HIV Antibody Level as a Marker of HIV Persistence and Low-Level Viral Replication

Potential for high dynamic range Sedia Limiting Antigen antibody assay to support viral load monitoring during antiretroviral therapy

INTRODUCTION

Viral Load (VL) monitoring is a crucial component of patient care during antiretroviral therapy (ART) but is not routinely available in many resource-constrained settings, where millions of patients will require care for decades to come. We hypothesise a serologic 'recent infection' test (Sedia LAg assay) which has a high dynamic range for detecting antigen-driven antibody response can provide informative proxies for VL trajectories.

METHODS

A retrospective study where we analysed data linked via specimens in a well-described repository for recent infection test benchmarking (CEPHIA collaboration). Patient panels were comprised of 1) observations straddling ART start; 2) observations from a period of stable viral suppression; 3) observations straddling rebound after a period of viral suppression. We analysed an individual's Sedia LAg ELISA normalised optical density (ODn) trends within these categories. Using groups 2) and 3) we evaluated the specificity and sensitivity of a proposed proxy for "the latest observation is at a time of VL rebound"; proxy was defined as follows: we estimated patient-specific mean-previous-ODn for all observations with at least two preceding virally suppressed observations. We considered various thresholds to define both "VL suppression" and "ODn uptick".

RESULTS

In regression analysis by category: 1) ODn gradients are statistically significantly negative just after ART-start (p = 0.010); 2) During periods of stable viral suppression, ODn tended to decline, but not statistically significantly, for a range of clinically meaningful "VL suppression" thresholds; 3) comparing ODn values just before, versus at, "VL rebound", ODn changes were statistically significantly increasing at rebound (p = 0.001). In the analysis comparing groups 2) and 3), at a Z score threshold of 0.8, the proposed proxy for a first viral rebound had an observed specificity and sensitivity both close to 90%.

CONCLUSION

The high dynamic range of serological tests previously investigated for defining 'recent infection' has potential, as demonstrated using the Sedia LAg ELISA, to provide meaningful information about the success of ART, during treatment initiation, at times of stable suppression, and to flag possible viral rebound. It should be investigated how this can be combined with patient management workflows and (clinical and) other data, to provide efficiencies in long-term monitoring viral control in resource-limited settings.

Immune targeting of HIV-1 reservoir cells: a path to elimination strategies and cure

Successful approaches for eradication or cure of HIV-1 infection are likely to include immunological mechanisms, but remarkably little is known about how human immune responses can recognize and interact with the few HIV-1-infected cells that harbour genome-intact viral DNA, persist long term despite antiretroviral therapy and represent the main barrier to a cure. For a long time regarded as being completely shielded from host immune responses due to viral latency, these cells do, on closer examination with single-cell analytic techniques, display discrete footprints of immune selection, implying that human immune responses may be able to effectively engage and target at least some of these cells. The failure to eliminate rebound-competent virally infected cells in the majority of persons likely reflects the evolution of a highly selected pool of reservoir cells that are effectively camouflaged from immune recognition or rely on sophisticated approaches for resisting immune-mediated killing. Understanding the fine-tuned interplay between host immune responses and viral reservoir cells will help to design improved interventions that exploit the immunological vulnerabilities of HIV-1 reservoir cells.

Dynamics and durability of HIV-1 neutralization are determined by viral replication

Human immunodeficiency virus type 1 (HIV-1)-neutralizing antibodies (nAbs) that prevent infection are the main goal of HIV vaccine discovery. But as no nAb-eliciting vaccines are yet available, only data from HIV-1 neutralizers-persons with HIV-1 who naturally develop broad and potent nAbs-can inform about the dynamics and durability of nAb responses in humans, knowledge which is crucial for the design of future HIV-1 vaccine regimens. To address this, we assessed HIV-1-neutralizing immunoglobulin G (IgG) from 2,354 persons with HIV-1 on or off antiretroviral therapy (ART). Infection with non-clade B viruses, CD4+ T cell counts <200 µl-1, being off ART and a longer time off ART were independent predictors of a more potent and broad neutralization. In longitudinal analyses, we found nAb half-lives of 9.3 and 16.9 years in individuals with no- or low-level viremia, respectively, and 4.0 years in persons who newly initiated ART. Finally, in a potent HIV-1 neutralizer, we identified lower fractions of serum nAbs and of nAb-encoding memory B cells after ART initiation, suggesting that a decreasing neutralizing serum activity after antigen withdrawal is due to lower levels of nAbs. These results collectively show that HIV-1-neutralizing responses can persist for several years, even at low antigen levels, suggesting that an HIV-1 vaccine may elicit a durable nAb response.

Serum globulin levels are associated with HIV reservoir size and immune restoration during long-term ART

OBJECTIVES

The objectives of this study were to analyze the relationship between serum globulin levels and immune restoration and HIV reservoir size during long-term antiretroviral therapy (ART).

METHODS

We enrolled 13 patients living with HIV who had been receiving ART for 5 years. We measured levels of serum globulin, cell-associated (CA) HIV DNA and RNA, and p24 antibody at 0, 1, 3, and 5 years of ART. CD38 and human leukocyte antigen - DR isotype (HLA-DR) were used as activation markers for T-cell activation. Serum concentrations of the inflammatory cytokines interferon gamma-inducible protein (IP)-10 and soluble CD163 (sCD163) were detected by enzyme-linked immunosorbent assay. We analyzed the relationship between serum globulin levels, HIV reservoir size, immune restoration, T-cell immune activation, and inflammatory levels during long-term ART.

RESULTS

Our data showed that serum globulin levels in people living with HIV were higher than in healthy controls and significantly decreased during the first year of ART. Serum globulin levels during long-term ART were positively correlated with CA HIV DNA, CA HIV RNA, p24 antibody levels, and CD8⁺ T-cell counts and negatively correlated with CD4⁺ T-cell counts and CD4/CD8 ratios. Moreover, serum globulin levels were positively correlated with CD4⁺ and CD8⁺ T-cell activation and the concentrations of inflammatory biomarkers IP-10 and sCD163 during long-term ART.

CONCLUSIONS

Our findings suggest that serum globulin levels may be associated with HIV reservoir size and immune restoration during long-term ART.

