HIV post-treatment controllers have distinct immunological and virological features.

HIV post-treatment controllers (PTCs) are rare individuals who maintain low levels of viremia after stopping antiretroviral therapy (ART). Understanding the mechanisms of HIV post-treatment control will inform development of strategies aiming at achieving HIV functional cure. In this study, we evaluated 22 PTCs from 8 AIDS Clinical Trials Group (ACTG) analytical treatment interruption (ATI) studies who maintained viral loads ≤400 copies/mL for ≥24 wk. There were no significant differences in demographics or frequency of protective and susceptible human leukocyte antigen (HLA) alleles between PTCs and post-treatment noncontrollers (NCs, n = 37). Unlike NCs, PTCs demonstrated a stable HIV reservoir measured by cell-associated RNA (CA-RNA) and intact proviral DNA assay (IPDA) during analytical treatment interruption (ATI). Immunologically, PTCs demonstrated significantly lower CD4+ and CD8+ T cell activation, lower CD4+ T cell exhaustion, and more robust Gag-specific CD4+ T cell responses and natural killer (NK) cell responses. Sparse partial least squares discriminant analysis (sPLS-DA) identified a set of features enriched in PTCs, including a higher CD4+ T cell% and CD4+/CD8+ ratio, more functional NK cells, and a lower CD4+ T cell exhaustion level. These results provide insights into the key viral reservoir features and immunological profiles for HIV PTCs and have implications for future studies evaluating interventions to achieve an HIV functional cure.

Impact of antiretroviral therapy during primary HIV infection on T-cell immunity after treatment interruption.

This study aims to understand the impact of early antiretroviral therapy (ART) on HIV-specific T-cell responses measured after treatment interruption may inform strategies to deliver ART-free immune-mediated viral suppression. HIV-specific T-cell immunity was analysed using gamma interferon enzyme-linked immunospot assays in two studies. SPARTAC included individuals with primary HIV infection randomised to 48 weeks of ART (n = 24) or no immediate therapy (n = 37). The PITCH (n = 7) cohort started antiretroviral therapy in primary infection for at least one year, followed by TI. In SPARTAC, participants treated in PHI for 48 weeks followed by TI for 12 weeks, and those who remained untreated for 60 weeks made similar HIV Gag-directed responses (both magnitude and breadth) at week 60. However, the treated group made a greater proportion of novel HIV Gag-directed responses by Week 60, suggestive of a greater reserve to produce new potentially protective responses. In the more intensively followed PITCH study, 6/7 participants showed dominant Gag and/or Pol-specific responses post-TI compared with pre-TI. Although early ART in PHI was not associated with major differences in HIV-specific immunity following TI compared with untreated participants, the potential to make more new Gag-directed responses warrants further investigation as this may inform strategies to achieve ART-free control.

Definition of Virological Endpoints Improving the Design of Human Immunodeficiency Virus (HIV) Cure Strategies Using Analytical Antiretroviral Treatment Interruption.

BACKGROUND: Analytical treatment interruption (ATI) is the gold standard in HIV research for assessing the capability of new therapeutic strategies to control viremia without antiretroviral treatment (ART). The viral setpoint is commonly used as endpoint to evaluate their efficacy. However, in line with recommendations from a consensus meeting, to minimize the risk of increased viremia without ART, trials often implement short ATI phases and stringent virological ART restart criteria. This approach can limit the accurate observation of the setpoint. METHODS: We analyzed viral dynamics in 235 people with HIV from 3 trials, examining virological criteria during ATI phases. Time-related (eg time to rebound, peak, and setpoint) and viral load magnitude-related criteria (peak, setpoint, and time-averaged AUC [nAUC]) were described. Spearman correlations were analyzed to identify (1) surrogate endpoints for setpoint and (2) optimal virological ART restart criteria mitigating the risks of ART interruption and the evaluation of viral control. RESULTS: Comparison of virological criteria between trials showed strong dependencies on ATI design. Similar correlations were found across trials, with nAUC the most strongly correlated with the setpoint, with correlations >0.70. A threshold >100 000 copies/mL for 2 consecutive measures is requested as a virological ART restart criterion. CONCLUSIONS: Our results are in line with recommendations and emphasize the benefits of an ATI phase >12 weeks, with regular monitoring, and a virological ART restart criterion of 10 000 copies/mL to limit the risk for patients while capturing enough information to keep nAUC as an optimal proxy to the setpoint.

