Plasma HIV viral rebound following protocol-indicated cessation of ART commenced in primary and chronic HIV infection

New latency-promoting agents for a block-and-lock functional cure strategy

PURPOSE OF REVIEW

Currently, HIV-infected patients are treated with antiretroviral therapy. However, when the treatment is interrupted, viral rebound occurs from latently infected cells. Therefore, scientists aim to develop an HIV-1 cure which eradicates or permanently silences the latent reservoir.

RECENT FINDINGS

Previously, scientists focused on the shock-and-kill cure strategy, which aims to eradicate the latent reservoir using latency-reactivating agents. Limited success shifts the interest towards the block-and-lock cure approach, which aims to achieve a functional cure by "blocking" HIV-1 transcription and "locking" the provirus in a deep latent state, resistant to treatment-interruption. In this strategy, latency promoting agents are used to induce transcriptional silencing and alter the epigenetics environment at the HIV promotor.

SUMMARY

For the block-and-lock cure strategy to succeed more investigation into the transcriptional and epigenetic regulation of HIV-1 gene expression is necessary to design optimal latency-promoting agents. In this review, we will discuss the latency promoting agents that have been described in literature during the past 2 years (2022-2023).

Novel Aptamers for the Reactivation of Latent HIV

INTRODUCTION

A "Shock and Kill" strategy has been proposed to eradicate the HIV latent viral reservoir. Effective Latency Reversal Agents (LRA) are a key requirement for this strategy. The search for LRAs with a novel mechanism of action is ongoing. This is the first study to propose aptamers for the reactivation of HIV.

OBJECTIVE

The purpose of this study was to identify an aptamer that potentially reactivates HIV via the NF-κβ pathway, specifically by binding to IkB and releasing NF-κβ.

METHODS

Aptamer selection was performed at Aptus Biotech (www.aptusbiotech.es), using ikB human recombinant protein with His tag bound to Ni-NTA agarose resin using the SELEX procedure. Activation of NF-κβ was measured by SEAP Assay. HIV reactivation was measured in JLat cells using a BD FACS-Canto™ II flow cytometer. All flow cytometry data were analyzed using Kaluza analyzing software.

RESULTS

Clones that had equivalent or greater activation than the positive control in the SEAP assay were regarded as potential reactivators of the NF-κβ pathway and were sequenced. The three ikb clones namely R6-1F, R6-2F, and R6-3F were found to potentially activate the NF-κβ pathway. Toxicity was determined by exposing lymphocytes to serial dilutions of the aptamers; the highest concentration of the aptamers that did not decrease viability by > 20% was used for the reactivation experiments. The three novel aptamers R6-1F, R6-2F, and R6-3F resulted in 4,07%, 6,72% and 3,42% HIV reactivation, respectively, while the untreated control showed minimal (<0.18%) fluorescence detection.

CONCLUSION

This study demonstrated the reactivation of latent HIV by aptamers that act via the NF-κβ pathway. Although the effect was modest and unlikely to be of clinical benefit, future studies are warranted to explore ways of enhancing reactivation.

The Role of Pannexin-1 Channels in HIV and NeuroHIV Pathogenesis

The human immunodeficiency virus-1 (HIV) enters the brain shortly after infection, leading to long-term neurological complications in half of the HIV-infected population, even in the current anti-retroviral therapy (ART) era. Despite decades of research, no biomarkers can objectively measure and, more importantly, predict the onset of HIV-associated neurocognitive disorders. Several biomarkers have been proposed; however, most of them only reflect late events of neuronal damage. Our laboratory recently identified that ATP and PGE₂, inflammatory molecules released through Pannexin-1 channels, are elevated in the serum of HIV-infected individuals compared to uninfected individuals and other inflammatory diseases. More importantly, high circulating ATP levels, but not PGE₂, can predict a decline in cognition, suggesting that HIV-infected individuals have impaired ATP metabolism and associated signaling. We identified that Pannexin-1 channel opening contributes to the high serological ATP levels, and ATP in the circulation could be used as a biomarker of HIV-associated cognitive impairment. In addition, we believe that ATP is a major contributor to chronic inflammation in the HIV-infected population, even in the anti-retroviral era. Here, we discuss the mechanisms associated with Pannexin-1 channel opening within the circulation, as well as within the resident viral reservoirs, ATP dysregulation, and cognitive disease observed in the HIV-infected population.

UK guideline for the use of HIV post-exposure prophylaxis 2021

We present the updated British Association for Sexual Health and HIV (BASHH) guidelines for post-exposure prophylaxis (PEP) to HIV following sexual exposures, occupational exposures and other nonoccupational exposures in the community. This serves as an update to the 2015 BASHH guideline on PEP following sexual exposures and the 2008 Expert Advisory Group on AIDS guidelines on HIV PEP. We aim to provide evidence-based guidance on best clinical practice in the provision, monitoring and support of PEP for the prevention of HIV acquisition following sexual, occupational and other nonoccupational exposures in the community. The guideline covers when to prescribe PEP, what antiretroviral agents to use and how to manage PEP. This includes (i) evidence of PEP efficacy; (ii) evidence relating to individual-level efficacy of antiretroviral therapy to prevent the sexual transmission of HIV; (iii) data on the detectable (transmissible) prevalence of HIV in specific populations; (iv) risk of HIV transmission following different types of sexual and occupational exposure; (v) baseline risk assessment; (vi) drug regimens and dosing schedules; (vii) monitoring PEP; (viii) baseline and follow-up blood-borne virus testing; (ix) the role of PEP within broader HIV prevention strategies, for example, HIV pre-exposure prophylaxis (PrEP). The guideline also covers special scenarios such as PEP in pregnancy, breastfeeding and chronic hepatitis B virus infection, and when PEP should be considered in people using HIV PrEP. The guidelines are aimed at clinical professionals directly involved in PEP provision and other stakeholders in the field. A proforma to assist PEP consultations is included. A public consultation process was undertaken prior to finalizing the recommendations.

Natural Killer Cell Receptors and Ligands Are Associated With Markers of HIV-1 Persistence in Chronically Infected ART Suppressed Patients

The latent HIV-1 reservoir represents a major barrier to achieving a long-term antiretroviral therapy (ART)-free remission or cure for HIV-1. Natural Killer (NK) cells are innate immune cells that play a critical role in controlling viral infections and have been shown to be involved in preventing HIV-1 infection and, in those who are infected, delaying time to progression to AIDS. However, their role in limiting HIV-1 persistence on long term ART is still uncharacterized. To identify associations between markers of HIV-1 persistence and the NK cell receptor-ligand repertoire, we used twin mass cytometry panels to characterize the peripheral blood NK receptor-ligand repertoire in individuals with long-term antiretroviral suppression enrolled in the AIDS Clinical Trial Group A5321 study. At the time of testing, participants had been on ART for a median of 7 years, with virological suppression <50 copies/mL since at most 48 weeks on ART. We found that the NK cell receptor and ligand repertoires did not change across three longitudinal samples over one year-a median of 25 weeks and 50 weeks after the initial sampling. To determine the features of the receptor-ligand repertoire that associate with markers of HIV-1 persistence, we performed a LASSO normalized regression. This analysis revealed that the NK cell ligands CD58, HLA-B, and CRACC, as well as the killer cell immunoglobulin-like receptors (KIRs) KIR2DL1, KIR2DL3, and KIR2DS4 were robustly predictive of markers of HIV-1 persistence, as measured by total HIV-1 cell-associated DNA, HIV-1 cell-associated RNA, and single copy HIV-RNA assays. To characterize the roles of cell populations defined by multiple markers, we augmented the LASSO analysis with FlowSOM clustering. This analysis found that a less mature NK cell phenotype (CD16⁺CD56^dimCD57^-LILRB1^-NKG2C^-) was associated with lower HIV-1 cell associated DNA. Finally, we found that surface expression of HLA-Bw6 measured by CyTOF was associated with lower HIV-1 persistence. Genetic analysis revealed that this was driven by lower HIV-1 persistence in HLA-Bw4/6 heterozygotes. These findings suggest that there may be a role for NK cells in controlling HIV-1 persistence in individuals on long-term ART, which must be corroborated by future studies.