No evidence that circulating HIV-specific immune responses contribute to persistent inflammation and immune activation in persons on long-term ART

OBJECTIVE

People with HIV (PWH) have persistently elevated levels of inflammation and immune activation despite suppressive antiretroviral therapy (ART), with specific biomarkers showing associations with non-AIDS-defining morbidities and mortality. We investigated the potential role of the HIV-specific adaptive immune response, which also persists under ART, in driving levels of these clinically relevant biomarkers.

DESIGN

Cohort-based study.

METHODS

HIV-specific IFN-γ-producing T-cell responses and antibody concentrations were measured in blood at study entry in the ACTG A5321 cohort, following a median of 7 years of suppressive ART. HIV persistence measures including cell-associated (CA)-DNA, CA-RNA, and plasma HIV RNA (single-copy assay) were also assessed at study entry. Plasma inflammatory biomarkers and T-cell activation and cycling were measured at a pre-ART time point and at study entry.

RESULTS

Neither the magnitudes of HIV-specific T-cell responses nor HIV antibody levels were correlated with levels of the inflammatory or immune activation biomarkers, including hs-CRP, IL-6, neopterin, sCD14, sCD163, TNF-α, %CD38 + HLA-DR + CD8 + and CD4 + cells, and %Ki67 + CD8 + and CD4 + cells - including after adjustment for pre-ART biomarker level. Plasma HIV RNA levels were modestly correlated with CD8 + T-cell activation ( r  = 0.25, P  = 0.027), but other HIV persistence parameters were not associated with these biomarkers. In mediation analysis, relationships between HIV persistence parameters and inflammatory biomarkers were not influenced by either HIV-specific T-cell responses or antibody levels.

CONCLUSION

Adaptive HIV-specific immune responses do not appear to contribute to the elevated inflammatory and immune activation profile in persons on long-term ART.

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.

Influence of Combination Antiretroviral Therapy on HIV-1 Serological Responses and Their Implications: A Systematic Review and Meta-Analysis

We aimed to analyze HIV-1 seroreversion caused by combination antiretroviral therapy (cART) and to explore antibody levels of anti-HIV-1 as an alternative biomarker of HIV-1 reservoir. We searched PubMed, Embase, the Cochrane Library, and Web of Science up to August 2021 for publications about the performance of HIV-1 serological assays or the association between antibody responses against HIV-1 and HIV-1 reservoirs. Potential sources of heterogeneity were explored by meta-regression analysis, including the year of publication, country, pretreatment viral load, sample size, the timing of treatment, time on cART, and principle or type of serological assay. Twenty-eight eligible studies with a total population of 1,883 were included in the meta-analysis. The pooled frequency of HIV-1 seronegativity is 38.0% (95% CI: 28.0%–49.0%) among children with vertical HIV-1 infection and cART initiation at the age of less than 6 months, while the percentage of HIV-1 seronegativity declined to 1.0% (95% CI: 0%–3.0%) when cART was initiated at the age of >6 months. For adult patients, 16.0% (95% CI: 9.0%–24.0%) of them were serologically negative when cART was initiated at acute/early infection of HIV-1, but the seronegative reaction was rarely detected when cART was started at chronic HIV-1 infection. Substantial heterogeneity was observed among the studies to estimate the frequency of HIV-1 seronegativity in the early-cART population (I² ≥ 70%, p < 0.05 and all), while mild heterogeneity existed for the deferred-cART subjects. Moreover, anti-HIV-1 antibody response positively correlates with HIV-1 reservoir size with a pooled rho of 0.43 (95% CI: 0.28–0.55), suggesting that anti-HIV antibody level may be a feasible biomarker of HIV-1 reservoir size.

Helios expressing regulatory T cells are correlated with decreased IL-2 producing CD8 T cells and antibody diversity in Mozambican individuals living chronically with HIV-1

Background

Human immunodeficiency virus type 1 (HIV-1) causes impairment of T and B cell responses, which begins during the acute phase of infection and is not completely restored by antiretroviral treatment. Regulatory T cell (Tregs) can improve overall disease outcome by controlling chronic inflammation but may also suppress beneficial HIV-1 specific immune responses. We aimed to analyze the profile of Tregs and their correlation with the status of T cells activation, the expression of IL-2 and IFNγ and the profile of HIV-1 specific antibodies response in Mozambican people living chronically with HIV-1 (PLWH-C).

Results

In PLWH-C, the proportion of total Tregs was positively correlated with the proportion of IL-2⁺CD4 T cells (r = 0.647; p = 0.032) and IL-2⁺IFNγ⁺CD8 T cells (r = 0.551; p = 0.014), while the proportions of Helios⁺Tregs correlated inversely with levels of IL-2⁺CD8 T cells (r = − 0.541; p = 0.017). Overall, PLWH-C, with (82%) or without virologic suppression (64%), were seronegative for at least HIV-1 p31, gp160 or p24, and the breadth of antibody responses was positively correlated with proportions of CD38⁺HLA-DR⁺CD8 T cells (r = 0.620; p = 0.012), viral load (r = 0.452; p = 0.040) and inversely with absolute CD4 T cells count (r = − 0.481; p = 0.027). Analysis of all individuals living HIV-1 showed that the breadth of HIV-1 antibody responses was inversely correlated with the proportion of Helios⁺Tregs (r = − 0.45; p = 0.02).

Conclusion

Among Mozambican people living with HIV-1, seronegativity to some HIV-1 proteins is common, particularly in virologically suppressed individuals. Furthermore, lower diversity of HIV-specific antibodies is correlated to lower immune activation, lower viral replication and higher CD4 counts, in PLWH-C. Elevation in the proportion of Helios⁺Tregs is related to a reduction of CD8 T expressing intracellular IL-2, in PLWH-C, but may contribute to impairment of B cell function.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-022-00487-3.

Are HIV-1-Specific Antibody Levels Potentially Useful Laboratory Markers to Estimate HIV Reservoir Size? A Review

Despite the benefits achieved by the widespread availability of modern antiretroviral therapy (ART), HIV RNA integration into the host cell genome is responsible for the creation of latent HIV reservoirs, and represents a significant impediment to completely eliminating HIV infection in a patient via modern ART alone. Several methods to measure HIV reservoir size exist; however, simpler, cheaper, and faster tools are required in the quest for total HIV cure. Over the past few years, measurement of HIV-specific antibodies has evolved into a promising option for measuring HIV reservoir size, as they can be measured via simple, well-known techniques such as the western blot and enzyme-linked immunosorbent assay (ELISA). In this article, we re-visit the dynamic evolution of HIV-1-specific antibodies and the factors that may influence their levels in the circulation of HIV-positive individuals. Then, we describe the currently-known relationship between HIV-1-specific antibodies and HIV reservoir size based on study of data from contemporary literature published during the past 5 years. We conclude by highlighting current trends, and discussing the individual HIV-specific antibody that is likely to be the most reliable antibody for potential future utilization for quantification of HIV reservoir size.

