Long-term complications in patients with poor immunological recovery despite virological successful HAART in Dutch ATHENA cohort

Association between CD4 lymphocyte count and the incidence of comorbidities in Human immunodeficiency virus positive patients with virological suppression after antiretroviral treatment

BACKGROUND

The incidence of comorbidities is higher in HIV-positive patients than in the general population due to factors, such as HIV-related chronic inflammation. There is no consensus on whether a low CD4 lymphocyte count after virological suppression at long-term follow-up increases the risk of comorbidities. This study evaluates the association between CD4 lymphocyte count and the incidence of comorbidities during the first 5 years of virological suppression after highly active antiretroviral treatment.

METHODS

We conducted a cohort study of HIV-positive adults who achieved virological suppression in an HIV program between 2002 and 2016 in Colombia. A generalized equation estimation model was used to estimate the association between CD4 lymphocyte count and the incidence of comorbidities.

RESULTS

A follow-up period of at least 1 year was completed in 921 HIV-positive patients with virological suppression. We found 71 comorbidities during a maximum of 5 years of follow-up; 41 (59%) were AIDS-defining comorbidities and 19 (46%) of them occurred during the first semester. Thirty cases of non-AIDS- defining comorbidities were diagnosed.We did not find any association between CD4 lymphocyte count and the incidence of comorbidities (OR 0.92, CI 95% 0.45 -1.91 for CD4 201-499 cells/µL vs CD4 ≤200 cells/µL, and OR 0.55, 95% CI 0.21-1.44 for CD4 ≥500 cells/µL vs CD4 ≤200 cells/µL).

CONCLUSION

No association was found between CD4 lymphocyte count and the incidence of AIDS-defining or non-AIDS-defining comorbidities in patients with virological suppression. Further studies are needed to assess the risk of comorbidities in this population to design interventions aimed at improving their prognosis.

Temporal changes in plasma metabolic signatures to predict immune response of antiretroviral therapy among people living with HIV

Antiretroviral therapy (ART) is an effective treatment for people living with HIV (PLHIVs), requiring an extended period to achieve immune reconstitution. Metabolic alterations induced by ART are crucial for predicting long-term therapeutic responses, yet comprehensive investigation through large-scale clinical studies is still lacking. Here, we collected plasma samples from 108 PLHIVs to the untargeted plasma metabolomics study, based on the longitudinal metabolomics design. Cross-sectional analyzes were performed at pre- and post-ART to explore the metabolic transformation induced by the therapy. Subsequently, delta values between pre- and post-ART measurements were calculated to quantify metabolic alterations. Then, the optimal set of metabolic traits and clinical signatures were further identified and applied to construct random forest model for predicting the future therapeutic responses to ART. We found distinct ART-induced metabolic transformation among PLHIVs. After confounder-adjustments, five metabolites exhibited significant associations with future immune response: tetracosatetraenoic acid (24:4n-6) (pre-ART) (odds ratio [OR]: 0.978, 95% confidence interval [CI]: 0.955~0.997), 1-(3,4-dihydroxyphenyl)-5-hydroxy-3-decanone (pre-ART) (OR: 1.298, 95% CI: 1.061~1.727), beta-PC-M6 (change) (OR: 0.967, 95% CI: 0.938~0.993), d-Galactaro-1,4-lactone (change) (OR: 1.032, 95% CI: 1.007~1.063), Annuionone C (change) (OR: 1.100, 95% CI: 1.030~1.190). The addition of plasma metabolites to clinical markers accurately predicted immune response to ART with an area under curve of 0.91. Notably, most disrupted metabolites were significantly correlated with blood lipids, suggesting that metabolic transformation might contribute to dyslipidemia among PLHIVs. This study highlights the distinct metabolic transformation post-ART among PLHIVs and reveals the potential role of metabolic transformation as key determinants of ART efficacy.

Progress in Early Detection of HIV in Tajikistan

HIV early detection (CD4 counts ≥350 cells/μL) is correlated with higher life expectancy among people living with HIV (PLHIV). Several factors, including physical, cultural, structural, and financial barriers, may limit early detection of HIV. This is a first-of-its-kind study on population-level differences in early detection of HIV across time within Tajikistan and any country in the Central Asia region. Utilizing the Tajikistan Ministry of Health's national HIV data (N = 10,700) spanning 2010 to 2023, we developed median regression models with the median CD4 cell count as the outcome and with the following predictors: time (years), region, age, gender, and area (urban/rural status). Individuals younger than 19 years old were detected early for HIV, whereas those older than 39 years were detected late. Females were detected earlier compared to their male counterparts regardless of region of residence. Rural populations were detected earlier in most years compared to their urban counterparts. The COVID-19 pandemic accelerated HIV early detection in 2021 but most regions have returned to near pre-pandemic levels of detection in 2022 and 2023. There were differences identified among different demographic and geographic groups which warrant further attention.

HIV immunological non-responders are characterized by extensive immunosenescence and impaired lymphocyte cytokine production capacity

Introduction

Immunological non-responders (INR) are people living with HIV (PLHIV) who fail to fully restore CD4+ T-cell counts despite complete viral suppression with antiretroviral therapy (ART). INR are at higher risk for non-HIV related morbidity and mortality. Previous research suggest persistent qualitative defects.

Methods

The 2000HIV study (clinical trials NTC03994835) enrolled 1895 PLHIV, divided in a discovery and validation cohort. PLHIV with CD4 T-cell count <350 cells/mm3 after ≥2 years of suppressive ART were defined as INR and were compared to immunological responders (IR) with CD4 T-cell count >500 cells/mm3. Logistic and rank based regression were used to analyze clinical data, extensive innate and adaptive immunophenotyping, and ex vivo monocyte and lymphocyte cytokine production after stimulation with various stimuli.

Results

The discovery cohort consisted of 62 INR and 1224 IR, the validation cohort of 26 INR and 243 IR. INR were older, had more advanced HIV disease before starting ART and had more frequently a history of non-AIDS related malignancy. INR had lower absolute CD4+ T-cell numbers in all subsets. Activated (HLA-DR+, CD38+) and exhausted (PD1+) subpopulations were proportionally increased in CD4 T-cells. Monocyte and granulocyte immunophenotypes were comparable. INR lymphocytes produced less IL-22, IFN-γ, IL-10 and IL-17 to stimuli. In contrast, monocyte cytokine production did not differ. The proportions of CD4+CD38+HLA-DR+ and CD4+PD1+ subpopulations showed an inversed correlation to lymphocyte cytokine production.

