Antiretroviral concentrations in small hair samples as a feasible marker of adherence in rural Kenya

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 One participant in the standard of care group was withdrawn at the 6-month visit due to HIV seroconversion.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.

Doxycycline Prophylaxis to Prevent Sexually Transmitted Infections in Women

BACKGROUND

Doxycycline postexposure prophylaxis (PEP) has been shown to prevent sexually transmitted infections (STIs) among cisgender men and transgender women, but data from trials involving cisgender women are lacking.

METHODS

We conducted a randomized, open-label trial comparing doxycycline PEP (doxycycline hyclate, 200 mg taken within 72 hours after condomless sex) with standard care among Kenyan women 18 to 30 years of age who were receiving preexposure prophylaxis against human immunodeficiency virus (HIV). The primary end point was any incident infection with Chlamydia trachomatis, Neisseria gonorrhoeae, or Treponema pallidum. Hair samples were collected quarterly for objective assessment of doxycycline use.

RESULTS

A total of 449 participants underwent randomization; 224 were assigned to the doxycycline-PEP group and 225 to the standard-care group. Participants were followed quarterly over 12 months. A total of 109 incident STIs occurred (50 in the doxycycline-PEP group [25.1 per 100 person-years] and 59 in the standard-care group [29.0 per 100 person-years]), with no significant between-group difference in incidence (relative risk, 0.88; 95% confidence interval [CI], 0.60 to 1.29; P = 0.51). Among the 109 incident STIs, chlamydia accounted for 85 (78.0%) (35 in the doxycycline-PEP group and 50 in the standard-care group; relative risk, 0.73; 95% CI, 0.47 to 1.13). No serious adverse events were considered by the trial investigators to be related to doxycycline, and there were no incident HIV infections. Among 50 randomly selected participants in the doxycycline-PEP group, doxycycline was detected in 58 of 200 hair samples (29.0%). All N. gonorrhoeae-positive isolates were resistant to doxycycline.

CONCLUSIONS

Among cisgender women, the incidence of STIs was not significantly lower with doxycycline PEP than with standard care. According to hair-sample analysis, the use of doxycycline PEP among those assigned to receive it was low. (Funded by the National Institutes of Health; dPEP ClinicalTrials.gov number, NCT04050540.).

A Trauma-Informed HIV Intervention (LinkPositively) to Improve HIV Care Among Black Women Affected by Interpersonal Violence: Protocol for a Pilot Randomized Controlled Trial

BACKGROUND

Black women bear a disproportionate burden of HIV, accounting for nearly 60% of new diagnoses among US women. Black women living with HIV often experience mutually reinforcing epidemics, known as syndemics, including interpersonal violence and substance use. Syndemics are associated with decreased HIV care engagement and treatment adherence and worsening HIV outcomes. Few HIV services and resources are tailored to be culturally and gender-responsive and trauma informed for Black women living with HIV. Technology-based, psychoeducational, and peer navigation programs offer promising pathways to tailored HIV support and improved HIV care outcomes. Therefore, the web-based, trauma-informed intervention LinkPositively was developed in collaboration with Black women living with HIV to promote uptake of HIV care and ancillary support services.

OBJECTIVE

This study primarily determines the feasibility and acceptability of the LinkPositively intervention among Black women living with HIV affected by interpersonal violence. The secondary aim is to examine the preliminary impact of the LinkPositively intervention on retention in HIV care, antiretroviral therapy adherence, and viral suppression while evaluating the role of mechanism of change variables (eg, social support) in the associations.

METHODS

The LinkPositively trial is a pilot randomized controlled trial conducted in California, United States, among 80 adult Black women living with HIV who have experienced interpersonal violence. Core components of LinkPositively include one-on-one peer navigation with phone and SMS text message check-ins; 5 weekly one-on-one video sessions to build coping and care navigation skills; and a mobile app that contains a peer support social networking platform, an educational database with healthy living and self-care tips, a GPS-enabled HIV and ancillary care resource locator, and a medication self-monitoring and reminder system. Participants are randomly assigned to the intervention (n=40) or control (Ryan White standard of care; n=40) arm, with follow-up at 3 and 6 months. At each assessment, participants complete an interviewer-administered survey and submit hair samples for the assessment of HIV medication adherence. All research staff and investigators adhere to ethical principles and guidelines for conducting research activities. Data will be analyzed using generalized estimating equations.

RESULTS

Final development and testing of the LinkPositively app were completed in July 2021. As of May 2023, we have screened 97 women for eligibility. Of the 97 women screened, 27 (28%) were eligible and have been enrolled in the study. The dissemination of preliminary results will occur in 2024.

CONCLUSIONS

This trial will advance HIV prevention science by harnessing technology to promote engagement in HIV care while improving social support through peers and social networking-all while being trauma informed for Black women living with HIV with experiences of interpersonal violence. If shown to be feasible and acceptable, LinkPositively has the potential to improve HIV care outcomes among Black women, a marginalized key population.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/46325.

Measurement Tools and Utility of Hair Analysis for Screening Adherence to Antihypertensive Medication

Poor adherence to the prescribed antihypertensive therapy is an understated public health problem and is one of the main causes of the high prevalence of uncontrolled hypertension in sub-Saharan Africa. Medication adherence is vital for the effectiveness of antihypertensive treatment and is key to ameliorating the clinical outcomes in hypertensive patients. However, it has often been ignored because the current methods used to assess medication adherence are not reliable, limiting their utilization in clinical practice. Therefore, the identification of the most accurate and clinically feasible method for measuring medication adherence is critical for tailoring effective strategies to improve medication adherence and consequently achieve blood pressure goals. This review not only explores various available methods for estimating medication adherence but also proposes therapeutic drug monitoring in hair for the measurement of medication adherence to the antihypertensive medication period.

Antiretroviral Therapy Adherence During and Postbreastfeeding Cessation Measured by Tenofovir Levels in Hair

BACKGROUND

We examined change in antiretroviral treatment (ART) adherence after breastfeeding (BF) cessation using hair tenofovir (TFV) concentrations as an objective metric of medication consumption.

METHODS

A subset of postpartum women in Zimbabwe randomized in IMPAACT PROMISE to take ART while BF and post-BF cessation had hair TFV measured longitudinally. Using linear mixed-effect models, we estimated differences in hair TFV levels after BF cessation, accounting for trends in levels over time regardless of BF status and change in slope after breastfeeding cessation. We also estimated the relative risk of viremia (>50 copies/mL) per doubling of hair TFV concentration.

RESULTS

Among 55 women (median age 26, interquartile range 24-29 years), hair TFV levels (n = 305) were available for a median of 9 visits per woman between 3 and 29 months postpartum. Hair TFV levels ranged from undetected to 0.25 ng/mg (median 0.04 ng/mg). Controlling for trends since delivery [decline of 2.2% per month, 95% confidence interval (CI): -5.3 to 1.0], TFV levels averaged 24.4% higher (95% CI: -5.1 to 63.1) post-BF cessation than during BF, with no change in slope (0.0% per month, 95% CI: -3.8 to 3.9). Postpartum, 42% of women were ever viremic. Higher TFV levels were strongly protective; relative risk of viremia per doubling of TFV was 0.52 (95% CI: 0.43 to 0.63; P < 0.0001).

CONCLUSIONS

Leveraging an objective metric of ART use, we observed modestly declining adherence across the postpartum period, but no additional decline associated with breastfeeding cessation. High viremia frequency and varying postpartum TFV levels observed highlight the importance of enhanced adherence support with viral load monitoring among postpartum women.

Measuring patient engagement with HIV care in sub-Saharan Africa: a scoping study

INTRODUCTION

Engagement with HIV care is a multi-dimensional, dynamic process, critical to maintaining successful treatment outcomes. However, measures of engagement are not standardized nor comprehensive. This undermines our understanding of the scope of challenges with engagement and whether interventions have an impact, complicating patient and programme-level decision-making. This study identified and characterized measures of engagement to support more consistent and comprehensive evaluation.

METHODS

We conducted a scoping study to systematically categorize measures the health system could use to evaluate engagement with HIV care for those on antiretroviral treatment. Key terms were used to search literature databases (Embase, PsychINFO, Ovid Global-Health, PubMed, Scopus, CINAHL, Cochrane and the World Health Organization Index Medicus), Google Scholar and stakeholder-identified manuscripts, ultimately including English evidence published from sub-Saharan Africa from 2014 to 2021. Measures were extracted, organized, then reviewed with key stakeholders.

RESULTS AND DISCUSSION

We screened 14,885 titles/abstracts, included 118 full-texts and identified 110 measures of engagement, categorized into three engagement dimensions ("retention," "adherence" and "active self-management"), a combination category ("multi-dimensional engagement") and "treatment outcomes" category (e.g. viral load as an end-result reflecting that engagement occurred). Retention reflected status in care, continuity of attendance and visit timing. Adherence was assessed by a variety of measures categorized into primary (prescription not filled) and secondary measures (medication not taken as directed). Active self-management reflected involvement in care and self-management. Three overarching use cases were identified: research to make recommendations, routine monitoring for quality improvement and strategic decision-making and assessment of individual patients.

