16 research outputs found

    Population Modeling Highlights Drug Disposition Differences Between Tenofovir Alafenamide and Tenofovir Disoproxil Fumarate in the Blood and Semen

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    Understanding antiretroviral disposition in the male genital tract, a distinct viral compartment, can provide insight for the eradication of HIV. Population pharmacokinetic modeling was conducted to investigate the disposition of tenofovir disoproxil fumarate (TDF), tenofovir alafenamide (TAF), and emtricitabine and their metabolites in blood and semen. Blood plasma and seminal plasma (SP) concentrations of tenofovir and emtricitabine were measured, as were tenofovir-diphosphate and emtricitabine-triphosphate concentrations in peripheral blood mononuclear cells (PBMCs) and seminal mononuclear cells. Sequential compartmental modeling described drug disposition in blood and semen. Our modeling suggests slower elimination of apparent tenofovir-diphosphate PBMC and faster elimination of tenofovir SP after administration of TAF compared with TDF, likely reflecting flip-flop kinetics. Additionally, TAF metabolism to tenofovir appeared slower in semen compared with blood; however, SP elimination of TAF-derived tenofovir appeared faster than its blood plasma elimination. These findings provide valuable insight for further mechanistic study of cellular entry and drug metabolism in the male genital tract

    Differential Extracellular, but Similar Intracellular, Disposition of two Tenofovir Formulations in the Male Genital Tract

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    Background: The male genital tract (MGT) is a viral sanctuary and likely HIV reservoir; understanding MGT pharmacokinet-ics (PK) of antiretrovirals (ARVs) used for curative strategies is critical to eradication and cure. Tenofovir alafenamide (TAF) is a tenofovir (TFV) formulation designed to maximize efficacy/minimize toxicity with unknown MGT PK. Methods: HIV-positive and HIV-negative men receiving TFV-based regimens provided six paired blood plasma (BP) and semen samples. Extracellular (TFV, TAF, emtricitabine [FTC]) drug concentrations in BP and seminal plasma (SP), and intracellular metabolite (IM) and endogenous nucleotide (EN) concentrations were measured in peripheral blood mononuclear cells (PBMCs) and seminal mononuclear cells (SMCs). Exposure ratios for SP:BP, SMC:PBMC and IM:EN were calculated from PK parameters generated by noncompartmental analysis. HIV viral load was measured in BP and SP. Results: Sixteen HIV-positive (n=8, TDF/FTC; n=8, TAF/FTC) and eight HIV-negative (TDF/FTC) men provided samples. Median TFV SP:BP ratios differed between TDF and TAF (1.5 versus 7.4), due to lower TFV BP concentrations with TAF coupled with TFV SP concentrations similar to TDF. FTC SP:BP ratios were approximately 3. SMC concentrations of IMs and ENs were a fraction of PBMC concentrations (1–22%), though IM:EN ratios exceed a suggested protective threshold. Conclusions: TAF SP PK was unexpected. IM SMC concentrations were low relative to PBMC, as were EN concentrations, suggesting differences in cell phenotype and lineage in the MGT; these differences in phenotype and pharmacology may have an impact on selecting and dosing ARVs used in cure strategies

    Test accuracy of human papillomavirus in urine for detection of cervical intraepithelial neoplasia

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    The objective was to assess the diagnostic test accuracy of high-risk human papillomavirus (hrHPV) testing of self-collected urine and cervicovaginal samples for the detection of cervical intraepithelial neoplasia grade 2 or higher (CIN2+). We recruited a convenience sample of women 25 to 65 years of age who were undergoing clinically indicated colposcopy at two medical centers in North Carolina between November 2016 and January 2019. Women with normal cytology results and positive hrHPV results were also recruited. Urine samples, self-collected cervicovaginal samples, provider-collected cervical samples, and cervical biopsy samples were obtained from all enrolled women. Samples were tested for hrHPV DNA using the Onclarity assay (Becton Dickinson, Sparks, MD). Biopsy samples were histologically graded as CIN2+ or <CIN2. We calculated the sensitivity and specificity for detection of CIN2+ and assessed agreement between sample collection methods. We included 307 women (median age, 36 years) with valid histology results and triplematched urine, self-collected cervicovaginal, and provider-collected cervical hrHPV results; 83 women (27%) had CIN2+. Urine-based hrHPV testing correctly identified 80% of CIN2+ cases (95% confidence interval [CI], 71 to 88%) using the PCR cycle threshold (CT) established for provider-collected cervical samples, but sensitivity remained below the estimates for self-collected cervicovaginal and provider-collected cervical samples (both 94% [95% CI, 89 to 99%]). Using a higher CT cutoff value of ≤40, 90% sensitivity was achieved for urine-based hrHPV testing. Agreement between results for urine samples and self-collected cervicovaginal samples (kappa = 0.58) or provider-collected cervical samples (kappa = 0.54) was moderate. Urinebased hrHPV testing may be a promising approach to improve cervical cancer screening coverage, especially among women with limited access to health care