Transcriptomic Signatures of Human Immunodeficiency Virus Post-Treatment Control.

Posttreatment controllers (PTCs) are rare HIV-infected individuals who can limit viral rebound after antiretroviral therapy interruption (ATI), but the mechanisms of this remain unclear. To investigate these mechanisms, we quantified various HIV RNA transcripts (via reverse transcription droplet digital PCR [RT-ddPCR]) and cellular transcriptomes (via RNA-seq) in blood cells from PTCs and noncontrollers (NCs) before and two time points after ATI. HIV transcription initiation did not significantly increase after ATI in PTCs or in NCs, whereas completed HIV transcripts increased at early ATI in both groups and multiply-spliced HIV transcripts increased only in NCs. Compared to NCs, PTCs showed lower levels of HIV DNA, more cell-associated HIV transcripts per total RNA at all times, no increase in multiply-spliced HIV RNA at early or late ATI, and a reduction in the ratio of completed/elongated HIV RNA after early ATI. NCs expressed higher levels of the IL-7 pathway before ATI and expressed higher levels of multiple cytokine, inflammation, HIV transcription, and cell death pathways after ATI. Compared to the baseline, the NCs upregulated interferon and cytokine (especially TNF) pathways during early and late ATI, whereas PTCs upregulated interferon and p53 pathways only at early ATI and downregulated gene translation during early and late ATI. In NCs, viral rebound after ATI is associated with increases in HIV transcriptional completion and splicing, rather than initiation. Differences in HIV and cellular transcription may contribute to posttreatment control, including an early limitation of spliced HIV RNA, a delayed reduction in completed HIV transcripts, and the differential expression of the IL-7, p53, and TNF pathways. IMPORTANCE The findings presented here provide new insights into how HIV and cellular gene expression change after stopping ART in both noncontrollers and posttreatment controllers. Posttreatment control is associated with an early ability to limit increases in multiply-spliced HIV RNA, a delayed (and presumably immune-mediated) ability to reverse an initial rise in processive/completed HIV transcripts, and multiple differences in cellular gene expression pathways. These differences may represent correlates or mechanisms of posttreatment control and may provide insight into the development and/or monitoring of therapeutic strategies that are aimed at a functional HIV cure.

Characteristics, predictors and consequences of tuberculosis treatment interruption: A multicentre retrospective cohort study.

OBJECTIVES: Treatment interruption is associated with poor tuberculosis (TB) treatment outcomes and increased drug resistance. To address the issue, we aimed to investigate the characteristics, predictors and consequences of treatment interruption. METHODS: We conducted a retrospective cohort study by retrieving 4 years (2018-2021) of TB patients' records at 10 public health clinics in Sarawak, Malaysia. Adult patients (≥18 years) with drug-susceptible TB were selected. Treatment interruption was defined as ≥2 weeks of cumulative interruption during treatment. The Chi-square test, Mann-Whitney U test, Kaplan-Meier and Cox proportional hazards regression were used to analyse the data, with p < 0.05 being considered statistically significant. RESULTS: Out of 2953 eligible patients, 475 (16.1%) experienced TB treatment interruption. Interruptions were most frequent during the intensive phase (46.9%, n = 223), with the greatest risk within the first 4 weeks of treatment. The median time to interruption was 2 weeks in the intensive phase and the cumulative interruption probability at the end of the intensive phase was 12.9%. Notably, treatment interruption occurred during both intensive and continuation phases for 144 patients (30.3%), while the remaining 108 (22.7%) experienced interruptions only during the continuation phase with a median time to interruption of 16 weeks. Three predictors were identified to increase the risk of treatment interruption: adverse drug reaction (aHR = 8.53, 95% Cl: 6.73-10.82), smoking (aHR = 2.67, 95% Cl: 2.03-3.53) and illicit drug use (aHR = 1.88, 95% Cl: 1.03-3.45). Conversely, underlying diabetes was associated with a reduced likelihood of treatment interruption (aHR = 0.72, 95% Cl: 0.58-0.90). Treatment interruption led to significant differences in treatment restarts (62.3% vs. 0.7%), changes in medications (47.8% vs. 4.9%), prolonged treatment duration (247 days [IQR = 105] vs. 194 days [IQR = 44.3]) and lower successful outcomes (86.5% vs. 99.9%). CONCLUSION: Understanding the temporal characteristics, predictors and negative consequences of treatment interruption can guide the development of time-relevant approaches to mitigate the problem.

