Antiretroviral Therapy Interruption Research Articles

HIV rebound in HIV controllers is associated with a specific fecal microbiome profile.

HIV infection is associated with gut dysbiosis, and microbiome variability may affect HIV control when antiretroviral therapy (ART) is stopped. The TLR7 agonist, vesatolimod, was previously associated with a modest delay in viral rebound following analytical treatment interruption in HIV controllers (HCs). Using a retrospective analysis of fecal samples from HCs treated with vesatolimod or placebo (NCT03060447), people with chronic HIV (CH; NCT02858401) or without HIV (PWOH), we examined fecal microbiome profile in HCs before/after treatment, and in CH and PWOH. Microbiome diversity and abundance were compared between groups to investigate the association between specific phyla/species, immune biomarkers, and viral outcomes during treatment interruption. Although there were no significant differences in gut microbiome diversity between people with and without HIV, HCs, and CH shared common features that distinguished them from PWOH. there was a trend toward greater microbiome diversity among HCs. Treatment with vesatolimod reduced dysbiosis in HCs. Firmicutes positively correlated with T-cell activation, while Bacteroidetes and Euryarchaeota inversely correlated with TLR7-mediated immune activation. Specific types of fecal microbiome abundance (e.g. Alistipes putredinis) positively correlated with HIV rebound. In conclusion, variability in the composition of the fecal microbiome is associated with markers of immune activation following vesatolimod treatment and ART interruption.

Anti-PD-1 chimeric antigen receptor T cells efficiently target SIV-infected CD4+ T cells in germinal centers.

Programmed cell death protein 1 (PD-1) is an immune checkpoint marker commonly expressed on memory T cells and enriched in latently HIV-infected CD4+ T cells. We engineered an anti-PD-1 chimeric antigen receptor (CAR) to assess the impact of PD-1 depletion on viral reservoirs and rebound dynamics in SIVmac239-infected rhesus macaques (RMs). Adoptive transfer of anti-PD-1 CAR T cells was done in 2 SIV-naive and 4 SIV-infected RMs on antiretroviral therapy (ART). In 3 of 6 RMs, anti-PD-1 CAR T cells expanded and persisted for up to 100 days concomitant with the depletion of PD-1+ memory T cells in blood and tissues, including lymph node CD4+ follicular helper T (TFH) cells. Loss of TFH cells was associated with depletion of detectable SIV RNA from the germinal center (GC). However, following CAR T infusion and ART interruption, there was a marked increase in SIV replication in extrafollicular portions of lymph nodes, a 2-log higher plasma viremia relative to controls, and accelerated disease progression associated with the depletion of CD8+ memory T cells. These data indicate anti-PD-1 CAR T cells depleted PD-1+ T cells, including GC TFH cells, and eradicated SIV from this immunological sanctuary.

Future HIV epidemic trajectories in South Africa and projected long-term consequences of reductions in general population HIV testing: a mathematical modelling study

