Virological Blips and Predictors of Post Treatment Viral Control After Stopping ART Started in Primary HIV Infection

Early antiretroviral therapy favors post-treatment SIV control associated with the expansion of enhanced memory CD8+ T-cells

HIV remission can be achieved in some people, called post-treatment HIV controllers, after antiretroviral treatment discontinuation. Treatment initiation close to the time of infection was suggested to favor post-treatment control, but the circumstances and mechanisms leading to this outcome remain unclear. Here we evaluate the impact of early (week 4) vs. late (week 24 post-infection) treatment initiation in SIVmac251-infected male cynomolgus macaques receiving 2 years of therapy before analytical treatment interruption. We show that early treatment strongly promotes post-treatment control, which is not related to a lower frequency of infected cells at treatment interruption. Rather, early treatment favors the development of long-term memory CD8+ T cells with enhanced proliferative and SIV suppressive capacity that are able to mediate a robust secondary-like response upon viral rebound. Our model allows us to formally demonstrate a link between treatment initiation during primary infection and the promotion of post-treatment control and provides results that may guide the development of new immunotherapies for HIV remission.

Understanding participant perspectives around HIV-1 cure-related studies involving antiretroviral analytical treatment interruptions in the United Kingdom

Background

To test efficacy, HIV cure-related trials often require a period of intensively monitored interruption of antiretroviral therapy (ART) (analytical treatment interruption or ATI). As individuals who started ART during primary HIV-1 infection (PHI) are often recruited, we have asked people already enrolled into an observational PHI study about their willingness and concerns around participating in cure-related studies involving ATIs.

Methods

People who were diagnosed with PHI and started ART, attending two London HIV clinics, provided informed consent to complete a digital survey in clinic between 21/07/21 to October 31, 2023. Questions comprised sociodemographics, motivations, concerns and practical considerations influencing willingness to participate in studies involving ATIs. Hierarchical clustering of responses was performed using the 'pheatmap' R statistical package and ranked from most to least concerned. Responses were cross-referenced with enrolment into an ATI study which recruited from this cohort.

Results

Of 352 eligible participants, 75 completed the survey. The majority were white, cisgender men who have sex with men, 34/75 (45 %) were born outside the UK. 29 (39 %) expressed interest in joining ATI studies. Participants who were interested or unsure in joining ATI studies were primarily motivated (53/65, 82 % very or moderately interested) by an altruistic desire to help scientific research. Across all participants, onward HIV transmission was the predominant concern (67/75, 89 % very or moderately concerned), and similar levels of concerns reported if the HIV-1 viral load threshold to restarting ART was increased from 500 to 50 000 copies/mL. Most participants preferred weekly (23/65, 35 %) or fortnightly (11/65, 17 %) viral load monitoring during an ATI. Before taking part in a study involving an ATI, participants stated they would prefer to discuss this with their HIV doctor (55/65, 85 %).

Conclusion

In this small survey, 39 % of respondents expressed interest in joining studies involving ATIs, primarily for altruistic reasons. Participants were more interested in joining a potential ATI study if a novel intervention was included than simply an ATI alone. The main concern expressed was risk of viral transmission. To inform practical and study design considerations for future ATI studies, unrestricted access for mitigation of transmission risk should be included, and regular, frequent viral load monitoring is preferred.

In-Depth Characterization of Full-Length Archived Viral Genomes after Nine Years of Posttreatment HIV Control