Optimal STI controls for HIV patients based on an efficient deep Q learning method.

We investigate an efficient computational tool to suggest useful treatment regimens for people infected with the human immunodeficiency virus (HIV). Structured treatment interruption (STI) is a regimen in which therapeutic drugs are periodically administered and withdrawn to give patients relief from an arduous drug therapy. Numerous studies have been conducted to find better STI treatment strategies using various computational tools with mathematical models of HIV infection. In this paper, we leverage a modified version of the double deep Q network with prioritized experience replay to improve the performance of classic deep learning algorithms. Numerical simulation results show that our methodology produces significantly more optimal cost values for shorter treatment periods compared to other recent studies. Furthermore, our proposed algorithm performs well in one-day segment scenarios, whereas previous studies only reported results for five-day segment scenarios.

Three-stage modeling of HIV infection and implications for antiretroviral therapy.

We consider a deterministic model of HIV infection that involves macrophages as a long-term active reservoir to describe all three stages of the disease process: the acute stage, chronic infection, and the transition to AIDS. The proposed model is shown to retain crucial properties, such as the positivity of solutions, regardless of variations in model parameters. A dynamical analysis is performed to identify the local stability properties of the viral clearance steady state. This analysis illustrates how chronically infected macrophages can explain the progression to AIDS and provoke viral explosion, while previous models do not. We further demonstrate that the infected T-cell population, even if not responsible for the majority of new infections that lead to viral explosion, may contribute significantly to the transition amongst the three stages of infection. Moreover, we explore the implications of the model for the administration of antiretroviral therapy (ART) and provide quantitative estimates that emphasize the time sensitive nature of treatment initiation and the level of drug efficacy. Finally, we study the effects of treatment interruption on the disease dynamics predicted by the model and elucidate the influence of both interruption time and duration.

Comparison of Different Prediction Models for Unplanned Interruption of Continuous Renal Replacement Treatment: A Systematic Review of Qualitative Analyses.

INTRODUCTION: This study will systematically search and evaluate the prediction models for unplanned interruption of continuous renal replacement treatment (CRRT) and to provide a reference for building a higher quality prediction model for unplanned interruption of CRRT. METHODS: PubMed, Embase, Cochrane Library, CINAHL, China National Knowledge Infrastructure (CNKI), SinoMed, and Wanfang Database were systematically searched for studies on prediction models for unexpected interruption of CRRT. The languages were limited to Chinese and English. The search time limit was from the establishment of the database to June 30, 2023. Two researchers screened the literature and extracted the data independently, and the risk of bias and applicability of the included literature were analyzed using the risk of bias assessment tool for predictive model studies. RESULTS: A total of nine studies were included, and the area under the receiver operating characteristic curve ranged from 0.679 to 0.997. The applicability of the prediction model in seven studies was good and in two studies was poor. CONCLUSION: More attention should be paid to the effectiveness of different risk assessment methods in future construction, so as to obtain better risk prediction models with high accuracy and provide certain reference and basis for formulating relevant prevention strategies.

The Effect of HIV Treatment Interruption on Subsequent Immunological Response.

Recovery of CD4-positive T lymphocyte count after initiation of antiretroviral therapy (ART) has been thoroughly examined among people with human immunodeficiency virus infection. However, immunological response after restart of ART following care interruption is less well studied. We compared CD4 cell-count trends before disengagement from care and after ART reinitiation. Data were obtained from the East Africa International Epidemiology Databases to Evaluate AIDS (IeDEA) Collaboration (2001-2011; n = 62,534). CD4 cell-count trends before disengagement, during disengagement, and after ART reinitiation were simultaneously estimated through a linear mixed model with 2 subject-specific knots placed at the times of disengagement and treatment reinitiation. We also estimated CD4 trends conditional on the baseline CD4 value. A total of 10,961 patients returned to care after disengagement from care, with the median gap in care being 2.7 (interquartile range, 2.1-5.4) months. Our model showed that CD4 cell-count increases after ART reinitiation were much slower than those before disengagement. Assuming that disengagement from care occurred 12 months after ART initiation and a 3-month treatment gap, CD4 counts measured at 3 years since ART initiation would be lower by 36.5 cells/µL than those obtained under no disengagement. Given that poorer CD4 restoration is associated with increased mortality/morbidity, specific interventions targeted at better retention in care are urgently required.

cART Restores Transient Responsiveness to IFN Type 1 in HIV-Infected Humanized Mice.