After successful intensive interventions to rapidly increase HIV awareness, coverage of antiretroviral therapy (ART), and viral suppression, HIV programmes in eastern and southern Africa are considering scaling back of some interventions, such as widespread general population HIV testing. We aimed to model whether scaling back of general population HIV testing in South Africa could result in a resurgence of the HIV epidemic or substantial slowing of declines in HIV incidence, resulting in increased long-term ART. In this modelling study, we used the Thembisa 4.5 model (a deterministic compartmental model of HIV transmission in South Africa) to project the South African HIV epidemic to 2100 assuming the continuation of 2022 epidemiological conditions and HIV programme implementation. We assessed how implementing reductions in general population HIV testing services in 2025 (while maintaining antenatal, symptom-based, and risk-based testing modalities and other HIV prevention services at 2022 levels) would affect HIV incidence and prevalence among people aged 15-49 years, the year in which incidence would reach one per 1000 people aged 15-49 years (the threshold for virtual elimination of HIV), and associated costs, as well as numbers of additional new HIV infections and AIDS-related deaths. We also modelled the effects of delaying reductions in general population testing services by 5-year increments. Additionally, we modelled the potential effects of reductions in general population testing services in combination with increases or decreases in ART interruption rates (ie, the annual rate at which people who are on ART discontinue ART) and condom usage in 2025-35. If general population HIV testing services and the HIV risk environment of 2022 were maintained, we projected that HIV incidence would steadily decline from 4·95 (95% CI 4·40-5·34) per 1000 population in 2025 to 0·14 (0·05-0·31) per 1000 in 2100, and that the so-called virtual elimination threshold of less than one new infection per 1000 population per year would be reached in 2055 (95% CI 2051-2060). Scaling back of general population HIV testing services by 25%, 50%, or 75% in 2025 delayed time to reaching the virtual elimination threshold by 5, 13, or 35 years, respectively, whereas complete cessation of general population testing would result in the threshold not being attained by 2100. Although the incidence of HIV continued to fall when general HIV testing services were reduced, our modelling suggested that, with reductions of between 25% and 100%, between 396 000 (95% CI 299 000-474 000) and 2·50 million (1·97 million-2·98 million) additional HIV infections and between 115 000 (94 000-135 000) and 795 000 (670 000-926 000) additional AIDS-related deaths would occur between 2025 and 2075, depending on the extent of reduction in testing. Delaying reductions in general population HIV testing services for 5-25 years mitigated some of these effects. HIV testing accounted for only 5% of total programmatic costs at baseline; reducing testing moderately reduced short-term total annual costs, but increased annual costs after 25 years. Increases in ART interruption and reductions in condom usage were projected to slow the decline in incidence and increase the coverage of general HIV testing services required to control transmission but did not cause rapid resurgence in HIV infections. Our modelling suggests that scaling back of general population HIV testing would not result in a resurgence of HIV infections, but would delay attainment of incidence-reduction targets and result in long-term increases in HIV infections, AIDS-related deaths, and costs (via increased need for ART provision). HIV programmes need to balance short-term potential resource savings with long-term epidemic control objectives. Bill & Melinda Gates Foundation.

HIV outcomes during the COVID-19 pandemic in people of Black ethnicities living with HIV in England.

To describe HIV care outcomes in people of Black ethnicities living in England during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; coronavirus disease 2019 [COVID-19]) pandemic. This was an observational cohort study of people of self-reported Black ethnicities attending for HIV care at nine HIV clinics across England. The primary outcome was a composite of antiretroviral therapy (ART) interruption and HIV viraemia (HIV RNA ≥200 copies/mL) ascertained via self-completed questionnaires and review of medical records. We used multivariable logistic regression to explore associations between ART interruption/HIV viraemia and demographic factors, pre-pandemic HIV immunovirological control, comorbidity status, and COVID-19 disease and vaccination status. We included 2290 people (median age 49.3 years; 56% female; median CD4 cell count 555 cells/mm3; 92% pre-pandemic HIV RNA <200 copies/mL), of whom 302 (13%) reported one or more ART interruption, 312 (14%) had documented HIV viraemia ≥200 copies/mL, and 401 (18%) experienced the composite endpoint of ART interruption/HIV viraemia. In multivariable analysis, a pre-pandemic HIV RNA <200 copies/mL (odds ratio [OR] 0.21; 95% confidence interval [CI] 0.15-0.30) and being vaccinated against SARS-CoV-2 (OR 0.41; 95% CI 0.30-0.55) were associated with reduced odds of ART interruption/HIV viraemia; pandemic-related disruptions to HIV care were common self-reported additional factors. During the COVID-19 pandemic, one in six people of Black ethnicities in this HIV cohort experienced an ART interruption/HIV viraemia. Some of these episodes resulted from pandemic-related healthcare disruptions. Associations with suboptimal engagement in HIV care pre-pandemic and not being vaccinated against SARS-CoV-2 suggest that wider health beliefs and/or poor healthcare access may have been contributory factors.

Evaluation of HIV-1 DNA levels among adolescents living with perinatally acquired HIV-1 in Yaounde, Cameroon: A contribution to paediatric HIV cure research in Sub-Saharan Africa