A Mycobacterium tuberculosis Specific IgG3 Signature of Recurrent Tuberculosis

South Africa has the highest prevalence of HIV and tuberculosis (TB) co-infection globally. Recurrent TB, caused by relapse or reinfection, makes up the majority of TB cases in South Africa, and HIV infected individuals have a greater likelihood of developing recurrent TB. Given that TB remains a leading cause of death for HIV infected individuals, and correlates of TB recurrence protection/risk have yet to be defined, here we sought to understand the antibody associated mechanisms of recurrent TB by investigating the humoral response in a longitudinal cohort of HIV co-infected individuals previously treated for TB with and without recurrent disease during follow-up, in order to identify antibody correlates of protection between individuals who do not have recurrent TB and individuals who do. We used a high-throughput, “systems serology” approach to profile biophysical and functional characteristics of antibodies targeting antigens from Mycobacterium tuberculosis (Mtb). Differences in antibody profiles were noted between individuals with and without recurrent TB, albeit these differences were largely observed close to the time of re-diagnosis. Individuals with recurrent TB had decreased Mtb-antigen specific IgG3 titers, but not other IgG subclasses or IgA, compared to control individuals. These data point to a potential role for Mtb-specific IgG3 responses as biomarkers or direct mediators of protective immunity against Mtb recurrence.

Characterizing the Relationship Between Neutralization Sensitivity and env Gene Diversity During ART Suppression

Although antiretroviral therapy (ART) successfully suppresses HIV-1 replication, ART-treated individuals must maintain therapy to avoid rebound from an integrated viral reservoir. Strategies to limit or clear this reservoir are urgently needed. Individuals infected for longer periods prior to ART appear to harbor more genetically diverse virus, but the roles of duration of infection and viral diversity in the humoral immune response remain to be studied. We aim to clarify a role, if any, for autologous and heterologous antibodies in multi-pronged approaches to clearing infection. To that end, we have characterized the breadths and potencies of antibody responses in individuals with varying durations of infection and HIV-1 envelope (env) gene diversity as well as the sensitivity of their inducible virus reservoir to broadly neutralizing antibodies (bNAbs). Plasma was collected from 8 well-characterized HIV-1+ males on ART with varied durations of active infection. HIV envs from reservoir-derived outgrowth viruses were amplified and single genome sequenced in order to measure genetic diversity in each participant. IgG from plasma was analyzed for binding titers against gp41 and gp120 proteins, and for neutralizing titers against a global HIV-1 reference panel as well as autologous outgrowth viruses. The sensitivity to bNAbs of these same autologous viruses was measured. Overall, we observed that greater env diversity was associated with higher neutralizing titers against the global panel and also increased resistance to certain bNAbs. Despite the presence of robust anti-HIV-1 antibody titers, we did not observe potent neutralization against autologous viruses. In fact, 3 of 8 participants harbored viruses that were completely resistant to the highest tested concentration of autologous IgG. That this lack of neutralization was observed regardless of ART duration or viral diversity suggests that the inducible reservoir harbors 'escaped' viruses (that co-evolved with autologous antibody responses), rather than proviruses archived from earlier in infection. Finally, we observed that viruses resistant to autologous neutralization remained sensitive to bNAbs, especially CD4bs and MPER bNAbs. Overall, our data suggest that the inducible reservoir is relatively resistant to autologous antibodies and that individuals with limited virus variation in the env gene, such as those who start ART early in infection, are more likely to be sensitive to bNAb treatment.

Production of HIV-1 Env-specific antibodies mediating innate immune functions depends on cognate IL-21- secreting CD4+ T cells

Antibodies with a functional Fc region were previously associated with protection from HIV-1 acquisition and spontaneous suppression of viral replication. Unlike broadly neutralizing antibodies, they are not restricted to neutralizing epitopes and do not require unconventional structural traits to exert their antiviral activity. They, therefore, develop earlier after infection and can be detected in the majority of cases. The conditions under which these antibodies are generated, however, remain largely unknown. Here we demonstrate that the generation of HIV-1 Env-specific antibodies facilitating Fc-dependent innate immune responses, including neutrophil phagocytosis (ADNP), complement deposition (ADCD), and NK cell activation, likely depends on help provided by CD4+ T and peripheral T follicular helper (pTfh) cells secreting IL-21. Other proteins, including CD40L, IFNγ, and IL-4/13, involved in crosstalk between B and T cells were linked to the production of antibodies with functional Fc region but only when co-expressed with IL-21. As a potential source of these antibodies, we identified a subset of Env-specific memory B cells known to be expanded in chronic HIV-1 infection. The frequency and level of Blimp-1 expression in Env-specific tissue-like memory B cells (TLM) correlated with the functional CD4+ T cell subsets associated with robust antibody-dependent innate responses. Thus, our data suggest a mechanism responsible for the generation of antibodies with functional Fc region in chronically HIV-1 infected individuals that is based on CD4+ T cell-induced activation of memory B cells.Importance To develop a vaccine or immunotherapy that would cure the HIV-1 infection it is important to identify helper T cells able to mount an efficient antibody response. Here, we demonstrate that the generation of HIV-1 Env-specific antibodies facilitating antibody-dependent innate immune responses likely depends on Env-specific IL-21-secreting CD4+ T and peripheral T follicular helper cells.