The lack of a human immunodeficiency virus (HIV) cure has heightened interest in immunotherapy. As such, type I interferons (IFNs), in particular, IFN alpha (IFN-α), have gained renewed attention. However, HIV pathogenesis is driven by sustained IFN-mediated immune activation, and the use of IFNs is rather controversial. The following questions therein remain: (i) which IFN-α subtype to use, (ii) at which regimen, and (iii) at what time point in HIV infection it might be beneficial. Here, we used IFN-α14 modified by PASylation for its long half-life in vivo to eventually treat HIV infection. We defined the IFN dosing regimen based on the maximum increase in interferon-stimulated gene (ISG) expression 6 h after its administration and a return to baseline of ubiquitin-specific protease 18 (USP18) prior to the next dose. Notably, USP18 is the major negative regulator of type I IFN signaling. HIV infection resulted in increased ISG expression levels in humanized mice. Intriguingly, high baseline ISG levels correlated with lower HIV load. No effect was observed on HIV replication when PASylated IFN-α14 was administered in the chronic phase. However, combined antiretroviral therapy (cART) restored responsiveness to IFN, and PASylated IFN-α14 administered during analytical cART interruption resulted in a transiently lower HIV burden than in the mock-treated mice. In conclusion, cART-mediated HIV suppression restored transient IFN responsiveness and provided a potential window for immunoenhancing therapies in the context of analytical cART interruption. IMPORTANCE cART is highly efficient in suppressing HIV replication in HIV-infected patients and has resulted in a dramatic reduction in morbidity and mortality in HIV-infected people, yet it does not cure HIV infection. In addition, cART has several disadvantages. Thus, the HIV research community is exploring novel ways to control HIV infection for longer periods without cART. Here, we explored novel, long-acting IFN-α14 for its efficacy to control HIV replication in HIV-infected humanized mice. We found that IFN-α14 had no effect on chronic HIV infection. However, when mice were treated first with cART, we observed a transiently restored responsiveness to INF and a transiently lower HIV burden after stopping cART. These data emphasize (i) the value of cART-mediated HIV suppression and immune reconstitution in creating a window of opportunity for exploring novel immunotherapies, (ii) the potential of IFNs for constraining HIV, and (iii) the value of humanized mice for exploring novel immunotherapies.

HIV infection dynamics and viral rebound: Modeling results from humanized mice.

Despite years of combined antiretroviral therapy (cART), HIV persists in infected individuals. The virus also rebounds after the cessation of cART. The sources contributing to viral persistence and rebound are not fully understood. When viral rebound occurs, what affects the time to rebound and how to delay the rebound remain unclear. In this paper, we started with the data fitting of an HIV infection model to the viral load data in treated and untreated humanized myeloid-only mice (MoM) in which macrophages serve as the target of HIV infection. By fixing the parameter values for macrophages from the MoM fitting, we fit a mathematical model including the infection of two target cell populations to the viral load data from humanized bone marrow/liver/thymus (BLT) mice, in which both CD4+ T cells and macrophages are the target of HIV infection. Data fitting suggests that the viral load decay in BLT mice under treatment has three phases. The loss of infected CD4+ T cells and macrophages is a major contributor to the first two phases of viral decay, and the last phase may be due to the latent infection of CD4+ T cells. Numerical simulations using parameter estimates from the data fitting show that the pre-ART viral load and the latent reservoir size at treatment cessation can affect viral growth rate and predict the time to viral rebound. Model simulations further reveal that early and prolonged cART can delay the viral rebound after cessation of treatment, which may have implications in the search for functional control of HIV infection.

Treatment interruptions and community connectedness among gbMSM living with HIV in Metro Vancouver, Canada.