In the search for control of human immunodeficiency virus type 1 (HIV-1) infection without antiretroviral therapy, posttreatment controllers (PTCs) are models of HIV remission. To better understand their mechanisms of control, we characterized the HIV blood reservoirs of 8 PTCs (median of 9.4 years after treatment interruption) in comparison with those of 13 natural HIV infection controllers (HICs) (median of 18 years of infection) and with those of individuals receiving efficient antiretroviral therapy initiated during either primary HIV infection (PHIs; n = 8) or chronic HIV infection (CHIs; n = 6). This characterization was performed with single-genome amplification and deep sequencing. The proviral diversity, which reflects the history of past viral replication, was lower in the PTCs, PHIs, and aviremic HICs than in the blipper HICs and CHIs. The proportions of intact and defective proviruses among the proviral pool in PTCs were not significantly different from those of other groups. When looking at the quantities of proviruses per million peripheral blood mononuclear cells (PBMCs), they had similar amounts of intact proviruses as other groups but smaller amounts of defective proviruses than CHIs, suggesting a role of these forms in HIV pathogenesis. Two HICs but none of the PTCs harbored only proviruses with deletion in nef; these attenuated strains could contribute to viral control in these participants. We show, for the first time, the presence of intact proviruses and low viral diversity in PTCs long after treatment interruption, as well as the absence of evolution of the proviral quasispecies in subsequent samples. This reflects low residual replication over time. Further data are necessary to confirm these results. IMPORTANCE Most people living with HIV need antiretroviral therapy to control their infection and experience viral relapse in case of treatment interruption, because of viral reservoir (proviruses) persistence. Knowing that proviruses are very diverse and most of them are defective in treated individuals, we aimed to characterize the HIV blood reservoirs of posttreatment controllers (PTCs), rare models of drug-free remission, in comparison with spontaneous controllers and treated individuals. At a median time of 9 years after treatment interruption, which is unprecedented in the literature, we showed that the proportions and quantities of intact proviruses were similar between PTCs and other individuals. Unlike 2/7 spontaneous controllers who harbored only nef-deleted proviruses, which are attenuated strains, which could contribute to their control, no such case was observed in PTCs. Furthermore, PTCs displayed low viral genetic diversity and no evolution of their reservoirs, indicating very low residual replication, despite the presence of intact proviruses.

Progressive transformation of the HIV-1 reservoir cell profile over two decades of antiviral therapy

HIV-1 establishes a life-long reservoir of virally infected cells which cannot be eliminated by antiretroviral therapy (ART). Here, we demonstrate a markedly altered viral reservoir profile of long-term ART-treated individuals, characterized by large clones of intact proviruses preferentially integrated in heterochromatin locations, most prominently in centromeric satellite/micro-satellite DNA. Longitudinal evaluations suggested that this specific reservoir configuration results from selection processes that promote the persistence of intact proviruses in repressive chromatin positions, while proviruses in permissive chromosomal locations are more likely to be eliminated. A bias toward chromosomal integration sites in heterochromatin locations was also observed for intact proviruses in study participants who maintained viral control after discontinuation of antiretroviral therapy. Together, these results raise the possibility that antiviral selection mechanisms during long-term ART may induce an HIV-1 reservoir structure with features of deep latency and, possibly, more limited abilities to drive rebound viremia upon treatment interruptions.

Blockade of TGF-β signaling reactivates HIV-1/SIV reservoirs and immune responses in vivo

TGF-β plays a critical role in maintaining immune cells in a resting state by inhibiting cell activation and proliferation. Resting HIV-1 target cells represent the main cellular reservoir after long-term antiretroviral therapy (ART). We hypothesized that releasing cells from TGF-β-driven signaling would promote latency reversal. To test our hypothesis, we compared HIV-1 latency models with and without TGF-β and a TGF-β type 1 receptor inhibitor, galunisertib. We tested the effect of galunisertib in SIV-infected, ART-treated macaques by monitoring SIV-env expression via PET/CT using the 64Cu-DOTA-F(ab')2 p7D3 probe, along with plasma and tissue viral loads (VLs). Exogenous TGF-β reduced HIV-1 reactivation in U1 and ACH-2 models. Galunisertib increased HIV-1 latency reversal ex vivo and in PBMCs from HIV-1-infected, ART-treated, aviremic donors. In vivo, oral galunisertib promoted increased total standardized uptake values in PET/CT images in gut and lymph nodes of 5 out of 7 aviremic, long-term ART-treated, SIV-infected macaques. This increase correlated with an increase in SIV RNA in the gut. Two of the 7 animals also exhibited increases in plasma VLs. Higher anti-SIV T cell responses and antibody titers were detected after galunisertib treatment. In summary, our data suggest that blocking TGF-β signaling simultaneously increases retroviral reactivation events and enhances anti-SIV immune responses.