CONCLUSIONS

Heterogeneity in conceptualizing engagement with HIV care is reflected by the broad range of measures identified and the lack of consensus on "gold-standard" indicators. This review organized metrics into five categories based on the dimensions of engagement; further work could identify a standardized, minimum set of measures useful for comprehensive evaluation of engagement for different use cases. In the interim, measurement of engagement could be advanced through the assessment of multiple categories for a more thorough evaluation, conducting sensitivity analyses with commonly used measures for more comparable outputs and using longitudinal measures to evaluate engagement patterns. This could improve research, programme evaluation and nuanced assessment of individual patient engagement in HIV care.

Measuring patient engagement with HIV care in sub-Saharan Africa: a scoping study

INTRODUCTION

Engagement with HIV care is a multi-dimensional, dynamic process, critical to maintaining successful treatment outcomes. However, measures of engagement are not standardized nor comprehensive. This undermines our understanding of the scope of challenges with engagement and whether interventions have an impact, complicating patient and programme-level decision-making. This study identified and characterized measures of engagement to support more consistent and comprehensive evaluation.

METHODS

We conducted a scoping study to systematically categorize measures the health system could use to evaluate engagement with HIV care for those on antiretroviral treatment. Key terms were used to search literature databases (Embase, PsychINFO, Ovid Global-Health, PubMed, Scopus, CINAHL, Cochrane and the World Health Organization Index Medicus), Google Scholar and stakeholder-identified manuscripts, ultimately including English evidence published from sub-Saharan Africa from 2014 to 2021. Measures were extracted, organized, then reviewed with key stakeholders.

RESULTS AND DISCUSSION

We screened 14,885 titles/abstracts, included 118 full-texts and identified 110 measures of engagement, categorized into three engagement dimensions ("retention," "adherence" and "active self-management"), a combination category ("multi-dimensional engagement") and "treatment outcomes" category (e.g. viral load as an end-result reflecting that engagement occurred). Retention reflected status in care, continuity of attendance and visit timing. Adherence was assessed by a variety of measures categorized into primary (prescription not filled) and secondary measures (medication not taken as directed). Active self-management reflected involvement in care and self-management. Three overarching use cases were identified: research to make recommendations, routine monitoring for quality improvement and strategic decision-making and assessment of individual patients.

CONCLUSIONS

Heterogeneity in conceptualizing engagement with HIV care is reflected by the broad range of measures identified and the lack of consensus on "gold-standard" indicators. This review organized metrics into five categories based on the dimensions of engagement; further work could identify a standardized, minimum set of measures useful for comprehensive evaluation of engagement for different use cases. In the interim, measurement of engagement could be advanced through the assessment of multiple categories for a more thorough evaluation, conducting sensitivity analyses with commonly used measures for more comparable outputs and using longitudinal measures to evaluate engagement patterns. This could improve research, programme evaluation and nuanced assessment of individual patient engagement in HIV care.

Relationship Dynamics are Associated with Self-Reported Adherence but not an Objective Adherence Measure in Malawi

Couple relationships can be leveraged to improve adherence to antiretroviral therapy (ART), but few studies have identified relationship factors to target in interventions in sub-Saharan Africa. We conducted a cross-sectional study with 211 couples in southern Malawi with at least one partner on ART to test for associations between ART adherence and relationship dynamics (intimacy, trust, relationship satisfaction, unity, commitment, and partner support). We measured ART adherence through subjective measures (patient and partner reports) and an objective measure (ART drug levels in hair) and hypothesized that more positive relationship dynamics (e.g., higher intimacy) would be associated with better adherence. Multi-level logistic and linear regression models were used to evaluate study hypotheses, controlling for the clustering of individuals within couples. High levels of adherence were found by all three measures. Unity, satisfaction, and partner support were associated with higher patient and partner reports of adherence, and additional relationship dynamics (intimacy, trust) were associated with higher partner reported adherence. No associations were found between relationship dynamics and drug levels in hair, although drug levels were high overall. Future studies should perform longitudinal assessments of relationship dynamics and objective metrics of adherence, and examine these associations in populations with lower adherence levels such as young women or individuals starting ART.

Mass Spectroscopy Imaging of Hair Strands Captures Short-Term and Long-Term Changes in Emtricitabine Adherence

Most measures of adherence to antiretroviral therapy require a blood sample, and none capture longitudinal daily adherence. A new noninvasive method for measuring daily adherence to antiretroviral regimens containing emtricitabine (FTC) was developed for intact hair strands using infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry imaging (MSI). A directly observed therapy study of daily and intermittent (3, 1, and 0 doses/week) FTC dosing (n = 12) benchmarked adherence in hair, revealing distinct accumulation patterns and median FTC signal abundance (1,702, 495, 352, and 0, respectively) with each dosing frequency. A threshold value of FTC_{signal abundance} of 500 differentiated daily dosing from 3 or fewer doses/week (specificity, 100%; sensitivity, 100% over 30 days and 80% over 60 days). Using these criteria, daily FTC hair adherence was classified in young men (n = 8) who have sex with men (YMSM) engaged in or initiating preexposure prophylaxis (PrEP). Four types of adherence profiles were observed in sequential 30-day periods: consistently high, occasional missed doses, improvement following study initiation, and intermittent. Discrete days of nonadherence were identified across the 60-day window, with the average number of consecutive days classified as nonadherent increasing across the four profile types (1, 2, 19, and 58 days, respectively). Additionally, cumulative FTC response in hair (60-day average) significantly correlated with dried blood spot tenofovir diphosphate concentrations collected simultaneously (r_s = 0.79, P = 0.03). Based on these data, IR-MALDESI FTC adherence classification in hair strands can better delineate short-term changes in adherence behaviors over a long retrospective window, offering great potential for noninvasive adherence monitoring and quick supportive interventions.

Nevirapine hair and plasma concentrations and HIV-1 viral suppression among HIV infected ante-partum and post-partum women attended in a mother and child prevention program in Maputo city, Mozambique

INTRODUCTION

Prevention of mother to child transmission of HIV (PMTCT) is frequently challenged by irregular access to more effective anti-retroviral therapy. Nevirapine single dose (sdNVP), sdNVP+AZT+3TC for MTCT prophylaxis and NVP+ AZT+3TC for treatment and PMTCT were withdrawn due to low genetic resistance barrier and low efficacy. However current PMTCT lines in Mozambique include DTG+3TC+TDF, TDF+3TC+EFV, DTG +ABC+3TC, and AZT + NVP syrup prophylaxis for exposed babies. We assessed NVP hair and plasma concentrations and association with HIV-1RNA suppression among HIV+ ante-partum and post-partum women under PMTCT in Maputo, Mozambique.

METHODS

From December 2013 to November 2014, prospectively were enrolled 200 HIV+ ante-partum women on 200mg nevirapine and zidovudine 300 plus lamivudine 150mg twice daily at least with 3 months treatment and seen again at 24 weeks post-partum. Self-reported pill-taking adherence, NVP concentrations in hair, plasma, hemoglobin, CD4 cell count, HIV-1 RNA load was evaluated. NVP concentration in hair and plasma was analyzed as categorical quartile variable based on better data fit. NVP concentration was set between ≤3.77 ng/ml in plasma and ≤17,20 ng/mg in hair in quartile one to ≥5.36 ng/ml in plasma and ≥53.21 ng/mg in hair in quartile four. Logistic regression models for repeated measures were calculated. Following the World Health Organization (WHO) guidelines we set viral suppression at HIV-1RNA < 1000 c/mL. Outcome was HIV-1 RNA<1000 copies/ml. Predictor was NVP concentration in hair categorized in quartiles.

RESULTS

In total 369 person-visits (median of 1.85) were recorded. Self-reported adherence was 98% (IQR 97-100%) at ante-partum. In 25% person visits, NVP concentrations were within therapeutic levels (3.77 ng/ml to 5.35 ng/ml) in plasma and (17.20 ng/mg to 53.20 ng/mg) in hair. In 50% person visits NVP concentrations were above 5.36 ng/ml in plasm and 53.21 ng/mg in hair. HIV-1 RNA suppression was found in 34.7% of women with two viral loads, one at enrollment and another in post-partum. Odds of HIV-1 RNA suppression in quartile 4, was about 6 times higher than in quartile 1 (p-value = 0.006) for NVP hair concentration and 7 times for NVP plasma concentration (p-value = 0.012).

CONCLUSIONS

The study results alert for potential low efficacy of current PMTCT drug regimens in use in Mozambique. Affordable means for individual monitoring adherence, ART plasma and hair levels, drug resistant and HIV-1 RNA levels monitoring are recommended for prompt identification of inadequate drug regimens exposure patterns and adjust accordingly.

Hair Zidovudine Concentrations Predict Virologic Outcomes Among People Living with HIV/AIDS in China

BACKGROUND

Hair antiretroviral concentrations are an objective and non-invasive measure of adherence to long-term antiretroviral therapy (ART) and can further predict virologic outcomes among people living with HIV/AIDS (PLWH). Zidovudine, one of the mainstream antiretrovirals in China, has been verified to have high reliability in adherence assessment, especially for its hair concentrations. However, data are limited in its predicting virologic outcomes. Therefore, this study aimed to characterize whether hair zidovudine concentrations can predict virologic suppression among Chinese PLWH compared with hair lamivudine concentrations and two self-reported measures, the overall frequency of adherence behaviors and percentage adherence.

METHODS

This cross-sectional study randomly recruited 564 PLWH currently treated with zidovudine, lamivudine, and other ART agents (efavirenz, nevirapine, or lopinavir/ritonavir) in Guangxi, China. Hair antiretroviral concentrations were determined using the LC-ESI⁺-MS/MS method. Receiver operating characteristic (ROC) curves were used to estimate the optimal classification thresholds of hair concentrations of zidovudine and lamivudine, and the two self-reported measures. Based on those optimal classification thresholds, logistic regression was used to examine whether those four adherence measures can predict virologic suppression (HIV-1 RNA <200 copies/mL).