HIV treatment interruptions are a major public health concern that demonstrate a lack of engagement in care and is detrimental to the health of people living with HIV. Community connectedness have demonstrated a protective effect for psychosocial health but are not well understood for HIV treatment outcomes. We explored associations between community connectedness and treatment interruptions among gay, bisexual and other men who have sex with men (gbMSM) living with HIV in Vancouver, British Columbia. We analyzed survey data from the Momentum Health Study and identified treatment interruptions through data linkages with the provincial HIV Drug Treatment Program as episodes lasting more than 60 days beyond an expected antiretroviral therapy refill date from February 2012 to July 2019. We built a mixed-effects logistic regression model, adjusting for confounders. Of 213 gbMSM living with HIV, 54 experienced treatment interruption (25.4%) over a median five-year follow-up. Multivariable results found the number gbMSM who spoken to in the past month (aOR = 0.995; 95% CI = 0.991, 1.000 (per 100-unit increase)) and attending a gay community meeting more than once per month (aOR = 0.32; 95% CI = 0.11, 0.89) were associated with lower odds of treatment interruptions. These results highlight the importance of social connections in facilitating effective HIV care.

Interruption of imatinib in advanced gastrointestinal stromal tumor after prolonged imatinib maintenance in the absence of gross tumor lesions.

BACKGROUND: Current guidelines recommend indefinite imatinib treatment for advanced gastrointestinal stromal tumor (GIST) patients. Imatinib-refractory progression-free survival (PFS) and overall survival were previously reported not to differ between GIST patients who interrupted imatinib and those who did not. METHODS: Clinical outcomes of 77 consecutive patients with recurrent or metastatic GIST who interrupted imatinib treatment after maintaining years of imatinib treatment in the absence of gross tumor lesions were retrospectively analyzed. Associations between clinical factors and progression-free survival (PFS) following imatinib interruption were analyzed. RESULTS: The median time from the absence of gross tumor lesions to imatinib interruption was 61.5 months. Since imatinib interruption, the median PFS was 19.6 months, and 4 patients (26.3%) remained progression-free for longer than 5 years. Among the patients who had progressive disease following the interruption, imatinib re-introduction led to an 88.6% objective response rate and a 100% disease control rate. Complete removal of the initial gross tumor lesion(s) and complete removal of the residual gross tumor lesion(s) by local treatment (vs. no local treatment or residual lesions after local treatment) were independently associated with favorable PFS. CONCLUSION: Interruption of imatinib following prolonged maintenance in the absence of gross tumor lesions led to disease progression in the majority of cases. However, re-introduction of imatinib resulted in effective tumor control. Unmaintained remission seems to be possible in some patients with metastatic or recurrent GIST after a prolonged remission with imatinib if there is complete removal of any gross tumor lesions.

Impact of weight loss on treatment interruption and unplanned hospital admission in head and neck cancer patients undergoing curative (chemo)-radiotherapy in Hong Kong.

PURPOSE: Malnutrition is highly prevalent in head and neck cancer (HNC) patients, with weight loss being one of the major nutritional indicators. The objective of this study was to investigate the impact of weight loss on treatment interruptions and unplanned hospital admissions in HNC patients undergoing radiotherapy (RT) with or without chemotherapy. METHODS: In this retrospective cohort study, consecutive HNC patients who started RT between January 2011 and December 2019 were included. Data from a total of 1086 subjects with 747 (68.8%) nasopharyngeal carcinomas (NPCs) and 31.2% (N=339) non-NPC patients were analysed. Body weight (BW) was measured before, during, and after RT treatment. Factors associated with ≥10% weight loss, treatment interruption, and unplanned admissions were analysed using multivariate logistic regression. RESULTS: The prevalence of ≥10% weight loss was 26.8% (N=288), with 32.7% (N=243) in NPC and 13.5% (N=45) in non-NPC patients. The prevalence of RT delay in patients with ≥10% vs. <10% weight loss was 6.2% vs. 7.0% (p=0.668) in NPC patients and 42.2% vs. 50.5% (p=0.300) in non-NPC patients. The prevalence of unplanned admissions in patients with ≥10% vs. <10% weight loss was 51.9% vs. 25.3% (p<0.001) in NPC patients and 68.9% vs. 27.0% (p<0.001) in non-NPC patients. CONCLUSION: In our study, ≥10% weight loss was found to be associated with a higher rate of unplanned admissions but not with RT delay or chemotherapy interruption. CLINICAL IMPLICATIONS: With the knowledge of the impact of weight loss on hospital admissions and the characteristics of patients with weight loss, nutritional intervention can be effectively focused on the stratification of patients for intensive nutritional support to reduce weight loss.

