Intracellular Tenofovir and Emtricitabine Concentrations in Younger and Older Women with HIV Receiving Tenofovir Disoproxil Fumarate/Emtricitabine

Cellular pharmacology of tenofovir alafenamide and emtricitabine in neutrophils and platelets in people with and without HIV

BACKGROUND

Previous studies have primarily focused on nucleos(t)ide reverse transcriptase inhibitor pharmacology in peripheral blood mononuclear cells (PBMCs) and erythrocytes via dried blood spots (DBS), but not other major blood cells.

OBJECTIVES

Our objectives were to describe and compare the concentrations of tenofovir-diphosphate (TFV-DP) and emtricitabine-triphosphate (FTC-TP) in DBS, PBMCs, neutrophils, and platelets in people with HIV (PWH) and people without HIV (PWOH).

METHODS

DBS, PBMCs, neutrophils, and platelets were isolated from whole blood drawn from PWH and PWOH receiving tenofovir alafenamide and emtricitabine. TFV-DP and FTC-TP concentrations were quantified using LC-MS/MS in each cell type. Linear regression models controlled for time on drug, adherence, and time since last dose, where applicable, to determine geometric mean percent differences (95% confidence interval) by HIV status and estimated half-lives.

RESULTS

Data were available in 13 PWH (96% male) and 30 PWOH (53% male). Compared with PWOH, TFV-DP in DBS was 48.9% (15.6%, 91.9%) higher and FTC-TP in platelets was 36.3% (4.5%, 77.7%) higher; TFV-DP in platelets also trended higher [43.5% (-3.24%, 113%)]. No other cell types significantly differed by HIV status. TFV-DP and FTC-TP demonstrated the longest half-lives in neutrophils, followed by PBMCs and then platelets. After normalizing to cell volume, both drugs accumulated from greatest to least in PBMCs, neutrophils, platelets, and erythrocytes across both PWH and PWOH.

CONCLUSIONS

Our findings highlight differential drug disposition across cell types that also vary by serostatus in DBS and platelets. The mechanisms and implications of these findings require additional research.

A Cross-Biomeasure Study to Optimize Antiretroviral Adherence Estimation

BACKGROUND

Incomplete adherence to daily tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) reduces effectiveness. Adherence biomeasures (ie, drug concentrations in biological specimen) are more accurate than self-report. TDF/FTC's intracellular active metabolites (tenofovir-diphosphate; TFVdp and FTC-triphosphate; FTCtp) can be quantified in different types of blood samples to estimate adherence. To optimize adherence estimation, we investigated approaches to measure TFVdp and FTCtp in 4 blood matrices.

METHODS

Twelve HIV-negative, healthy volunteers were enrolled in a single-center, open-label, 3-phase, directly observed therapy study. LC-MS/MS methods quantified TFVdp/FTCtp in dried blood spots, volumetrically accurate microsampling, upper layer packed cells, and peripheral blood mononuclear cells (PBMCs). Noncompartmental analysis estimated half-lives and accumulation ratios. Correlations characterized relationships between clinical variables and exposure. Regression models were fit to determine concentrations associated with <4 and ≥4 doses/week; correct classification percentages were determined.

RESULTS

Terminal half-life estimates of 3-4 vs 15-22 days distinguished between moderate-term (FTCtp in all samples; TFVdp in PBMCs) versus long-term (TFVdp in red blood cell-containing matrices) measures. Model-derived thresholds accurately categorized <4 and ≥4 doses/week when including both metabolites for 14- and 28-day dosing periods (81%-91% and 82%-85%, respectively). Within each classification and regression trees analyses containing both moderate- and long-term measures, dried blood spots exhibited highest accuracy to predict stable (74%-94%) and changing (42%-47%) adherence patterns.

CONCLUSIONS

We demonstrate higher accuracy of moderate-term biomeasures to classify adherence over a 14-day period compared with long-term biomeasures to classify adherence over a 28-day period. Combined moderate- and long-term biomeasures predicted stable and changing adherence patterns, with dried blood spots exhibiting highest accuracy.

A Systematic Review and Meta-Analysis of Social Cognition Among People Living with HIV: Implications for Non-Social Cognition and Social Everyday Functioning

Social cognition-the complex mental ability to perceive social stimuli and negotiate the social environment-has emerged as an important cognitive ability needed for social functioning, everyday functioning, and quality of life. Deficits in social cognition have been well documented in those with severe mental illness including schizophrenia and depression, those along the autism spectrum, and those with other brain disorders where such deficits profoundly impact everyday life. Moreover, subtle deficits in social cognition have been observed in other clinical populations, especially those that may have compromised non-social cognition (i.e., fluid intelligence such as memory). Among people living with HIV (PLHIV), 44% experience cognitive impairment; likewise, social cognitive deficits in theory of mind, prosody, empathy, and emotional face recognition/perception are gradually being recognized. This systematic review and meta-analysis aim to summarize the current knowledge of social cognitive ability among PLHIV, identified by 14 studies focused on social cognition among PLHIV, and provides an objective consensus of the findings. In general, the literature suggests that PLHIV may be at-risk of developing subtle social cognitive deficits that may impact their everyday social functioning and quality of life. The causes of such social cognitive deficits remain unclear, but perhaps develop due to (1) HIV-related sequelae that are damaging the same neurological systems in which social cognition and non-social cognition are processed; (2) stress related to coping with HIV disease itself that overwhelms one's social cognitive resources; or (3) may have been present pre-morbidly, possibly contributing to an HIV infection. From this, a theoretical framework is proposed highlighting the relationships between social cognition, non-social cognition, and social everyday functioning.