RESULTS

ROC curves demonstrated good classification performance for association with virologic suppression of zidovudine with the optimal threshold at 58 pg/mg and lamivudine at 255 pg/mg but no self-reported measures. PLWH with hair zidovudine concentrations >58 pg/mg had an adjusted odds ratio (aOR) of 43.191 (95% confidence interval (CI) = 10.171‒183.418, p < 0.001) for virologic suppression. Hair lamivudine concentrations were also associated with virologic suppression (aOR = 10.656, 95% CI = 3.670‒30.943, p < 0.001). However, two self-reported measures did not predict virologic suppression (aORs = 1.157 and 2.488, ps >0.149).

CONCLUSION

Hair zidovudine concentrations can be served as an alternative tool for clinically predicting virologic suppression among PLWH in China.

Simultaneous Determination of 6 Antiretroviral Drugs in Human Hair Using an LC-ESI+-MS/MS Method: Application to Adherence Assessment

BACKGROUND

The determination of antiretroviral drugs in hair is receiving considerable research interest to assess long-term adherence to antiretroviral therapy (ART). Currently in China, lamivudine, zidovudine, nevirapine, efavirenz, ritonavir, and lopinavir are combined as first-line and second-line free therapy regimens and are recommended for people living with HIV (PLWH). Simultaneous determination of the 6 antiretroviral drugs in human hair is important for accurately and widely assessing long-term adherence in Chinese PLWH receiving different ART regimens.

METHODS

Six drugs were extracted from 10-mg hair samples incubated in methanol for 16 hours at 37°C and then analyzed by liquid chromatography with tandem mass spectrometry using a mobile phase of 95% methanol, with an electrospray ionization source in multiple reaction monitoring and positive mode.

RESULTS

The LC-ESI+-MS/MS method exhibited a linear range (R2 > 0.99) within 6-5000, 10-5000, 6-50,000, 12-50,000, 8-5000, and 8-12,500 pg/mg for lamivudine, zidovudine, nevirapine, efavirenz, ritonavir, and lopinavir. For all 6 drugs, the limits of quantification ranged between 6 and 12 pg/mg. The intraday and interday coefficients of variation were within 15%, and the recoveries ranged from 91.1% to 113.7%. Furthermore, the other validation parameters (ie, selectivity, matrix effect, stability, and carryover) met the acceptance criteria stipulated by guidelines of the US Food and Drug Administration and European Medicines Agency. Significant intergroup differences were observed between high-adherence and low-adherence groups, with high intercorrelations in the hair content of the 6 drugs.

CONCLUSIONS

The developed method demonstrated good reliability, to comprehensively and accurately assess adherence in PLWH receiving different ART regimens.

Factors influencing hair lamivudine concentration among people living with HIV in Guangxi, China

BACKGROUND

Hair antiretroviral concentration has served as an innovative and objective measure of antiretroviral adherence. However, some factors (for example, pharmacokinetics and hair characteristics) may contribute to the variability of hair antiretroviral concentration that may threaten the validity and reliability of the hair measure as a biomarker of adherence. This study aimed to examine the potential factors that may influence the measure of hair antiretroviral concentration.

METHODS

Hair samples from a cohort of 372 people living with HIV (PLHIV) receiving lamivudine (300 mg/day) in Guangxi, China. Lamivudine concentration was analysed using liquid chromatography-tandem mass spectrometry. Multivariable linear regression was used to evaluate the associations of hair lamivudine concentration with age, sex, ethnicity, height, weight, body mass index, duration of HIV diagnosis, duration of current regimen, dosing schedule, concomitant antiretroviral medications, frequency of hair washing, hair care products use, hair cosmetic treatment and self-reported adherence.

RESULTS

Multivariable models revealed that frequency of hair washing (β=-0.221, P=0.001), dosing schedule (β=0.141, P=0.036) and self-reported adherence (β=0.160, P=0.002) were associated with hair lamivudine concentration.

CONCLUSIONS

We observed that, among those potential factors, hair lamivudine concentration was influenced by frequency of hair washing and dosing schedule. Therefore, frequency of hair washing and dosing schedule should be considered in future research using hair lamivudine concentration as a measure of lamivudine exposure and biomarker of adherence.

High Acceptability of Donating Hair and Other Biological Samples for Research Among People Living with HIV in an Outpatient Clinic in Lagos, Nigeria

Willingness to donate hair samples is a rate-limiting step for assaying antiretroviral (ARV) concentrations in hair, an emerging technique for HIV prevention and treatment monitoring. We surveyed ethnically diverse Nigerians to determine their willingness to donate hair for biomedical research. A cross-sectional survey of people living with HIV on ARV therapy (ART) was conducted at the HIV clinic of Nigerian Institute of Medical Research, using systematic sampling. The researcher-administered questionnaire was designed to capture sociodemographic data, length of time on ART, and willingness to donate hair. Univariate analysis was performed on sociodemographic characteristics, and independent-samples t-test and chi-square tests were used for bivariate analysis. Multivariable logistic regression analysis was performed to assess factors associated with willingness to donate hair samples, with a significance level of 0.05. Of the 398 participants enrolled in the study, 258 (64.8%) were female, the average age was 40 years (±9.8), and the average time spent on ART was 7.3 years (±4.2). More than half (64.8%) of the respondents were willing to donate hair samples for biomedical research and they were 1.5 times more likely to donate hair than blood. For one-third of the participants, the anticipated benefit from the eventual research findings was the primary motivation to donate hair samples. Fear of use of hair for rituals was the most common stated reason for unwillingness to donate hair samples (21.2%). In an ethnically diverse, urban-based Nigerian study population, nearly two-thirds of the participants were willing to donate hair samples for biomedical research. These findings support the feasibility of hair sampling for future HIV clinical research conducted within Nigeria.

Antiretroviral hair levels, self-reported adherence, and virologic failure in second-line regimen patients in resource-limited settings

OBJECTIVE

To evaluate associations between hair antiretroviral hair concentrations as an objective, cumulative adherence metric, with self-reported adherence and virologic outcomes.

DESIGN

Analysis of cohort A of the ACTG-A5288 study. These patients in resource-limited settings were failing second-line protease inhibitor-based antiretroviral therapy (ART) but were susceptible to at least one nucleoside reverse transcriptase inhibitor (NRTI) and their protease inhibitor, and continued taking their protease inhibitor-based regimen.

METHODS

Antiretroviral hair concentrations in participants taking two NRTIs with boosted atazanavir (n = 69) or lopinavir (n = 112) were analyzed at weeks 12, 24, 36 and 48 using liquid-chromatography--tandem-mass-spectrometry assays. Participants' self-reported percentage of doses taken in the previous month; virologic failure was confirmed HIV-1 RNA at least 1000 copies/ml at week 24 or 48.

RESULTS

From 181 participants with hair samples (61% women, median age: 39 years; CD4+ cell count: 167 cells/μl; HIV-1 RNA: 18 648 copies/ml), 91 (50%) experienced virologic failure at either visit. At 24 weeks, median hair concentrations were 2.95 [interquartile range (IQR) 0.49-4.60] ng/mg for atazanavir, 2.64 (IQR 0.73--7.16) for lopinavir, and 0.44 (IQR 0.11--0.76) for ritonavir. Plasma HIV-1 RNA demonstrated inverse correlations with hair levels (rs -0.46 to -0.74) at weeks 24 and 48. Weaker associations were seen with self-reported adherence (rs -0.03 to -0.24). Decreasing hair concentrations were significantly associated with virologic failure, the hazard ratio (95% CI) for ATV, LPV, and RTV were 0.69 (0.56-0.86), 0.77 (0.68-0.87), and 0.12 (0.06-0.27), respectively.

CONCLUSION

Protease inhibitor hair concentrations showed stronger associations with subsequent virologic outcomes than self-reported adherence in this cohort. Hair adherence measures could identify individuals at risk of second-line treatment failure in need of interventions.

Association of Hair Concentrations of Antiretrovirals with Virologic Outcomes Among People Living with HIV in Guangxi, China

BACKGROUND

Hair concentrations of antiretrovirals are an innovative and non-invasive method for measuring cumulative antiretroviral exposure and assessing long-term antiretroviral adherence. This study aimed to examine hair concentrations of antiretrovirals in relation to virologic outcomes among PLHIV in Guangxi, China.

METHODS

Cross-sectional data of hair concentrations of antiretrovirals and HIV viral load were collected from 215 PLHIV in Guangxi, China. Multivariate logistic regression analyses were used to examine the association of hair concentrations of antiretrovirals with virologic outcomes.

RESULTS

Of the 215 participants, 215, 67, and 163 PLHIV are receiving lamivudine, zidovudine, and efavirenz, respectively. Multivariate analysis revealed that hair concentrations of lamivudine [odds ratio = 16.52, 95% CI 2.51-108.60, p = 0.004] and efavirenz [odds ratio = 14.26, 95% CI 1.18-172.01, p = 0.036], but not zidovudine [odds ratio = 1.77, 95% CI 0.06-56.14, p = 0.747], were the strongest independent predictor of virologic suppression when controlling for sociodemographic and other HIV-related characteristics.