Serodiscordance predictors among couples in the HIV context: implications for health care

Background

After HIV diagnosis, people maintain, reestablish their sexual lives, or build new relationships, often with HIV seronegative partners. Therefore, understanding the factors concerning couple-vulnerability is essential in order to design effective HIV preventive strategies. We examined HIV serodiscordant couples prevalence and their associated factors from a Brazilian city.

Methods

This is a cross-sectional analytical study carried out with people living with HIV (PLHIV) who had an active sex life and were engagement in HIV health care follow-up. Data were collected using a semi-structured questionnaire during individual interviews. We analyzed data using bivariate and multiple logistic regression analyses.

Results

There was 72.0% of HIV serodiscordant partnerships. Those who inconsistently used condoms (aOR: 0.3[0.13–0.7]) and/or had HIV detectable viral load (aOR: 0.29 [0.12–0.7]) were less likely to have an HIV serodiscordant sexual partner. On other hand, the lack of HIV transmission counseling by the health service (aOR: 5.08 [2.02–12.76]), or those who had a casual partner (aOR: 8.12 [1.7–38.8]) or a steady and casual one concomitantly (aOR: 24.82 [1.46–420.83]), were more likely to indicate an HIV serodiscordant partnership.

Conclusion

The findings showed a high prevalence of serodiscordant partnerships in PLHIV. Greater visibility among couples in the health services is needed as well as a reassessment in order to provide PLHIV and their sexual partners with care strategies, by the health professionals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11835-0.

Rapid initiation of darunavir/cobicistat/emtricitabine/tenofovir alafenamide in acute and early HIV-1 infection: a DIAMOND subgroup analysis

BACKGROUND

Treatment during acute or early human immunodeficiency virus (HIV)-1 infection is associated with immunologic and virologic benefits.

OBJECTIVE

To evaluate darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) efficacy/safety among patients with acute or early HIV-1 infection who rapidly initiate treatment.

METHODS

DIAMOND (ClinicalTrials.gov Identifier: NCT03227861), a phase 3 study, evaluated the efficacy/safety of D/C/F/TAF 800/150/200/10 mg in rapid initiation. Adults aged ≥18 years began D/C/F/TAF within 14 days of diagnosis, prior to the availability of screening/baseline laboratory results. In this subgroup analysis, virologic response (HIV-1 RNA <50 copies/mL) was assessed at Week 48 by intent-to-treat FDA snapshot (ITT-FDA snapshot) and observed (excluding patients with missing data) analyses in patients with acute (HIV-1 antibody negative and HIV-1 RNA positive/p24 positive) or early (HIV-1 antibody positive and suspected infection ≤6 months before screening/baseline) infection.

RESULTS

Among 109 patients, 13 had acute and 43 had early HIV-1 infection. High rates of virologic response were demonstrated at Week 48 by ITT-FDA snapshot (acute: 10/13 [76.9%]; early: 37/43 [86.0%]) and observed (acute: 10/11 [90.9%]; early: 37/38 [97.4%]) analyses. No patients discontinued or required regimen change due to baseline resistance or lack of efficacy, or developed protocol-defined virologic failure. Through Week 48, 7 (53.8%) acute and 22 (51.2%) early infection patients had a D/C/F/TAF-related adverse event (AE); none had a D/C/F/TAF-related grade 4 or serious AE.

CONCLUSIONS

High rates of viral suppression during acute/early infection were achieved with D/C/F/TAF rapid initiation, no treatment-emergent resistant mutations were observed, and D/C/F/TAF was safe and well tolerated.

Exploring the Association Between the Quality of HIV Care in Nursing Homes and Hospitalization

ABSTRACT

Persons living with HIV/AIDS (PLWH) are living long enough to need age-related and HIV-related nursing home (NH) care. Nursing home quality of care has been associated with risk for hospitalization, but it is unknown if quality of HIV care in NHs affects hospitalization in this population. We assessed HIV care quality with four national measures adapted for the NH setting. We applied the measures to 2011-2013 Medicare claims linked to Minimum Data Set assessments of resident health, prescription dispensing data, and national reports of NH characteristics. Cox proportional hazards models calculated the risk of all-cause and HIV/AIDS-related hospitalization by HIV care compliance. We identified 1,246 PLWH in 201 NHs with 382 all-cause and 63 HIV/AIDS-related hospitalizations. Nursing home HIV care compliance varied from 24.9% to 64.7%. After regression adjustment, we could detect no difference in all-cause or HIV/AIDS-related hospitalizations by NH HIV care compliance. We postulate that the lack of association may be due to inappropriate HIV care quality measures that do not accurately represent NHs ability to care for PLWH. There is urgent need to create valid NH HIV care quality measures.

Block-And-Lock: New Horizons for a Cure for HIV-1

HIV-1/AIDS remains a global public health problem. The world health organization (WHO) reported at the end of 2019 that 38 million people were living with HIV-1 worldwide, of which only 67% were accessing antiretroviral therapy (ART). Despite great success in the clinical management of HIV-1 infection, ART does not eliminate the virus from the host genome. Instead, HIV-1 remains latent as a viral reservoir in any tissue containing resting memory CD4⁺ T cells. The elimination of these residual proviruses that can reseed full-blown infection upon treatment interruption remains the major barrier towards curing HIV-1. Novel approaches have recently been developed to excise or disrupt the virus from the host cells (e.g., gene editing with the CRISPR-Cas system) to permanently shut off transcription of the virus (block-and-lock and RNA interference strategies), or to reactivate the virus from cell reservoirs so that it can be eliminated by the immune system or cytopathic effects (shock-and-kill strategy). Here, we will review each of these approaches, with the major focus placed on the block-and-lock strategy.

Efficacy, pharmacokinetics and neurocognitive performance of dual, NRTI-sparing antiretroviral therapy in acute HIV-infection

OBJECTIVES

The aim of this study was to evaluate penetration of antiretrovirals into compartments and efficacy of a dual, NRTI-sparing regimen in acute HIV infection (AHI).

DESIGN

Single-arm, open-label pilot study of participants with AHI initiating ritonavir-boosted darunavir 800 mg once daily and etravirine 400 mg once daily or 200 mg twice daily within 30 days of AHI diagnosis.

METHODS

Efficacy was defined as HIV RNA less than 200 copies/ml by week 24. Optional sub-studies included pharmacokinetics analysis from genital fluids (weeks 0-4, 12, 48), cerebrospinal fluid (CSF) (weeks 2-4, 24 and 48) and endoscopic biopsies (weeks 4-12 and 36-48). Neuropsychological performance was assessed at weeks 0, 24 and 48.

RESULTS

Fifteen AHI participants were enrolled. Twelve (80%) participants achieved HIV RNA less than 200 copies/ml by week 24. Among 12 participants retained through week 48, nine (75%) remained suppressed to less than 50 copies/ml. The median time from ART initiation to suppression less than 200 and less than 50 copies/ml was 59 and 86 days, respectively. The penetration ratios for etravirine and darunavir in gut associated lymphoid tissue were 19.2 and 3.05, respectively. Most AHI participants achieving viral suppression experienced neurocognitive improvement. Of the three participants without overall improvement in neurocognitive functioning as measured by impairment ratings (more than two tests below 1 SD), two had virologic failure.