BackgroundWith the advent of antiretroviral therapy (ART), most children living with HIV in sub-Saharan Africa (SSA) are growing toward adolescence, with scarcity of evidence on the size of viral reservoirs to enhance paediatric cure research strategies. This study aims to compare HIV-1 proviral DNA levels according to virological response among adolescents living with perinatally acquired HIV-1 (ALPHIV) and identify associated-factors in the Cameroonian context. MethodsIn this observational cohort study, HIV-1 RNA viremia and CD4+ T-cell count were assessed through RT-PCR and flow cytometry respectively at three time-points over 18 months of observation. At the third time-point, 80 randomly-selected participants were classified as with viremia (≥50 HIV-1 copies/mL; n = 40) or without viremia (<50 HIV-1 copies/mL; n = 40); immune-competent (≥500 CD4+ T cells/mm3) or immunocompromised (<500 CD4+ T cells/mm3). Among these participants, total HIV-1 DNA load was quantified through droplet digital PCR using Bio-Rad QX200. ResultsOf the 80 randomly-selected adolescents, median [IQR] age was 15 (13-17) years, 56.2% were female, duration on ART was 9.3 [5.4–12.2] years. Among the 40 viremic ones (median viremia 7312 [283–71482]) HIV-1 copies/ml, 75.0% (30/40) were in virological failure (≥1000 HIV-1 copies/ml), while median of CD4 T cells were 494 [360–793] cell/mm3 with 48.8% (39/80) immunocompromised. No significant variation in HIV-1 RNA viremia and CD4 T cell count was observed between the three time-points, and 13.7% (11/80) adolescents remained aviremic and immune-competent throughout (stable adolescents). A positive and moderate correlation (r = 0.59; p < 0.001) was found between HIV-1 DNA levels and HIV- 1 RNA viremia. Regarding the CD4 T cell count, a negative and weak correlation (r = −0.28; p = 0.014) was found with HIV-1 DNA loads only among adolescents with viremia. Starting ART within the first year of life, ART for over 9 years and aviremia appear as predictors of low HIV-1 DNA loads. ConclusionAmong ALPHIV, high HIV-1 RNA indicates an elevated viral reservoir size, representing a drawback to cure research. Interestingly, early ART initiation and longer ARTduration lead to sustained viral control and limited HIV-1 reservoir size. As limited size of viral reservoir appears consistent with viral control and immune competence, adolescents with sustained viral control (about 14% of this target population) would be candidates for analytical ART interruptions toward establishing paediatric post-treatment controllers in SSA.

Mortality and associated factors among people living with HIV admitted at a tertiary-care hospital in Uganda: a cross-sectional study

BackgroundHospital admission outcomes for people living with HIV (PLHIV) in resource-limited settings are understudied. We describe in-hospital mortality and associated clinical-demographic factors among PLHIV admitted at a tertiary-level public hospital in Uganda.MethodsWe performed a cross-sectional analysis of routinely collected data for PLHIV admitted at Kiruddu National Referral Hospital between March 2020 and March 2023. We estimated the proportion of PLHIV who had died during hospitalization and performed logistic regression modelling to identify predictors of mortality.ResultsOf the 5,827 hospitalized PLHIV, the median age was 39 years (interquartile range [IQR] 31–49) and 3,293 (56.51%) were female. The median CD4 + cell count was 109 cells/µL (IQR 25–343). At admission, 3,710 (63.67%) were active on antiretroviral therapy (ART); 1,144 (19.63%) had interrupted ART > 3 months and 973 (16.70%) were ART naïve. In-hospital mortality was 26% (1,524) with a median time-to-death of 3 days (IQR 1–7). Factors associated with mortality (with adjusted odds ratios) included ART interruption, 1.33, 95% confidence intervals (CI) 1.13–1.57, p 0.001; CD4 + counts ≤ 200 cells/µL 1.59, 95%CI 1.33–1.91, p < 0.001; undocumented CD4 + cell count status 2.08, 95%CI 1.73–2.50, p < 0.001; impaired function status 7.35, 95%CI 6.42–8.41, p < 0.001; COVID-19 1.70, 95%CI 1.22–2.37, p 0.002; liver disease 1.77, 95%CI 1.36–2.30, p < 0.001; co-infections 1.53, 95%CI 1.32–1.78, p < 0.001; home address > 20 km from hospital 1.23, 95%CI 1.04–1.46, p 0.014; hospital readmission 0.7, 95%CI 0.56–0.88, p 0.002; chronic lung disease 0.62, 95%CI 0.41–0.92, p 0.019; and neurologic disease 0.46, 95%CI 0.32–0.68, p < 0.001.ConclusionOne in four admitted PLHIV die during hospitalization. Identification of risk factors (such as ART interruption, function impairment, low/undocumented CD4 + cell count), early diagnosis and treatment of co-infections and liver disease could improve outcomes.