CONCLUSION

Hair concentrations of lamivudine and efavirenz were the strongest independent predictor of virologic suppression among Chinese PLHIV. Hair analysis of antiretrovirals may provide a non-invasive, cost-effective tool that predicts virologic suppression among PLHIV in China.

Real-Time Monitoring and Point-of-Care Testing: A Review of the Current Landscape of PrEP Adherence Monitoring

BACKGROUND

Despite pre-exposure prophylaxis (PrEP) being highly effective at preventing HIV, HIV infections among individuals prescribed PrEP continue to occur. The vast majority of these new infections occur among individuals with sub-optimal adherence. One factor that is likely to decrease HIV incidence among PrEP users is a real-time, objective measurement of adherence. Monitoring adherence to PrEP can identify those at risk of becoming lost to follow-up and therefore at greater risk of HIV infection, those in need of additional layers of support to overcome barriers to PrEP, and individuals who need enhanced adherence support.

OBJECTIVE

This paper reviews subjective and objective methods for monitoring PrEP including self-report, drug level monitoring (including serum, plasma, peripheral blood mononuclear cells [PBMC], red blood cell dried blood spots [DBS], hair, and urine) and by measuring participant interaction with the study drug (pill counts, medication event monitoring systems [MEMS] caps).

CLINICAL USE

A multitude of methods exist for monitoring and supporting adherence. Objective monitoring using DBS and urine will provide a more accurate picture of adherence compared to subjective and non-biomarker objective methods. Preliminary data show that detection of non-adherence using biomarkers, followed by augmented adherence support and counseling, is associated with improved adherence, although more research is needed. PrEP providers will need knowledge of and access to these various strategies, which will require investment and resource allocation from clinics and other PrEP care sites to provide these tools.

Detectable HIV RNA in late pregnancy associated with low tenofovir hair levels at time of delivery among women living with HIV in the United States

OBJECTIVE

We evaluated peripartum tenofovir (TFV) exposure via hair measures among women living with HIV in the United States.

DESIGN

Observational cohort study.

METHODS

Hair samples were collected at or shortly after childbirth among mothers enrolled in the Surveillance Monitoring for Antiretroviral Therapy Toxicities Study of the Pediatric HIV/AIDS Cohort Study between 6/2014 and 7/2016. Among mothers receiving TFV disoproxil fumarate (TDF)-based regimens during pregnancy, TFV hair concentrations were analyzed using liquid chromatography/tandem mass spectrometry. Weight-normalized TFV concentrations were log10 transformed. Multivariable linear regression assessed correlates of TFV concentrations.

RESULTS

Overall, 121 mothers on TDF-based antiretroviral therapy during pregnancy had hair specimens tested for TFV concentrations and were included in the analysis. Median age at delivery was 31 years [interquartile range (IQR) 26-36]; 71% self-identified as non-Hispanic black, and 10% had unsuppressed viral loads in late pregnancy (HIV RNA ≥ 400 copies/ml). Median time from birth to hair collection was 3 days (IQR 1-14) and median TFV hair concentration was 0.02 ng/mg (IQR 0.01-0.04). In multivariable models, an unsuppressed viral load in late pregnancy was associated with 80% lower adjusted mean peripartum TFV concentrations than pregnancies with viral suppression (95% confidence interval: -90% to -59%, P < 0.001). Use of TDF only in the first trimester and attaining high school graduation were also associated with lower TFV hair concentrations.

CONCLUSION

Unsuppressed viral load during late pregnancy was strongly associated with lower maternal TFV hair concentrations at birth, though viremia was rare. Efforts to improve maternal virological outcomes and eliminate vertical HIV transmission could incorporate drug exposure monitoring using hair or other metrics.

Diagnostic accuracy of a liquid chromatography-tandem mass spectrometry assay in small hair samples for rifampin-resistant tuberculosis drug concentrations in a routine care setting

Background

Treatment monitoring of drug-resistant tuberculosis (DR-TB) in resource-limited settings is challenging. We developed a multi-analyte assay for eleven anti-TB drugs in small hair samples as an objective metric of drug exposure.

Methods

Small hair samples were collected from participants at various timepoints during directly observed RR-TB treatment at an inpatient tertiary referral facility in South Africa (DR-TB cohort). We assessed qualitative determination (i.e., detection above limit of detection) of bedaquiline, linezolid, clofazimine, pretomanid, levofloxacin, moxifloxacin, pyrazinamide, isoniazid, ethambutol, ethionamide, and prothionamide in an LC-MS/MS index panel assay against a reference standard of inpatient treatment records. Because treatment regimens prior to hospitalization were not available, we also analyzed specificity (for all drugs except isoniazid) using an external cohort of HIV-positive patients treated for latent TB infection with daily isoniazid (HIV/LTBI cohort) in Uganda.

Results

Among the 57 DR-TB patients (58% with pre-XDR/XDR-TB; 70% HIV-positive) contributing analyzable hair samples, the sensitivity of the investigational assay was 94% or higher for all drugs except ethionamide (58.5, 95% confidence interval [CI], 40.7–99.9). Assay specificity was low across all tested analytes within the DR-TB cohort; conversely, assay specificity was 100% for all drugs in the HIV/LTBI cohort.

Conclusions

Hair drug concentrations reflect long-term exposure, and multiple successive regimens commonly employed in DR-TB treatment may result in apparent false-positive qualitative and falsely elevated quantitative hair drug levels when prior treatment histories within the hair growth window are not known.

Medication Beliefs, HIV-Related Stigmatization, and Adherence to Antiretroviral Therapy: An Examination of Alternative Models

HIV-related stigma and beliefs about medication necessity and concerns have separately demonstrated significant associations with antiretroviral adherence in people with HIV. However, no work has examined both of these associations in the same model. Based on the necessity-concerns framework, this study examined four alternative models of relationships among HIV-related stigma, medication beliefs, and adherence. Cross-sectional analyses were used to test the four alternative models to best depict associations among HIV-related stigma, medication beliefs, and medication adherence. Models tested included two indirect effects models, an interaction model, and a simple predictors model with no interaction or indirect effects. The outcome variable was HIV medication adherence, and model fit was determined by variance accounted for, Akaike information criterion (AIC), and Bayesian information criterion (BIC) values. An interaction model between internalized stigma and medication concerns accounted for the most variance in adherence. There was also a significant indirect effect of internalized stigma on adherence via medication concerns. Medication concerns are a promising target for interventions focusing on increasing adherence among people with HIV.

Approaches to Objectively Measure Antiretroviral Medication Adherence and Drive Adherence Interventions

PURPOSE OF REVIEW

Traditional methods to assess antiretroviral adherence, such as self-report, pill counts, and pharmacy refill data, may be inaccurate in determining actual pill-taking to both antiretroviral therapy (ART) or pre-exposure prophylaxis (PrEP). HIV viral loads serve as surrogates of adherence on ART, but loss of virologic control may occur well after decreases in adherence and viral loads are not relevant to PrEP.

RECENT FINDINGS

Pharmacologic measures of adherence, electronic adherence monitors, and ingestible electronic pills all serve as more objective metrics of adherence, surpassing self-report in predicting outcomes. Pharmacologic metrics can identify either recent adherence or cumulative adherence. Recent dosing measures include antiretroviral levels in plasma or urine, as well as emtricitabine-triphosphate in dried blood spots (DBS) for those on tenofovir-emtricitabine-based therapy. A urine tenofovir test has recently been developed into a point-of-care test for bedside adherence monitoring. Cumulative adherence metrics assess adherence over weeks to months and include measurement of tenofovir-diphosphate in peripheral blood mononuclear cells or DBS, as well as ART levels in hair. Electronic adherence monitors and ingestible electronic pills can track pill bottle openings or medication ingestion, respectively. New and objective approaches in adherence monitoring can be used to detect nonadherence prior to loss of prevention efficacy or virologic control with PrEP or ART, respectively.

Social Support Mitigates Negative Impact of Food Insecurity on Antiretroviral Adherence Among Postpartum Women in Western Kenya

Food insecurity (FI), low social support, and low health-related quality of life (HRQoL) are associated with self-reported nonadherence to antiretroviral therapy (ART) among postpartum women, but these relationships have not been evaluated using objective adherence indicators. Hair samples were therefore analyzed among 83 postpartum Kenyan women living with HIV on efavirenz and nevirapine ART drug regimens in an observational cohort (NCT02974972). FI (0-27), social support (0-40), and HRQoL (8-40) in the prior month were also assessed. In multivariable models, each point increase in FI and decrease in HRQoL were associated with a 45.1% (95% CI: -64.3%, -15.6%) and 10.5% decrease (95% CI: 1.0%, 22.1%) in hair ART drug concentrations respectively, when social support was held constant. A significant interaction between social support and FI (β = 0.02, p = 0.017) indicated that greater social support was predicted to mitigate the negative impacts of FI on ART adherence. Addressing these modifiable barriers could improve ART adherence during this critical period.

Food Insecurity Is Associated With Lower Levels of Antiretroviral Drug Concentrations in Hair Among a Cohort of Women Living With Human Immunodeficiency Virus in the United States

BACKGROUND

Food insecurity is a well-established determinant of suboptimal, self-reported antiretroviral therapy (ART) adherence, but few studies have investigated this association using objective adherence measures. We examined the association of food insecurity with levels of ART concentrations in hair among women living with human immunodeficiency virus (WLHIV) in the United States.