Conclusions

INR compared to IR have hyperactivated and exhausted CD4+ T-cells in combination with lymphocyte functional impairment, while innate immune responses were comparable. Our data provide a rationale to consider the use of anti-PD1 therapy in INR.

Persistent HIV-1 transcription during ART: time to reassess its significance?

PURPOSE OF REVIEW

Despite suppressive antiretroviral therapy (ART), HIV-1 reservoirs persist and reignite viral replication if therapy is interrupted. Persistence of the viral reservoir in people with HIV-1 (PWH) is the main obstacle to an HIV-1 cure. The reservoirs are not transcriptionally silent, and viral transcripts can be detected in most ART-treated individuals. Here, we review the recent progress in the characterization of persistent HIV-1 transcription during ART.

RECENT FINDINGS

Evidence from several studies indicates that, although cell-associated unspliced (US) HIV-1 RNA is abundantly expressed in ART-treated PWH, intact full-length US transcripts are rare and most US RNA is derived from defective proviruses. The transcription- and translation-competent defective proviruses, previously considered irrelevant, are increasingly being linked to residual HIV-1 pathogenesis under suppressive ART. Recent data suggest a continuous crosstalk between the residual HIV-1 activity under ART and the immune system. Persistent HIV-1 transcription on ART, despite being mostly derived from defective proviruses, predicts viral rebound upon therapy interruption, suggesting its role as an indicator of the strength of the host antiviral immune response that is shaping the viral rebound.

SUMMARY

In light of the recent findings, the significance of persistent HIV-1 transcription during ART for the long-term health of PWH and the cure research should be reassessed.

Clinical outcomes and risk factors for immune recovery and all-cause mortality in Latin Americans living with HIV with virological success: a retrospective cohort study

INTRODUCTION

Immune reconstitution following antiretroviral therapy (ART) initiation is crucial to prevent AIDS and non-AIDS-related comorbidities. Patients with suppressed viraemia who fail to restore cellular immunity are exposed to an increased risk of morbidity and mortality during long-term follow-up, although the underlying mechanisms remain poorly understood. We aim to describe clinical outcomes and factors associated with the worse immune recovery and all-cause mortality in people living with HIV (PLWH) from Latin America following ART initiation.

METHODS

Retrospective cohort study using the CCASAnet database: PLWH ≥18 years of age at ART initiation using a three drug-based combination therapy and with medical follow-up for ≥24 months after ART initiation and undetectable viral load were included. Patients were divided into four immune recovery groups based on rounded quartiles of increase in CD4 T-cell count at 2 years of treatment (<150, [150, 250), [250, 350] and >350 cells/mm3 ). Primary outcomes included all-cause mortality, AIDS-defining events and non-communicable diseases that occurred >2 years after ART initiation. Factors associated with an increase in CD4 T-cell count at 2 years of treatment were evaluated using a cumulative probability model with a logit link.

RESULTS

In our cohort of 4496 Latin American PLWH, we found that patients with the lowest CD4 increase (<150) had the lowest survival probability at 10 years of follow-up. Lower increase in CD4 count following therapy initiation (and remarkably not a lower baseline CD4 T-cell count) and older age were risk factors for all-cause mortality. We also found that older age, male sex and higher baseline CD4 T-cell count were associated with lower CD4 count increase following therapy initiation.

CONCLUSIONS

Our study shows that PLWH with lower increases in CD4 count have lower survival probabilities. CD4 increase during follow-up might be a better predictor of mortality in undetectable PLWH than baseline CD4 count. Therefore, it should be included as a routine clinical variable to assess immune recovery and overall survival.

Trends and the associated factors of optimal immunological response and virological response in late anti-retroviral therapy initiation HIV cases in Taiwan from 2009 to 2020

BACKGROUND

Late cART initiation (CD4 count ≤200 cells/μL or AIDS-defining opportunistic illnesses [AOIs] at cART initiation) impedes CD4 count recovery and virologic suppression after cART initiation. However, studies to evaluate trends of and modifiable factors for optimal immunological response (IR) and virological response (VR) in people living with HIV (PLWH) with late cART initiation with the current HIV treatment strategies are limited.

METHODS

We retrospectively identified 475 PLWH with late cART initiation in 2009-2020. Patients were grouped based on the presence of IR (CD4 count ≥200 cells/μL) or VR (plasma viral load [PVL] ≤ 50 copies/mL) within 18 months after cART initiation (403 [84.8%] IR(+) and 72 [15.2%] IR(-); 422 [88.8%] VR(+) and 53 [11.2%] VR(-)). We used Joinpoint regression to identify IR (+) and VR(+) proportion changes.

RESULTS

From 2009 to 2020, the proportion of IR(+) patients remained unchanged (75% to 90%, P = 0.102), whereas that of VR(+) patients increased significantly (75% to 95%, P = 0.007). No join point was identified for either IR(+) or VR(+), and the annual percentage change was 0.56% (nonsignificant) and 1.35% (significant) for IR(+) and VR(+), respectively. Compared to IR(-) patients, IR(+) patients were more likely to have a higher pre-cART PVL, to start with a first-line INSTI-based regimen, or to start cART within 14 days of HIV diagnosis but were less likely to have chronic kidney disease, composite AOIs, or a lower pre-cART CD4 count. Compared to VR(-) patients, VR(+) patients were more likely to start a single-tablet regimen but were less likely to have a higher pre-cART PVL.

CONCLUSIONS

Our study identified several modifiable factors for optimal IR (rapid cART initiation and INSTI-based regimen initiation) and for optimal VR (STR initiation) among late initiators, which may guide early treatment modifications to reduce their AIDS-defining event incidence and mortality.

Role of thymosin α1 in restoring immune response in immunological nonresponders living with HIV

BACKGROUND

Immunological nonresponders (INRs) living with HIV are at increased risk of co-infection and multiple tumors, with no effective strategy currently available to restore their T-cell immune response. This study aimed to explore the safety and efficacy of thymosin α1 in reconstituting the immune response in INRs.

METHODS

INRs with CD4 + T cell counts between 100 and 350 cells/μL were enrolled and received two-staged 1.6 mg thymosin α1 subcutaneous injections for 24 weeks (daily in the first 2 weeks and biweekly in the subsequent 22 weeks) while continuing antiretroviral therapy. T cell counts and subsets, the expression of PD-1 and TIM-3 on T cells, and signal joint T cell receptor excision circles (sjTREC) at week 24 were evaluated as endpoints.