It's all about connection: Determinants of social support and the influence on HIV treatment interruptions among people living with HIV in British Columbia, Canada.

BACKGROUND: Social support has previously been found to be associated with improved health outcomes of individuals managing chronic illnesses, including amongst people living with HIV (PLWH). For women and people who use injection drugs who continue to experience treatment disparities in comparison to other PLWH, social support may have potential in facilitating better treatment engagement and retention. In this analysis, we examined determinants of social support as measured by the Medical Outcomes Study - Social Support Survey (MOS-SSS) scale, and quantified the relationship between MOS-SSS and HIV treatment interruptions (TIs) among PLWH in British Columbia, Canada. METHODS: Between January 2016 and September 2018, we used purposive sampling to enroll PLWH, 19 years of age or older living in British Columbia into the STOP HIV/AIDS Program Evaluation study. Participants completed a baseline survey at enrolment which included the MOS-SSS scale, where higher MOS-SSS scores indicated greater social support. Multivariable linear regression modeled the association between key explanatory variables and MOS-SSS scores, whereas multivariable logistic regression modeled the association between MOS-SSS scores and experiencing TIs while controlling for confounders. RESULTS: Among 644 PLWH, we found that having a history of injection drug use more than 12 months ago but not within the last 12 months, self-identifying as Indigenous, and sexual activity in the last 12 months were positively associated with MOS-SSS, while being single, divorced, or dating (vs. married), experiences of lifetime violence, and diagnosis of a mental health disorder were inversely associated. In a separate multivariable model adjusted for gender, ethnicity, recent homelessness, sexual activity in the last 12 months, and recent injection drug use, we found that higher MOS-SSS scores, indicating more social support, were associated with a lower likelihood of HIV treatment interruptions (adjusted odds ratio: 0.90 per 10-unit increase, 95% confidence interval: 0.83, 0.99). CONCLUSIONS: Social support may be an important protective factor in ensuring HIV treatment continuity among PLWH. Future research should examine effective means to build social support among communities that have potential to promote increased treatment engagement.

A minor population of macrophage-tropic HIV-1 variants is identified in recrudescing viremia following analytic treatment interruption.

HIV-1 persists in cellular reservoirs that can reignite viremia if antiretroviral therapy (ART) is interrupted. Therefore, insight into the nature of those reservoirs may be revealed from the composition of recrudescing viremia following treatment cessation. A minor population of macrophage-tropic (M-tropic) viruses was identified in a library of recombinant viruses constructed with individual envelope genes that were obtained from plasma of six individuals undergoing analytic treatment interruption (ATI). M-tropic viruses could also be enriched from post-ATI plasma using macrophage-specific (CD14) but not CD4+ T cell-specific (CD3) antibodies, suggesting that M-tropic viruses had a macrophage origin. Molecular clock analysis indicated that the establishment of M-tropic HIV-1 variants predated ATI. Collectively, these data suggest that macrophages are a viral reservoir in HIV-1-infected individuals on effective ART and that M-tropic variants can appear in rebounding viremia when treatment is interrupted. These findings have implications for the design of curative strategies for HIV-1.

Evaluating lncRNA Expression Patterns during HIV-1 Treatment Interruption.

Lately, the interest in long non-coding RNAs (lncRNAs) as potential drug targets and predictive markers in the context of HIV-1 has peaked, but their in vivo expression and regulation remains largely unexplored. Therefore, the present study examined lncRNA expression patterns during a clinical antiretroviral treatment interruption (ATI) trial. Peripheral blood mononuclear cells were isolated from ten patients at four timepoints: prior to ATI, 7-15 days after stop, at viral rebound and 3 months post antiretroviral therapy re-initiation. RNA was extracted and RT-qPCR on five known HIV-1-related lncRNAs (HEAL, MALAT1, NEAT1, GAS5 and NRON) was performed and correlated with HIV-1 and host marker expression. All lncRNAs correlated stronger with interferon stimulated genes (ISGs) than with HIV-1 reservoir and replication markers. However, one lncRNA, HEAL, showed significant upregulation at viral rebound during ATI compared to baseline and re-initiation of therapy (p = 0.0010 and p = 0.0094, respectively), following a similar viral-load-driven expression pattern to ISGs. In vitro knockdown of HEAL caused a significant reduction in HIV-1 infection levels, validating HEAL's importance for HIV-1 replication. We conclude that the HIV-1-promoting lncRNA HEAL is upregulated at viral rebound during ATI, most likely induced by viral cues.