METHODS

We analyzed longitudinal data collected semiannually from 2013 through 2015 from the Women's Interagency HIV Study, a multisite, prospective, cohort study of WLHIV and controls not living with HIV. Our sample comprised 1944 person-visits from 677 WLHIV. Food insecurity was measured using the US Household Food Security Survey Module. ART concentrations in hair, an objective and validated measure of drug adherence and exposure, were measured using high-performance liquid chromatography with mass spectrometry detection for regimens that included darunavir, atazanavir, raltegravir, or dolutegravir. We conducted multiple 3-level linear regressions that accounted for repeated measures and the ART medication(s) taken at each visit, adjusting for sociodemographic and clinical characteristics.

RESULTS

At baseline, 67% of participants were virally suppressed and 35% reported food insecurity. In the base multivariable model, each 3-point increase in food insecurity was associated with 0.94-fold lower ART concentration in hair (95% confidence interval, 0.89 to 0.99). This effect remained unchanged after adjusting for self-reported adherence.

CONCLUSIONS

Food insecurity was associated with lower ART concentrations in hair, suggesting that food insecurity may be associated with suboptimal ART adherence and/or drug absorption. Interventions seeking to improve ART adherence among WLHIV should consider and address the role of food insecurity.

A group-based mental health intervention for young people living with HIV in Tanzania: results of a pilot individually randomized group treatment trial

BACKGROUND

Increasing numbers of young people living with HIV (YPLWH) have unaddressed mental health challenges. Such challenges are associated with poor antiretroviral therapy (ART) adherence and high mortality. Few evidence-based mental health interventions exist to improve HIV outcomes among YPLWH.

METHODS

This pilot group treatment trial individually randomized YPLWH from two clinical sites in Tanzania, evaluated acceptability, feasibility, and preliminary effectiveness of a mental health intervention, Sauti ya Vijana (SYV; The Voice of Youth), was compared to the local standard-of-care (SOC) for improving ART adherence and virologic suppression. Enrolled YPLWH were 12-24 years of age and responded to mental health and stigma questionnaires, self-reported adherence, objective adherence measures (ART concentration in hair), and HIV RNA at baseline and 6-months (post-intervention). Feasibility and acceptability were evaluated, and potential effectiveness was assessed by comparing outcomes between arms using mixed effects modeling.

RESULTS

Between June 2016 and July 2017, 128 YPLWH enrolled; 105 were randomized and 93 (55 in SYV) followed-up at 6-months and were thereby included in this analysis. Mean age was 18.1 years; 51% were female; and 84% were HIV-infected perinatally. Attendance to intervention sessions was 86%; 6-month follow-up was 88%, and fidelity to the protocol approached 100%. Exploratory analyses of effectiveness demonstrated self-reported adherence improved by 7.3 percentage points (95% CI: 2.2, 12.3); and the pooled standard deviation for all ART concentration values increased by 0.17 units (95% CI: - 0.52, 0.85) in the SYV arm compared to SOC. Virologic suppression rates (HIV RNA < 400 copies/mL) at baseline were 65% in both arms but increased to 75% in the SYV arm while staying the same in the SOC arm (RR 1.13; 95% CI: 0.94, 1.36).

CONCLUSIONS

YPLWH often have poor HIV outcomes, making interventions to improve outcomes in this population critical. This pilot trial of the Tanzania-based SYV intervention demonstrated trends towards improvement in ART adherence and virologic outcomes among YPLWH, supporting efforts to scale the intervention into a fully-powered effectiveness trial.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02888288 . Registered August 9, 2016. Retrospectively registered as first participant enrolled June 16, 2016.

A population pharmacokinetic model is beneficial in quantifying hair concentrations of ritonavir-boosted atazanavir: a study of HIV-infected Zimbabwean adolescents

BACKGROUND

Adolescents experience higher levels of non-adherence to HIV treatment. Drug concentration in hair promises to be reliable for assessing exposure to antiretroviral (ARV) drugs. Pharmacokinetic modelling can explore utility of drug in hair. We aimed at developing and validating a pharmacokinetic model based on atazanavir/ritonavir (ATV/r) in hair and identify factors associated with variabilities in hair accumulation.

METHODS

We based the study on secondary data analysis whereby data from a previous study on Zimbabwean adolescents which collected hair samples at enrolment and 3 months follow-up was used in model development. We performed model development in NONMEM (version 7.3) ADVAN 13.

RESULTS

There is 16% / 18% of the respective ATV/r in hair as a ratio of steady-state trough plasma concentrations. At follow-up, we estimated an increase of 30% /42% of respective ATV/r in hair. We associated a unit increase in adherence score with 2% increase in hair concentration both ATV/r. Thinner participants had 54% higher while overweight had 21% lower atazanavir in hair compared to normal weight participants. Adolescents receiving care from fellow siblings had atazanavir in hair at least 54% less compared to other forms of care.

CONCLUSION

The determinants of increased ATV/r concentrations in hair found in our analysis are monitoring at follow up event, body mass index, and caregiver status. Measuring drug concentration in hair is feasibly accomplished and could be more accurate for monitoring ARV drugs exposure.

Perinatal Food Insecurity and Postpartum Psychosocial Stress are Positively Associated Among Kenyan Women of Mixed HIV Status

Stress and food insecurity (FI) are associated with poor perinatal and HIV outcomes. We hypothesized that FI would increase postpartum stress among women in Kenya, and that the impact would be greater in women with HIV. Among 371 pregnant women, we identified latent FI trajectories across the perinatal period, and estimated their association with postpartum stress. Stress metrics included the Perceived Stress Scale (PSS) and hair cortisol concentrations (HCC). We identified two FI trajectories: persistent moderate FI and persistent mild FI. Moderate FI (vs. mild) was associated with higher PSS; this association was stronger among HIV-negative women. We observed a trend towards higher HCC associated with moderate FI, which did not differ by HIV status. HCC and PSS were not correlated. In summary, moderate FI (vs. mild) was associated with increased stress. The lack of PSS-HCC correlation could reflect different physiological pathways. Interventions to mitigate FI could alleviate postpartum stress.

Hyphenated mass spectrometry techniques for assessing medication adherence: advantages, challenges, clinical applications and future perspectives

Nonadherence to prescribed pharmacotherapy is an understated public health problem globally and is costing many patients their chance to return to good health and healthcare systems billions. Clinicians need an accurate assessment of adherence to medications to aid the clinical decision-making process in the event of poor patient progress and to maximise the patient health outcomes from the drug therapies prescribed. An overview of indirect and direct methods used to measure medication adherence is presented, highlighting the potential for accurate measuring of drugs in biological samples using hyphenated mass spectrometry (MS) techniques to provide healthcare professionals with a reliable evidence base for clinical decision making. In this review we summarise published applications of hyphenated MS techniques for a diverse range of clinical areas demonstrating the rise in the use of such direct methods for assessing medication adherence. Although liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods using plasma, serum and urine samples are the most popular, in recent years increased attention has been given to liquid chromatography high-resolution mass spectrometry (LC-HRMS) methods and alternative biosample matrices including hair, saliva and blood microsamples. The advantages and challenges of using hyphenated MS techniques to address this healthcare problem are also discussed alongside future perspectives.

Comparing self-reported medication adherence measures with hair antiretroviral concentration among people living with HIV in Guangxi, China

BACKGROUND

Antiretroviral adherence is essential to HIV treatment efficacy. Various self-reported measures are commonly used for assessing antiretroviral adherence. Limited data are available regarding the validity of those self-reported measures in comparison with long-term objective biomarkers of adherence measures such as hair measures.

METHODS

Self-reported adherence (frequency, percentage, and visual analog scale [VAS]) and hair tenofovir concentration were evaluated at a single time point from 268 people living with HIV in China. The responses to each of three self-reported measures were converted into percentage and then dichotomized as "optimal" (100%) vs. "suboptimal" (less than 100%) adherence. Two composite adherence scores (CAS) were created from the three self-reported measures: (1) an overall adherence was the average percentage of the three self-reported measures; (2) responses were termed optimal adherence if participants reporting optimal adherence in all three self-reported measures, while were termed suboptimal adherence. Hair tenofovir concentration was also dichotomized as "optimal" (above the limit of quantitation, 36 pg/mg) vs. "suboptimal" adherence (blow 36 pg/mg). Spearman correlation, kappa statistics, and logistic regression analysis were used to calculate the correlations, agreements, and predictions of self-reported measures with hair measure, respectively.

RESULTS

Overall adherence, but any of the three self-reported adherence, was correlated with hair tenofovir concentration (r = 0.13, p < 0.05). Self-reported optimal adherence in VAS and CAS measures were agreed with and predicted optimal adherence assessed by hair measure (Kappa = 0.107, adjusted OR = 1.88, 95% CI 1.03-3.45; Kappa = 0.109, adjusted OR = 1.80, 95% CI 1.02-3.18; all p < 0.05, respectively).

CONCLUSION

VAS may be a good individual self-reported measure for antiretroviral adherence, and CAS may be a good composite self-reported measure for antiretroviral adherence.