RESULTS

Twenty three INRs were screened for eligibility, and 20 received treatment. The majority were male (19/20), with a median age of 48.1 years (interquartile range: 40.5-57.0) and had received antiretroviral therapy for 5.0 (3.0, 7.3) years. Multiple comparisons indicated that CD4 + T cell count and sjTREC increased after initiation of treatment, although no significant differences were observed at week 24 compared to baseline. Greatly, levels of CD4 + T cell proportion (17.2% vs. 29.1%, P < 0.001), naïve CD4 + and CD8 + T cell proportion (17.2% vs. 41.1%, P < 0.001; 13.8% vs. 26.6%, P = 0.008) significantly increased. Meanwhile, the proportion of CD4 + central memory T cells of HIV latent hosts (42.7% vs. 10.3%, P < 0.001) significantly decreased. Moreover, the expression of PD-1 on CD4 + T cells (14.1% vs. 6.5%, P < 0.001) and CD8 + T cells (8.5% vs. 4.1%, P < 0.001) decreased, but the expression of TIM-3 on T cellsremained unaltered at week 24. No severe adverse events were reported and HIV viral loads kept stable throughout the study.

CONCLUSIONS

Thymosin α1 enhance CD4 + T cell count and thymic output albeit as a trend rather than an endpoint. Importantly, it improves immunosenescence and decreases immune exhaustion, warranting further investigation.

TRIAL REGISTRATION

This single-arm prospective study was registered with ClinicalTrials.gov (NCT04963712) on July 15, 2021.

PSGL-1, a Strategic Biomarker for Pathological Conditions in HIV Infection: A Hypothesis Review

P-selectin glycoprotein ligand-1 (PSGL-1) has been established to be a cell adhesion molecule that is involved in the cellular rolling mechanism and the extravasation cascade, enabling the recruitment of immune cells to sites of inflammation. In recent years, researchers have established that PSGL-1 also functions as an HIV restriction factor. PSGL-1 has been shown to inhibit the HIV reverse transcription process and inhibit the infectivity of HIV virions produced by cells expressing PSGL-1. Cumulative evidence gleaned from contemporary literature suggests that PSGL-1 expression negatively affects the functions of immune cells, particularly T-cells, which are critical participants in the defense against HIV infection. Indeed, some researchers have observed that PSGL-1 expression and signaling provokes T-cell exhaustion. Additionally, it has been established that PSGL-1 may also mediate virus capture and subsequent transfer to permissive cells. We therefore believe that, in addition to its beneficial roles, such as its function as a proinflammatory molecule and an HIV restriction factor, PSGL-1 expression during HIV infection may be disadvantageous and may potentially predict HIV disease progression. In this hypothesis review, we provide substantial discussions with respect to the possibility of using PSGL-1 to predict the potential development of particular pathological conditions commonly seen during HIV infection. Specifically, we speculate that PSGL-1 may possibly be a reliable biomarker for immunological status, inflammation/translocation, cell exhaustion, and the development of HIV-related cancers. Future investigations directed towards our hypotheses may help to evolve innovative strategies for the monitoring and/or treatment of HIV-infected individuals.

Prevalence of and prognosis for poor immunological recovery by virally suppressed and aged HIV-infected patients

Background

Antiretroviral therapy (ART) prolongs lifespan and decreases mortality of HIV infected patients. However, many patients do not achieve optimal immune reconstitution. The influence of non-optimal immune recovery on non-AIDS related diseases is not well defined in aged HIV-infected patients receiving ART.

Methods

A retrospective study was conducted at Tianjin Second People's Hospital, China to evaluate the association of an inadequate immunological response and non-AIDS diseases in HIV infected patients ≥60 years of age and virally suppressed for at least 2 years by ART.

Results

The study included patients (n = 666) who initiated ART between August 2009 and December 2020. The prevalence of patients with an inadequate immunological response was 29.6%. The percentage of non-AIDS diseases such as hypertension, cardiovascular disease (CVD), diabetes, tumor, and chronic kidney disease (CKD) was 32.9, 9.9, 31, 4.1, and 13%, respectively. In addition to baseline CD4+ T cell counts, CVD and tumor were associated with poor immune reconstitution in aged Chinese HIV-1 infected patients. The adjusted odds ratios (95% confidence interval) were AOR 2.45 (95% CI: 1.22-4.93) and 3.06 (95% CI: 1.09-8.56, p = 0.03). Inadequate immunological response was associated with greater mortality (AOR: 2.83, 95% CI: 1.42-5.67, p = 0.003) in this cohort.

Conclusion

These results tend to demonstrate appropriate drug selection at ART initiation and prevention of non-AIDS complications during ART decreased mortality of and an inadequate immunological response in aged HIV infected patients.

Effect of immunological non-response on incidence of Non-AIDS events in people living with HIV: A retrospective multicenter cohort study in Taiwan

BACKGROUND

People living with HIV (PLWH) are susceptible to non-AIDS-related events, particularly those with immunological nonresponses (INRs) to highly active antiretroviral therapy (HAART). This study assessed the association of INRs with incident non-AIDS-related events among PLWH.

METHODS

This multicenter retrospective cohort study enrolled PLWH who had newly diagnosed stage 3 HIV and received HAART between January 1, 2008, and December 31, 2019. The patients were divided into two groups according to their immunological responses on the 360th day after HAART initiation: INR and non-INR groups. Cox regression and sensitivity analyses were conducted to estimate the effects of INRs on overall and individual categories of non-AIDS-related events (malignancies, vascular diseases, metabolic disorders, renal diseases, and psychiatric disorders). Patient observation started on the 360th day after HAART initiation and continued until February 28, 2022, death, or an outcome of interest, whichever occurred first.

RESULTS

Among the 289 included patients, 44 had INRs. Most of the included patients were aged 26-45 years (69.55%) and were men who have sex with men (89.97%). Many patients received HIV diagnoses between 2009 and 2012 (38.54%). INRs (vs. non-INRs) were associated with composite non-AIDS-related events (adjusted hazard ratio [aHR] = 1.80; 95% confidence interval [CI]: 1.19-2.73) and metabolic disorders (aHR = 1.75; 95% CI: 1.14-2.68). Sensitivity analyses revealed consistent results for each Cox regression model for both composite non-AIDS-related events and metabolic diseases.