Chronic and Early Antiretroviral Therapy Impact Human Immunodeficiency Virus (HIV) Serological Assay Sensitivity, Leading to More False-Negative Test Results in HIV Diagnosis

This retrospective study evaluated the reactivity of 3 human immunodeficiency virus (HIV) confirmatory assays (INNO-LIA, Geenius, and MP) and 7 HIV rapid tests on samples from 2 different study populations in Belgium. For the early-treated cohort (83 HIV-1 adult patients treated within 3 months after infection), HIV-1 diagnosis was not obtained in at least 1 confirmatory assay in 12.0% (10/83) and in an HIV rapid test in 31.3% (26/83). Confirmation assay sensitivities ranged from 87.5% to 95.2%, whereas rapid test assay sensitivities ranged from 75.9% to 100%. The time to treatment initiation or the length of time on treatment did not have a statistical influence on the probability to obtain a false-negative test result. The fastest reversion was demonstrated after 4 months of treatment. Among the long-term treated cohort (390 HIV-1 patients with ≥ 9 years of undetectable viral load), false-negative test results were found in at least 1 HIV confirmatory assay for 2.1% (8/390) of the patients and in a HIV rapid test for 4.9% (19/390). Confirmation assay sensitivities ranged from 98.1% to 99.5%, whereas rapid test sensitivities ranged from 96.2% to 100%. Longer treatment increased nonreactivity of the HIV rapid tests (P = .033). Undetectable viral load decreases the sensitivities of HIV diagnostic tests, and further monitoring of the performance of serological assays is advised.

Viral Rebound Kinetics Correlate with Distinct HIV Antibody Features

Plasma viremia reoccurs in most HIV-infected individuals once antiretroviral therapy is interrupted, and interindividual differences in the kinetics of viral rebound have been associated with virological and immunological factors. Antibody features, including Fc functionality and Fc glycosylation, have been identified as sensitive surrogates for disease activity in multiple diseases.

Plasma viremia reoccurs in most HIV-infected individuals once antiretroviral therapy (ART) is interrupted. The kinetics of viral rebound, specifically the time until plasma virus becomes detectable, differ quite substantially between individuals, and associations with virological and immunological factors have been suggested. Standard clinical measures, like CD4 T-cell counts and plasma HIV RNA levels, however, are poor predictive markers. Antibody features, including Fc functionality and Fc glycosylation have been identified as sensitive surrogates for disease activity in multiple diseases. Here, we analyzed HIV-specific antibody quantities and qualitative differences like antibody-mediated functions, Fc gamma receptor (FcγR) binding, and IgG Fc glycosylation as well as cytokine profiles and cellular HIV DNA and RNA levels in 23 ART-suppressed individuals prior to undergoing an analytical ART interruption (ATI). We found that antibodies with distinct functional properties and Fc glycan signatures separated individuals into early and delayed viral rebounders (≤4 weeks versus >4 weeks) and tracked with levels of inflammatory cytokines and transcriptional activity of the viral reservoir. Specifically, individuals with early viral rebound exhibited higher levels of total HIV-specific IgGs carrying inflammatory Fc glycans, while delayed rebounders showed an enrichment of highly functional antibodies. Overall, only four features, including enhanced antibody-mediated NK cell activation in delayed rebounders, were necessary to discriminate the groups. These data suggest that antibody features can be used as sensitive indicators of HIV disease activity and could be included in future ATI studies.

Recommendations for measuring HIV reservoir size in cure-directed clinical trials

Therapeutic strategies are being clinically tested either to eradicate latent HIV reservoirs or to achieve virologic control in the absence of antiretroviral therapy. Attaining this goal will require a consensus on how best to measure the numbers of persistently infected cells with the potential to cause viral rebound after antiretroviral-therapy cessation in assessing the results of cure-directed strategies in vivo. Current measurements assess various aspects of the HIV provirus and its functionality and produce divergent results. Here, we provide recommendations from the BEAT-HIV Martin Delaney Collaboratory on which viral measurements should be prioritized in HIV-cure-directed clinical trials.

Anti-gp41 antibody levels reflect HIV viral suppression and cellular reservoir in long-term antiretroviral-treated trial participants

BACKGROUND

A major challenge to HIV cure strategies is the quantification of persistent reactivation-prone virus in people living with HIV.

OBJECTIVES

To determine whether anti-gp41 antibody levels correlate with viral suppression and HIV-1 DNA levels in patients on ART.

METHODS

Participants with plasma HIV-1 RNA below 50 copies/mL for >12 months were included from three ANRS cohorts (COPANA, MONOI and APROCO). Antibody levels to gp41 were measured by a low-sensitivity enzyme-linked immunoassay. Correlations with patient and virus characteristics, plasma HIV-1 RNA load (standard and ultrasensitive tests) and cell-associated HIV-1 DNA were assessed.

RESULTS

Median age was 41 years and 77.5% of the 683 participants were men. Median CD4+ T cell count was 582 cells/mm3 and median viral suppression duration was 6.6 years (IQR 2.0-9.5). The overall median anti-gp41 antibody titre was 1.3 (IQR 0.6-1.9); median HIV-1 DNA level was 2.6 (IQR 2.1-3.0) log10 copies/106 leucocytes; and HIV-1 RNA was undetectable in 56% of samples. A lower titre of anti-gp41 antibodies correlated with male gender, longer viral suppression and lower HIV-1 DNA burden. Sustained undetectable HIV-1 RNA was associated with lower anti-gp41 levels [median 1.1 (IQR 0.5-1.6) versus 1.4 (IQR 0.7-1.9), P = 0.009].

CONCLUSIONS

Anti-gp41 levels decreased with the duration of antiviral suppression on ART. Lower titres were associated with lower HIV-1 DNA levels and longer duration of viral suppression, reflecting minimal antigen stimulation. Anti-gp41 antibody titration may be a useful biomarker reflecting long-term HIV-1 suppression on ART.

Quantitative Human Immunodeficiency Virus (HIV)-1 Antibodies Correlate With Plasma HIV-1 RNA and Cell-associated DNA Levels in Children on Antiretroviral Therapy

BACKGROUND

This study measured serial plasma human immunodeficiency virus (HIV)-1-specific antibody (Ab) levels in children who initiated antiretroviral therapy (ART) prior to 2 years of age, and evaluated their relationship to peripheral blood HIV-1 RNA and DNA levels.

METHODS

We studied 46 HIV-1-infected children, stratified by age at ART initiation (<3 mo, early therapy [ET]; >3 mo-2 years, late therapy [LT]) and by virologic response (R) or non-response (NR), before and up to 4 years following ART. We studied 20 HIV-1-uninfected children born to HIV-1-infected mothers (seroreverters [SR]) as controls. Plasma immunoglobulin G (IgG) Ab levels directed against HIV-1 envelope (gp160, gp41), gag (capsid, p24; matrix, p17), reverse transcriptase (p66/51), and integrase (p31) were serially measured using quantitative enzyme-linked immunosorbent assays. HIV-1 Ab rates of decline were estimated over the first 15 months of the study.

