Abstract
Background
Antiretroviral drugs have been associated with changes in lipids, fat mass and dat distribution. Tenofovir disoproxil fumarate (TDF) has been shown to have a more favorable ...metabolic profile than other drugs in its class. However, the metabolic effects of TDF in preexposure prophylaxis (PrEP) are unknown.
Methods
We evaluated the effects of TDF/emtricitabine (FTC) on lipids and body composition in a blinded, placebo-controlled PrEP trial. Participants enrolled in a metabolic subcohort (N = 251, TDF/FTC; N = 247, placebo) consented to fasting lipid panels, dual-energy X-ray absorptiometry scans for body composition, and pharmacologic testing of drug metabolites at baseline and every 24 weeks thereafter.
Results
Lean body mass was stable and unaffected by TDF/FTC. Body weight increased in both groups but was lower on TDF/FTC through week 72. This difference was explained by lower fat accumulation on TDF/FTC. The net median percent difference (standard error, P value) for TDF/FTC vs placebo at week 24 was −0.8% (0.4%, P = .02), +0.3% (0.4%, P = .46), and −3.8% (1.4%, P = .009) for total, lean, and fat mass, respectively. There was no apparent differential regional fat accumulation on TDF/FTC. Decreases in cholesterol, but not triglycerides, were seen in TDF/FTC participants, with detectable drug levels compared to placebo.
Conclusions
TDF/FTC for PrEP showed cholesterol reductions and appeared to transiently suppress the accumulation of weight and body fat compared to placebo. There was no evidence of altered fat distribution or lipodystrophy during daily oral TDF/FTC PrEP.
Clinical Trials Registration
NCT00458393.
Preexposure prophylaxis (PrEP) with tenofovir disoproxil fumarate /emtricitabine (TDF/FTC) leads to small losses of body fat but does not appear to affect fat distribution or lean body mass. It does modestly lower lipid levels as observed in HIV treatment.
OBJECTIVE:To evaluate for changes in sexual behaviors associated with daily pill use among men who have sex with men (MSM) participating in a preexposure prophylaxis trial.
DESIGN:Randomized, ...double-blind, placebo-controlled trial. Participants were randomized 1:1:1:1 to receive tenofovir disoproxil fumarate or placebo at enrollment or after a 9-month delay and followed for 24 months.
METHODS:Four hundred HIV-negative MSM reporting anal sex with a man in the past 12 months and meeting other eligibility criteria enrolled in San Francisco, Atlanta, and Boston. Sexual risk was assessed at baseline and quarterly visits using Audio Computer-Assisted Self-Interview. The association of pill taking with sexual behavior was evaluated using logistic and negative-binomial regressions for repeated measures.
RESULTS:Overall indices of behavioral risk declined or remained stable during follow-up. Mean number of partners and proportion reporting unprotected anal sex declined during follow-up (P < 0.05), and mean unprotected anal sex episodes remained stable. During the initial 9 months, changes in risk practices were similar in the group that began pills immediately vs. those in the delayed arm. These indices of risk did not differ significantly after initiation of pill use in the delayed arm or continuation of study medication in the immediate arm. Use of poppers, amphetamines, and sexual performance–enhancing drugs were independently associated with one or more indices of sexual risk.
CONCLUSIONS:There was no evidence of risk compensation among HIV-uninfected MSM in this clinical trial. Monitoring for risk compensation should continue now that preexposure prophylaxis has been shown to be efficacious in MSM and other populations and will be provided in open-label trials and other contexts.
HLA tapasin independence Bashirova, Arman A.; Viard, Mathias; Naranbhai, Vivek ...
Proceedings of the National Academy of Sciences - PNAS,
11/2020, Volume:
117, Issue:
45
Journal Article
Peer reviewed
Open access
Human leukocyte antigen (HLA) class I allotypes vary in their ability to present peptides in the absence of tapasin, an essential component of the peptide loading complex.We quantified tapasin ...dependence of all allotypes that are common in European and African Americans (n = 97), which revealed a broad continuum of values. Ex vivo examination of cytotoxic T cell responses to the entire HIV-1 proteome from infected subjects indicates that tapasin-dependent allotypes present a more limited set of distinct peptides than do tapasin-independent allotypes, data supported by computational predictions. This suggests that variation in tapasin dependence may impact the strength of the immune responses by altering peptide repertoire size. In support of this model, we observed that individuals carrying HLA class I genotypes characterized by greater tapasin independence progress more slowly to AIDS and maintain lower viral loads, presumably due to increased breadth of peptide presentation. Thus, tapasin dependence level, like HLA zygosity, may serve as a means to restrict or expand breadth of the HLA-I peptide repertoire across humans, ultimately influencing immune responses to pathogens and vaccines.