CONCLUSION

Clinicians should be vigilant and implement early intervention and rigorous monitoring for non-AIDS-related events in PLWH with INRs to HAART.

Particular Aspects Related to CD4+ Level in a Group of HIV-Infected Patients and Associated Acute Coronary Syndrome

People living with HIV infection are at high risk for cardiovascular events due to inflammation and atherosclerosis. Also, some antiretroviral therapies may contribute to the risk of cardiovascular complications. Immune status is highly dependent on the level of lymphocyte T helper CD4+. There are data suggesting that immune status and CD4+ cell count may be involved in the development of cardiovascular complications in these patients. Our study is longitudinal and retrospective and included a total number of 50 patients with HIV infection associated with acute coronary syndrome, divided into two subgroups based on the nadir of CD4+ cells. This study analyzes the relationship between the immune status of HIV patients, assessed by the nadir of the CD4+ T-cell count, and the outcome of these patients. Also, secondary endpoints were the assessment of the magnitude of coronary lesions and of thrombotic and bleeding risk assessed by specific scores. Clinical and biological parameters and also the extension and complexity of coronary lesions were assessed. Although patients with poor immune status had more complex coronary lesions and increased operative risk and bleeding risk at one year, this was not associated with significant differences in major adverse cardiac and cerebrovascular events at the 30-day and 1-year outcomes.

Cardiovascular events in delayed presentation of HIV: the prospective PISCIS cohort study

Objectives

People with HIV (PWH) have a higher cardiovascular risk than the general population. It remains unclear, however, whether the risk of cardiovascular disease (CVD) is higher in late HIV presenters (LP; CD4 ≤ 350 cells/μL at HIV diagnosis) compared to PWH diagnosed early. We aimed to assess the rates of incident cardiovascular events (CVEs) following ART initiation among LP compared to non-LP.

Methods

From the prospective, multicentre PISCIS cohort, we included all adult people with HIV (PWH) initiating antiretroviral therapy (ART) between 2005 and 2019 without prior CVE. Additional data were extracted from public health registries. The primary outcome was the incidence of first CVE (ischemic heart disease, congestive heart failure, cerebrovascular, or peripheral vascular disease). The secondary outcome was all-cause mortality after the first CVE. We used Poisson regression.

Results

We included 3,317 PWH [26 589.1 person/years (PY)]: 1761 LP and 1556 non-LP. Overall, 163 (4.9%) experienced a CVE [IR 6.1/1000PY (95%CI: 5.3-7.1)]: 105 (6.0%) LP vs. 58 (3.7%) non-LP. No differences were observed in the multivariate analysis adjusting for age, transmission mode, comorbidities, and calendar time, regardless of CD4 at ART initiation [aIRR 0.92 (0.62-1.36) and 0.84 (0.56-1.26) in LP with CD4 count <200 and 200- ≤ 350 cells/μL, respectively, compared to non-LP]. Overall mortality was 8.5% in LP versus 2.3% in non-LP (p < 0.001). Mortality after the CVE was 31/163 (19.0%), with no differences between groups [aMRR 1.24 (0.45-3.44)]. Women vs. MSM and individuals with chronic lung and liver disease experienced particularly high mortality after the CVE [aMRR 5.89 (1.35-25.60), 5.06 (1.61-15.91), and 3.49 (1.08-11.26), respectively]. Sensitivity analyses including only PWH surviving the first 2 years yielded similar results.

Conclusion

CVD remains a common cause of morbidity and mortality among PWH. LP without prior CVD did not exhibit an increased long-term risk of CVE compared with non-LP. Identifying traditional cardiovascular risk factors is essential for CVD risk reduction in this population.

Immune reconstitution efficacy after combination antiretroviral therapy in male HIV-1 infected patients with homosexual and heterosexual transmission

We aimed to explore the impact of sexual transmission modes on immune reconstitution after combined antiretroviral therapy (cART). We have retrospectively analyzed longitudinal samples from 1557 treated male patients with virological suppression (HIV-1 RNA<50 copies/ml) for at least 2 years. Both heterosexuals (HET) and men who have sex with men (MSM) patients showed an increasing annual trend in CD4⁺ T cell counts after receiving cART (HET, β: 23.51 (cell/µl)/year, 95% CI: 16.70 to 30.31; MSM, β: 40.21 (cell/µl)/year, 95% CI: 35.82 to 44.61). However, the CD4⁺ T cell recovery rate was much lower in HET patients than MSM patients, determined by both the generalized additive mixed model (P < 0.001) and generalized estimating equations (P = 0.026). Besides HIV-1 subtypes, baseline CD4⁺ T cell counts and age at cART initiation, HET was an independent risk factor for immunological non-responders (adjusted OR: 1.73; 95% CI: 1.28 to 2.33). HET was also associated with lower probability of achieving conventional immune recovery (adjusted HR: 1.37; 95%CI: 1.22 to 1.67) and optimal immune recovery (adjusted HR: 1.48, 95%CI: 1.04-2.11). Male HET patients might have poorer immune reconstitution ability even after effective cART. Early initiation of cART after diagnosis and clinical monitoring for male HET patients should be highly emphasized.

Enteropathy and gut dysbiosis as obstacles to achieve immune recovery in undetectable people with HIV: a clinical view of evidence, successes, and projections

Immune performance following antiretroviral therapy initiation varies among patients. Despite achieving viral undetectability, a subgroup of patients fails to restore CD4+ T-cell counts during follow-up, which exposes them to non-AIDS defining comorbidities and increased mortality. Unfortunately, its mechanisms are incompletely understood, and no specific treatment is available. In this review, we address some of the pathophysiological aspects of the poor immune response from a translational perspective, with emphasis in the interaction between gut microbiome, intestinal epithelial dysfunction, and immune system, and we also discuss some studies attempting to improve immune performance by intervening in this vicious cycle.

Contribution of Reinfection to Annual Rate of Tuberculosis Infection (ARI) and Incidence of Tuberculosis Disease

BACKGROUND

Modeling studies have concluded that 60-80% of tuberculosis (TB) infections result from reinfection of previously infected persons. The annual rate of infection (ARI), a standard measure of the risk of TB infection in a community, may not accurately reflect the true risk of infection among previously infected persons. We constructed a model of infection and reinfection with Mycobacterium tuberculosis to explore the predictive accuracy of ARI and its effect on disease incidence.