RESULTS

The HIV-1 Ab rates of decline in the ET-R group were similar to those in the SR group for all Ab specificities, except for p17 (P = .01). Ab decline rates in the LT-R group and the NR group were significantly slower than in the SR group for all tested Ab specificities. After 1 year of age, Ab levels to p31 and p17 were significantly associated with HIV-1 RNA levels (P < .001); Ab levels to gp160 (P < .001) and gp41 (P < .001) were significantly associated with cell-associated HIV-1 DNA levels.

CONCLUSIONS

Quantitative HIV-1-specific Ab levels may be useful for screening children on ART for viral suppression or for residual, cell-associated HIV-1 DNA levels.

CLINICAL TRIALS REGISTRATION

NCT00000872.

Extremely low viral reservoir in treated chronically HIV-1-infected individuals

BACKGROUND

Small viral reservoirs are found predominantly in HIV-1 controllers and individuals treated during acute/early HIV-1 infection. However, other HIV⁺ individuals could naturally also harbour low viral reservoirs.

METHODS

We screened 451 HIV-1-infected treated-individuals with suppressed plasma viremia for at least 3 years and stored cryopreserved peripheral blood mononuclear cells (PBMCs). Total HIV-DNA was analysed in PBMCs with ddPCR. Individuals with <50 HIV-DNA copies/10⁶ PBMCs constitute the 'Low Viral Reservoir Treated' cohort (LoViReT). Longitudinal samples were obtained from 12 chronically treated LoViReT and compared to 13 controls (>50 HIV-DNA copies/10⁶ PBMCs) to analyse total HIV-DNA, T-cell and NK-cell populations, HIV-1 specific antibodies, and plasma inflammation markers.

FINDINGS

We found that 9.3% of the individuals screened had <50 HIV-DNA copies/10⁶ PBMCs. At least 66% initiated cART during the chronic phase of HIV-1 infection (cp-LoViReT). Cp-LoViReT harboured lower levels of HIV-DNA before cART and after treatment introduction the decays were greater compared to controls. They displayed a marked decline in quantity and avidity in HIV-specific antibodies after initiation of cART. Cp-LoViReT had fewer CD8⁺ T_TM and T_EMRA in the absence of cART, and higher CD8⁺ T_N after 18 months on therapy.

INTERPRETATION

Treated chronically HIV-1-infected LoViReT represent a new phenotype of individuals characterized by an intrinsically reduced viral reservoir, less impaired CD8⁺ T-cell compartment before cART, and low circulating HIV-1 antigens despite being treated in the chronic phase of infection. The identification of this unique group of individuals is of great interest for the design of future eradication studies.

FUNDING

MSD Spain.

Brief Report: Association Between Low HIV-1 DNA and Western Blot Reactivity to HIV-1 Pol in Chronically Infected Individuals

BACKGROUND

The aim of the study was to evaluate whether negative HIV-1 pol on Western blot (WB) was associated with low HIV-DNA in adults with chronic HIV-1 infection and suppressive antiretroviral therapy.

METHODS

Cross-sectional parent study of the APACHE trial, conducted in subjects with chronic infection, HIV-1 RNA <50 copies/mL for ≥10 years, no residual viremia for ≥5 years and CD4 >500 cells/µL screened for HIV-1 DNA. HIV-1 DNA was quantified in peripheral blood mononuclear cells (PBMCs) by real-time polymerase chain reaction and HIV-1 serostatus was tested by HIV Blot 2.2 WB assay. Multivariate logistic regression was used to determine factors associated with low HIV-1 DNA.

RESULTS

We evaluated 96 patients: 78 (81%) and 18 (19%) subjects with HIV-1 DNA ≥100 copies/10 PBMCs and with HIV-1 DNA <100 copies/10 PBMCs, respectively. Median age was 32.5 (25.3-38.9), and 61 (64%) were men; moreover, we reported that nadir CD4 was 253 (167-339) cells/µL and HIV-RNA <50 copies/mL for 11.7 (10.6-14.0) years. At multivariate analysis, higher nadir CD4 [adjusted odds ratio (AOR) [95% confidence interval (CI) 1.35 (95% CI: 1.03 to 1.76), P = 0.029], longer years of HIV-1 RNA <50 copies/mL [AOR (95% CI) 2.98 (95% CI: 1.25 to 7.10), P = 0.014], a R5-tropic virus [AOR (R5 vs. non-R5) 0.20 (95% CI: 0.04 to 0.96), P = 0.044], and negative HIV-1 pol [AOR 6.59 (95% CI: 1.47 to 29.54), P = 0.014] were associated with low HIV-1 DNA.

CONCLUSIONS

In patients with chronic HIV-1 infection and suppressive antiretroviral therapy, negative HIV-1 pol on WB was associated with low HIV-1 DNA as well as higher nadir CD4, longer years of HIV-1 RNA <50 copies/mL, and a R5-tropic virus.

Brief Report: Diagnostic Accuracy of Oral Mucosal Transudate Tests Compared with Blood-Based Rapid Tests for HIV Among Children Aged 18 Months to 18 Years in Kenya and Zimbabwe

Gaps persist in HIV testing for children who were not tested in prevention of mother-to-child HIV transmission programs. Oral mucosal transudate (OMT) rapid HIV tests have been shown to be highly sensitive in adults, but their performance has not been established in children.

Reduction of anti-HIV antibody responses in subjects receiving antiretroviral therapy during chronic HIV-1 infection

OBJECTIVE

Antiretroviral therapy (ART) can lead to a decline or absence of anti-HIV antibodies in HIV-infected children or acutely HIV-infected (AHI) subjects. However, the characteristics of anti-HIV antibody response in the subjects who are treated during chronic HIV-1 infection (CHI) have not yet been fully investigated.

METHODS

Different anti-HIV antibodies were longitudinally quantified and analyzed in 81 CHI adults under ART. The factors associated with antibody decline were evaluated by binary logistic regression analysis.

RESULTS

ART led to 36.0% (27/75) and 52.1% (38/73) of the patients whose anti-HIV levels reduced by more than 75% of the baseline levels at 12 and 24 months post-ART, respectively. The reduction of anti-HIV antibodies correlated with the decline of HIV-1 viral load with correlation coefficients in the range 0.556-0.848 or R2 value of 0.576-0.873 (P < 0.001). However, no negative detection of anti-HIV antibody was observed at 24 months post-ART. The time from HIV-1 diagnosis to ART initiation and the baseline anti-HIV levels were the key factors associated with quick decline of anti-HIV antibodies during ART.