Full text
Available for:
BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Background. Blinded clinical trials have reported a modest and transient "start-up syndrome" with initiation of tenofovir-based pre-exposure prophylaxis (PrEP). We evaluate this phenomenon and its ...effect on adherence in an open-label PrEP study. Methods. In the iPrEx open-label extension (OLE) study, an 18-month open-label, multi-site PrEP cohort taking daily oral coformulated tenofovir/emtricitabine, we examined the prevalence and duration of PrEP-associated symptoms and their effect on adherence, assessed by drug levels in dried blood spots tested monthly for the first 3 months. Results. Symptom reports peaked within the first month, with 39% reporting potentially PrEP-related symptoms compared to 22% at baseline. Symptoms largely resolved to pre-PrEP levels by 3 months. Symptoms varied substantially in frequency by study site (range in 1-month symptoms: 11% to 70%). Nongastrointestinal (GI) symptoms were not associated with adherence (odds ratio OR = 1.2, 95% confidence interval CI, .4–3.7); however, GI-associated symptoms in the first 4 weeks were inversely associated with adherence at 4 weeks (OR = 0.47, 95% CI, .23–.96). Reports of GI symptoms were associated with 7% (95% CI, 4%–11%) of suboptimal adherence in this cohort. Conclusions. PrEP-associated symptoms in the open-label setting occur in a minority of users and largely resolve within 3 months. GI symptoms are associated with a modest reduction in PrEP adherence, but good adherence is possible even in the presence of frequent symptom reports. Clinical Trials Registration. Clinicaltrials.gov NCT00458393.
Background: Young men who have sex with men and transgender women (YMSM/TGW) have disproportionately high HIV incidence and lower PrEP adherence. Point-of-care (POC) urine tenofovir (TFV) rapid assay ...(UTRA) testing permits real-time monitoring for nonadherence within clinical settings. We performed UTRA testing among PrEP users to examine the relationship between low PrEP adherence and future PrEP discontinuation, and the accuracy of POC testing compared to gold-standard liquid chromatography tandem mass spectrometry (LC/MS/MS). Methods: YMSM/TGW participants (n = 100) were recruited during a daily PrEP visit. Logistic regression models analyzed the relationship between the primary predictor of urine POC assay results (cutoff 1,500 ng/mL) and the primary outcome of PrEP discontinuation, defined as no PrEP follow-up or prescription within 120 days. Results: Overall, 19% of participants had low urine TFV and 21% discontinued PrEP, while 11% of participants self-reported low PrEP adherence (< 4 pills per week), which was only 43% sensitive/84% specific in predicting low TFV levels and was not associated with PrEP discontinuation. Low urine TFV level predicted PrEP discontinuation (AOR 6.1; 95% CI: 1.4–11; p = 0.005) and was 71% sensitive/90% specific for discontinuation after 120 days. Compared to LC/MS/MS, UTRA testing had a 98% positive and 100% negative predictive value. Conclusions: In a sample of YMSM/TGW on daily PrEP, POC UTRA testing predicted PrEP discontinuation more accurately than self-reported adherence, with high predictive values compared to LC/MS/MS. UTRA testing may be a clinical tool for directing preventive interventions towards those likelier to discontinue PrEP despite ongoing HIV vulnerability.
Pre-exposure prophylaxis (PrEP) for HIV prevention is a promising experimental approach currently being tested globally. A number of PrEP trials are evaluating the safety and effectiveness of PrEP in ...men who have sex with men (MSM) and other populations at risk for HIV, and results will be available from this first generation of efficacy trials over the next few years. Here we review the rationale for orally-administered antiretrovirals for prevention, and outline issues the first generation trials will address as well as questions that may be addressed in future studies. We also describe the rationale for combination prevention approaches that may combine PrEP with other prevention modalities as part of a larger prevention package.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, VSZLJ, ZAGLJ
ABSTRACTCurrent strategies to prevent sexually transmitted infections (STIs) are not controlling the epidemic. The efficacy of doxycycline STI postexposure prophylaxis shows promise in pilot studies, ...but wider acceptability is unknown. A majority (84%) of diverse individuals using a gay social networking application were interested in doxycycline STI postexposure prophylaxis. Doxycycline STI postexposure prophylaxis should be examined in larger trials.
Three trials have demonstrated the prophylactic effect of male circumcision (MC) for HIV acquisition among heterosexuals, and MC interventions are underway throughout sub-Saharan Africa. Similar ...efforts for men who have sex with men (MSM) are stymied by the potential for circumcised MSM to acquire HIV easily through receptive sex and transmit easily through insertive sex. Existing work suggests that MC for MSM should reach its maximum potential in settings where sexual role segregation is historically high and relatively stable across the lifecourse; HIV incidence among MSM is high; reported willingness for prophylactic circumcision is high; and pre-existing circumcision rates are low. We aim to identify the likely public health impact that MC interventions among MSM would have in one setting that fulfills these conditions-Peru-as a theoretical upper bound for their effectiveness among MSM generally.