The impact of the COVID-19 pandemic on people living with HIV: a cross-sectional study in Caracas, Venezuela

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic has disrupted multiple health services, including human immunodeficiency virus (HIV) testing, care, and treatment services, jeopardizing the achievement of the Joint United Nations Programme on HIV/AIDS 90-90-90 global target. While there are limited studies assessing the impact of the COVID-19 pandemic on people living with HIV (PLHIV) in Latin America, there are none, to our knowledge, in Venezuela. This study aims to assess the impact of the COVID-19 pandemic among PLHIV seen at the outpatient clinic of a reference hospital in Venezuela.MethodsWe conducted a cross-sectional study among PLHIV aged 18 years and over seen at the Infectious Diseases Department of the University Hospital of Caracas, Venezuela between March 2021 and February 2022.ResultsA total of 238 PLHIV were included in the study. The median age was 43 (IQR 31–55) years, and the majority were male (68.9%). Most patients (88.2%, n = 210) came for routine check-ups, while 28 (11.3%) were newly diagnosed. The majority of patients (96.1%) were on antiretroviral therapy (ART), but only 67.8% had a viral load test, with almost all (95.6%) being undetectable. Among those who attended regular appointments, 11.9% reported missing at least one medical consultation, and 3.3% reported an interruption in their ART refill. More than half of the patients (55.5%) had received at least one dose of the COVID-19 vaccine, while the rest expressed hesitancy to get vaccinated. Most patients with COVID-19 vaccine hesitancy were male (65.1%), younger than 44 years (57.5%), employed (47.2%), and had been diagnosed with HIV for less than one year (33%). However, no statistically significant differences were found between vaccinated patients and those with COVID-19 vaccine hesitancy. Older age was a risk factor for missing consultations, while not having an alcoholic habit was identified as a protective factor against missing consultations.ConclusionThis study found that the COVID-19 pandemic had a limited impact on adherence to medical consultations and interruptions in ART among PLHIV seen at the University Hospital of Caracas, Venezuela.

Lymphoid tissues contribute to plasma viral clonotypes early after antiretroviral therapy interruption in SIV-infected rhesus macaques.

The rebound-competent viral reservoir, composed of a virus that is able to persist during antiretroviral therapy (ART) and mediate reactivation of systemic viral replication and rebound viremia after ART interruption (ATI), remains the biggest obstacle to treating HIV infection. A better understanding of the cellular and tissue origins and the dynamics of viral populations that initiate rebound upon ATI could help develop therapeutic strategies for reducing the rebound-competent viral reservoir. In this study, barcoded simian immunodeficiency virus (SIV), SIVmac239M, was used to infect rhesus macaques to enable monitoring of viral barcode clonotypes contributing to virus detectable in plasma after ATI. Blood and tissues from secondary lymphoid organs (spleen, mesenteric lymph nodes, and inguinal lymph nodes) and from the colon, ileum, lung, liver, and brain were analyzed using viral barcode sequencing, intact proviral DNA assay, single-cell RNA sequencing, and combined CODEX and RNAscope in situ hybridization. Four of seven animals had viral barcodes detectable by deep sequencing of plasma at necropsy, although plasma viral RNA remained below 22 copies per milliliter. Among the tissues studied, mesenteric lymph nodes, inguinal lymph nodes, and spleen contained viral barcodes detected in plasma. CD4+ T cells were the main cell type harboring viral RNA after ATI. Furthermore, T cell zones in lymphoid tissues showed higher viral RNA abundance than B cell zones for most animals. These findings are consistent with lymphoid tissues contributing to the virus present in plasma early after ATI.

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

BackgroundTo 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 infection (PHI) are often recruited, we asked people already enrolled in an observational PHI study about their willingness and concerns around participating in cure-related studies involving ATIs. MethodsPeople 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 of sociodemographics, motivations, concerns and practical considerations influencing willingness to participate in studies involving ATI. 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. ResultsOf 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 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 %). ConclusionIn 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.

Preferential selection of viral escape mutants by CD8+ T cell 'sieving' of SIV reactivation from latency.