Pharmacokinetic Model of Tenofovir and Emtricitabine and Their Intracellular Metabolites in Patients in the ANRS 134-COPHAR 3 Trial Using Dose Records

Tenofovir (TFV) and emtricitabine (FTC) are part of the recommended highly active antiretroviral therapy (ART). Both molecules show a large interindividual pharmacokinetic (PK) variability. Here, we modeled the concentrations of plasma TFV and FTC and their intracellular metabolites (TFV diphosphate [TFV-DP] and FTC triphosphate [FTC-TP]) collected after 4 and 24 weeks of treatment in 34 patients from the ANRS 134-COPHAR 3 trial. These patients received daily (QD) atazanavir (300 mg), ritonavir (100 mg), and a fixed-dose combination of coformulated TFV disoproxil fumarate (300 mg) and FTC (200 mg). Dosing history was collected using a medication event monitoring system. A three-compartment model with absorption delay (Tlag) was selected to describe the PK of, respectively, TFV/TFV-DP and FTC/FTC-TP. TFV and FTC apparent clearances, 114 L/h (relative standard error [RSE] = 8%) and 18.1 L/h (RSE = 5%), respectively, were found to decrease with age. However, no significant association was found with the polymorphisms ABCC2 rs717620, ABCC4 rs1751034, and ABCB1 rs1045642. The model allows prediction of TFV-DP and FTC-TP concentrations at steady state with alternative regimens.

Genital Inflammation Is Not Associated With Decreased Vaginal Tenofovir Concentrations in Women Taking Oral PrEP

BACKGROUND

We evaluated the association of inflammation and dysbosis on cervicovaginal fluid (CVF) tenofovir (TFV) concentrations in women taking oral tenofovir disoproxil fumarate/emtricitable for HIV pre-exposure prophylaxis (PrEP) in the United States.

SETTING

Thirty-five women in a HIV PrEP implementation study attended their week 24 visit at a San Diego research clinic and provided CVF specimens.

METHODS

Women in the Adherence Enhancement Guided by Individualized Texting and Drug Levels study had their CVF specimens evaluated for (1) sexually transmitted bacterial (Neisseria gonorrhoeae, Chlamydia trachomatis, Gardnerella, and Trichomonas vaginalis), viral (human papillomavirus, cytomegalovirus and herpes simplex virus-1/2) and fungal (Candida) infections; (2) microbiome composition by 16 S sequencing (V3-V4 region); and (3) cytokine profiles by enzyme-linked immunoassay (Interleukin-8, macrophage Inflammatory protein-1a, macrophage Inflammatory Protein-1b and interferon-γ-inducible protein-10). Univariate statistical analysis was used to determine factors associated with CVF TFV concentrations. CVF TFV of 100-1000 ng/mL benchmarked typical genital concentrations and TFV-diphosphate in dried blood spots of 700 fmol/punch was considered adequate adherence.

RESULTS

Thirty-five women had CVF specimens collected. No factor was associated with CVF TFV concentrations or discordance of blood and vaginal concentrations. Among 27 participants assessed for vaginosis (Candida, Gardnerella or Trichomonas), women with Gardnerella (n = 11) were more likely to have high (>1000 ng/mL) CVF TFV concentrations (82% versus 33%, P = 0.02).

CONCLUSIONS

Presence of genital viruses, cytokines, or vaginal community state types were not associated with low CVF TFV concentrations in cisgender women taking oral tenofovir disoproxil fumarate/emtricitable for PrEP. The surprising association observed between presence of Gardnerella and higher vaginal TFV concentrations needs further evaluation.

Current Considerations for Clinical Management and Care of People with HIV: Findings from the 11th Annual International HIV and Aging Workshop

The number of people with HIV (PWH) aged 50 years or older continues to steadily increase. The convergence of age- and HIV-related complications in these individuals presents a challenge for both patients and clinicians alike. New findings continue to emerge, as numerous researchers evaluate the combined impact of these two factors on quality of life, physiological systems, and mental health in PWH. Since its first occurrence in 2009, the International Workshop on HIV and Aging has served as a multidisciplinary meeting to share basic biomedical data, clinical trial results, treatment strategies, and epidemiological recommendations, toward better understanding and outcomes among like-minded scientific professionals. In this article, we share a selection of key findings presented in plenary talks at the 11th Annual International Workshop on HIV and Aging, held virtually from September 30, 2020 to October 2, 2020. We will also address the future directions of HIV and aging research, to further assess how the aging process intersects with chronic HIV.