We use a dynamic, stochastic sexual network model based in exponential-family random graph modeling and parameterized from multiple behavioral surveys of Peruvian MSM. We consider three enrollment criteria (insertive during 100%, >80% or >60% of UAI) and two levels of uptake (25% and 50% of eligible men); we explore sexual role proportions from two studies and different frequencies of switching among role categories. Each scenario is simulated 10 times. We estimate that efficiency could reach one case averted per 6 circumcisions. However, the population-level impact of an optimistic MSM-MC intervention in this setting would likely be at most ∼5-10% incidence and prevalence reductions over 25 years.
Roll-out of MC for MSM in Peru would not result in a substantial reduction in new HIV infections, despite characteristics in this population that could maximize such effects. Additional studies are needed to confirm these results for other MSM populations, and providers may consider the individual health benefits of offering MC to their MSM patients.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
OBJECTIVE:We examined the relationship between urine tenofovir (TFV) levels measured with a novel immunoassay, which permits point-of-care testing, with HIV seroconversion and objective adherence ...metrics in a large preexposure prophylaxis (PrEP) demonstration project.
DESIGN:Secondary analysis of stored specimens from an open-label PrEP cohort study.
METHODS:We examined the association between undetectable urine TFV levels and HIV seroconversion in iPrEx open-label extension using generalized estimating equations. We examined rank correlations between levels of TFV and emtricitabine in urine, dried blood spots (DBS), and hair and determined the sensitivity and specificity of undetectable urine TFV for predicting dosing cut-offs in DBS.
RESULTS:The median urinary TFV level was 15 000 ng/ml in those who remained HIV-negative (n = 105; interquartile range1000–45 000); 5500 in those who eventually seroconverted (n = 11; interquartile range1000–12 500); and all were undetectable at seroconversion (n = 9; P < 0.001). Decreasing strata of urine TFV levels were associated with future HIV seroconversion (P = 0.03). An undetectable urine TFV was 100% sensitive and 81% specific when compared with an undetectable DBS TFV-diphosphate level and 69% sensitive, but 94% specific when compared with low adherence by DBS (<2 doses/week).
CONCLUSION:Urine TFV detection by a novel antibody-based assay was associated with protection from HIV acquisition among individuals on PrEP. Urine TFV levels were correlated with hair and DBS levels and undetectable urine TFV was 100% sensitive in detecting nonadherence. By implementing the immunoassay into a point-of-care strip test, PrEP nonadherence could be detected in real-time, allowing rapid intervention.
Abstract
Background
After coronavirus disease 2019 (COVID-19) shelter-in-place (SIP) orders, viral suppression (VS) rates initially decreased within a safety-net human immunodeficiency virus (HIV) ...clinic in San Francisco, particularly among people living with HIV (PLWH) who are experiencing homelessness. We sought to determine if proactive outreach to provide social services, scaling up of in-person visits, and expansion of housing programs could reverse this decline.
Methods
We assessed VS 24 months before and 13 months after SIP using mixed-effects logistic regression followed by interrupted time series (ITS) analysis to examine changes in the rate of VS per month. Loss to follow-up (LTFU) was assessed via active clinic tracing.
Results
Data from 1816 patients were included; the median age was 51 years, 12% were female, and 14% were experiencing unstable housing/homelessness. The adjusted odds of VS increased 1.34 fold following institution of the multicomponent strategies (95% confidence interval CI, 1.21–1.46). In the ITS analysis, the odds of VS continuously increased 1.05 fold per month over the post-intervention period (95% CI, 1.01–1.08). Among PLWH who previously experienced homelessness and successfully received housing support, the odds of VS were 1.94-fold higher (95% CI, 1.05–3.59). The 1-year LTFU rate was 2.8 per 100 person-years (95% CI, 2.2–3.5).
Conclusions
The VS rate increased following institution of the multicomponent strategies, with a lower LFTU rate compared with prior years. Maintaining in-person care for underserved patients, with flexible telemedicine options, along with provision of social services and permanent expansion of housing programs, will be needed to support VS among underserved populations during the COVID-19 pandemic.
After an initial destabilization following coronavirus disease 2019 shelter-in-place orders, human immunodeficiency virus viral suppression increased with the institution of intensified social services outreach, expanded housing programs, and scaling up of in-person visits while maintaining telemedicine options, assessed via an interrupted time series analysis.
PDF