CONCLUSION

NRTI-sparing ART started during AHI resulted in rapid viral suppression similar to NRTI-based regimens. More novel and compact two-drug treatments for AHI should be considered. Early institution of ART during AHI appears to improve overall neurocognitive function and may reduce the risk of subsequent neurocognitive impairment. CLINICALTRIALS.GOV:: NCT00855413.

No HIV-1 molecular evolution on long-term antiretroviral therapy initiated during primary HIV-1 infection

OBJECTIVE

Most studies about HIV-1 molecular evolution have shown the lack of viral evolution on effective antiretroviral therapy (ART), although controversial results have been documented. We therefore aimed to look for evidence of HIV-1 evolution in patients who initiated ART at the time of primary HIV-1 infection (PHI).

DESIGN

We included retrospectively 20 patients diagnosed at PHI, treated at the time of acute infection and with subsequent effective long-term suppressive ART (HIV viral load <20 copies/ml during at least 5 years without any blips).

METHODS

Longitudinal blood samples were deep sequenced using Illumina Miseq. Drug-resistance-associated mutations were retained at 2% cutoff and interpreted using the latest Agence Nationale de Recherches sur le Sida et les Hépatites Virales resistance algorithm. Viral evolution was established when temporal structure on maximum-likelihood phylogenetic tree and significant change over time of HIV-1 genetic diversity measured as the average pairwise distance was observed.

RESULTS

Emergences or disappearances of drug-resistance-associated mutations were detected in the blood cells during follow-up despite sustained virological control. In all patients, tree topologies showed an absence of segregation between sequences and blood viral populations from all time-points were intermingled. Comparison of the average pairwise distance showed the absence of significant viral diversity at the time of primary infection and afterwards during 5 years of full virological control under ART.

CONCLUSION

Despite a slight variation of minority resistance-associated mutation variants, there was no clear evidence of viral evolution during a prolonged period of time in this population of highly controlled adult patients treated at time of PHI.

Analytical treatment interruption in chronic HIV-1 infection: time and magnitude of viral rebound in adults with 10 years of undetectable viral load and low HIV-DNA (APACHE study)

OBJECTIVES

Despite the fact that there are individuals who have chronic HIV infection, few studies have investigated ART interruption in this setting. The aim of this study was to evaluate the ability to spontaneously control viral replication during analytical treatment interruption (ATI) in adults with chronic HIV-1 infection, on ART, with suppressed viraemia for >10 years and with a low reservoir.

PATIENTS AND METHODS

This was a prospective, open-label, single-arm, non-randomized, proof-of-concept study (NCT03198325) of subjects with chronic HIV-1 infection, HIV-RNA <50 copies/mL for ≥10 years, without residual viraemia for ≥5 years, CD4+ >500 cells/mm3, HIV-DNA <100 copies/106 PBMCs and without comorbidities or AIDS-defining diseases. Enrolled patients were strictly monitored. The ART regimen in use at ATI was resumed in the case of confirmed viral rebound (CVR, two consecutive HIV-RNA >50 copies/mL). Results are reported as median (IQR).

RESULTS

Nine patients underwent ATI. All participants experienced CVR [4.84 (IQR: 3.47-6.47) HIV-RNA log10 copies/mL] after ATI at a median time of 21 days (range 14-56) and restarted ART. After ART resumption, all the subjects achieved HIV-RNA <50 copies/mL in a median of 88 days (range 15-197). No serious adverse event occurred; one subject experienced acute retroviral syndrome. No significant correlation between baseline factors and time to viral rebound was observed, while the magnitude of viral rebound was significantly associated with pre-ART HIV-1 RNA (Spearman r = 0.786, P = 0.036), nadir CD4+ (Spearman r = -0.800, P = 0.010), baseline CD4+ (Spearman r = -0.667, P = 0.049) and years with undetectable viral load (Spearman r = -0.717, P = 0.030).

CONCLUSIONS

Despite a long period of HIV viral load suppression and a low viral reservoir, early and consistent viral rebound was observed during ATI in all subjects.

Predictors of incomplete viral response and virologic failure in patients with acute and early HIV infection. Results of Italian Network of ACuTe HIV InfectiON (INACTION) cohort

OBJECTIVES

The aim of this study was to evaluate the factors that can influence an incomplete viral response (IVR) after acute and early HIV infection (AEHI).

METHODS

This was a retrospective, observational study including patients with AEHI (Fiebig stages I-V) diagnosed between January 2008 and December 2014 at 20 Italian centres. IVR was defined by: (1) viral blip (51-1000 HIV-1 RNA copies/mL after achievement of < 50 HIV-1 RNA copies/mL); (2) virologic failure [> 1000 copies/mL after achievement of < 200 copies/mL, or ≥ 200 copies/mL after 24 weeks on an antiretroviral therapy (ART)]; (3) suboptimal viral response (> 50 copies/mL after 48 weeks on ART or two consecutive HIV-1 RNA levels with ascending trend during ART). Cox regression analysis was used to calculate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) for IVR.

RESULTS

In all, 263 patients were studied, 227 (86%) males, with a median [interquartile range (IQR)] age of 38 (30-46) years. During a median follow-up of 13.0 (5.7-31.1) months, 38 (14.4%) had IVR. The presence of central nervous system (CNS) symptoms was linked to a higher risk of IVR (HR = 4.70, 95% CI: 1.56-14.17), while a higher CD4/CD8 cell count ratio (HR = 0.13, 95% CI: 0.03-0.51 for each point increase) and first-line ART with three-drug regimens recommended by current guidelines (HR = 0.40, 95% CI: 0.18-0.91 compared with other regimens including four or five drugs, older drugs or non-standard backbones) were protective against IVR.

CONCLUSIONS

Patients with lower CD4/CD8 ratio and CNS symptoms could be at a higher risk of IVR after AEHI. The use of recommended ART may be relevant for improving short-term viral efficacy in this group of patients.

Assessing the Quality of Human Immunodeficiency Virus Care in Nursing Homes

BACKGROUND

Quality of human immunodeficiency virus (HIV) care in nursing homes (NHs) has never been measured.

DESIGN

A cross-sectional study.

SETTING

NHs.

PARTICIPANTS

A total of 203 NHs and 1375 persons living with HIV.

MEASUREMENTS

Medicare claims from 2011 to 2013 were linked to assessments of resident health, prescription dispensing data, and national reports of NH characteristics. Five nationally validated HIV care quality measures (prescription of antiretroviral therapy; CD4/viral load monitoring; frequency of medical visits; gaps in medical visits; and Pneumocystis pneumonia prophylaxis) were adapted and applied to NHs. Logistic regression predicted compliance by organizational factors. Random intercept logistic regression predicted if persons living with HIV received care by person and organizational factors.

RESULTS

Compliance ranged from 43.3% (SD = 31.1%) for CD4/viral load monitoring to 92.4% (SD = 13.6%) for gaps in medical visits. More substantiated complaints against an NH decreased the likelihood of high compliance with CD4/viral load monitoring (odds ratio [OR] = 0.846; 95% confidence interval [CI] = 0.726-0.986), while NH-reported incidents increased the likelihood of high compliance with pneumocystis pneumonia prophylaxis (OR = 1.173; 95% CI = 1.044-1.317). Differences between NHs explained 21.2% or less of variability in receipt of care.

CONCLUSIONS

Since 2013, the population with HIV and NH HIV care quality has inevitably evolved; however, this study provides previously unknown baseline metrics on NH HIV care quality and highlights significant challenges when measuring HIV care in NHs. J Am Geriatr Soc 68:1226-1234, 2020.