Antiretroviral Concentration in Hair as a Measure for Antiretroviral Medication Adherence: A Systematic Review of Global Literature

This review aims to validate hair antiretroviral concentration (HAC) as a measure for antiretroviral medication adherence. This review included 31 studies that analyzed a total of 11 ARV drugs in four different drug classes. The associations between HAC and non-pharmacokinetic measures were generally lower than the association between HAC and other pharmacokinetic measures: the correlation coefficients (r) ranged from - 0.20 to 0.38 for self-report or pill counts and 0.20 to 0.85 for electronic drug monitoring; HAC and other pharmacokinetic measures were positively correlated with the correlation coefficients (r) ranging from 0.20 to 0.72, 0.34 to 0.86, 0.50 to 0.85 for antiretroviral concentration in plasma, peripheral blood mononuclear cells, and dried blood spots, respectively. HAC was one of the strongest independent predictors of virologic responses. HAC of tenofovir was significantly associated with renal toxicity in large sample studies. This review suggests that HAC is a valid biomarker of antiretroviral medication adherence.

Moving Antiretroviral Adherence Assessments to the Modern Era: Correlations Among Three Novel Measures of Adherence

There is no gold standard for estimating antiretroviral therapy (ART) adherence. Feasible, acceptable, and objective measures that are cost- and time-effective are needed. US adults (N = 93) on ART for ≥ 3 months, having access to a mobile phone and internet, and willing to mail in self-collected hair samples, were recruited into a pilot study of remote adherence data collection methods. We examined the correlation of self-reported adherence and three objective remotely collected adherence measures: text-messaged photographs of pharmacy refill dates for pharmacy-refill-based adherence, text-messaged photographs of pills for pill-count-based adherence, and assays of home-collected hair samples for pharmacologic-based adherence. All measures were positively correlated. The strongest correlation was between pill-count- and pharmacy-refill-based adherence (r = 0.68; p < 0.001), and the weakest correlation was between self-reported adherence and hair drug concentrations (r = 0.14, p = 0.34). The three measures provide objective adherence data, are easy to collect, and are viable candidates for future HIV treatment and prevention research.

Positive affect and medication adherence in chronic conditions: A systematic review

OBJECTIVE

This review aims to inform research and clinical care on the current state of knowledge on the relationship between positive affect and medication adherence.

METHOD

Searches were carried out in PsycINFO, PubMed MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL, and Embase. There were no limits on study type, publication date, language, or participant demographics. Studies reporting a relationship between positive affect and medication adherence were eligible for inclusion if positive affect was measured prior to or concurrently with medication adherence.

RESULTS

Nine studies met inclusion criteria. All studies were prospective cohort or cross-sectional and examined positive affect and medication adherence in people living with HIV or cardiovascular conditions. The majority of results indicated positive associations between positive affect and medication adherence, with Cohen's d effect sizes ranging from -0.40 to 1.27.

CONCLUSIONS

Consistent with previous theoretical work, this systematic review provides evidence of a link between positive affect and improved medication adherence. Better measurement of both affect and medication adherence across chronic conditions is an important focus for future research and will inform targeted interventions to improve adherence and, ultimately, decrease the morbidity, mortality, and cost associated with suboptimal adherence in chronic physical conditions. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Tenofovir concentrations in hair strongly predict virologic suppression in breastfeeding women

BACKGROUND

Antiretroviral treatment (ART) adherence is often suboptimal in the perinatal period. We measured hair tenofovir (TFV) concentrations as a metric of adherence in postpartum women to understand patterns and predictors of adherence throughout this critical period. In addition, we examined the association between hair TFV concentrations and virologic outcomes.

METHODS

Between 12/2012 and 09/2016, hair samples were collected longitudinally from delivery through breastfeeding from women on ART in the Promoting Maternal and Infant Survival Everywhere study (NCT01061151) in sub-Saharan Africa. Hair TFV levels were measured using validated methods. Using generalized estimating equations, we estimated the association between hair TFV levels and virologic suppression (<400 copies/ml) over time and assessed predictors of hair TFV levels.

RESULTS

Hair TFV levels were measured at 370 visits in 71 women from delivery through a median of 14 months (interquartile range 12-15) of breastfeeding. Levels ranged from below detection (0.002) to 1.067 ng/mg (geometric mean: 0.047). After at least 90 days on ART, 69 women had at least one viral load measured (median 5 measures, range 1-9); 18 (26%) experienced viremia at least once. Each doubling of TFV level more than doubled odds of concurrent virologic suppression [odds ratio 2.35, 95% confidence interval (CI): 1.44-3.84, P = 0.0006] and was associated with 1.43 times the odds of future suppression (95% CI: 0.75-2.73, P = 0.28). Relative to the first 3 months after delivery, hair levels were highest in months 6-12 (1.42-fold higher, 95% CI: 1.09-1.85, P = 0.01).

CONCLUSION

Hair TFV levels strongly predicted concurrent virologic suppression among breastfeeding women. Objective adherence metrics can supplement virologic monitoring to optimize treatment outcomes in this important transition period.

Motivational Interviewing to Reduce Drug Use and HIV Incidence Among Young Men Who Have Sex With Men in Relationships and Are High Priority for Pre-Exposure Prophylaxis (Project PARTNER): Randomized Controlled Trial Protocol

Background

Men who have sex with men (MSM) currently account for more than two-thirds of new HIV diagnoses in the United States and, among young MSM (YMSM) aged 20 to 29 years, as many as 79% to 84% of new infections occur between primary partners. Contributing to HIV risk, YMSM use drugs at comparatively high rates. To date, no interventions have been developed that specifically address the unique needs of partnered YMSM or incorporate a focus on relationship factors in addressing personal motivation for change.

Objective

The study’s primary aim is to evaluate the efficacy of the PARTNER intervention and evaluate potential moderators or mediators of intervention effects. The study’s secondary aims were to gather ideographic data to inform a future effectiveness implementation study and develop a novel biomarker for pre-exposure prophylaxis (PrEP) adherence by analyzing PrEP drug levels in fingernails.

Methods

PARTNER is a 4-session motivational interviewing–based intervention that integrates video-based communication training to address drug use and HIV prevention among partnered YMSM. This study utilizes a randomized controlled trial design to compare the PARTNER intervention with an attention-matched psychoeducation control arm that provides information about HIV-risk reduction, PrEP, and substance use. Participants are randomized in a 1-to-1 ratio stratified on age disparity between partners, racial composition of the couple, and relationship length. Follow-up assessments are conducted at 3-, 6-, 9-, and 12-months postbaseline. The study recruits and enrolls 240 partnered YMSM aged between 18 to 29 years at a research center in New York City. Participants will be HIV-negative and report recent (past 30-day) drug use and condomless anal sex with casual partners; a nonmonogamous primary partner (regardless of HIV status); or a serodiscordant primary partner (regardless of sexual agreement). Primary outcomes (drug use and HIV sexual transmission risk behavior) are assessed via a Timeline Follow-back interview. Biological markers of outcomes are collected for drug use (fingernail assay), sexual HIV transmission risk (rectal and urethral gonorrhea and chlamydia testing), and PrEP adherence (dried blood spots and fingernails for a novel PrEP drug level assay).

Results

The study opened for enrollment in February 2018. Anticipated completion of enrollment is October 2021. Primary outcome analyses will begin after final follow-up completion.

Conclusions

Existing research on partnered YMSM within the framework of Couples Interdependence Theory (CIT) has suggested that relationship factors (eg, dyadic functioning and sexual agreements) are meaningfully related to drug use and HIV transmission risk. Results pertaining to the efficacy of the proposed intervention and the identification of putative moderators and mediators will substantially inform the tailoring of interventions for YMSM in relationships and contribute to a growing body of relationship science focused on enhancing health outcomes.

Trial Registration

ClinicalTrials.gov NCT03396367; https://clinicaltrials.gov/ct2/show/NCT03396367 (Archived by WebCite at http://www.webcitation.org/78ti7esTc.

International Registered Report Identifier (IRRID)

DERR1-10.2196/13015

Willingness to Donate Hair Samples for Research Among People Living with HIV/AIDS Attending a Tertiary Health Facility in Ibadan, Nigeria

The use of hair samples in biomedical research is a rapidly growing field. High acceptability rates for hair collection have been demonstrated in multiple settings. Each setting may have unique issues and, to our knowledge, no previous study has assessed the acceptability of hair sampling for HIV-related research in Nigeria. This study aimed to assess the willingness to donate hair for research among people living with HIV (PLWH). A cross-sectional study was conducted among 381 PLWH in a tertiary institution in Southwest Nigeria, using convenience sampling. An interviewer-administered questionnaire was used to collect data from consenting participants, including a question on willingness to donate hair for research. The mean age of respondents was 42.1 ± 10.5 years and more than three-quarters of the respondents were females. Two hundred and eighty-eight (75.8%) respondents had at least a tertiary education. Only 51.4% of the respondents were willing to donate their hair for research. Possible sample diversion for rituals was the major (60.5%) reason cited for unwillingness to donate hair. In multivariate analysis, respondents with primary education or less exhibited a trend toward being more willing to donate hair than those with secondary education or more (p = .091). Muslims were 1.7 times more willing to donate hair than Christians even after adjusting for other demographic covariates (95% confidence interval: 1.11-2.72); p = .016. There is a moderate willingness to donate hair for research among our population of PLWH in Nigeria. These results underscore the importance of cultural sensitivity and community education when introducing innovative HIV research techniques to new settings.

Measuring Adherence to Antiretroviral Therapy via Hair Concentrations in India

BACKGROUND

Objective adherence measures are of increasing interest in antiretroviral treatment (ART) monitoring. Hair ART levels predict virologic suppression, and hair is easy to collect and store. No previous study has examined hair levels in an India-based cohort or laboratory.