METHODS

We created a deterministic simulation of the progression from TB infection to disease and simulated the prevalence of TB infection at the beginning and end of a theoretical year of infection. We considered 10 disease prevalence scenarios ranging from 100/100 000 to 1000/100 000 in simulations where TB exposure probability was homogeneous across the whole simulated population or heterogeneously stratified into high-risk and low-risk groups. ARI values, rates of progression from infection to disease, and the effect of multiple reinfections were obtained from published studies.

RESULTS

With homogeneous exposure risk, observed ARI values produced expected numbers of infections. However, when heterogeneous risk was introduced, observed ARI was seen to underestimate true ARI by 25-58%. Of the cases of TB disease that occurred, 36% were among previously infected persons when prevalence was 100/100 000, increasing to 79% of cases when prevalence was 1000/100 000.

CONCLUSIONS

Measured ARI underestimates true ARI as a result of heterogeneous population mixing. The true force of infection in a community may be greater than previously appreciated. Hyperendemic communities likely contribute disproportionally to the global TB disease burden.

CD4+ T lymphocyte recovery in the modern antiretroviral therapy era: Toward a new threshold for defining immunological non-responders

Introduction

Despite the high level of efficacy of modern antiretroviral therapy (ART) in reducing HIV viremia and the control of viral replication, some people living with HIV (PLWH) do not recover their CD4+ T cell count.

Methods

To evaluate the frequency and predictive factors of discordant immune responses, we performed a retrospective cohort study of 324 antiretroviral-naïve PLWH who initiated first-line ART between 2008 and 2018 and maintained HIV RNA &lt; 50 copies/ml during 36 months of follow-up. PLWH were defined as immunological non-responders (INRs) when CD4+ T cell count was &lt; 20% compared with baseline (INR20%), or &lt; 500 cells/mm3 (INR500) or &lt; 200 cells/mm3 (INR200) at 36 months.

Results

The prevalence of INR20%, INR500, and INR200 was 12.5%, 34.6%, and 1.5%, respectively. After adjustment for possible confounders, CD4 nadir showed a significant association with all INR definitions, with lower values predicting INR500 (aOR 0.98, 95% CI 0.98–0.99, p &lt; 0.001) and INR200 (aOR 0.98, 95% CI 0.95–1.01, p = 0.096). Moreover, a higher baseline CD4/CD8 ratio was inversely related to the probability of being INR500 (OR 0.03, 95% CI 0.01–0.12, p &lt; 0.001) and INR200 (OR 0.002, 95% CI 18–7–67.72, p = 0.255). By contrast, INR20% had a higher CD4 nadir and CD4/CD8 ratio than other INRs, suggesting the identification of an heterogenous population with such definition.

Discussion

The present study highlights how INR200 has become rare in the contemporary ART era, and about one-third of PLWH meet the criteria for INR500. Overcoming the threshold of 500 CD4/mm3 could be an appropriate definition of immune response, in contrast with the older definitions of INR200 and INR20%. Early diagnosis and rapid treatment initiation, before CD4 counts and the CD4/CD8 ratio begin to decline, are critical for achieving an optimal immune response.

Determinants of long-term survival in late HIV presenters: The prospective PISCIS cohort study

Background

Late HIV diagnosis (i.e CD4≤350 cells/µL) is associated with poorer outcomes. However, determinants of long-term mortality and factors influencing immune recovery within the first years after antiretroviral treatment (ART) initiation are poorly defined.

Methods

From PISCIS cohort, we included all HIV-positive adults, two-year survivors after initiating ART between 2005-2019. The primary outcome was all-cause mortality according to the two-year CD4 count. We used Poisson regression. The secondary outcome was incomplete immune recovery (i.e., two-year CD4<500 cells/µL). We used logistic regression and propensity score matching.

Findings

We included 2,719 participants (16593·1 person-years): 1441 (53%) late presenters (LP) and 1278 non-LP (1145 non-LP with two-year CD4 count >500 cells/µL, reference population). Overall, 113 patients (4·2%) died. Mortality was higher among LP with two-year CD4 count 200-500 cells/µL (aMRR 1·95[95%CI:1·06-3·61]) or <200 cells/µL (aMRR 4·59[2·25-9·37]).Conversely, no differences were observed in participants with two-year CD4 counts >500 cells/µL, regardless of being initially LP or non-LP (aMRR 1·05[0·50-2·21]). Mortality rates within each two-year CD4 strata were not affected by the initial CD4 count at ART initiation (test-interaction, p = 0·48). The stronger factor influencing immune recovery was the CD4 count at ART initiation. First-line integrase-inhibitor-(INSTI)-based regimens were associated with reduced mortality compared to other regimens (aMRR 0·54[0·31-0·93]) and reduced risk of incomplete immune recovery in LP (aOR 0·70[0·52-0·95]).

Interpretation

Two-year immune recovery is a good early predictor of long-term mortality in LP after surviving the first high-risk 2 years. Nearly half experienced a favorable immune recovery with a life expectancy similar to non-LP. INSTI-based regimens were associated with higher rates of successful immune recovery and better survival compared to non-INSTI regimens.

Funding

Southern-Denmark University, Danish AIDS-foundation, and Region of Southern Denmark.

Analysis of the Influencing Factors of Immunological Nonresponders in Wuhan, China

Objective

CD4⁺ cell recovery is hampered in some human immunodeficiency virus (HIV)-infected patients, despite a successful highly active antiretroviral therapy (HAART) with suppressed viral replication. We investigated the factors that might have hindered the CD4⁺ cell recovery in these patients.

Methods

In this retrospective study, we collected the data of all immune nonresponders (INRs) in Wuhan, China, until the end of 2020. A linear model was constructed based on the data from 220 patients with baseline and follow-up records. The response variables in this study were the CD4⁺ cell count increase. The predictor variables considered in this study were those factors likely to affect the CD4⁺ cell recovery.

Results

Our findings revealed that the plasma HIV-1 viral load of all patients was suppressed and 87.3% patients' CD4⁺ cells was increased after more than one year of the HAART treatment. In addition, their last follow-up showed a significant reduction in complications. In our results, the body mass index (BMI), number of months since HIV diagnosis to HAART start, and nonuse of co-trimoxazole were negatively correlated with the increase in CD4⁺ cells (P < 0.05). However, there were positive associations between serum creatinine levels and CD4⁺ cell recovery (P < 0.05). Further stratified analyses indicated that the associations between HAART replacement or creatinine usage and CD4⁺ cell growth were only observed in those participants with a BMI <18.5 (P < 0.05).