Viral and Host Biomarkers of HIV Remission Post Treatment Interruption

PURPOSE OF REVIEW

HIV rebound/remission after antiretroviral therapy (ART) interruption is likely influenced by (a) the size of the inducible replication-competent HIV reservoir and (b) factors in the host environment that influence immunological pressures on this reservoir. Identifying viral and/or host biomarkers of HIV rebound after ART cessation may improve the safety of treatment interruptions and our understanding of how the viral-host interplay results in post-treatment control. Here we review the predictive and functional significance of recently suggested viral and host biomarkers of time to viral rebound and post-treatment control following ART interruption.

RECENT FINDINGS

There are currently no validated viral or host biomarkers of viral rebound; however, several biomarkers have been recently suggested. A combination of viral and host factors will likely be needed to predict viral rebound and to better understand the mechanisms contributing to post-treatment control of HIV, critical steps to developing a cure for HIV infection.

Challenges and Promise of Human Immunodeficiency Virus Remission

Antiretroviral therapy effectively controls human immunodeficiency virus (HIV) replication but it is unable to fully eradicate the HIV reservoir and treatment must be life-long. Progress toward a strategy for HIV remission will require overcoming key hurdles to fill gaps in our understanding of HIV persistence, but the identification of individuals who have attained sterilizing or functional HIV cure show that such a goal is achievable. In this review, we first outline challenges in targeting the HIV reservoir, including difficulties identifying HIV-infected cells, ongoing work elucidating the complex intracellular environment that contribute to HIV latency, and barriers to reactivating and clearing the HIV reservoir. We then review reported cases of HIV sterilizing cure and explore natural models of HIV remission and the promise that such HIV spontaneous and posttreatment controllers may hold in our search for a broadly-applicable strategy for the millions of patients living with HIV.

Viral, inflammatory, and reservoir characteristics of posttreatment controllers

PURPOSE OF REVIEW

To provide an overview of studies to date that have identified posttreatment controllers (PTCs) and to explore current evidence around clinical characteristics, immune effector function, and inflammatory and viral reservoir characteristics that may underlie the control mechanism.

RECENT FINDINGS

PTCs are broadly defined as individuals capable of maintaining control of HIV replication after cessation of antiretroviral therapy (ART). While starting ART early after HIV infection is associated with PTC, genetic disposition or CD8+ T-cell function do not appear to explain this phenomenon, but these features have not been exhaustively analyzed in PTCs. A lower frequency of latently infected cells prior to stopping ART has been associated with achieving PTC, including a lower level of intact HIV DNA, but more studies are needed to map the genetic location, epigenetic characteristics, and tissue distribution of the intact HIV reservoir in PTCs.

SUMMARY

Current studies are small and heterogeneous and there is a significant need to agree on a uniform definition of PTC. Many aspects of PTC are still unexplored including whether specific features of genetic disposition, immune effector functions, and/or viral reservoir characteristics play a role in PTC. A large multisite international cohort study could aide in providing the important insights needed to fully understand PTC.

Abrupt and altered cell-type specific DNA methylation profiles in blood during acute HIV infection persists despite prompt initiation of ART

HIV-1 disrupts the host epigenetic landscape with consequences for disease pathogenesis, viral persistence, and HIV-associated comorbidities. Here, we examined how soon after infection HIV-associated epigenetic changes may occur in blood and whether early initiation of antiretroviral therapy (ART) impacts epigenetic modifications. We profiled longitudinal genome-wide DNA methylation in monocytes and CD4⁺ T lymphocytes from 22 participants in the RV254/SEARCH010 acute HIV infection (AHI) cohort that diagnoses infection within weeks after estimated exposure and immediately initiates ART. We identified monocytes harbored 22,697 differentially methylated CpGs associated with AHI compared to 294 in CD4⁺ T lymphocytes. ART minimally restored less than 1% of these changes in monocytes and had no effect upon T cells. Monocyte DNA methylation patterns associated with viral load, CD4 count, CD4/CD8 ratio, and longitudinal clinical phenotypes. Our findings suggest HIV-1 rapidly embeds an epigenetic memory not mitigated by ART and support determining epigenetic signatures in precision HIV medicine.