CONCLUSIONS

ART-induced kinetics of anti-HIV antibody response was different among the subjects with AHI and CHI. Misdiagnosis of HIV-1 infection may not be a serious issue in HIV-1 chronically infected subjects under ART, and could ideally be avoided by using multiple HIV-1 antigens for screening purposes.

The HIV-1 antibody response: a footprint of the viral reservoir in children vertically infected with HIV

Several assays have been developed to measure and characterise the replication-competent HIV-1 reservoir, which constitutes the barrier to cure. To date, the application of these assays to studies in children and in limited-resource settings has been minimal, primarily because of their expense, the large required blood volumes, and labour-intensive technologies. For children vertically infected with HIV-1 who initiated suppressive antiretroviral therapy (ART) regimens in infancy, HIV-1-specific antibody concentrations are associated with viral persistence and could be used to estimate the size of the residual latent reservoir on ART. This strategy could be particularly useful for screening children on suppressive ART for enrolment into therapeutic vaccine trials and other protocols aimed at achieving HIV-1 remission.

Brief Report: HIV Antibodies Decline During Antiretroviral Therapy but Remain Correlated With HIV DNA and HIV-Specific T-Cell Responses

BACKGROUND

In people with HIV on antiretroviral therapy (ART), the relationship between HIV-specific immune responses and measures of HIV persistence is uncertain.

METHODS

We evaluated 101 individuals on suppressive ART in the AIDS Clinical Trials Group A5321 cohort. Cell-associated (CA) HIV DNA and RNA levels and HIV antibody concentrations and avidity to Env/p24 were measured longitudinally at years 1, 4, and 6-15 after ART initiation. Plasma HIV RNA by single copy assay and T-cell responses (IFN-γ ELISPOT) against multiple HIV antigens were measured at the last time point.

RESULTS

HIV antibody levels declined significantly with increasing time on ART (19%/year between year 1 and 4). HIV antibody levels correlated with T-cell responses to HIV Pol (r = 0.28, P = 0.014) and to Nef/Tat/Rev (r = 0.34; P = 0.002). HIV antibody and T-cell responses were positively associated with HIV DNA levels; for example, at the last time point (median 7 years on ART), r = 0.35 for antibody levels and HIV DNA (P < 0.001); r = 0.23 for Nef/Tat/Rev-specific T-cell responses and HIV DNA (P = 0.03). Neither antibody nor T-cell responses correlated with cell-associated HIV RNA or plasma RNA by single copy assay.

CONCLUSIONS

In individuals on long-term ART, HIV-specific antibody and T-cell responses correlate with each other and with HIV DNA levels. The positive correlation between HIV immune responses and HIV DNA implies that the immune system is sensing, but not clearing, infected cells, perhaps because of immune dysfunction. Measuring immune responses to HIV antigens may provide insight into the impact of reservoir-reducing strategies.

HIV antibodies level as a marker of HIV persistence: the role of hepatitis C virus coinfection

Human immunodeficiency virus (HIV) antibodies have been proposed as a measure of the size of the HIV reservoir. The aim of our study is to quantify the anti-HIV antibodies level in a cohort of people living with HIV (PLWH), stratified based on the presence of continuous undetectable HIV viral load and the co-existence of hepatitis C virus infection. A sample of 229 HIV-monoinfected (n = 114) or HIV/HCV-coinfected [either with resolved HCV infection (n = 75) or active HCV coinfection (n = 40)] patients, followed up a median of 34 (IQR 20-44) months, was studied. Anti-HIV index was obtained as the 1:800 dilution of HIV antibodies. CD4+ T cell count, time with undetectable HIV viral load, annual increase of CD4+ T cell count, anti-HCV therapy, and diagnosis of cirrhosis were analyzed. Patients with a continued suppressed HIV viral load had significant lower anti-HIV index compared with those with virologic failure during the follow-up. Significant higher CD4+ T cell increase was observed in those with a lower anti-HIV index. HIV-monoinfected patients showed an anti-HIV index significantly lower than patients with HCV coinfection. Resolved HCV infection after interferon-based therapy, but not with direct acting antivirals, was associated with a lower anti-HIV index. HIV/HCV-coinfected patients showed higher HIV antibodies level when compared with HIV-monoinfected individuals. A decrease in anti-HIV index in HIV/HCV-coinfected patients was detected when a sustained virological HCV response was obtained after interferon-based therapy, in possible relation with the direct or indirect effect of interferon on PLWH CD4 T cells.

Why and where an HIV cure is needed and how it might be achieved

Despite considerable global investment, only 60% of people who live with HIV currently receive antiretroviral therapy. The sustainability of current programmes remains unknown and key incidence rates are declining only modestly. Given the complexities and expenses associated with lifelong medication, developing an effective curative intervention is now a global priority. Here we review why and where a cure is needed, and how it might be achieved. We argue for expanding these efforts from resource-rich regions to sub-Saharan Africa and elsewhere: for any intervention to have an effect, region-specific biological, therapeutic and implementation issues must be addressed.

Decreased Seroreactivity in Individuals Initiating Antiretroviral Therapy during Acute HIV Infection