Conclusions

An early initiation of HAART and co-trimoxazole preventive therapy (CPT) can promote immune reconstitution. BMI and serum creatinine can serve as monitoring indicators of immune reconstitution prognosis after the HAART.

Clinical effects of durability of immunosuppression in virologically suppressed ART-initiating persons with HIV in Latin America. A retrospective cohort study

Background

Clinical outcomes are rarely studied in virologically suppressed people living with HIV (PWH) and incomplete CD4 recovery. To explore whether time living with severe immunosuppression predict clinical outcomes better than baseline or time updated CD4, we estimated the association between cumulative percentage of time with CD4 <200 cells/μL during viral suppression (VS) (%tCD4<200), and mortality and comorbidities during 2000-2019.

Methods

In a retrospective cohort analysis, we followed PWH initiating ART in Latin America from first VS (HIV-RNA<200 copies/μL) to death, virological failure or loss to follow-up. We fit Cox models to estimate risk of death and/or AIDS-defining and serious non-AIDS-defining events (ADE and SNADE -cancer, cardiovascular, liver, and renal diseases) by %tCD4<200 (continuous variable). We predicted survival probabilities for each event and calculated risks of hypothetical cases of different %tCD4<200.

Findings

In 8,369 patients with 34·9 months of follow-up (median, IQR: 16·7, 69·1), 4,274 (51%) started ART with CD4<200 cells/μL. Median %tCD4<200 was 0% (IQR: 0, 15%). We identified 195 (2·3%) deaths and 584 (7·2%) patients with ADE/SNADE. For an increased %tCD4<200 of 15% (e.g., 15% vs. 0%), the adjusted relative hazard (aHR) of death was 1·27 (95% confidence interval [CI]: 1·19 - 1·35), of ADE/SNADE was 1·13 (95%CI: 1·09 - 1·17), of SNADE was 0·96 (95%CI: 0·89 - 1·02) and of death/ADE/SNADE was 1·11 (95%CI: 1·07 - 1·14). Estimates were similar after adjusting for time updated CD4 count.

Interpretation

In virologically suppressed PWH, increased time living with severe immunosuppression had an increased risk of death and ADE/SNADE in this Latin American cohort, independently of time updated CD4 count.

Funding

This work was supported by the NIH-funded Caribbean, Central and South America network for HIV epidemiology (CCASAnet, U01AI069923), a member cohort of the International Epidemiologic Databases to Evaluate AIDS (leDEA). This award is funded by the following institutes: Eunice Kennedy Shriver National Institute Of Child Health & Human Development (NICHD), National Cancer Institute (NCI), National Institute Of Allergy And Infectious Diseases (NIAID), National Institute Of Mental Health (NIMH), the National Heart, Lung, and Blood Institute (NHLBI), the National Institute on Alcohol Abuse and Alcoholism (NIAAA), the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), and the Fogarty International Center (FIC). Specific funding was provided from the Fogarty International Center (FIC) for lead author, Yanink Caro-Vega, for the Fogarty-IeDEA Mentorship Program (FIMP).

Adipokines as New Biomarkers of Immune Recovery: Apelin Receptor, RBP4 and ZAG Are Related to CD4+ T-Cell Reconstitution in PLHIV on Suppressive Antiretroviral Therapy

A significant proportion of people living with HIV (PLHIV) who successfully achieve virological suppression fail to recover CD4⁺ T-cell counts. Since adipose tissue has been discovered as a key immune organ, this study aimed to assess the role of adipokines in the HIV immunodiscordant response. This is a multicenter prospective study including 221 PLHIV starting the first antiretroviral therapy (ART) and classified according to baseline CD4⁺ T-cell counts/µL (controls > 200 cells/µL and cases ≤ 200 cells/µL). Immune failure recovery was considered when cases did not reach more than 250 CD4⁺ T cells/µL at 144 weeks (immunological nonresponders, INR). Circulating adipokine concentrations were longitudinally measured using enzyme-linked immunosorbent assays. At baseline, apelin receptor (APLNR) and zinc-alpha-2-glycoprotein (ZAG) concentrations were significantly lower in INRs than in immunological responders (p = 0.043 and p = 0.034), and they remained lower during all ART follow-up visits (p = 0.044 and p = 0.028 for APLNR, p = 0.038 and p = 0.010 for ZAG, at 48 and 144 weeks, respectively). ZAG levels positively correlated with retinol-binding protein 4 (RBP4) levels (p < 0.01), and low circulating RBP4 concentrations were related to a low CD4⁺ T-cell gain (p = 0.018 and p = 0.039 at 48 and 144 weeks, respectively). Multiple regression adjusted for clinical variables and adipokine concentrations confirmed both low APLNR and RBP4 as independent predictors for CD4⁺ T cells at 144 weeks (p < 0.001). In conclusion, low APLNR and RBP4 concentrations were associated with poor immune recovery in treated PLHIV and could be considered predictive biomarkers of a discordant immunological response.

The importance of taking ART appropriately in children and adolescents with HIV-1 to reach the highest capacity of immune function later in life

Current antiretroviral therapy (ART) guidelines recommend treating all children with HIV-1 infection. This has changed from the broader use of ART to treat children to improve morbidity and minimise mortality. However, prior to current recommendations, not everyone with HIV-1 received timely treatment. What happens to the paediatric immune system when HIV-1 replication is not appropriately supressed remains unclear. 11 samples from adolescents with HIV-1 on ART and uninfected controls in the UK, aged 12-25 years, were examined; overall, adolescents with CD4⁺ counts > 500/μl and a viral load < 50 copies/ml were compared with adolescents with CD4⁺ counts < 500/μl and a viral load > 50 copies/ml at time of sampling. Measurements of thymic output were combined with high throughput next generation sequencing and bioinformatics to systematically organize CD4⁺ and CD8⁺ T cell receptor (TCR) repertoires. TCR repertoire diversity, clonal expansions, TCR sequence sharing, and formation of TCR clusters in HIV-1 infected adolescents with successful HIV-1 suppression were compared to adolescents with ineffective HIV-1 suppression. Thymic output and CD4⁺ T cell numbers were decreased in HIV-1 infected adolescents with poor HIV-1 suppression. A strong homeostatic TCR response, driven by the decreased CD4⁺ T cell compartment and reduced thymic output was observed in the virally uncontrolled HIV-1-infected adolescents. Formation of abundant robust TCR clusters and structurally related TCRs were found in the adolescents with effective HIV-1 suppression. Numerous CD4⁺ T cell numbers in the virally controlled adolescents emphasize the importance of high thymic output and formation of robust TCR clusters in the maintenance of HIV-1 suppression. While the profound capacity for immune recovery in children may allow better opportunity to deal with immunological stress, when ART is taken appropriately, this study demonstrates new insights into the unique paediatric immune system and the immunological changes when HIV-1 replication is ongoing.