Trial Registration:NCT00782808 and NCT00796146.

The epigenetic marker, DNA methylation, plays a key role regulating the immune system during host-pathogen interactions. Using cell-type specific DNA methylation profiling, we explored whether epigenetic changes occurred soon after HIV infection and following early treatment with anti-HIV drugs. Acute infection was associated with early DNA methylation changes in purified monocytes and CD4⁺ T cells isolated from blood. In monocytes, rapid anti-HIV treatment minimally restored DNA methylation changes associated with infection and unexpectedly had no impact in CD4⁺ T cells. DNA methylation patterns before treatment informed long term clinical outcomes including CD4⁺ T cell counts and favorable clinical phenotypes. These findings identify candidates for consideration in epigenome editing approaches in HIV prevention, treatment, and cure strategies.

Predicting Post-treatment HIV Remission: Does Size of the Viral Reservoir Matter?

Combination antiretroviral therapy (ART) suppresses human immunodeficiency virus (HIV) replication and improves immune function. However, due to the persistence of long-lived HIV reservoirs, therapy interruption almost inevitably leads to a fast viral rebound. A small percentage of individuals who are able to control HIV replication for extended periods after therapy interruption are of particular interest because they may represent a model of long-term HIV remission without ART. These individuals are characterized by a limited viral reservoir and low reservoir measures can predict post-treatment HIV remission. However, most individuals with a low reservoir still experience fast viral rebound. In this Perspective, we discuss the possible reasons behind this and propose to develop an integral profile, composed of viral and host biomarkers, that could allow the accurate prediction of post-treatment HIV remission. We also propose to incorporate information on the chromatin context of the proviral integration sites into the characterization of the HIV reservoir, as this likely influences the reactivation capacity of latent proviruses and, together with the actual number of intact proviruses, contributes to the replication competence of the reservoir.

Viral Blips After Treatment Initiation During Acute Human Immunodeficiency Virus Infection

Transient viral blips ≥20 copies/mL were observed in 16.9% of acutely treated adults with HIV. Blip incidence increased from 0.0 (95% CI, 0.0-2.9)/100 person-years after ART in Fiebig I to 15.9 (7.6-29.2) in Fiebig V. Increasing viral load and Fiebig stage at ART initiation were independently predictive of blips.

Enhanced immunovirological response in women compared to men after antiretroviral therapy initiation during acute and early HIV-1 infection: results from a longitudinal study in the French ANRS Primo cohort

Introduction

Previous studies have reported better immunovirological characteristics in women compared with men after HIV seroconversion. We investigated whether differences persisted under long‐term antiretroviral therapy (ART) in individuals treated since acute and early HIV‐1 infection (AHI).

Methods

Data were obtained for 262 women and 1783 men enrolled between 1996 and 2017 in the French multicentre ANRS PRIMO cohort. We modelled the viral response, long‐term immune recovery and HIV DNA decay in the 143 women and 1126 men who initiated ART within the first three months of infection.

Results

The participants were mostly white. The mean age was 37 years at AHI diagnosis. Pre‐ART viral loads were lower in women than men, 5.2 and 5.6 log₁₀ copies/mL (p = 0.001). After ART initiation, women more rapidly achieved viral suppression than men (adjusted hazard ratio: 1.33, 95% confidence interval 1.09 to 1.69). They also experienced a faster increase in CD4⁺ T‐cell count and CD4:CD8 ratio during the first months of treatment. Sex‐related differences in CD4⁺ T‐cell counts were more pronounced with increasing age. This led to a sustained mean difference of 99 to 168 CD4⁺ T‐cells/µL depending on age between women and men at 150 months of ART. Moreover, CD4:CD8 ratio of women was higher than that of men by 0.31, at 150 months of ART. There was no statistically significant difference between sexes for the levels of HIV DNA over time (mean estimate at the last modelling point: 1.9 log₁₀ copies/10⁶ PBMCs after 70 months of ART for both sexes).