Antiretroviral therapy (ART) during acute HIV infection (AHI) interrupts viral dynamics and may delay the emergence of serological markers targeted by current HIV screening and confirmatory assays, thus creating challenges for correctly classifying HIV infection status. The performance of three HIV antigen/antibody combination (HIV Ag/Ab Combo) assays (the Bio-Rad GS, Abbott Architect, and Bio-Rad BioPlex 2200 assays) was evaluated with samples collected from RV254/South East Asia Research Collaboration in HIV 010 (RV254/SEARCH010) study (Bangkok, Thailand) participants at weeks 12 and 24 following the initiation of ART at Fiebig stage I (FI) (n = 23), FII (n = 39), or FIII/IV (n = 22). Supplemental, confirmatory testing was performed by the Geenius HIV 1/2 and HIV-1 Western blot assays (Bio-Rad). Samples from 30 untreated, HIV-1-infected individuals demonstrated robust HIV Ag/Ab Combo assay reactivity with well-developed HIV-1 Western blotting profiles by 24 weeks after infection. In contrast, 52.2% of samples from individuals initiating ART at FI, 7.7% of samples from individuals initiating ART at FII, and 4.5% of samples from individuals initiating ART at FIII/IV were nonreactive by the HIV Ag/Ab Combo assays, with 36.4 to 39.1% of samples having low signal-to-cutoff (S/CO) results by the Architect and BioPlex assays (S/CO < 10). Seroreversion from a reactive to a nonreactive status was observed in 10 individuals initiating ART at FII and 3 individuals initiating ART at FIII/IV. The Geenius and HIV-1 Western blot assay results were negative or indeterminate for 73.9% and 69.6% of individuals, respectively, treated at FI; 50.0% and 26.3% of individuals, respectively, treated at FII; and 54.5% and 40.9% of individuals, respectively, treated at FIII/IV. Virologic suppression of HIV-1 by ART during AHI impedes seroconversion to biomarkers of infection, limiting the utility of HIV Ag/Ab Combo and supplemental, confirmatory assays for infection status determination.

Nonreactive Human Immunodeficiency Virus Type 1 Rapid Tests After Sustained Viral Suppression Following Antiretroviral Therapy Initiation During Primary Infection

We assessed the impact of early antiretroviral treatment (ART) on human immunodeficiency virus (HIV) antibody detection by rapid tests in 44 individuals after several years of successful ART. HIV self-tests and point-of-care tests were negative in 30% and 7%-9% of cases, respectively. These data reinforce the message that patients should never be retested after entering HIV care.

Challenges to the performance of current HIV diagnostic assays and the need for centralized specimen archives: a review of the Consortium for the Evaluation and Performance of HIV Incidence Assays (CEPHIA) repository

Background: New challenges for diagnosis of HIV infection abound, including the impact on key viral and immunological markers of HIV vaccine studies, pre-exposure prophylaxis usage and breakthrough infections, and very early initiation of anti-retroviral treatment. These challenges impact the performance of current diagnostic assays, and require suitable specimens for development and evaluation. In this article we review and describe an archive developed by the Consortium for the Evaluation and Performance of HIV Incidence Assays (CEPHIA), in order to identify the critical features required to create a centralized specimen archive to support these current and future developments. Review and Findings: We review and describe the CEPHIA repository, a large, consolidated repository comprised of over 31,000 highly-selected plasma samples and other body fluid specimen types, with over 50 purposely designed specimen panels distributed to 19 groups since 2012. The CEPHIA repository provided financial return on investment, supported the standardization of HIV incidence assays, and informed guidance and standards set by the World Health Organization and UNAIDS. Unified data from extensively characterized specimens has allowed this resource to support biomarker discovery, assay optimization, and development of new strategies for estimating duration of HIV infection. Critical features of a high-value repository include 1) extensively-characterized samples, 2) high-quality clinical background data, 3) multiple collaborations facilitating ongoing sample replenishment, and 4) sustained history of high-level specimen utilization. Conclusion: With strong governance and leadership, a large consolidated archive of samples from multiple studies provides investigators and assay developers with easy access to diverse samples designed to address challenges associated with HIV diagnosis, helping to enable improvements to HIV diagnostic assays and ultimately elimination of HIV. Its creation and ongoing utilization should compel funders, institutions and researchers to address and improve upon current approaches to sharing specimens.

Anti-Human Immunodeficiency Virus Antibodies in the Cerebrospinal Fluid: Evidence of Early Treatment Impact on Central Nervous System Reservoir?

Background

Despite effective antiretroviral therapy (ART), human immunodeficiency virus (HIV) likely persists in the central nervous system (CNS) in treated individuals. We examined anti-HIV antibodies in cerebrospinal fluid (CSF) and blood as markers of persistence.

Methods

Human immunodeficiency virus antibodies were measured in paired CSF and serum before and after long-term treatment of chronic (n = 10) and early infection (n = 12), along with untreated early infection (n = 10).

Results

Treatment of chronic infection resulted in small reductions of anti-HIV antibodies in CSF and serum despite >10 years of suppressive ART. In untreated early infection, anti-HIV antibodies emerged in blood by day 30, whereas CSF antibodies reached similar levels 2 weeks later. Compared with long-term treatment of chronic infection, early ART initiation reduced CSF antibodies by 43-fold (P > .0001) and blood antibodies by 7-fold (P = .0003). Two individuals receiving pre-exposure prophylaxis and then ART early after infection failed to develop antibodies in CSF or blood, whereas CSF antibodies were markedly reduced in the Berlin patient.

Conclusions

To the extent that differential CSF and blood antibodies indicate HIV persistence, these data suggest a relative delay in establishment of the CNS compared with the systemic HIV reservoir that provides an opportunity for early treatment to have a greater impact on the magnitude of long-term CNS infection.

Evaluation of the Performance of Three Biomarker Assays for Recent HIV Infection Using a Well-Characterized HIV-1 Subtype C Incidence Cohort

Biomarkers for detecting early HIV infection and estimating HIV incidence should minimize false-recent rates (FRRs) while maximizing mean duration of recent infection (MDRI). We compared HIV subtypes B, E and D (BED) capture enzyme immunoassay (BED), Sedia limiting antigen (LAg) avidity enzyme immunoassay, and Bio-Rad avidity incidence (BRAI) assays using samples from Zimbabwean postpartum women infected with clade C HIV. We calculated MDRIs using 590 samples from 351 seroconverting postpartum women, and FRRs using samples from 2,825 women known to be HIV positive for >12 months. Antibody kinetics were more predictable with LAg and had higher precision compared with BED or BRAI. BRAI also exhibited more variability, and avidity reversal in some cases. For BED, LAg, and BRAI, used alone or with viral load, MDRI values in days were: BED-188 and 170 at normalized optical density (ODn) 0.8; LAg-104 and 100 at ODn cutoff 1.5; BRAI-135 and 134 at avidity index cutoff 30%. Corresponding FRRs were: BRAI 1.1% and 1.0% and LAg 0.57% and 0.35%: these were 3.8-10.9 times lower than BED values of 4.8% and 3.8%. BRAI and LAg have significantly lower FRRs and MDRIs than in published studies, and much lower than BED and could be used to estimate incidence in perinatal women and to measure population-level HIV incidence in HIV control operations in Africa.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

CONCLUSION

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

Discrimination between recent and non-recent HIV infections using routine diagnostic serological assays