New Frontiers in Measuring and Characterizing the HIV Reservoir

A cure for HIV infection remains elusive due to the persistence of replication-competent HIV proviral DNA during suppressive antiretroviral therapy (ART). With the exception of rare elite or post-treatment controllers of viremia, withdrawal of ART invariably results in the rebound of viremia and progression of HIV disease. A thorough understanding of the reservoir is necessary to develop new strategies in order to reduce or eliminate the reservoir. However, there is significant heterogeneity in the sequence composition, genomic location, stability, and expression of the HIV reservoir both within and across individuals, and a majority of proviral sequences are replication-defective. These factors, and the low frequency of persistently infected cells in individuals on suppressive ART, make understanding the reservoir and its response to experimental reservoir reduction interventions challenging. Here, we review the characteristics of the HIV reservoir, state-of-the-art assays to measure and characterize the reservoir, and how these assays can be applied to accurately detect reductions in reservoir during efforts to develop a cure for HIV infection. In particular, we highlight recent advances in the development of direct measures of provirus, including intact proviral DNA assays and full-length HIV DNA sequencing with integration site analysis. We also focus on novel techniques to quantitate persistent and inducible HIV, including RNA sequencing and RNA/gag protein staining techniques, as well as modified viral outgrowth methods that seek to improve upon throughput, sensitivity and dynamic range.

Potential for early antiretroviral therapy to reduce central nervous system HIV-1 persistence

: Although treatment with antiretroviral therapy (ART) improves central nervous inflammation, limits viral replication detected in the cerebrospinal fluid, and prevents severe clinical neurological disease in most individuals, HIV-1 can persist in the central nervous system (CNS) despite ART. Recent observations that initiation of ART early in the course of infection limits the size of systemic HIV reservoirs, parallel clinical reports of increased rates of posttreatment viral control in early treatment cohorts, and an understanding of the dynamics of HIV-1 infection and neuropathogenesis during early infection provides rationale to consider that ART started early in the course of HIV-1 infection may have a beneficial effect on CNS HIV-1 persistence. Early ART may restrict the initial establishment of HIV-1 infection in cells of the CNS, and furthermore, may reduce levels of immune activation and inflammation that allow perpetuation of CNS infection. In this review, we consider the precedent set by studies of the impact of early treatment on systemic HIV-1 reservoirs, summarize the current understanding of early CNS HIV-1 exposure and its effects, and examine the evidence for a benefit in the CNS compartment of early treatment.

National and sub-national HIV/AIDS-related mortality in Iran, 1990-2015: a population-based modeling study

Surveillance of HIV/AIDS mortality is crucial to evaluate a country’s response to the disease. With a modified estimation approach, this study aimed to provide more accurate estimates on deaths due to HIV/AIDS in Iran from 1990 to 2015 at national and sub-national levels. Using a comprehensive data set, death registration incompleteness and misclassification were addressed by demographical and statistical methods. Trends of mortality due to HIV/AIDS at national and sub-national levels were estimated by applying a set of models. A total of 474 men (95% uncertainty interval [UI]: 175–1332) and 256 women (95% UI: 36–1871) died due to HIV/AIDS in 2015 in Iran. Peaked in 1995, HIV/AIDS-related mortality has steadily declined among both genders. Mortality rates were remarkably higher among men than women during the period studied. At the sub-national level, the highest and the lowest annual percent change were found at 10.97 and −1.36% for women, and 4.04 and −3.47% for men, respectively. The findings of our study (731 deaths) were remarkably lower than the Joint United Nations Programme on HIV and AIDS (4000) but higher than Global Burden of Disease (339) estimates in 2015. The overall decrease in mortality due to HIV/AIDS may be attributed to the increasing burden of noncommunicable diseases; however, the role of the national and international organizations to fight HIV/AIDS should not be overlooked. To decrease HIV/AIDS mortality and to achieve international goals, evidence-based action is required. To fast-track targets, the priority must be to prevent infection, promote early diagnosis, provide access to treatment, and to ensure treatment adherence among patients.

Time to viral rebound and safety after antiretroviral treatment interruption in postpartum women compared with men

OBJECTIVE(S)

The short-term safety of treatment interruptions, a necessary part of cure studies, is not well established, particularly in women. We explored viral rebound kinetics and safety in a group of postpartum women discontinuing ART and compared results to men in historical interruption trials.

DESIGN

Prospective evaluation of time to virologic rebound.

METHODS

One thousand and seventy-six asymptomatic, virally suppressed, postpartum women living with HIV enrolled in the PROMISE trial with baseline CD4 cell counts at least 350 cells/μl underwent antiretroviral treatment (ART) discontinuation. Proportion with virologic suppression at weeks 4 and 12 were compared with participants in ACTG treatment interruption trials (91% male population).

RESULTS

In PROMISE, using interval censored methods, the estimated median time to HIV viral rebound was 2 weeks. An estimated 6% of women would remain virally suppressed at 30 weeks. Of those who had viral rebound by 30 weeks (N = 993), less than 4% experienced grade 3 or higher laboratory events, and 1% experienced WHO stage 2 or higher clinical events. Overall, less than 1% of participants progressed from WHO Stage 1 to Stage 2 or higher after discontinuation of ART, and 3.9% experienced a decline in CD4 cell count to less than 350 cells/μl or local treatment guidelines. A significantly higher proportion of women in PROMISE (25.4%) were virologically suppressed (<400 copies/ml) at 12 weeks compared with ACTG NWCS 371 participants (6.4%).

CONCLUSION

Temporary treatment interruptions in healthy, HIV-infected women with high CD4 cell counts can be well tolerated. Potential sex differences need to be considered in cure studies examining time to virologic rebound.

Integrase strand-transfer inhibitors for treatment of early HIV infection: A case series

This study evaluated whether the interval from the first clinic visit until the start of antiretroviral treatment (ART) was correlated with common parameters of immunological recovery among patients with early HIV infection (EHI).We reviewed the medical records of patients with EHI who started ART using integrase strand-transfer inhibitors (ISTIs) within the first 6 months after diagnosis. Simple linear regression analyses were performed to determine whether the interval from the first visit to the start of ART was correlated with 1-year changes in CD4+ cell count, CD8+ cell count, CD4+ percentage, and CD4+/CD8+ ratio.Fifty-three patients with probable or definite EHI started ART using ISTIs between April 2014 and August 2016. Forty-nine patients completed 1 year of follow-up, including 48 men. The routes of HIV transmission were 1 case of needle sharing, 5 cases of heterosexual activity, and 43 cases of men who had sex with men. None of the immunological recovery parameters were correlated with time to the start of ART (CD4+ cell count: R = .12, P = .42; CD8+ cell count: R = .107, P = .5; CD4+ percentage: R = .14, P = .34; CD4+/CD8+ ratio: R = .23, P = .14). Furthermore, subgroup sensitivity analyses failed to detect significant correlations based on definite or probable diagnoses, treatment using elvitegravir or dolutegravir, or the time from HIV diagnosis to ART initiation.This series of EHI cases indicate that using ART with ISTI-based regimens is efficacious and well-tolerated. However, earlier initiation of treatment was not significantly correlated with common parameters of immunological recovery.

Broadly neutralizing antibodies for treatment and prevention of HIV-1 infection

PURPOSE OF REVIEW

Several anti-HIV-1 broadly neutralizing antibodies (bNAbs) with exceptional breadth and potency that target different HIV-1 envelope epitopes have been identified. bNAbs are an attractive new strategy for HIV-1 prevention and therapy, and potentially, for long-term remission or cure. Here, we discuss findings from early clinical studies that have evaluated these novel bNAbs.

RECENT FINDINGS

Phase 1 studies of bNAbs targeting two distinct HIV-1 envelope epitopes have demonstrated their favorable safety and pharmacokinetic profile. Single bNAb infusions led to significant, but transient, decline in viremia with selection of escape variants. A single bNAb also delayed viral rebound in ART-treated participants who discontinued ART. Importantly, in-vivo efficacy was related to antibody potency and to the level of preexisting resistance. Studies in animal models showed that bNAbs can clear HIV-infected cells and modulate host immune responses. These findings suggest that bNAbs may target the latent HIV reservoir in humans and could contribute to long-term remission of HIV-1 infection.