Conclusions

The high level of immune recovery and decrease in total HIV DNA levels achieved after ART initiation during AHI reinforce the importance of early diagnosis of HIV infection and immediate ART initiation. The immunological benefit of being female increased throughout prolonged ART duration, which may give women additional protection from adverse clinical events and premature ageing.

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.

Virologic and Immunologic Features of Simian Immunodeficiency Virus Control Post-ART Interruption in Rhesus Macaques

Antiretroviral therapy (ART) cannot eradicate human immunodeficiency virus (HIV) and a rapid rebound of virus replication follows analytical treatment interruption (ATI) in the vast majority of HIV-infected individuals. Sustained control of HIV replication without ART has been documented in a subset of individuals, defined as posttreatment controllers (PTCs). The key determinants of post-ART viral control remain largely unclear. Here, we identified 7 SIV_mac239-infected rhesus macaques (RMs), defined as PTCs, who started ART 8 weeks postinfection, continued ART for >7 months, and controlled plasma viremia at <10⁴ copies/ml for up to 8 months after ATI and <200 copies/ml at the latest time point. We characterized immunologic and virologic features associated with post-ART SIV control in blood, lymph node (LN), and colorectal (RB) biopsy samples compared to 15 noncontroller (NC) RMs. Before ART initiation, PTCs had higher CD4 T cell counts, lower plasma viremia, and SIV-DNA content in blood and LN compared to NCs, but had similar CD8 T cell function. While levels of intestinal CD4 T cells were similar, PTCs had higher frequencies of Th17 cells. On ART, PTCs had significantly lower levels of residual plasma viremia and SIV-DNA content in blood and tissues. After ATI, SIV-DNA content rapidly increased in NCs, while it remained stable or even decreased in PTCs. Finally, PTCs showed immunologic benefits of viral control after ATI, including higher CD4 T cell levels and reduced immune activation. Overall, lower plasma viremia, reduced cell-associated SIV-DNA, and preserved Th17 homeostasis, including at pre-ART, are the main features associated with sustained viral control after ATI in SIV-infected RMs.IMPORTANCE While effective, antiretroviral therapy is not a cure for HIV infection. Therefore, there is great interest in achieving viral remission in the absence of antiretroviral therapy. Posttreatment controllers represent a small subset of individuals who are able to control HIV after cessation of antiretroviral therapy, but characteristics associated with these individuals have been largely limited to peripheral blood analysis. Here, we identified 7 SIV-infected rhesus macaques that mirrored the human posttreatment controller phenotype and performed immunologic and virologic analysis of blood, lymph node, and colorectal biopsy samples to further understand the characteristics that distinguish them from noncontrollers. Lower viral burden and preservation of immune homeostasis, including intestinal Th17 cells, both before and after ART, were shown to be two major factors associated with the ability to achieve posttreatment control. Overall, these results move the field further toward understanding of important characteristics of viral control in the absence of antiretroviral therapy.

Cell-associated HIV-1 RNA predicts viral rebound and disease progression after discontinuation of temporary early ART

Plasma viral load (VL) and CD4+ T cell count are widely used as biomarkers of HIV type 1 (HIV-1) replication, pathogenesis, and response to antiretroviral therapy (ART). However, the clinical potential of cell-associated (CA) HIV-1 molecular markers is much less understood. Here, we measured CA HIV-1 RNA and DNA in HIV-infected individuals treated with temporary ART initiated during primary HIV-1 infection. We demonstrate substantial predictive value of CA RNA for (a) the virological and immunological response to early ART, (b) the magnitude and time to viral rebound after discontinuation of early ART, and (c) disease progression in the absence of treatment. Remarkably, when adjusted for CA RNA, plasma VL no longer appeared as an independent predictor of any clinical endpoint in this cohort. The potential of CA RNA as an HIV-1 clinical marker, in particular as a predictive biomarker of virological control after stopping ART, should be explored in the context of HIV-1 curative interventions.

Electrocautery ablation of anal high-grade squamous intraepithelial lesions: Effectiveness and key factors associated with outcomes

BACKGROUND

Electrocautery ablation (EA) is a common treatment modality for patients with anal high-grade squamous intraepithelial lesions (HSILs), but to the authors' knowledge its effectiveness has been understudied. The objective of the current study was to determine ablation outcomes and to identify clinicopathological factors associated with postablation disease recurrence.