The suitability of routine diagnostic HIV assays to accurately discriminate between recent and non-recent HIV infections has not been fully investigated. The aim of this study was to compare an established HIV recency assay, the Sedia limiting antigen HIV avidity assay (LAg), with the diagnostic assays; Abbott ARCHITECT HIV Ag/Ab Combo and INNO-LIA HIV line assays. Samples from all new HIV diagnoses in Ireland from January to December 2016 (n = 455) were tested. An extended logistic regression model, the Spiegelhalter-Knill-Jones method, was utilised to establish a scoring system to predict recency of HIV infection. As proof of concept, 50 well-characterised samples were obtained from the CEPHIA repository whose stage of infection was blinded to the authors, which were tested and analysed. The proportion of samples that were determined as recent was 18.1% for LAg, 6.4% with the ARCHITECT, and 14.5% in the INNO-LIA assay. There was a significant correlation between the ARCHITECT S/CO values and the LAg results, r = 0.717, p < 0.001. ROC analysis revealed that an ARCHITECT S/CO < 250 had a sensitivity and specificity of 90.32% and 89.83%, respectively. Combining the Abbott ARCHITECT HIV Ag/Ab Combo assay and INNO-LIA HIV assays resulted in an observed risk of being recent of 100%. Analysis of the CEPHIA samples revealed a strong agreement between the LAg assay and the combination of routine assays (κ = 0.908, p < 0.001). Our findings provide evidence that assays routinely employed to diagnose and confirm HIV infection may be utilised to determine the recency of HIV infection.

A simple and high-throughput luciferase immunosorbent assay for both qualitative and semi-quantitative detection of anti-HIV-1 antibodies

In this study, we described an ultrasensitive and high-throughput luciferase immunosorbent assay (LISA) for qualitative and quantitative detection of anti-HIV-1 antibody. Anti-HIV antibody in serum or plasma samples was captured by protein A/G-coated microtiter plate and detected with crude cell lysates expressing Nanoluc luciferase (Nluc) enzyme fused with HIV-1 p24 or gp41 antigen without the need of protein purification. After the addition of furimazine substrate, anti-HIV antibodies were quantitatively measured as luciferase light units. LISA showed a wide linear range of detection and was about 10⁴-fold more sensitive than ELISA. For the detection of both anti-p24 and anti-gp41, LISA showed extraordinary sensitivity (99.5% and 100%, respectively) and equivalent specificity (100%). LISA could also monitor the change in the anti-HIV-1 antibody response over time in antiretroviral therapy (ART) treated individuals, and can sufficiently distinguish between recent and long-term HIV-1 infections. Our preliminary results indicate that LISA may provide a novel universal immunoassay platform for simultaneous HIV-1 detection, quantitative measurement of anti-HIV antibodies as well as the differentiation of HIV-1 infection stages.

Human Immunodeficiency Virus (HIV)-Antibody Repertoire Estimates Reservoir Size and Time of Antiretroviral Therapy Initiation in Virally Suppressed Perinatally HIV-Infected Children

BACKGROUND

Assays to estimate human immunodeficiency virus (HIV) reservoir size require large amounts of blood, which represents a drawback especially in pediatric settings. We investigated whether HIV-antibody repertoire could estimate the viral reservoir size. Moreover, we assessed the magnitude of HIV-antibody response as a predictor of time of antiretroviral therapy (ART) initiation.

METHODS

Human immunodeficiency virus-antibody responses to 10 different viral proteins were evaluated by HIV Western blot (WB) kit and a WB score was assigned to each patient. Patients were classified in 2 subgroups based on the timing of ART initiation (early treated [ET], 0-24 weeks and late treated [LT], >24 weeks). Human immunodeficiency virus-deoxyribonucleic acid (DNA) was quantified using real-time quantitative polymerase chain reaction on total peripheral blood mononuclear cells. Logistic regression and principal component analysis were built on these data to test the ability of WB score to predict the expected value of HIV-DNA and the timing of ART initiation.

RESULTS

Sixty-nine perinatally HIV-infected children were evaluated. Reduced HIV-specific antibody responses and lower size of HIV-DNA were observed in ET compared with LT patients (P < .001 and P = .02, respectively). We found that WB score correlates with HIV-DNA (P = .032) and timing of ART initiation (P < .001). Based on the logistic regression analysis, we found that WB score can predict the HIV-DNA size and the timing of ART initiation with an Akaike information criterion of -118.13 and -151.51, respectively.

CONCLUSIONS

Western blot score can estimate HIV-DNA size and timing of ART initiation in long-term virally suppressed children. This rapid, inexpensive, and easily reproducible tool can provide useful information to identify potential candidates for HIV remission studies.

Frontline Science: Plasma and immunoglobulin G galactosylation associate with HIV persistence during antiretroviral therapy

Global antibody glycosylation is dynamic and plays critical roles in shaping different immunological outcomes and direct antibody functionality during HIV infection. However, the relevance of global antibody or plasma glycosylation patterns to HIV persistence after antiretroviral therapy (ART) has not been characterized. First, we compared glycomes of total plasma and isolated immunoglobulin G (IgG) from HIV+ ART-suppressed, HIV+ viremic, and HIV-negative individuals. Second, in ART-suppressed individuals, we examined the associations between glycomes and (1) levels of cell-associated HIV DNA and RNA in PBMCs and isolated CD4+ T cells, (2) CD4 count and CD4%, and (3) expression of CD4+ T-cell activation markers. HIV infection is associated with persistent alterations in the IgG glycome including decreased levels of disialylated glycans, which is associated with a lower anti-inflammatory activity, and increased levels of fucosylated glycans, which is associated with lower antibody-dependent cell-mediated cytotoxicity (ADCC). We also show that levels of certain mono- and digalactosylated nonfucosylated glycomic traits (A2G1, A2G2, and A2BG2), which have been reported to be associated with higher ADCC and higher anti-inflammatory activities, exhibit significant negative correlations with levels of cell-associated total HIV DNA and HIV RNA in ART-suppressed individuals. Finally, levels of certain circulating anti-inflammatory glycans are associated with higher levels of CD4 T cells and lower levels of T-cell activation. Our findings represent the first proof-of-concept evidence that glycomic alterations, known to be associated with differential states of inflammation and ADCC activities, are also associated with levels of HIV persistence in the setting of ART suppression.