    Racial and Ethnic Differences in Acceptability of Urine and Cervico-Vaginal Sample Self-Collection for HPV-Based Cervical Cancer Screening

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    Background: We compared women's acceptability of urine and cervico-vaginal sample self-collection for high-risk (oncogenic) human papillomavirus (hrHPV) testing and assessed whether acceptability varied across racial/ethnic groups. Methods: As part of a test accuracy study of urine-based hrHPV testing, we recruited a convenience sample of women 25-65 years of age at two colposcopy clinics in North Carolina between November 2016 and January 2019. After self-collection of urine and cervico-vaginal samples, women completed a questionnaire on the acceptability of the sample collection methods. We coded open-ended questions inductively. All results are presented stratified by racial/ethnic group. Results: We included 410 women (119 Hispanic, 115 non-Hispanic Black, 154 non-Hispanic White, and 22 women with other racial identities). Most women (79%, 95% confidence interval [CI] = 76%-83%) had positive feelings about urine-based hrHPV testing. Women generally preferred urine (78%, 95% CI = 74%-82%) over cervico-vaginal self-collection (18%, 95% CI = 14%-22%), but the degree differed by racial/ethnic group, increasing from 75% in non-Hispanic Black to 82% in Hispanic women (p = 0.011). Most women reported at least one positive aspect of urine (89%) and cervico-vaginal self-collection (85%) for hrHPV testing with the most common positive aspect being easy sample collection, although 16% of women were concerned about performing the cervico-vaginal self-collection correctly. Conclusions: Self-collection for hrHPV-based cervical cancer screening is highly acceptable to women across different racial/ethnic groups in the United States, and most women in our study would be more likely to attend future cervical cancer screening appointments if screening were urine based. Urine-based hrHPV testing is a promising approach to improve cervical cancer screening coverage

    Extended HPV genotyping to compare hpv type distribution in self- And provider-collected samples for cervical cancer screening

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    Background: Primary high-risk human papillomavirus (hr- HPV) testing of self-collected cervico-vaginal swabs could increase cervical cancer screening coverage, although triage strategies are needed to reduce unnecessary colposcopies. We evaluated the use of extended hr-HPV genotyping of self-collected samples for cervical cancer screening. Methods: We recruited women ages 25-65 years at two colposcopy clinics in North Carolina between November 2016 and January 2019, and obtained self-collected cervico-vaginal samples, providercollected cervical samples, and cervical biopsies from all enrolled women. Self- and provider-collected samples were tested for 14 hr- HPV genotypes using the Onclarity Assay (Becton Dickinson). We calculated hr-HPV genotype-specific prevalence and assessed agreement between results in self- and provider-collected samples. We ranked the hr-HPV genotypes according to their positive predictive value (PPV) for the detection of cervical intraepithelial neoplasia (CIN) grade 2 or higher (CIN2+). Results: A total of 314 women participated (median age, 36 years); 85 women (27%) had CIN2+. More women tested positive for any hr-HPV on self-collected (76%) than on provider- collected samples (70%; P = 0.009) with type-specific agreement ranging from substantial to almost perfect. HPV-16 was the most common genotype in self-collected (27%) and provider-collected samples (20%), and HPV-16 prevalence was higher in self- than provider-collected samples (P < 0.001). In self- and provider-collected samples, HPV-16 had the highest PPV for CIN2+ detection. Conclusions: Overall sensitivity for CIN2+ detection was similar for both sample types, but the higher HPV-16 prevalence in self-collected samples could result in increased colposcopy referral rates. Impact: Additional molecular markers might be helpful to improve the triage of women who are hr-HPV positive on selfcollected samples

    Brief Report: Blood and Genital Fluid Viral Load Trajectories Among Treated and Untreated Persons With Acute HIV Infection in Malawi