SUMMARY

bNAbs may offer advantages over traditional ART for both the prevention and treatment of HIV-1 infection. In addition, bNAbs may target the latent viral reservoir. bNAb combinations and bNAbs engineered for prolonged half-life and increased potency are currently undergoing clinical evaluation.

Control of viral infections by epigenetic-targeted therapy

Epigenetics is defined as the science that studies the modifications of gene expression that are not owed to mutations or changes in the genetic sequence. Recently, strong evidences are pinpointing toward a solid interplay between such epigenetic alterations and the outcome of human cytomegalovirus (HCMV) infection. Guided by the previous possibly promising experimental trials of human immunodeficiency virus (HIV) epigenetic reprogramming, the latter is paving the road toward two major approaches to control viral gene expression or latency. Reactivating HCMV from the latent phase ("shock and kill" paradigm) or alternatively repressing the virus lytic and reactivation phases ("block and lock" paradigm) by epigenetic-targeted therapy represent encouraging options to overcome latency and viral shedding or otherwise replication and infectivity, which could lead eventually to control the infection and its complications. Not limited to HIV and HCMV, this concept is similarly studied in the context of hepatitis B and C virus, herpes simplex virus, and Epstein-Barr virus. Therefore, epigenetic manipulations stand as a pioneering research area in modern biology and could constitute a curative methodology by potentially consenting the development of broad-spectrum antivirals to control viral infections in vivo.

Novel therapies/hopes for HIV cure in perinatally acquired HIV-positive adolescents

PURPOSE OF REVIEW

Successful roll-out of paediatric antiretroviral therapy (ART) has led to a significant increase in survival of adolescents and young people growing up with HIV. Those on suppressive ART since childhood represent a unique group particularly well positioned to interrupt ART and achieve post-treatment control (PTC), or HIV remission. This maybe a consequence of early and sustained treatment since infancy, the small size of the HIV reservoir, the presence of a functioning thymus and a more 'flexible' immune system better able to respond to novel immune therapeutic interventions when compared with adults who acquired HIV at a time of immunological maturity and thymic involution.

RECENT FINDINGS

In the past year, there have been additional case reports of post-treatment viral control amongst perinatally acquired HIV adolescents and young adults (PaHIV-AYA). In this article, we review and compare the characteristics of PTC in PaHIV-AYA and discuss the potential implications of these observations for the growing population of adolescents living with HIV. The correlation between low levels of HIV DNA and seroreversion may provide a feasible screening tool to select candidates most suitable for future intervention studies and viral remission.

CONCLUSION

Whilst it is premature to anticipate an HIV cure, there is much anticipation that with early ART and additional interventions to perturb the residual viral reservoir, future viral remission off ART might be feasible for PaHIV-AYA. However, given the safety and effectiveness of current ART, a critical debate must evaluate the risks against benefits of any novel intervention, especially amongst adolescents as they become sexually active.

Intermittent treatment of severe influenza

Severe, long-lasting influenza infections are often caused by new strains of the virus. The long duration of these infections leads to an increased opportunity for the emergence of drug resistant mutants. This is particularly problematic since for new strains there is often no vaccine, so drug treatment is the first line of defense. One strategy for trying to minimize drug resistance is to apply drugs periodically. During treatment phases the wild-type virus decreases, but resistant virus might increase; when there is no treatment, wild-type virus will hopefully out-compete the resistant virus, driving down the number of resistant virus. A stochastic model of severe influenza is combined with a model of drug resistance to simulate long-lasting infections and intermittent treatment with two types of antivirals: neuraminidase inhibitors, which block release of virions; and adamantanes, which block replication of virions. Each drug's ability to reduce emergence of drug resistant mutants is investigated. We find that cell regeneration is required for successful implementation of intermittent treatment and that the optimal cycling parameters change with regeneration rate.

Brief Report: Relationship Among Viral Load Outcomes in HIV Treatment Interruption Trials

Viral load (VL) rebound timing and set point were analyzed in 235 participants undergoing analytic treatment interruption (ATI) in 6 AIDS Clinical Trials Group studies. There was no significant association between rebound timing and ATI VL set point for those who rebounded ≤12 weeks. VL set points were lower in participants with rebound >12 weeks (P < 0.001) and participants treated during early infection (P < 0.001). Pre-antiretroviral therapy VL correlated with set point, though 68% of participants had a set point lower than pre-antiretroviral therapy VL. These results illustrate complex relationships between post-ATI virologic outcomes and the potential presence of biological factors mediating rebound timing and set point.

Modelling the evolution of HIV-1 virulence in response to imperfect therapy and prophylaxis

Average HIV-1 virulence appears to have evolved in different directions in different host populations since antiretroviral therapy first became available, and models predict that HIV drugs can select for either higher or lower virulence, depending on how treatment is administered. However, HIV virulence evolution in response to "leaky" therapy (treatment that imperfectly suppresses viral replication) and the use of preventive drugs (pre-exposure prophylaxis) has not been explored. Using adaptive dynamics, we show that higher virulence can evolve when antiretroviral therapy is imperfectly effective and that this evolution erodes some of the long-term clinical and epidemiological benefits of HIV treatment. The introduction of pre-exposure prophylaxis greatly reduces infection prevalence, but can further amplify virulence evolution when it, too, is leaky. Increasing the uptake rate of these imperfect interventions increases selection for higher virulence and can lead to counterintuitive increases in infection prevalence in some scenarios. Although populations almost always fare better with access to interventions than without, untreated individuals could experience particularly poor clinical outcomes when virulence evolves. These findings predict that antiretroviral drugs may have underappreciated evolutionary consequences, but that maximizing drug efficacy can prevent this evolutionary response. We suggest that HIV virulence evolution should be closely monitored as access to interventions continues to improve.

Antiretroviral Therapy Interruption Among HIV Postive People Who Use Drugs in a Setting with a Community-Wide HIV Treatment-as-Prevention Initiative

HIV Treatment as Prevention (TasP) initiatives promote antiretroviral therapy (ART) access and optimal adherence (≥95 %) to produce viral suppression among people living with HIV (PLHIV) and prevent the onward transmission of HIV. ART treatment interruptions are common among PLHIV who use drugs and undermine the effectiveness of TasP. Semi-structured interviews were conducted with 39 PLHIV who use drugs who had experienced treatment ART interruptions in a setting with a community-wide TasP initiative (Vancouver, Canada) to examine influences on these outcomes. While study participants attributed ART interruptions to "treatment fatigue," our analysis revealed individual, social, and structural influences on these events, including: (1) prior adverse ART-related experiences among those with long-term treatment histories; (2) experiences of social isolation; and, (3) breakdowns in the continuity of HIV care following disruptive events (e.g., eviction, incarceration). Findings reconceptualise 'treatment fatigue' by focusing attention on its underlying mechanisms, while demonstrating the need for comprehensive structural reforms and targeted interventions to optimize TasP among drug-using PLHIV.

Nonhuman Primate Models for Studies of AIDS Virus Persistence During Suppressive Combination Antiretroviral Therapy

Nonhuman primate (NHP) models of AIDS represent a potentially powerful component of the effort to understand in vivo sources of AIDS virus that persist in the setting of suppressive combination antiretroviral therapy (cART) and to develop and evaluate novel strategies for more definitive treatment of HIV infection (i.e., viral eradication "cure", or sustained off-cART remission). Multiple different NHP models are available, each characterized by a particular NHP species, infecting virus, and cART regimen, and each with a distinct capacity to recapitulate different aspects of HIV infection. Given these different biological characteristics, and their associated strengths and limitations, different models may be preferred to address different questions pertaining to virus persistence and cure research, or to evaluate different candidate intervention approaches. Recent developments in improved cART regimens for use in NHPs, new viruses, a wider array of sensitive virologic assay approaches, and a better understanding of pathogenesis should allow even greater contributions from NHP models to this important area of HIV research in the future.