HIV rapidly rebounds after interruption of antiretroviral therapy (ART). HIV-specific CD8+ T cells may act to prevent early events in viral reactivation. However, the presence of viral immune escape mutations may limit the effect of CD8+ T cells on viral rebound. Here, we studied the impact of CD8 immune pressure on post-treatment rebound of barcoded SIVmac293M in 14 Mamu-A*01 positive rhesus macaques that initiated ART on day 14, and subsequently underwent two analytic treatment interruptions (ATIs). Rebound following the first ATI (seven months after ART initiation) was dominated by virus that retained the wild-type sequence at the Mamu-A*01 restricted Tat-SL8 epitope. By the end of the two-month treatment interruption, the replicating virus was predominantly escaped at the Tat-SL8 epitope. Animals reinitiated ART for 3 months prior to a second treatment interruption. Time-to-rebound and viral reactivation rate were significantly slower during the second treatment interruption compared to the first. Tat-SL8 escape mutants dominated early rebound during the second treatment interruption, despite the dominance of wild-type virus in the proviral reservoir. Furthermore, the escape mutations detected early in the second treatment interruption were well predicted by those replicating at the end of the first, indicating that escape mutant virus in the second interruption originated from the latent reservoir as opposed to evolving de novo post rebound. SL8-specific CD8+ T cell levels in blood prior to the second interruption were marginally, but significantly, higher (median 0.73% vs 0.60%, p = 0.016). CD8+ T cell depletion approximately 95 days after the second treatment interruption led to the reappearance of wild-type virus. This work suggests that CD8+ T cells can actively suppress the rebound of wild-type virus, leading to the dominance of escape mutant virus after treatment interruption.

Timing of initiation of anti-retroviral therapy predicts post-treatment control of SIV replication.

One approach to 'functional cure' of HIV infection is to induce durable control of HIV replication after the interruption of antiretroviral therapy (ART). However, the major factors that determine the viral 'setpoint' level after treatment interruption are not well understood. Here we combine data on ART interruption following SIV infection for 124 total animals from 10 independent studies across 3 institutional cohorts to understand the dynamics and predictors of post-treatment viral control. We find that the timing of treatment initiation is an important determinant of both the peak and early setpoint viral levels after treatment interruption. During the first 3 weeks of infection, every day of delay in treatment initiation is associated with a 0.22 log10 copies/ml decrease in post-rebound peak and setpoint viral levels. However, delay in initiation of ART beyond 3 weeks of infection is associated with higher post-rebound setpoint viral levels. For animals treated beyond 3 weeks post-infection, viral load at ART initiation was the primary predictor of post-rebound setpoint viral levels. Potential alternative predictors of post-rebound setpoint viral loads including cell-associated DNA or RNA, time from treatment interruption to rebound, and pre-interruption CD8+ T cell responses were also examined in the studies where these data were available. This analysis suggests that optimal timing of treatment initiation may be an important determinant of post-treatment control of HIV.

AZD5582 plus SIV-specific antibodies reduce lymph node viral reservoirs in antiretroviral therapy-suppressed macaques

The main barrier to HIV cure is a persistent reservoir of latently infected CD4+ T cells harboring replication-competent provirus that fuels rebound viremia upon antiretroviral therapy (ART) interruption. A leading approach to target this reservoir involves agents that reactivate latent HIV proviruses followed by direct clearance of cells expressing induced viral antigens by immune effector cells and immunotherapeutics. We previously showed that AZD5582, an antagonist of inhibitor of apoptosis proteins and mimetic of the second mitochondrial-derived activator of caspases (IAPi/SMACm), induces systemic reversal of HIV/SIV latency but with no reduction in size of the viral reservoir. In this study, we investigated the effects of AZD5582 in combination with four SIV Env-specific Rhesus monoclonal antibodies (RhmAbs) ± N-803 (an IL-15 superagonist) in SIV-infected, ART-suppressed rhesus macaques. Here we confirm the efficacy of AZD5582 in inducing SIV reactivation, demonstrate enhancement of latency reversal when AZD5582 is used in combination with N-803 and show a reduction in total and replication-competent SIV-DNA in lymph-node-derived CD4+ T cells in macaques treated with AZD5582 + RhmAbs. Further exploration of this therapeutic approach may contribute to the goal of achieving an HIV cure.

Over forty percent of women living with HIV report interruption in antiretroviral therapy during intrapartum and early postpartum inpatient stay: findings from five hospitals in Ghana.

Antiretroviral therapy (ART) adherence during and after pregnancy is essential to reduce perinatal transmission of HIV. However, little is known about adherence during the intrapartum and early postpartum inpatient hospital stay. Using secondary data from a hospital-based cohort study focused on the relationship between birthweight and engagement in HIV care, we examined the magnitude of, reasons for, and factors associated with incomplete intrapartum and early postpartum ART adherence among adult women (18 years or older) living with HIV who delivered within the previous two weeks at one of five hospitals in Accra, Ghana. Of the 142 enrolled participants who had complete adherence data and reported being on ART at the time of hospital admission, 43% (61/142) reported missing at least one ART dose during labor, delivery, and postpartum, including almost 20% (28/142) missing 2 or more consecutive doses. Women who reported frequently missing ART doses during pregnancy had higher odds of reporting missed doses during their intrapartum and postpartum hospital stays. Among those with inpatient ART interruption, the most frequently cited reasons were: forgetting medication at home (42%) and challenges of being in or recovering from labor (29%). Maternal perception of infant health at birth, hospital level of care, and frequency of missing HIV medications during pregnancy were associated with incomplete ART adherence during the intrapartum and early postpartum inpatient stay. An enabling clinical environment to facilitate access to ART during inpatient stays may have positive implications for ART adherence.