METHODS

Small hair samples were collected from HIV-positive participants on either efavirenz (EFV)-based or nevirapine (NVP)-based ART in a South India-based study. Hair samples were split and analyzed for EFV or NVP in the University of California, San Francisco -based Hair Analytical Laboratory and the analytic laboratory of the Division of Nutrition at St. John's Research Institute, Bangalore, India, using liquid chromatography/tandem mass spectrometry. Agreement (using Bland-Altman methods) and rank correlation between the 2 laboratories' hair levels were calculated. Rank correlation between self-reported adherence (SRA) over the previous month using a visual analog scale and hair ART levels was calculated.

RESULTS

Among 75 participants (38 on NVP; 37 on EFV), the correlation between NVP levels generated by the 2 laboratories was 0.66 (P < 0.0001) and between EFV levels was 0.87 (P < 0.0001). Measurements from St. John's Research Institute were usually within 20% of those from the University of California, San Francisco Hair Analytical Laboratory. SRA was essentially uncorrelated with hair antiretroviral levels for either drug (all correlations < 0.04). Hair levels showed variability in adherence although SRA was >85% in all participants.

CONCLUSIONS

Hair ART levels measured by both an India-based laboratory and the standard U.S.-based laboratory showed generally high agreement and correlation, demonstrating local capacity. As in many other cohorts, hair ART levels and SRA were not well-correlated, likely indicating limitations in self-report and the need for objective adherence monitoring in resource-limited settings.

Adherence Measurements in HIV: New Advancements in Pharmacologic Methods and Real-Time Monitoring

PURPOSE OF REVIEW

In this review, we present new developments in antiretroviral adherence, focusing on pharmacological measures and real-time adherence monitoring. In addition, new strategies on how to incorporate these new measures into research and clinical care are proposed.

RECENT FINDINGS

Antiretroviral drug concentrations in hair and dried blood spots are two novel pharmacological measures of cumulative drug adherence and exposure that have been recently evaluated in HIV treatment and pre-exposure prophylaxis. Real-time adherence monitoring using electronic devices has also proven highly informative, feasible, and well accepted, offering the possibility for an immediate intervention when non-adherence is detected. Both approaches offer considerable advantages over traditional adherence measures in predicting efficacy. New methods to objectively monitor adherence in real-time and over long time periods have been developed. Further research is required to better understand how these measures can optimize adherence and, ultimately, improve clinical outcomes in HIV treatment and prevention.

Correlation of hair and plasma efavirenz concentrations in HIV-positive South Africans

BACKGROUND

Antiretroviral concentrations in hair provide a longer window of drug detection and are useful for measuring longer-term drug exposure. Efavirenz is an important component of first-line treatment in resource-limited settings, but its concentrations in hair have not been well studied.

METHODS

This study is a supplementary to a randomised controlled trial of an adherence intervention using an electronic adherence measuring device. Hair and plasma samples were collected from human immunodeficiency virus-positive patients in Cape Town, South Africa. Previously validated liquid chromatography tandem mass spectrometry methods were used to measure efavirenz concentrations in the collected hair and plasma samples. CYP2B6 genotyping of participants was also performed. Data analysis was performed using descriptive and comparative statistics as well as regression modelling.

RESULTS

Hair samples were collected from 59% of patients enrolled in the parent study. Results indicated that hair efavirenz concentrations were significantly influenced by participants' CYP2B6 metaboliser status. Median efavirenz concentrations for extensive, intermediate and slow metaboliser genotypes were 3.54 ng/mg, 5.11 ng/mg and 10.66 ng/mg, respectively. A strong correlation was observed between the efavirenz concentrations measured in hair and plasma samples (Spearman's correlation coefficients, 0.672-0.741, p < 0.0001). No relationship between hair efavirenz concentrations and virological failure or adherence measured using an electronic adherence was shown.

CONCLUSION

The results from this study provide further insight into the potential of using hair as a matrix for measuring antiretroviral concentrations. However, challenges experienced in collecting hair samples suggest that this adherence measure may have limited utility in an African population.

Antiretroviral Concentrations in Hair Strongly Predict Virologic Response in a Large Human Immunodeficiency Virus Treatment-naive Clinical Trial

Concentrations of antiretrovirals in hair are associated with virologic outcomes in cohorts of human immunodeficiency virus (HIV)-positive individuals but have never been examined in a clinical trial. We show for the first time the predictive utility of hair antiretroviral concentrations in a large HIV treatment-naive trial (AIDS Clinical Trials Group protocol A5257).

Development and clinical assessment of new objective adherence markers for four microbicide delivery systems used in HIV prevention studies

Background

Adherence is critical for successful topical, vaginally delivered anti-retroviral (ARV)-based HIV pre-exposure prophylaxis (PrEP). Quantitating systemic or tissue ARV levels through LC–MS/MS is currently viewed as the most reliable measure of adherence. However, for placebo-controlled trials, this is a high cost analysis that measures adherence only in the drug treatment group. A desirable marker of adherence is one that is measured in both placebo and drug treatment groups using a simple on-site clinical laboratory test, which allows necessary interventions for supporting participant adherence. Our objective was to develop adherence markers for four vaginal placebo products currently used as microbicide delivery systems: gel, film, insert, and intravaginal ring. Excipient and spectroscopy-based approaches were used for preclinical development of the placebo markers and subsequently validated by the CONRAD 135 study. The study collected vaginal swabs collected each day for 1 week post vaginal application of gel, film, or insert in the clinic with or without sex. Intravaginal rings were collected after 1 day, 7, and 30 days of use.

Results

Placebo gel, film, and insert in vaginal swabs were successfully detected by specific excipient colorimetric or probe-based assays for hydroxyethylcellulose, glycerin, and sorbitol respectively, as well as spectroscopy-based prediction models. The range of detection for gel, film, and insert in swabs collected up to 16 h post vaginal application was 70-100% of the total swabs per time point, with some markers showing potential for longer duration. Decreasing residual glycerin levels and increasing bioanalyte penetration of vaginally used intravaginal rings showed significant changes between 1 and 30 days of use.

Conclusions

We demonstrated clinical proof-of-concept that adherence markers for placebo product can be measured using simple, lower cost approaches. Measuring adherence in both placebo and drug arms of a HIV PrEP study would better inform future trial designs.

Electronic supplementary material

The online version of this article (10.1186/s40169-018-0213-6) contains supplementary material, which is available to authorized users.

Association of Depressive Symptoms with Lapses in Antiretroviral Medication Adherence Among People Living with HIV: A Test of an Indirect Pathway

Viral suppression, a critical component of HIV care, is more likely when individuals initiate antiretroviral therapy (ART) early in disease progression and maintain optimal levels of adherence to ART regimens. Although several studies have documented the negative association of depressive symptoms with ART adherence, less is known about how depressed mood relates to intentional versus unintentional lapses in adherence as well as the mechanisms underlying this association. The purpose of the current study was to examine the association of depressive symptoms with ART adherence, assessed as a multidimensional construct. Secondarily, this study conducted preliminary indirect path models to determine if medication self-efficacy could explain the depressed mood-adherence relationship. Depressive symptoms were not associated with 95% ART taken, self-reported viral load, deliberate adjustments to ART regimens or skipped ART doses. However, the indirect association of depressive symptoms via decrements in medication self-efficacy was significant for 95% ART taken, self-reported viral load and skipped ART doses, but not deliberate changes to ART regimens. In this sample of HIV-positive outpatients, there is evidence to support medication self-efficacy as a potential mechanism underlying the association between depressive symptoms and ART adherence. Additional longitudinal studies are needed to formally examine medication taking self-efficacy as a mediator.

Antiretroviral drug concentrations in hair are associated with virologic outcomes among young people living with HIV in Tanzania

OBJECTIVE

We assessed the relationship of self-reported adherence versus antiretroviral therapy (ART) concentrations in hair with virologic outcomes among young people living with HIV.

DESIGN

This was a cross-sectional study that enrolled young people living with HIV age 11-24 years, who attended a youth HIV clinic in Moshi, Tanzania.

METHODS

ART adherence was assessed by self-report, drug concentration in hair samples, and plasma HIV-1 RNA measurements. Those with virologic failure, defined as plasma HIV-1 RNA more than 400 copies/ml, had genotypic resistance assessed. Receiver operating characteristic curves were used to evaluate ART-concentration threshold cutoffs for virologic suppression, after excluding those with known high-level resistance mutations.

RESULTS

Among 280 young people enrolled, 227 were included in the final analysis. Seventy-two (32%) self-reported inadequate adherence and 91 (40%) had virologic failure. Hair ART-concentration (P < 0.001), but not self-reported adherence (P = 0.53), was associated with virologic outcome. Sixty-seven (74%) of those with virologic failure had resistance testing performed, of whom 60% had high-level resistance. Receiver operating characteristic curves demonstrated moderate or high classification performance for association with virologic suppression with specific hair ART-concentration cutoffs for lopinavir (1.8 ng/mg), efavirenz (1.04 ng/mg), and nevirapine (33.2 ng/mg).

CONCLUSION

Hair ART-concentrations were significantly associated with virologic outcomes among young people living with HIV. ART-concentration thresholds associated with virologic suppression are proposed. Hair analysis may provide a noninvasive, cost-effective adherence assessment tool in settings with limited second and third-line treatment options.