Fixed-dose combination emtricitabine/tenofovir/efavirenz initiated during acute HIV infection; 96-week efficacy and durability

BACKGROUND

Updated guidelines recommend immediate antiretroviral treatment (ART) during acute HIV infection (AHI), but efficacy data on regimens during AHI are limited.

METHODS

We provide final data on a prospective, single-arm 96-week open-label study of once-daily emtricitabine/tenofovir/efavirenz initiated during AHI. The primary endpoint was the proportion of responders with HIV RNA less than 200 copies/ml by week 24. We examined time to viral suppression, retention, and CD8 cell activation through week 96 in relation to baseline characteristics.

RESULTS

Between January 2005 and December 2011, 92 AHI participants enrolled. Most participants (78%) were men who have sex with men (MSM), and 42% were young MSM (18-25 years of age). Two participants withdrew leaving 90 patients for analysis. Eighty-one (90%) remained on therapy and achieved viral suppression to less than 200 copies/ml by week 24, and 71 (79%) to less than 50 copies/ml at week 48. The median time from ART initiation to suppression less than 200 copies/ml was 65 days (range 7-523) and to less than 50 copies/ml was 105 days (range 14-523). The frequency of immune activation declined from a median of 67% to 16% through week 96. Retention on study was maintained in 92% of participants at week 48 and in 83% through week 96. Among 75 participants retained through week 96, 92% were suppressed to less than 50 copies/ml. Among 39 young MSM, 79% completed a week 96 visit and 67% were suppressed at week 96.

CONCLUSION

ART during AHI resulted in rapid and sustained viral suppression with high rates of retention in care and on ART in this cohort including a large proportion of young MSM.

Multi-dose Romidepsin Reactivates Replication Competent SIV in Post-antiretroviral Rhesus Macaque Controllers

Viruses that persist despite seemingly effective antiretroviral treatment (ART) and can reinitiate infection if treatment is stopped preclude definitive treatment of HIV-1 infected individuals, requiring lifelong ART. Among strategies proposed for targeting these viral reservoirs, the premise of the “shock and kill” strategy is to induce expression of latent proviruses [for example with histone deacetylase inhibitors (HDACis)] resulting in elimination of the affected cells through viral cytolysis or immune clearance mechanisms. Yet, ex vivo studies reported that HDACis have variable efficacy for reactivating latent proviruses, and hinder immune functions. We developed a nonhuman primate model of post-treatment control of SIV through early and prolonged administration of ART and performed in vivo reactivation experiments in controller RMs, evaluating the ability of the HDACi romidepsin (RMD) to reactivate SIV and the impact of RMD treatment on SIV-specific T cell responses. Ten RMs were IV-infected with a SIVsmmFTq transmitted-founder infectious molecular clone. Four RMs received conventional ART for >9 months, starting from 65 days post-infection. SIVsmmFTq plasma viremia was robustly controlled to <10 SIV RNA copies/mL with ART, without viral blips. At ART cessation, initial rebound viremia to ~10⁶ copies/mL was followed by a decline to < 10 copies/mL, suggesting effective immune control. Three post-treatment controller RMs received three doses of RMD every 35–50 days, followed by in vivo experimental depletion of CD8⁺ cells using monoclonal antibody M-T807R1. RMD was well-tolerated and resulted in a rapid and massive surge in T cell activation, as well as significant virus rebounds (~10⁴ copies/ml) peaking at 5–12 days post-treatment. CD8⁺ cell depletion resulted in a more robust viral rebound (10⁷ copies/ml) that was controlled upon CD8⁺ T cell recovery. Our results show that RMD can reactivate SIV in vivo in the setting of post-ART viral control. Comparison of the patterns of virus rebound after RMD administration and CD8⁺ cell depletion suggested that RMD impact on T cells is only transient and does not irreversibly alter the ability of SIV-specific T cells to control the reactivated virus.

Antiretroviral therapy (ART) does not eradicate HIV-1 in infected individuals due to virus persistence in latently infected reservoir cells, despite apparently effective ART. The persistent virus and can rekindle infection when ART is interrupted. The goal of the “shock and kill” viral clearance strategy is to induce expression of latent proviruses and eliminate the infected cells through viral cytolysis or immune clearance mechanisms. Latency reversing agents (LRAs) tested to date have been reported to have variable effects, both on virus reactivation and on immune functions. We performed in vivo reactivation experiments in SIV-infected RMs that controlled viral replication after a period of ART to evaluate the ability of the histone deacetylase inhibitor romidepsin (RMD) to reactivate SIV and its impact on SIV-specific immune responses. Our results suggest that RMD treatment can increase virus expression in this setting, and that it does not markedly or durably impair the ability of SIV-specific T cells to control viral replication.

UK guideline for the use of HIV Post-Exposure Prophylaxis Following Sexual Exposure, 2015

We present the updated British Association for Sexual Health and HIV guidelines for HIV post-exposure prophylaxis following sexual exposure (PEPSE). This document includes a review of the current data to support the use of PEPSE, considers how to calculate the risks of infection after a potential exposure, and provides recommendations on when PEPSE should and should not be considered. We also review which medications to use for PEPSE, provide a checklist for initial assessment, and make recommendations for monitoring individuals receiving PEPSE. Special scenarios, cost-effectiveness of PEPSE, and issues relating to service provision are also discussed. Throughout the document, the place of PEPSE within the broader context of other HIV prevention strategies is considered.

A curative regimen would decrease HIV prevalence but not HIV incidence unless targeted to an ART-naïve population

HIV curative strategies currently under development aim to eradicate latent provirus, or prevent viral replication, progression to AIDS, and transmission. The impact of implementing curative programs on HIV epidemics has not been considered. We developed a mathematical model of heterosexual HIV transmission to evaluate the independent and synergistic impact of ART, HIV prevention interventions and cure on HIV prevalence and incidence. The basic reproduction number was calculated to study the potential for the epidemic to be eliminated. We explored scenarios with and without the assumption that patients enrolled into HIV cure programs need to be on antiretroviral treatment (ART). In our simulations, curative regimes had limited impact on HIV incidence if only ART patients were eligible for cure. Cure implementation had a significant impact on HIV incidence if ART-untreated patients were enrolled directly into cure programs. Concurrent HIV prevention programs moderately decreased the percent of ART treated or cured patients needed to achieve elimination. We project that widespread implementation of HIV cure would decrease HIV prevalence under all scenarios but would only lower rate of new infections if ART-untreated patients were targeted. Current efforts to identify untreated HIV patients will gain even further relevance upon availability of an HIV cure.

Animal Models for HIV Cure Research

The HIV-1/AIDS pandemic continues to spread unabated worldwide, and no vaccine exists within our grasp. Effective antiretroviral therapy (ART) has been developed, but ART cannot clear the virus from the infected patient. A cure for HIV-1 is badly needed to stop both the spread of the virus in human populations and disease progression in infected individuals. A safe and effective cure strategy for human immunodeficiency virus (HIV) infection will require multiple tools, and appropriate animal models are tools that are central to cure research. An ideal animal model should recapitulate the essential aspects of HIV pathogenesis and associated immune responses, while permitting invasive studies, thus allowing a thorough evaluation of strategies aimed at reducing the size of the reservoir (functional cure) or eliminating the reservoir altogether (sterilizing cure). Since there is no perfect animal model for cure research, multiple models have been tailored and tested to address specific quintessential questions of virus persistence and eradication. The development of new non-human primate and mouse models, along with a certain interest in the feline model, has the potential to fuel cure research. In this review, we highlight the major animal models currently utilized for cure research and the contributions of each model to this goal.