Impact of a TLR9 agonist and broadly neutralizing antibodies on HIV-1 persistence: the randomized phase 2a TITAN trial

Inducing antiretroviral therapy (ART)-free virological control is a critical step toward a human immunodeficiency virus type 1 (HIV-1) cure. In this phase 2a, placebo-controlled, double-blinded trial, 43 people (85% males) with HIV-1 on ART were randomized to (1) placebo/placebo, (2) lefitolimod (TLR9 agonist)/placebo, (3) placebo/broadly neutralizing anti-HIV-1 antibodies (bNAbs) or (4) lefitolimod/bNAb. ART interruption (ATI) started at week 3. Lefitolimod was administered once weekly for the first 8 weeks, and bNAbs were administered twice, 1 d before and 3 weeks after ATI. The primary endpoint was time to loss of virologic control after ATI. The median delay in time to loss of virologic control compared to the placebo/placebo group was 0.5 weeks (P = 0.49), 12.5 weeks (P = 0.003) and 9.5 weeks (P = 0.004) in the lefitolimod/placebo, placebo/bNAb and lefitolimod/bNAb groups, respectively. Among secondary endpoints, viral doubling time was slower for bNAb groups compared to non-bNAb groups, and the interventions were overall safe. We observed no added benefit of lefitolimod. Despite subtherapeutic plasma bNAb levels, 36% (4/11) in the placebo/bNAb group compared to 0% (0/10) in the placebo/placebo group maintained virologic control after the 25-week ATI. Although immunotherapy with lefitolimod did not lead to ART-free HIV-1 control, bNAbs may be important components in future HIV-1 curative strategies. ClinicalTrials.gov identifier: NCT03837756.

Arsenic trioxide-induced apoptosis contributes to suppression of viral reservoir in SIV-infected rhesus macaques.

Latent viral reservoir is recognized as the major obstacle to achieving a functional cure for HIV infection. We previously reported that arsenic trioxide (As2O3) combined with antiretroviral therapy (ART) can reactivate the viral reservoir and delay viral rebound after ART interruption in chronically simian immunodeficiency virus (SIV)-infected macaques. In this study, we further investigated the effect of As2O3 independent of ART in chronically SIV-infected macaques. We found that As2O3-only treatment significantly increased the CD4/CD8 ratio, improved SIV-specific T cell responses, and reactivated viral latency in chronically SIVmac239-infected macaques. RNA-sequencing analysis revealed that As2O3 treatment downregulated the expression levels of genes related to HIV entry and infection, while the expression levels of genes related to transcription initiation, cell apoptosis, and host restriction factors were significantly upregulated. Importantly, we found that As2O3 treatment specifically induced apoptosis of SIV-infected CD4+ T cells. These findings revealed that As2O3 might not only impact viral latency, but also induce the apoptosis of HIV-infected cells and thus block the secondary infection of bystanders. Moreover, we investigated the therapeutic potential of this regimen in acutely SIVmac239-infected macaques and found that As2O3 + ART treatment effectively restored the CD4+ T cell count, delayed disease progression, and improved survival in acutely SIV-infected macaques. In sum, this work provides new insights to develop As2O3 as a component of the "shock-and-kill" strategy toward HIV functional cure. IMPORTANCE Although antiretroviral therapy (ART) can effectively suppress the viral load of AIDS patients, it cannot functionally cure HIV infection due to the existence of HIV reservoir. Strategies toward HIV functional cure are still highly anticipated to ultimately end the pandemic of AIDS. Herein, we investigated the direct role of As2O3 independent of ART in chronically SIV-infected macaques and explored the underlying mechanisms of the potential of As2O3 in the treatment of HIV/SIV infection. Meanwhile, we investigated the therapeutic effects of ART+As2O3 in acutely SIVmac239-infected macaques. This study showed that As2O3 has the potential to be launched into the "shock-and-kill" strategy to suppress HIV/SIV reservoir due to its latency-reversing and apoptosis-inducing properties.