METHODS

A total of 330 people living with HIV with de novo intra-anal HSIL who were treated with EA from 2009 to 2016 were studied retrospectively. Using long-term, surveillance high-resolution anoscopy biopsy data, treatment failures were classified as local recurrence (HSIL noted at the treated site at the time of surveillance) or overall recurrence (HSIL noted at treated or untreated sites). The associations between these outcomes and clinical factors were analyzed using Cox proportional hazards models.

RESULTS

Approximately 88% of participants were men who have sex with men. The median age of study  participants was 45.5 years (range, 35-51 years) and approximately 49% had multiple index HSILs (range, 2-6 index HSILs). At a median of 12.2 months postablation (range, 6.3-20.9 months postablation), approximately 45% of participants had developed local recurrence whereas 60% had developed overall recurrence. Current cigarette smoking, HIV viremia (HIV-1 RNA ≥100 copies/mL), and multiple index HSILs were found to be predictive of local recurrence. Overall recurrence was more common in current smokers and those with multiple index lesions. In multivariable models that included human papillomavirus (HPV) genotypes, baseline and persistent infections with HPV-16 and/or HPV-18 were found to be significantly associated with both local and overall recurrence.

CONCLUSIONS

EA is an effective treatment modality for anal HSIL in people living with HIV, but rates of disease recurrence are substantial. Multiple index HSILs, HIV viremia, current cigarette smoking, and both baseline and persistent infection with HPV-16 and/or HPV-18 appear to negatively impact treatment success. Ongoing surveillance is imperative to capture recurrence early and improve long-term treatment outcomes.

Learning From the Exceptions: HIV Remission in Post-treatment Controllers

Among the top priorities of the HIV field is the search for therapeutic interventions that can lead to sustained antiretroviral therapy (ART)-free HIV remission. Although the majority of HIV-infected persons will experience rapid viral rebound after ART interruption, there are rare individuals, termed post-treatment controllers (PTCs), who demonstrate sustained virologic suppression for months or years after treatment cessation. These individuals are considered an ideal example of durable HIV control, with direct implications for HIV cure research. However, understanding of the mechanisms behind the capacity of PTCs to control HIV remains incomplete. This is in part due to the scarcity of PTCs identified through any one research center or clinical trial, and in part because of the limited scope of studies that have been performed in these remarkable individuals. In this review, we summarize the results of both clinical and basic research studies of PTCs to date, explore key differences between PTCs and HIV spontaneous controllers, examine potential mechanisms of post-treatment control, and discuss unanswered questions and future research directions in this field.

Post-treatment and spontaneous HIV control

PURPOSE OF REVIEW

The aim of the current review is to explore the evidence around virological remission in ART-treated and untreated individuals living with HIV. With increasing evidence and interest in post-treatment control within the HIV-cure field, it is now increasingly important to agree on definitions to allow different 'controller' phenotypes to be clearly distinguished and mechanisms compared.

RECENT FINDINGS

This review explores recent data on potential predictors and mechanisms driving spontaneous and post-treatment control. We explore data on the role of the reservoir as a determinant of control and the challenges associated with its study, including the safety of treatment interruption. We explore options around deriving a consensus on how to define different forms of control and the longer term utility of achieving remission.

SUMMARY

Post-treatment control and remission following treatment interruption are becoming increasingly common measures of intervention efficacy in cure trials. As well as a need to show treatment interruption protocols are well tolerated and acceptable, for these measures to be robust and comparable between studies, clear and consensual definitions need to be agreed.

Virological remission after antiretroviral therapy interruption in female African HIV seroconverters

INTRODUCTION

There are few data on the frequency of virological remission in African individuals after treatment with antiretroviral therapy (ART) in primary HIV infection (PHI).