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    Background: Persons with acute HIV infection (AHI) are highly infectious and responsible for a disproportionate share of incident infections. Immediate antiretroviral therapy (ART) rapidly reduces blood viral loads (VLs), but genital VLs after ART initiation during AHI are less well described. Setting: Lilongwe, Malawi, 2012-2014.Methods:HIV-seronegative and HIV-serodiscordant persons aged ≥18 years were screened for AHI (RNA positive) and randomized to standard of care, behavioral intervention, or behavioral intervention plus short-term ART (raltegravir/emtricitabine/tenofovir) (1:2:2). Persons who were ART eligible under Malawi guidelines could receive first-line therapy. Blood and genital VLs were assessed at weeks 1, 4, 8, and 12. Fisher's Exact test was used to compare viral suppression by ART status. Results: Overall, 46 persons with AHI were enrolled; of whom, 17 started ART within 12 weeks. Median blood VL at AHI diagnosis was 836,115 copies/mL. At week 12, 7% (1/14) of those who initiated ART had a blood VL of ≥400 copies/mL, compared with 100% (23/23; P < 0.0001) of those who did not initiate ART (median VL: 61,605 copies/mL). Median genital VL at week 1 was 772 copies/mL, with 13 of 22 (59%) having VL of ≥400 copies/mL. At week 12, 0 of 10 (0%) of those who initiated ART had genital VL of ≥400 copies/mL, compared with 7 of 15 (47%) of those who did not initiate ART (P = 0.02). Conclusion: Although highly correlated, VLs in blood and genital fluids occupy discrete biological compartments with distinct virologic dynamics. Our results corroborate the dramatic reduction in both compartments after ART initiation. Increasing AHI screening and rapidly initiating treatment is key to interrupting transmission

    Near Real-Time Identification of Recent Human Immunodeficiency Virus Transmissions, Transmitted Drug Resistance Mutations, and Transmission Networks by Multiplexed Primer ID–Next-Generation Sequencing in North Carolina

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    Background: The identification of recent human immunodeficiency virus (HIV) 1 infections among people with new HIV diagnoses is important to both tailoring and assessing the impact of HIV-1 prevention strategies. Methods: We developed a multiplexed Primer ID-next-generation sequencing approach to identify recent infections by measuring the intrahost viral diversity over multiple regions of the HIV-1 genome, in addition to detecting drug resistance mutations (DRMs) and phylogenetically linked clusters. We summarize the field implementation of this all-in-one platform among persons with newly diagnosed HIV-1 by the North Carolina State Laboratory of Public Health in 2018. Results: Overall, recent infection was identified in 94 (35%) of 268 patients with new HIV diagnoses. People <30 years old, and people who inject drugs were more likely to have diagnoses of recent infection. The reverse-transcriptase region K103N was the most commonly detected DRM (prevalence, approximately 15%). We found a total of 28 clusters, and persons with recent infection were more likely to be cluster members than were those with chronic infections (P =. 03). Conclusions: We demonstrate the rapid identification of recent infection and pretreatment DRMs coupled with cluster analysis that will allow prioritization of linkage to care, treatment, and prevention interventions to those at highest risk of onward transmission

    Female genital tract shedding of HIV-1 is rare in women with suppressed HIV-1 in plasma

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    Objective: Determine the frequency of genital HIV-1 shedding in a large cohort of women on long-term suppressive antiretroviral therapy (ART) and its association with mucosal inflammation.Design:We measured levels of HIV-1 RNA and inflammation biomarkers in cervicovaginal lavage (CVL) from HIV-seropositive women enrolled in the Women's Interagency HIV Study (WIHS).Methods:HIV-1 was quantified (Abbott RealTime HIV-1 assay) from CVL samples of 332 WIHS participants with and without clinical evidence of genital inflammation at the time of CVL collection; participants had suppressed plasma viral load (PVL; limit of quantitation less than 20-4000copies/ml depending on year of collection) for a median of 7.1 years [interquartile range (IQR) 3.4-9.8, Group 1] or for a median of 1.0 years (IQR=0.5-1.0, Group 2). Twenty-two biomarkers of inflammation were measured in CVL to compare with clinical markers.Results:HIV-1 was detected in 47% of 38 pre-ART CVL samples (median 668copies/ml) and detection in CVL was associated with higher pre-ART PVL. HIV-1 was detected in only 1 of 38 CVL samples from these women on suppressive antiretroviral therapy for 1 year. No HIV-1 RNA was detected in 294 CVL samples from a cross-sectional set of women with suppressed PVL for a median of 7 years. Clinical inflammation markers were correlated with inflammatory biomarkers in CVL specimens, although genital inflammation was not associated with measurable genital HIV-1 shedding in these WIHS participants on ART.Conclusion:ART that suppresses HIV-1 in the plasma of women also prevents genital tract HIV-1 shedding, even in the presence of genital tract inflammation. Copyright © 2019 The Author(s)
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