spreading. Among other approaches investigated among molecular approaches and PCR or recognition of viral diseases, LAMP-based methods and LFAs are of great importance for their numerous benefits, which can be helpful to design a universal platform for detection of future emerging pathogenic viruses.