METHODS

We studied participants (n = 82) from South Africa and Uganda in Short Pulse Antiretroviral Treatment at HIV-1 Seroconversion, the first trial of treatment interruption in African individuals with PHI randomized to deferred ART or 48 weeks of immediate ART. All were female and infected with non-B HIV subtypes, mainly C. We measured HIV DNA in CD4+ T cells, CD4+ cell count, plasma viral load (pVL), cell-associated HIV RNA and T-cell activation and exhaustion. We explored associations with clinical progression and time to pVL rebound after treatment interruption (n = 22). Data were compared with non-African Short Pulse Antiretroviral Treatment at HIV-1 Seroconversion participants.

RESULTS

Pretherapy pVL and integrated HIV DNA were lower in Africans compared with non-Africans (median 4.16 vs. 4.72 log10 copies/ml and 3.07 vs. 3.61 log10 copies/million CD4+ T cells, respectively; P < 0.001). Pre-ART HIV DNA in Africans was associated with clinical progression (P = 0.001, HR per log10 copies/million CD4+ T cells increase (95% CI) 5.38 (1.95-14.79)) and time to pVL rebound (P = 0.034, HR per log10 copies/ml increase 4.33 (1.12-16.84)). After treatment interruption, Africans experienced longer duration of viral remission than non-Africans (P < 0.001; HR 3.90 (1.75-8.71). Five of 22 African participants (22.7%) maintained VL less than 400 copies/ml over a median of 188 weeks following treatment interruption.

CONCLUSION

We find evidence of greater probability of virological remission following treatment interruption among African participants, although we are unable to differentiate between sex, ethnicity and viral subtype. The finding warrants further investigation.

HIV control: Is getting there the same as staying there?

In this brief review and perspective, we address the question of whether the immune responses that bring about immune control of acute HIV infection are the same as, or distinct from, those that maintain long-term viral suppression once control of viremia has been achieved. To this end, we describe the natural history of elite and post-treatment control, noting the lack of data regarding what happens acutely. We review the evidence suggesting that the two clinical phenotypes may differ in terms of the mechanisms required to achieve and maintain control, as well as the level of inflammation that persists once a steady state is achieved. We then describe the evidence from longitudinal studies of controllers who fail and studies of biologic sex (male versus female), age (children versus adults), and simian immunodeficiency virus (SIV) (pathogenic/experimental versus nonpathogenic/natural infection). Collectively, these studies demonstrate that the battle between the inflammatory and anti-inflammatory pathways during acute infection has long-term consequences, both for the degree to which control is maintained and the health of the individual. Potent and stringent control of HIV may be required acutely, but once control is established, the chronic inflammatory response can be detrimental. Interventional approaches designed to bring about HIV cure and/or remission should be nuanced accordingly.

Quantification of HIV-1 RNA Among Men Who Have Sex With Men Using an At-Home Self-Collected Dried Blood Spot Specimen: Feasibility Study

BACKGROUND

Suboptimal antiretroviral therapy (ART) adherence and disengagement in care present significant public health challenges because of the increased probability of HIV transmission. In the United States, men who have sex with men (MSM) continue to be disproportionately affected by HIV, highlighting a critical need to engage high-risk MSM living with HIV who are not engaged or retained in care.

OBJECTIVE

The aim of the study was to assess the feasibility of at-home blood self-collection and laboratory quantification of HIV-1 RNA viral load (VL) to report laboratory-based VL outcomes and compare self-reported and laboratory-reported VL.

METHODS

Between 2016 and 2017, 766 US HIV-positive MSM enrolled in a Web-based behavioral intervention were invited to participate in an at-home dried blood spot (DBS) collection study using HemaSpot-HF kits (Spot On Sciences, Inc, Austin, TX) for laboratory-quantified VL.

RESULTS

Of those invited to participate, 72.3% (554/766) enrolled in the DBS study. Most (79.2%, 439/554) men enrolled reported attempting to collect their blood, 75.5% (418/554) of participants mailed a DBS specimen to the research laboratory, and 60.8% (337/554) had an adequate blood sample for VL testing. Of the 337 specimens tested for VL by the laboratory, 52.5% (177/337) had detectable VL (median: 3508 copies/mL; range: 851-1,202,265 copies/mL). Most men (83.9%, 135/161) who returned a DBS specimen with laboratory-quantified detectable VL self-reported an undetectable VL during their last clinical visit.