Probiotics to HIV-Infected Immunological Nonresponders: Altered Mucosal Immunity and Microbial Diversity Restricted to Ileum

BACKGROUND

HIV-infected immunological nonresponders (INRs) have increased risk of non-AIDS morbidity and compromised gut barrier immunity. Probiotics are widely used to improve health. We assessed the effects of probiotics in INRs with a comprehensive analysis of gut immunity and microbiome in terminal ileum and sigmoid colon.

METHODS

The study involved clinical intervention with five-strain probiotic capsules (1.2 × 1010 CFUs/d) for 8 weeks in 20 INRs with CD4+ T-cell counts <400 cells/µL and plasma HIV RNA <50 copies/mL for more than 3.5 years. Colonoscopy with sampling of gut biopsies from terminal ileum and sigmoid colon and fecal and blood sampling were performed before and after the intervention. Flow cytometry (cytokine production, immune activation, and exhaustion), ELISA (inflammation, microbial translocation, and enterocyte damage), and 16S rRNA sequencing analyses were applied.

RESULTS

In the terminal ileum, increased alpha diversity, increased abundance of Bifidobacterium sp., and decreased frequencies of IL-22+ CD4+ T cells were observed. The increased abundance of Bifidobacterium sp. in the terminal ileum correlated with increased fraction of CD4+ T cells in the same compartment (r = 0.54, P = 0.05) and increased CD4/CD8 ratio in peripheral blood (r = 0.49, P = 0.05). There were no corresponding changes in the sigmoid colon and no changes in fecal microbiome. Probiotic intervention did not affect peripheral blood CD4 count, viral load, or soluble markers of inflammation and microbial translocation.

CONCLUSIONS

Probiotics induced segment-specific changes in the terminal ileum but did not affect systemic CD4 counts in INRs. Further clinical studies are warranted to recommend probiotics to INRs.

Persistent low-Level viremia in persons living with HIV undertreatment: An unresolved status

Antiretroviral therapy (ART) allows suppressed viremia to reach less than 50 copies/mL in most treated persons living with HIV (PLWH). However, the existence of PLWH that show events of persistent low-level viremia (pLLV) between 50 and 1000 copies/mL and with different virological consequences have been observed. PLLV has been associated with higher virological failure (VF), viral genotype resistance, adherence difficulties and AIDS events. Moreover, some reports show that pLLV status can lead to residual immune activation and inflammation, with an increased risk of immunovirological failure and a pro-inflammatory cytokine level which can lead to a higher occurrence of non-AIDS defining events (NADEs) and other adverse clinical outcomes. Until now, however, published data have shown controversial results that hinder understanding of the true cause(s) and origin(s) of this phenomenon. Molecular mechanisms related to viral reservoir size and clonal expansion have been suggested as the possible origin of pLLV. This review aims to assess recent findings to provide a global view of the role of pLLV in PLWH and the impact this status may cause on the clinical progression of these patients.

Enhanced Gut-Homing Dynamics and Pronounced Exhaustion of Mucosal and Blood CD4+ T Cells in HIV-Infected Immunological Non-Responders

Immunological non-responders (INR), a subgroup of people living with HIV (PLHIV) who fail to restore CD4⁺ T cell numbers upon effective antiretroviral treatment, have impaired gut mucosal barrier function and an inferior clinical prognosis compared with immunological responders (IR). The contribution of gut-homing and exhaustion of mucosal T cells to the INR phenotype was previously unknown. Flow cytometry analysis of mononuclear cells from peripheral blood and ileal and colonic lamina propria showed that INR had higher fractions of gut-homing CD4⁺ T cells in blood compared with IR. In addition, gut-homing cells were more likely to display signs of exhaustion in INR. The increased CD4⁺ T cell exhaustion in INR was ubiquitous and not restricted to subpopulations defined by activation, differentiation or regulatory T cell markers. In INR, colon CD4⁺ T cell exhaustion correlated negatively with the fraction of CD4⁺ T cells in the same compartment, this was not apparent in the ileum. The fraction of exhausted mucosal CD4⁺ T cells correlated with I-FABP and REG3α, markers of enterocyte damage. We conclude that alterations of gut-homing and exhaustion of T cells may contribute to impaired gut immune and barrier functions associated with immunological non-response in PLHIV.

Increased homeostatic cytokines and stability of HIV-infected memory CD4 T-cells identify individuals with suboptimal CD4 T-cell recovery on-ART

Clinical outcomes are inferior for individuals with HIV having suboptimal CD4 T-cell recovery during antiretroviral therapy (ART). We investigated if the levels of infection and the response to homeostatic cytokines of CD4 T-cell subsets contributed to divergent CD4 T-cell recovery and HIV reservoir during ART by studying virologically-suppressed immunologic responders (IR, achieving a CD4 cell count >500 cells/μL on or before two years after ART initiation), and virologically-suppressed suboptimal responders (ISR, did not achieve a CD4 cell count >500 cells/μL in the first two years after ART initiation). Compared to IR, ISR demonstrated higher levels of HIV-DNA in naïve, central (CM), transitional (TM), and effector (EM) memory CD4 T-cells in blood, both pre- and on-ART, and specifically in CM CD4 T-cells in LN on-ART. Furthermore, ISR had higher pre-ART plasma levels of IL-7 and IL-15, cytokines regulating T-cell homeostasis. Notably, pre-ART PD-1 and TIGIT expression levels were higher in blood CM and TM CD4 T-cells for ISR; this was associated with a significantly lower fold-changes in HIV-DNA levels between pre- and on-ART time points exclusively on CM and TM T-cell subsets, but not naïve or EM T-cells. Finally, the frequency of CM CD4 T-cells expressing PD-1 or TIGIT pre-ART as well as plasma levels of IL-7 and IL-15 predicted HIV-DNA content on-ART. Our results establish the association between infection, T-cell homeostasis, and expression of PD-1 and TIGIT in long-lived CD4 T-cell subsets prior to ART with CD4 T-cell recovery and HIV persistence on-ART.