The size of the expressed HIV reservoir predicts timing of viral rebound after treatment interruption

OBJECTIVES

Therapies to achieve sustained antiretroviral therapy-free HIV remission will require validation in analytic treatment interruption (ATI) trials. Identifying biomarkers that predict time to viral rebound could accelerate the development of such therapeutics.

DESIGN

A pooled analysis of participants from six AIDS Clinical Trials Group ATI studies to identify predictors of viral rebound.

METHODS

Cell-associated DNA (CA-DNA) and CA-RNA were quantified in pre-ATI peripheral blood mononuclear cell samples, and residual plasma viremia was measured using the single-copy assay.

RESULTS

Participants who initiated antiretroviral therapy (ART) during acute/early HIV infection and those on a non-nucleoside reverse transcriptase inhibitor-containing regimen had significantly delayed viral rebound. Participants who initiated ART during acute/early infection had lower levels of pre-ATI CA-RNA (acute/early vs. chronic-treated: median <92 vs. 156 HIV-1 RNA copies/10 CD4 cells, P < 0.01). Higher pre-ATI CA-RNA levels were significantly associated with shorter time to viral rebound (≤4 vs. 5-8 vs. >8 weeks: median 182 vs. 107 vs. <92 HIV-1 RNA copies/10 CD4 cells, Kruskal-Wallis P < 0.01). The proportion of participants with detectable plasma residual viremia prior to ATI was significantly higher among those with shorter time to viral rebound.

CONCLUSION

Higher levels of HIV expression while on ART are associated with shorter time to HIV rebound after treatment interruption. Quantification of the active HIV reservoir may provide a biomarker of efficacy for therapies that aim to achieve ART-free HIV remission.

Post-transcriptional gene silencing, transcriptional gene silencing and human immunodeficiency virus

While human immunodeficiency virus 1 (HIV-1) infection is controlled through continuous, life-long use of a combination of drugs targeting different steps of the virus cycle, HIV-1 is never completely eradicated from the body. Despite decades of research there is still no effective vaccine to prevent HIV-1 infection. Therefore, the possibility of an RNA interference (RNAi)-based cure has become an increasingly explored approach. Endogenous gene expression is controlled at both, transcriptional and post-transcriptional levels by non-coding RNAs, which act through diverse molecular mechanisms including RNAi. RNAi has the potential to control the turning on/off of specific genes through transcriptional gene silencing (TGS), as well as fine-tuning their expression through post-transcriptional gene silencing (PTGS). In this review we will describe in detail the canonical RNAi pathways for PTGS and TGS, the relationship of TGS with other silencing mechanisms and will discuss a variety of approaches developed to suppress HIV-1 via manipulation of RNAi. We will briefly compare RNAi strategies against other approaches developed to target the virus, highlighting their potential to overcome the major obstacle to finding a cure, which is the specific targeting of the HIV-1 reservoir within latently infected cells.

The effect of short-course antiretroviral therapy initiated in primary HIV-1 infection on interleukin-6 and D-dimer levels

OBJECTIVE

Interruption of antiretroviral therapy (ART) in chronic HIV disease is associated with increased mortality, predicted by elevations in interleukin-6 (IL-6) and D-dimer. The effect of ART interruption in primary HIV-1 infection on these biomarkers is unknown.

METHODS

Plasma samples from 200 HIV seroconverters enrolled in the Short Pulse Anti-Retroviral Therapy At HIV Seroconversion trial of deferred ART (standard of care) - 12 or 48 week ART (ART12 or ART48, respectively) - were analysed for IL-6 and D-dimer at weeks 0, 12, 16, 48, 52, 60 and 108 after randomization. Changes in log10 levels from weeks 0 to 12 were analysed using linear regression, as were changes from baseline to 4 weeks after stopping ART. Areas under the biomarker-time curves (AUC) to week 108 were adjusted for baseline values, and compared across all arms.

RESULTS

Median (inter-quartile range) baseline IL-6 and D-dimer were 1.45 (0.88, 2.41) pg/ml and 0.34 (0.20, 0.50) mg/l, respectively. At week 12, D-dimer levels were significantly lower among treated compared to untreated individuals (P < 0.001), whereas IL-6 levels were similar (P = 0.23). Within 4 weeks from stopping ART, IL-6 and D-dimer levels rose by 22 and 18%, reaching pre-ART levels. Over 108-week follow-up, there was no difference between arms in IL-6 AUC (P = 0.53), but D-dimer AUC was significantly lower for ART12 and ART48 compared to standard of care (overall P = 0.008).

CONCLUSION

Stopping ART in primary HIV-1 infection leads to inflammatory biomarker rebound to pre-treatment levels. However, over 108-week follow-up, we found no evidence that biomarker levels were higher for those interrupting ART, compared to those remaining ART-naïve, and D-dimer levels were significantly lower.

Intrapatient Evolutionary Dynamics of Human Immunodeficiency Virus Type 1 in Individuals Undergoing Alternative Treatment Strategies with Reverse Transcriptase Inhibitors

Structured treatment interruption (STI) has been trialed as an alternative to lifelong antiretroviral therapy (ART). We retrospectively performed single genome sequencing of the HIV-1 pol region from three patients representing different scenarios. They were either failing on continuous therapy (CT-F), failing STI (STI-F), or suppressing on STI (STI-S). Over 460 genomes were generated from three to five different time points over a 2-year period. We found multiple-linked-resistant mutations in both treatment failures. However, the CT-F patient showed a stepwise accumulation of diverse, linked mutations whereas the STI-F patient had lineage turnover between treatment periods with recirculation of wild-type and resistant variants from reservoirs. The STI-F patient showed a 7-fold increase in the third codon position substitution rate relative to the first and second positions compared to a 2-fold increase for CT-F and increased purifying selection in the pol gene (62 vs. 22 sites, respectively). An understanding of intrapatient viral dynamics could guide the future direction of treatment interruption strategies.

A Murine Viral Outgrowth Assay to Detect Residual HIV Type 1 in Patients With Undetectable Viral Loads

BACKGROUND

Sensitive assays are needed for detection of residual human immunodeficiency virus (HIV) in patients with undetectable plasma viral loads to determine whether eradication strategies are effective. The gold standard quantitative viral outgrowth assay (QVOA) underestimates the magnitude of the viral reservoir. We sought to determine whether xenograft of leukocytes from HIV type 1 (HIV)-infected patients with undetectable plasma viral loads into immunocompromised mice would result in viral amplification.

METHODS

Peripheral blood mononuclear cells or purified CD4(+) T cells from HIV or simian immunodeficiency virus (SIV)-infected subjects with undetectable plasma viral loads were adoptively transferred into NOD.Cg-Prkdc(scid)Il2rg(tm1Wjl)/SzJ (NSG) mice. The mice were monitored for viremia following depletion of human CD8(+) T cells to minimize antiviral activity. In some cases, humanized mice were also treated with activating anti-CD3 antibody.

RESULTS

With this murine viral outgrowth assay (MVOA), we successfully amplified replication-competent HIV or SIV from all subjects tested, including 5 HIV-positive patients receiving suppressive antiretroviral therapy (ART) and 6 elite controllers or suppressors who were maintaining undetectable viral loads without ART, including an elite suppressor from whom we were unable to recover virus by QVOA.

CONCLUSIONS

Our results suggest that the MVOA has the potential to serve as a powerful tool to identify residual HIV in patients with undetectable viral loads.