Development and Validation of a Risk Score for Predicting Non-Adherence to Antiretroviral Therapy.

Several patient-related factors that influence adherence to antiretroviral therapy (ART) have been described. However, studies that propose a practical and simple tool to predict nonadherence after ART initiation are still scarce. In this study, we develop and validate a score to predict the risk of nonadherence in people starting ART. The model/score was developed and validated using a cohort of people living with HIV starting ART at the Hospital del Mar, Barcelona, between 2012 and 2015 (derivation cohort) and between 2016 and 2018 (validation cohort),. Adherence was evaluated every 2 months using both pharmacy refills and patient self-reports. Nonadherence was defined as taking <90% of the prescribed dose and/or ART interruption for more than 1 week. Predictive factors for nonadherence were identified by logistic regression. Beta coefficients were used to develop a predictive score. Optimal cutoffs were identified using the bootstrapping methodology, and performance was evaluated with the C statistic. Our study is based on 574 patients: 349 in the derivation cohort and 225 in the validation cohort. A total of 104 patients (29.8%) of the derivation cohort were nonadherent. Nonadherence predictors were patient prejudgment; previous medical appointment failures; cultural and/or idiomatic barriers; heavy alcohol use; substance abuse; unstable housing; and severe mental illness. The cutoff point (receiver operating characteristic curve) for nonadherence was 26.3 (sensitivity 0.87 and specificity 0.86). The C statistic (95% confidence interval) was 0.91 (0.87-0.94). These results were consistent with those predicted by the score in the validation cohort. This easy-to-use, highly sensitive, and specific tool could be easily used to identify patients at highest risk for nonadherence, thus allowing resource optimization and achieving optimal treatment goals.

Smoothed simulated pseudo-maximum likelihood estimation for nonlinear mixed effects models with censored responses.

Nonlinear mixed effects models have been widely applied to analyses of data that arise from biological, agricultural, and environmental sciences. Estimation of and inference on parameters in nonlinear mixed effects models are often based on the specification of a likelihood function. Maximizing this likelihood function can be complicated by the specification of the random effects distribution, especially in the presence of multiple random effects. The implementation of nonlinear mixed effects models can be further complicated by left-censored responses, representing measurements from bioassays where the exact quantification below a certain threshold is not possible. Motivated by the need to characterize the nonlinear human immunodeficiency virus RNA viral load trajectories after the interruption of antiretroviral therapy, we propose a smoothed simulated pseudo-maximum likelihood estimation approach to fit nonlinear mixed effects models in the presence of left-censored observations. We establish the consistency and asymptotic normality of the resulting estimators. We develop testing procedures for the correlation among random effects and for testing the distributional assumptions on random effects against a specific alternative. In contrast to the existing variants of expectation-maximization approaches, the proposed methods offer flexibility in the specification of the random effects distribution and convenience in making inference about higher-order correlation parameters. We evaluate the finite-sample performance of the proposed methods through extensive simulation studies and illustrate them on a combined dataset from six AIDS Clinical Trials Group treatment interruption studies.

Lymph-Node-Based CD3+ CD20+ Cells Emerge from Membrane Exchange between T Follicular Helper Cells and B Cells and Increase Their Frequency following Simian Immunodeficiency Virus Infection.

CD4+ T follicular helper (TFH) cells are key targets for human immunodeficiency virus (HIV)/simian immunodeficiency virus (SIV) replication and contribute to the virus reservoir under antiretroviral therapy (ART). Here, we describe a novel CD3+ CD20+ double-positive (DP) lymphocyte subset, resident in secondary lymphoid organs of humans and rhesus macaques (RMs), that appear predominantly after membrane exchange between TFH and B cells. DP lymphocytes are enriched in cells displaying a TFH phenotype (CD4+ PD1hi CXCR5hi), function (interleukin 21 positive [IL-21+]), and gene expression profile. Importantly, expression of CD40L upon brief in vitro mitogen stimulation identifies, by specific gene-expression signatures, DP cells of TFH-cell origin versus those of B-cell origin. Analysis of 56 RMs showed that DP cells (i) significantly increase following SIV infection, (ii) are reduced after 12 months of ART in comparison to pre-ART levels, and (iii) expand to a significantly higher frequency following ART interruption. Quantification of total SIV-gag DNA on sorted DP cells from chronically infected RMs showed that these cells are susceptible to SIV infection. These data reinforce earlier observations that CD20+ T cells are infected and expanded by HIV infection, while suggesting that these cells phenotypically overlap activated CD4+ TFH cells that acquire CD20 expression via trogocytosis and can be targeted as part of therapeutic strategies aimed at HIV remission. IMPORTANCE The HIV reservoir is largely composed of latently infected memory CD4+ T cells that persist during antiretroviral therapy and constitute a major barrier toward HIV eradication. In particular, CD4+ T follicular helper cells have been demonstrated as key targets for viral replication and persistence under ART. In lymph nodes from HIV-infected humans and SIV-infected rhesus macaques, we show that CD3+ CD20+ lymphocytes emerge after membrane exchange between T cells and B cells and are enriched in phenotypic, functional, and gene expression profiles found in T follicular helper cells. Furthermore, in SIV-infected rhesus macaques, these cells expand following experimental infection and after interruption of ART and harbor SIV DNA at levels similar to those found in CD4+ T cells; thus, CD3+ CD20+ lymphocytes are susceptible to SIV infection and can contribute to SIV persistence.