CONCLUSIONS

Home collection of DBS samples from HIV-positive MSM is feasible and has the potential to support clinical VL monitoring. Discrepant laboratory HIV-1 RNA values and self-reported VL indicate a need to address perceived VL status, especially in the era of treatment as prevention. Most participants were willing to use an at-home DBS kit in the future, signaling an opportunity to engage high-risk MSM in long-term HIV care activities.

Highlights from the 22nd International AIDS Conference (AIDS 2018), 22-27 July 2018, Amsterdam, the Netherlands

Important data on the social, epidemiological and clinical aspects of HIV-1, comorbidities and hepatitis as well as data on novel antiretroviral agents and the cure agenda were presented at AIDS 2018. This report covers some of the highlights.

Combination therapy with anti-HIV-1 antibodies maintains viral suppression

HIV-1-infected individuals require lifelong antiretroviral therapy (ART) because treatment interruption leads to rapid rebound viremia. Here we report on a phase 1b clinical trial in which a combination of 3BNC117 and 10-1074, two potent monoclonal anti-HIV-1 broadly neutralizing antibodies that target independent sites on the HIV-1 envelope spike, was administered during analytical treatment interruption. Participants received three infusions of 30 mg/kg of each antibody at 0, 3 and 6 weeks. Infusions of the two antibodies were generally well tolerated. The nine enrolled individuals with antibody-sensitive latent viral reservoirs maintained suppression for 15 to > 30 weeks (median = 21 weeks), and none developed viruses resistant to both antibodies. We conclude that the combination of anti-HIV-1 monoclonal antibodies 3BNC117 and 10-1074 can maintain long-term suppression in the absence of ART in individuals with antibody-sensitive viral reservoirs.

A study on the dynamics of temporary HIV treatment to assess the controversial outcomes of clinical trials: An in-silico approach

It is still unclear under which conditions temporary combined antiretroviral therapy (cART) results in a prolonged remission after interruption. Clinical trials have contradicting reposts about the effect of cART during primary HIV infection on the disease progression. Here we propose that the apparent contradiction is due the presence of a window of opportunity for cART treatment observed in the in silico studies. We study non-linear correlations in the HIV dynamics over time using information theory. This approach requires a large dataset of CD4+ T lymphocytes and viral load concentrations over time. Since it is unfeasible to collect the required amount of data in clinical trials we use C-ImmSim, a clinically validated in silico model of the HIV infection, to simulate the HIV infection and temporary cART in 500 virtual patients for a period of 6 years post infection in time steps of 8 hours. We validate the results of our model with two published clinical trials of temporary cART in acute infection and analyse the impact of cART on the immune response. Our quantitative analysis predicts a “window of opportunity” of about ten months after the acute phase during which a temporary cART has significantly longer-lasting beneficial effects on the immune system as compared to treatment during the chronic phase. This window may help to explain the controversial outcomes of clinical trials that differ by the starting time and duration of the short-term course cART and provides a critical insight to develop appropriate protocols for future clinical trials.

Immune Interventions to Eliminate the HIV Reservoir

Inducing HIV remission is a monumental challenge. A potential strategy is the "kick and kill" approach where latently infected cells are first activated to express viral proteins and then eliminated through cytopathic effects of HIV or immune-mediated killing. However, pre-existing immune responses to HIV cannot eradicate HIV infection due to the presence of escape variants, inadequate magnitude, and breadth of responses as well as immune exhaustion. The two major approaches to boost immune-mediated elimination of infected cells include enhancing cytotoxic T lymphocyte mediated killing and harnessing antibodies to eliminate HIV. Specific strategies include increasing the magnitude and breadth of T cell responses through therapeutic vaccinations, reversing the effects of T cell exhaustion using immune checkpoint inhibition, employing bispecific T cell targeting immunomodulatory proteins or dual-affinity re-targeting molecules to direct cytotoxic T lymphocytes to virus-expressing cells and broadly neutralizing antibody infusions. Methods to steer immune responses to tissue sites where latently infected cells are located need to be further explored. Ultimately, strategies to induce HIV remission must be tolerable, safe, and scalable in order to make a global impact.