Influence of lifelong cumulative HIV viremia on long-term recovery of CD4+ cell count and CD4+/CD8+ ratio among patients on combination antiretroviral therapy

OBJECTIVE

We explored the impact of lifelong cumulative HIV viremia on immunological recovery during antiretroviral therapy, according to the timing of treatment initiation.

METHODS

We estimated lifelong cumulative HIV viremia in patients followed in the ANRS PRIMO cohort since primary infection, including 244 patients who started treatment during PHI and had at least one treatment interruption, and 218 patients who started treatment later but with no interruptions. The impact of cumulative viremia on current immunological status was analysed using linear and logistic regression models.

RESULTS

At the last visit on treatment, median CD4 cell count was 645 cells/μl in the early/intermittent treatment group (median time from infection 9.5 years, 4.8 years of continuous treatment since last resumption), and 654 cells/μl in the deferred/continuous treatment group (median time from infection 6.1 years, 3.0 years of continuous treatment). Only 36.1 and 39.8% of patients achieved a CD4/CD8 ratio of more than 1, respectively. Current CD4 cell count was not associated with cumulative HIV viremia in either group. In contrast, patients with high cumulative HIV viremia (>66th percentile vs. <33rd percentile) were less likely to achieve a CD4/CD8 ratio of more than 1 (26.8 vs. 43.3%, P = 0.003), even after controlling for the baseline CD4/CD8 ratio, treatment duration, sex and age. Much higher CD4 cell count and CD4/CD8 ratio were reached in early/continuous treatment, that is low viremia exposure group.

CONCLUSION

Our results underline the critical need in early-treated patients to maintain adherence, in order to limit cumulative HIV viremia and optimize immunological recovery, notably the CD4/CD8 ratio.

HIV reservoir dynamics in the face of highly active antiretroviral therapy

Upon discontinuation of highly active antiretroviral therapy (HAART), human immunodeficiency virus (HIV)-infected individuals experience a brisk rebound in blood plasma viremia due to the exodus of HIV from various body reservoirs. Assessment of HIV dynamics during HAART and following treatment discontinuation is essential to better understand HIV persistence. Here we will first provide a brief overview of the molecular mechanisms involved in HIV reservoir formation and persistence. After a summary of HAART-mediated HIV decay within peripheral blood, we discuss findings from clinical studies examining the effects of HAART initiation and interruption on HIV reservoir dynamics in major anatomical compartments, including lymph nodes and spleen, gut associated lymphoid tissue, reproductive organs, the central nervous system, and the lungs. Features contributing to these reservoirs as distinct compartments, including anatomical features, the presence of drug transporters, and the effect of co-infection, are also discussed.

Acute Human Immunodeficiency Virus (HIV) Syndrome After Nonadherence to Antiretroviral Therapy in a Patient With Chronic HIV Infection: A Case Report

We report a rare case of acute human immunodeficiency virus (HIV) syndrome in a patient with chronic HIV infection with acute illness indistinguishable from acute retroviral syndrome. The patient presented with an acute febrile mononucleosis-like illness after increasing nonadherence to antiretroviral therapy. A marked increase in HIV RNA level of 1 220 000 copies/mL from less than 20 copies/mL occurred within 3 weeks. The diagnosis of acute HIV syndrome was made after alternative causes of illness were ruled out.

HIV eradication: combinatorial approaches to activate latent viruses

The concept of eradication of the Human Immune Deficiency Virus (HIV) from infected patients has gained much attention in the last few years. While combination Anti-Retroviral Therapy (c-ART) has been extremely effective in suppressing viral replication, it is not curative. This is due to the presence of a reservoir of latent HIV infected cells, which persist in the presence of c-ART. Recently, pharmaceutical approaches have focused on the development of molecules able to induce HIV-1 replication from latently infected cells in order to render them susceptible to viral cytopathic effects and host immune responses. Alternative pathways and transcription complexes function to regulate the activity of the HIV promoter and might serve as molecular targets for compounds to activate latent HIV. A combined therapy coupling various depressors and activators will likely be the most effective in promoting HIV replication while avoiding pleiotropic effects at the cellular level. Moreover, in light of differences among HIV subtypes and variability in integration sites, the combination of multiple agents targeting multiple pathways will increase likelihood of therapeutic effectiveness and prevent mutational escape. This review provides an overview of the mechanisms that can be targeted to induce HIV activation focusing on potential combinatorial approaches.

Socially-integrated transdisciplinary HIV prevention

Current ideas about HIV prevention include a mixture of primarily biomedical interventions, socio-mechanical interventions such as sterile syringe and condom distribution, and behavioral interventions. This article presents a framework for socially-integrated transdisciplinary HIV prevention that may improve current prevention efforts. It first describes one socially-integrated transdisciplinary intervention project, the Transmission Reduction Intervention Project. We focus on how social aspects of the intervention integrate its component parts across disciplines and processes at different levels of analysis. We then present socially-integrated perspectives about how to improve combination antiretroviral treatment (cART) processes at the population level in order to solve the problems of the treatment cascade and make "treatment as prevention" more effective. Finally, we discuss some remaining problems and issues in such a social transdisciplinary intervention in the hope that other researchers and public health agents will develop additional socially-integrated interventions for HIV and other diseases.

Structural insights on the role of antibodies in HIV-1 vaccine and therapy

Despite 30 years of effort, there is no effective vaccine for HIV-1. However, antibodies can prevent HIV-1 infection in humanized mice and macaques when passively transferred. New single-cell-based methods have uncovered many broad and potent donor-derived antibodies, and structural studies have revealed the molecular bases for their activities. The new data suggest why such antibodies are difficult to elicit and inform HIV-1 vaccine development efforts. In addition to protecting against infection, the newly identified antibodies can suppress active infections in mice and macaques, suggesting they could be valuable additions to anti-HIV-1 therapies and to strategies to eradicate HIV-1 infection.

Quantification of HIV-1 latency reversal in resting CD4+ T cells from patients on suppressive antiretroviral therapy

Reversal of proviral latency is being pursued as a curative strategy for HIV-1 infection. Recent clinical studies of in vivo administration of the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA; vorinostat) show increases in unspliced cellular HIV-1 RNA levels in resting CD4(+) T cells. A critical unknown, however, is the proportion of latent proviruses that can be transcriptionally reactivated by SAHA or T-cell activation. In this study, we quantified the fraction of HIV-1 proviruses in resting CD4(+) T cells from patients on suppressive antiretroviral therapy that were reactivated ex vivo with SAHA or antibodies to CD3/CD28. At concentrations of SAHA achieved clinically, only 0.079% of proviruses in resting CD4(+) T cells were reactivated to produce virions, compared with 1.5% of proviruses in cells treated with anti-CD3/CD28 antibodies after correcting for spontaneous virion production in the medium control. A significant positive correlation (ρ = 0.67, P < 0.001) was found between levels of virions in the supernatant and unspliced cellular HIV-1 RNA following anti-CD3/CD28 treatment, but not following SAHA treatment (ρ = 0.21, P = 0.99). These results reveal that the majority of HIV-1 proviruses are not reactivated by current therapeutic approaches and that more effective means of reversing proviral latency will likely be required to deplete HIV-1 reservoirs.

Antiretroviral treatment in HIV-infected infants and young children: novel issues raised by the Mississippi baby

The recent case report of an HIV-infected child in Mississippi with viral control post-antiretroviral therapy (ART) interruption has sparked interest in the possibility of 'functional cure' in infants if they initiate ART very soon after birth. The 'Mississippi baby' also raises many new questions around the clinical care of HIV-infected infants and young children, including when treatment should be initiated, why treatment should be initiated, what treatment should be initiated, and how to identify infants early enough to treat them adequately. Here, we review research conducted before the report of the 'Mississippi baby' highlighting the important new issues that now need to be taken into consideration.