Antiretroviral treatment interruption and resumption within 16 weeks among HIV-positive adults in Jinan, China: a retrospective cohort study.

Treatment interruption has been found to increase the risk of opportunistic infections and death among HIV-positive adults, posing a challenge to fully realizing antiretroviral therapy (ART). However, it has been observed that short-term interruption (<16 weeks) was not associated with significant increases in adverse clinical events. There remains a dearth of evidence concerning the interruption and resumption of ART after short-term discontinuation in China. HIV-positive adults who initiated ART in Jinan between 2004 and 2020 were included in this study. We defined ART interruption as more than 30 consecutive days off ART and used Cox regression to identify predictors of interruption. ART resumption was defined as a return to ART care within 16 weeks following discontinuation, and logistic regression was used to identify barriers. A total of 2,506 participants were eligible. Most of them were male [2,382 (95%)] and homosexual [2,109 (84%)], with a median age of 31 (IQR: 26-40) years old. Of all participants, 312 (12.5%) experienced a treatment interruption, and the incidence rate of interruption was 3.2 (95% CI: 2.8-3.6) per 100 person-years. A higher risk of discontinuation was observed among unemployed individuals [adjusted hazard ratio (aHR): 1.45, 95% CI: 1.14-1.85], with a lower education level (aHR: 1.39, 95% CI: 1.06-1.82), those with delayed ART initiation (aHR: 1.43, 95% CI: 1.10-1.85), receiving Alafenamide Fumarate Tablets at ART initiation (aHR: 5.19, 95% CI: 3.29-8.21). About half of the interrupters resumed ART within 16 weeks, and participants who delayed ART initiation, missed the last CD4 test before the interruption and received the "LPV/r+NRTIs" regimen before the interruption were more likely to discontinue treatment for the long term. Antiretroviral treatment interruption remains relatively prevalent among HIV-positive adults in Jinan, China, and assessing socioeconomic status at treatment initiation will help address this issue. While almost half of the interrupters returned to care within 16 weeks, further focused measures are necessary to reduce long-term interruptions and maximize the resumption of care as soon as possible to avoid adverse clinical events.

High frequency of memory stem cells with a distinct gene signature in HIV patients with treatment interruption.

Reservoirs of HIV remain a major obstacle to the complete eradication of virus despite regular anti-retroviral therapy (ART). Memory stem cells (Tscm), one of the major reservoirs, are relatively less studied owing to their presence in lower numbers and inaccessible anatomical locations. We have evaluated the molecular characteristics of Tscms in patients with ART interruption (n=15) versus patients on uninterrupted ART (n=12) using flow cytometry. RNA sequencing was done in the sorted Tscms to study the differential gene expression. Patients with ART interruption had significantly lower baseline CD4+T-cell counts and high viral loads as compared to patients on ART. The former group had significantly higher frequency of CD4+ and CD8+Tscms with a higher expression of PD-1 on CD8+Tscms. The transcriptome profile of Tscm was significantly different among the patient groups. The main pathways were cellular and metabolic pathways, cellular development pathways, cell differentiation and negative regulation of cellular migratory pathways. An increased yet dysfunctional CD8+ memory stem cells describe HIV-1-infected patients with break-in ART and a distinct transcriptional signature of CD4+ Tscm as compared to those of patients on ART. A more detailed understanding of the biology and dynamics of Tscm in future studies is warranted. Strategies to improve the functionality of the CD8+ Tscm will help these patients to tackle the outburst of viral replication that occurs after the cessation of therapy.