Balancing Statistical Power and Risk in HIV Cure Clinical Trial Design.

BACKGROUND: Analytical treatment interruptions (ATI) are pauses of antiretroviral therapy (ART) in the context of human immunodeficiency virus (HIV) cure trials. They are the gold standard in determining if interventions being tested can achieve sustained virological control in the absence of ART. However, withholding ART comes with risks and discomforts to trial participant. We used mathematical models to explore how ATI study design can be improved to maximize statistical power, while minimizing risks to participants. METHODS: Using previously observed dynamics of time to viral rebound (TVR) post-ATI, we modelled estimates for optimal sample size, frequency, and ATI duration required to detect a significant difference in the TVR between control and intervention groups. Groups were compared using a log-rank test, and analytical and stochastic techniques. RESULTS: In placebo-controlled TVR studies, 120 participants are required in each arm to detect 30% difference in frequency of viral reactivation at 80% power. There was little statistical advantage to measuring viral load more frequently than weekly, or interrupting ART beyond 5 weeks in a TVR study. CONCLUSIONS: Current TVR HIV cure studies are underpowered to detect statistically significant changes in frequency of viral reactivation. Alternate study designs can improve the statistical power of ATI trials.

Time to Viral Rebound After Interruption of Modern Antiretroviral Therapies.

BACKGROUND: Development of human immunodeficiency virus (HIV) remission strategies requires precise information on time to HIV rebound after treatment interruption, but there is uncertainty regarding whether modern antiretroviral therapy (ART) regimens and timing of ART initiation may affect this outcome. METHODS: AIDS Clinical Trials Group (ACTG) A5345 enrolled individuals who initiated ART during chronic or early HIV infection and on suppressive ART for ≥2 years. Participants underwent carefully monitored antiretroviral interruption. ART was restarted upon 2 successive viral loads ≥1000 copies/mL. We compared participants of A5345 with participants of 6 historic ACTG treatment interruption studies. RESULTS: Thirty-three chronic-treated and 12 early-treated participants interrupted ART with evaluable time to viral rebound. Median time to viral rebound ≥1000 HIV RNA copies/mL was 22 days. Acute retroviral rebound syndrome was diagnosed in 9% of the chronic-treated and none of the early-treated individuals. All participants of the historic studies were on older protease inhibitor-based regimens, whereas 97% of A5345 participants were on integrase inhibitor-based ART. There were no differences in the timing of viral rebound comparing A5345 versus historic studies. In a combined analysis, a higher percentage of early-treated participants remained off ART at posttreatment interruption week 12 (chronic vs early: 2% vs 9%, P = .0496). One chronic-treated and one early-treated A5345 participant remained off ART for >24 weeks. All participants resuppressed after ART reinitiation. CONCLUSIONS: Early ART initiation, using either older or newer ART regimens, was associated with a significant delay in the time to HIV rebound after ART interruption, lowering the barrier for HIV remission.

Attitudes About Analytic Treatment Interruption (ATI) in HIV Remission Trials with Different Antiretroviral Therapy (ART) Resumption Criteria.

HIV remission trials often require temporary stopping of antiretroviral therapy (ART)-an approach called analytic treatment interruption (ATI). Trial designs resulting in viremia raise risks for participants and sexual partners. We conducted a survey on attitudes about remission trials, comparing ART resumption criteria (lower-risk "time to rebound" and higher-risk "sustained viremia") among participants from an acute HIV cohort in Thailand. Analyses included Wilcoxon-Ranks and multivariate logistic analysis. Most of 408 respondents supported ATI trials, with slightly higher approval of, and willingness to participate in, trials using time to rebound versus sustained viremia criteria. Less than half of respondents anticipated disclosing trial participation to partners and over half indicated uncertainty or unwillingness about whether partners would be willing to use PrEP. Willingness to participate was higher among those who rated higher trial approval, lower anticipated burden, and those expecting to make the decision independently. Our findings support acceptability of ATI trials among most respondents. Participant attitudes and anticipated behaviors, especially related to transmission risk, have implications for future trial design and informed consent.