Acceptability of obtaining hair samples for assessing antiretroviral therapy (ART) exposure amongst alcohol drinking ART recipients in Tshwane, South Africa

To achieve the maximal therapeutic benefits of antiretroviral therapy (ART), high adherence is required. In South Africa, ART recipients are usually counselled by their health care providers to stop drinking alcohol, as heavy alcohol use compromises ART adherence. Patients who continue drinking alcohol tend to hide their alcohol-related adherence challenges from their health care providers. Objective measures of ART adherence/exposure may help to better identify drinkers who could benefit from ART adherence enhancement interventions. To evaluate the acceptability of collecting hair samples to objectively assess ART exposure among alcohol drinkers, we conducted four mixed-gender focus group discussions (FGDs) with alcohol drinking ART recipients at two ART sites in Tshwane, South Africa. Data were analysed using content analysis. ART recipients found hair sample testing for ART exposure to be novel and therefore expected that some ART recipients would initially be hesitant to provide a sample. Participants thought that the acceptability of hair sample collection could be enhanced by providing a full explanation of how the hair sample would be obtained and what the testing would entail. Participants also viewed hair sample testing as a viable and desirable alternative to blood sample testing for ART exposure. Some worries about the possible use of hair samples for witchcraft and the symbolic nature of hair were brought up, but these were not seen as insurmountable concerns. In conclusion, hair sample testing is a potentially acceptable method of assessing ART exposure amongst ART recipients who drink alcohol.

Development and validation of an assay to analyze atazanavir in human hair via liquid chromatography/tandem mass spectrometry

RATIONALE

Assays to quantify antiretrovirals in hair samples are increasingly used to monitor adherence and exposure in both HIV prevention and treatment studies. Atazanavir (ATV) is a protease inhibitor used in combination antiretroviral therapy (ART). We developed and validated a liquid chromatography/tandem mass spectrometry (LC/MS/MS)-based method to quantify ATV in human hair, per the NIH Division of AIDS Clinical Pharmacology Quality Assurance (CPQA) program and the FDA bioanalytical method validation guidelines.

METHODS

ATV was extracted from hair using optimized methods and the extracts were injected onto a BDS C-18 column (5 μm, 4.6 × 100 mm), followed by isocratic elution via a mobile phase composed of 55% acetonitrile, 45% water, 0.15% acetic acid, and 4 mM ammonium acetate, at a flow rate of 0.8 mL/min prior to analysis by MS/MS. Levels were quantified using positive electrospray ionization by multiple reaction monitoring (MRM) for the transitions MH⁺ m/z 705.3 to m/z 168.0 and MH⁺ m/z 710.2 to m/z 168.0 for ATV and ATV-d5 (internal standard), respectively.

RESULTS

Our assay demonstrated a linear standard curve (r = 0.99) over the concentration range of 0.0500 ng ATV/mg hair to 20.0 ng/mg hair. The inter- and intraday accuracy of ATV quality control (QC) samples was -1.33 to 4.00% and precision (% coefficient of variation (%CV)) was 1.75 to 6.31%. The %CV for ATV levels in hair samples from highly adherent patients (incurred samples) was less than 10%. No significant endogenous peaks or crosstalk were observed in the specificity test with other HIV drugs. The overall extraction efficiency of ATV from incurred hair samples was greater than 95%.

CONCLUSIONS

This highly sensitive, highly specific and validated assay can be considered for therapeutic drug monitoring for HIV-infected patients on ATV-based ART.

Brief Report: Lopinavir Hair Concentrations Are the Strongest Predictor of Viremia in HIV-Infected Asian Children and Adolescents on Second-Line Antiretroviral Therapy

BACKGROUND

Children/adolescents display suboptimal antiretroviral therapy (ART) adherence and outcomes versus adults. Hair ART concentrations are objective adherence measures that predict viremia in adults but longitudinal data on hair levels in pediatric populations is limited. We assessed the predictive utility of hair lopinavir (LPV) levels on viremia among youth on second-line ART.

METHODS

We examined predictors of viremia (HIV-1 RNA >400 and >1000 copies/mL) at least 24 weeks after switch to LPV-based second-line ART in a cohort of HIV-infected Asian children followed between 2011 and 2014. Small hair samples, HIV-1 RNA, and self-reported adherence were collected biannually. Hair concentrations of LPV were measured through liquid chromatography/tandem mass spectrometry using validated methods. Time-to-first viremia was examined using discrete-time Cox models.

RESULTS

Overall, 244 children met the inclusion criteria for the present analysis. Approximately half (55%) were boys and the median age 10 years [interquartile range (IQR) 7-13]; 40% were older than 11 years. At switch to second-line ART, median CD4 count was 300 (IQR 146-547) cells/mm and median HIV-RNA level was 5.0 (IQR 4.3-5.6) log10/mL. Median time of study follow-up was 48 weeks and a median of 3 (range 1-5) hair samples were collected from each participant. Adjusting for age, sex, country, self-reported adherence, CD4, and HIV-RNA, higher LPV hair concentrations were the strongest predictor of lower odds of viremia (HIV-RNA >400 copies/mL adjusted odds ratio = 0.41 per doubling in hair concentration, 95% confidence interval: 0.29 to 0.58, P < 0.001; HIV-RNA >1000 copies/mL, adjusted odds ratio = 0.54, 95% confidence interval: 0.45 to 0.65, P < 0.001).

CONCLUSIONS

Hair concentrations predict viremia among children with HIV on second-line ART and could guide clinical decisions for this population.

Isoniazid hair concentrations in children with tuberculosis: a proof of concept study

Assessing treatment adherence and quantifying exposure to anti-tuberculosis drugs among children is challenging. We undertook a 'proof of concept' study to assess the drug concentrations of isoniazid (INH) in hair as a therapeutic drug monitoring tool. Children aged <12 years initiated on a thrice-weekly treatment regimen including INH (10 mg/kg) for newly diagnosed tuberculosis were enrolled. INH concentrations in hair were measured using liquid chromatography-tandem mass spectrometry at 1, 2, 4 and 6 months after initiating anti-tuberculosis treatment. We found that INH hair concentrations in all children on thrice-weekly INH were detectable and displayed variability across a dynamic range.

Comparing pharmacologic measures of tenofovir exposure in a U.S. pre-exposure prophylaxis randomized trial

It is critical to assess adherence to pre-exposure prophylaxis (PrEP) in clinical trials. The relationship between pharmacokinetic measures of PrEP adherence and other adherence measures used in PrEP trials requires further characterization. Plasma, peripheral blood mononuclear cells (PBMCs), and hair samples were collected from 88 HIV-uninfected men who have sex with men in a placebo-controlled randomized PrEP trial; announced pill counts, medication electronic monitoring (MEMS), and self-report using visual analog scale (VAS) were also collected. Tenofovir (TFV or TFV-DP) in plasma, hair, and PBMCs were quantified. Proportions with drug detection, Spearman correlation coefficients, and univariate and multivariable regression models were used. Drug detection in plasma, PBMC, and hair samples was highly concordant with treatment arm assignment. TFV or TFV-DP levels were detected in most active-arm participants: 44/47 (94%) in plasma, 46/47 (98%) in hair, and 44/47 (94%) in PBMCs and in only 1/41 placebo arm participant. Correlation coefficients were r = 0.59 for plasma and PBMC, r = 0.34 for PBMC and hair and r = 0.36 for plasma and hair. MEMS and announced pill-counts were moderately correlated (r = 0.52) but less so with pharmacologic measures (range of r = 0.12 to 0.38). Self-reported adherence by visual analog scale demonstrated essentially no correlation with drug levels (r = 0.06 for hair, PBMC or plasma) and was a poor indicator of exposure to study product. Indices of drug exposure are important indicators in assessing adherence to PrEP; accounting for variability between measures may improve interpretation and use of adherence measures in future PrEP studies.

Comparison of Measures of Adherence to Human Immunodeficiency Virus Preexposure Prophylaxis Among Adolescent and Young Men Who Have Sex With Men in the United States

Background

Young men-who-have-sex-with-men (MSM) are disproportionately impacted by human immunodeficiency virus (HIV). Preexposure prophylaxis (PrEP) could reduce HIV acquisition among youth, but suboptimal adherence threatens effectiveness. Optimal metrics of PrEP adherence among adolescents have remain undefined.

Methods

The Adolescent Trials Network 110/113 studies provided daily oral PrEP with tenofovir (TFV) disoproxil fumarate/emtricitabine over 48 weeks to a diverse population of MSM (aged 15-22 years). Self-reported adherence was assessed and PrEP drug concentrations measured from hair and dried blood spot (DBS) samples; 23% of participants received Wisepill electronic monitoring devices. The average number of PrEP doses per week taken was estimated, and concordance between measures assessed.

Results

Among 243 participants, hair samples were collected at 1186/1238 (96%) person-visits. The concordance of TFV levels in hair and TFV-diphosphate in DBS around thresholds consistent with taking ≥4 and 7 PrEP doses/week was high (76% and 80%). Hair and DBS concentrations correlated poorly with self-report and Wisepill metrics. Through week 12, 40%-60% of participants (by hair and DBS), ≤31% (Wisepill), and >85% (self-report) were estimated to have taken ≥4 PrEP doses/week (a threshold associated with protection among MSM). For all measures except self-report, adherence declined over time, with half of participants taking <2 doses/week by week 48.

Conclusions

Among youth on PrEP, adherence waned over time. Self-report overestimated adherence, and use of Wisepill was limited. Hair collection was highly acceptable and provided similar interpretations to DBS. Incorporation of either metric in future PrEP studies among youth could identify suboptimal adherence and trigger interventions.