Late presentation for HIV impairs immunological but not virological response to antiretroviral treatment

OBJECTIVES

The aim of this study was to examine the impact of late presentation (CD4+ cell count <350 cells/μl or an AIDS-defining event) on effectiveness and safety of initial antiretroviral therapy (ART) and to evaluate whether treatment response depends on first-line ART regimen in late presenters.

DESIGN

ART-naive adults from the Cohort of the Spanish HIV/AIDS Research Network (CoRIS) starting triple ART between 2010 and 2018.

METHODS

We used multivariable models to assess differences in viral suppression (viral load <50 copies/ml), immunological response (change in CD4+ cell count, CD4% (>29%) and CD4/CD8 normalization (>0.4 and >1) multiple T-cell marker recovery (MTMR): CD4+ cell count more than 500 cells/μl and CD4% >29% and CD4/CD8 >1), and treatment discontinuation due to adverse events (TDAE) at 48 weeks from ART initiation.

RESULTS

Out of 8002 participants, 48.7% were late presenters. Of them, 45.8% initiated ART with a NNRTI- (mostly TDF/FTC/EFV), 33.9% with a protease inhibitor (mostly TDF/FTC+boosted DRV) and 20.3% with an INI-based regimen (mostly ABC/3TC/DTG). At 48 weeks, late presenters had similar viral suppression, but worse immunological response, than non-late presenters with no difference on TDAE. Late presenters initiating with NNRTI-based regimens were more likely to achieve viral suppression than those starting with INI-based, due to the higher chance of achieving viral suppression observed with TDF/FTC/RPV compared to ABC/3TC/DTG. Initial treatment with NNRTI or protease inhibitor based showed similar immunological response than the INI-based regimens, which showed lower rates of TDAE than NNRTI- and protease inhibitor based regimens.

CONCLUSION

Despite safety and effectiveness of initial ART in terms of viral suppression, late presenters may not experience complete immunological response. In late presenters, effectiveness and safety depends on both the class and the specific first-line ART regimen.

Prevalence and Outcomes for Heavily Treatment-Experienced Individuals Living With Human Immunodeficiency Virus in a European Cohort

BACKGROUND

Although antiretroviral treatments have improved survival of persons living with HIV, their long-term use may limit available drug options. We estimated the prevalence of heavily treatment-experienced (HTE) status and the potential clinical consequences of becoming HTE.

SETTING

EuroSIDA, a European multicenter prospective cohort study.

METHODS

A composite definition for HTE was developed, based on estimates of antiretroviral resistance and prior exposure to specific antiretroviral regimens. Risks of progressing to clinical outcomes were assessed by Poisson regression, comparing every HTE individual with 3 randomly selected controls who never became HTE.

RESULTS

Of 15,570 individuals under follow-up in 2010-2016, 1617 (10.4%, 95% CI: 9.9% to 10.9%) were classified as HTE. 1093 individuals became HTE during prospective follow-up (HTE incidence rate 1.76, CI: 1.66 to 1.87 per 100 person-years of follow-up). The number of HTE individuals was highest in West/Central Europe (636/4019 persons, 15.7%) and lowest in East Europe (26/2279 persons, 1.1%). Although most HTE individuals maintained controlled viral loads (<400 copies/mL), many had low CD4 counts (≤350 cells/µL). After controlling for age, immunological parameters and pre-existing comorbidities, HTE status was not associated with the risk of new AIDS (adjusted incidence rate ratio, aIRR 1.44, CI: 0.86 to 2.40, P = 0.16) or non-AIDS clinical events (aIRR 0.96, CI: 0.74 to 1.25, P = 0.77).

CONCLUSIONS

HTE prevalence increased with time. After adjusting for key confounding factors, there was no evidence for an increased risk of new AIDS or non-AIDS clinical events in HTE. Additional therapeutic options and effective management of comorbidities remain important to reduce clinical complications in HTE individuals.

Late presentation for HIV remains a major health issue in Spain: Results from a multicenter cohort study, 2004-2018

OBJECTIVES

With the purpose of reducing the well-known negative impact of late presentation (LP) on people living with HIV (PLWH), guidelines on early HIV diagnosis were published in 2014 in Spain, but since then no data on LP prevalence have been published. To estimate prevalence and risk factors of LP and to evaluate their impact on the development of clinical outcomes in the Cohort of the Spanish HIV/AIDS Research Network (CoRIS) during 2004-2018.

METHODS

CoRIS is an open prospective multicenter cohort of PLWH, adults, naive to ART at entry. LP was defined as HIV diagnosis with CD4 count ≤350 cells/μL or an AIDS defining event (ADE). Multivariable Poisson regression models were used to estimate both prevalence ratios (PR) for the association of potential risk factors with LP and Incidence rate ratios (IRRs) for its impact on the development of the composite endpoint (first ADE, first serious non-AIDS event [SNAE] or overall mortality).

RESULTS

14,876 individuals were included. Overall, LP prevalence in 2004-2018 was 44.6%. Risk factors for LP included older age, having been infected through injection drug use or heterosexual intercourse, low educational level and originating from non-European countries. LP was associated with an increased risk of the composite endpoint (IRR: 1.34; 95%CI 1.20, 1.50), ADE (1.39; 1.18, 1.64), SNAE (1.22; 1.01, 1.47) and mortality (1.71; 1.41, 2.08).

CONCLUSIONS

LP remains a health problem in Spain, mainly among certain populations, and is associated with greater morbidity and mortality. Public policies should be implemented to expand screening and early diagnosis of HIV infection, for a focus on those at greatest risk of LP.

Probiotics to manage inflammation in HIV infection

PURPOSE OF REVIEW

To evaluate the current scientific basis for administering probiotics to people living with HIV (PLHIV) to alleviate chronic inflammation and subsequently improve their prognosis.

RECENT FINDINGS

The gut microbiome is a potential contributing factor to low-grade inflammation in HIV infection, and there is a scientific rationale for attempting to attenuate inflammation by administering probiotics. Sixteen reports from clinical studies in antiretroviral therapy (ART)-treated PLHIV assessing inflammation after probiotic intervention have been identified; half of them randomized control trials (RCT). Some of the studies report improvement in some parameters of inflammation, but results are inconsistent. No studies report improvement of CD4 counts. None of the RCTs report improvements in any markers of inflammation when analyzed according to protocol.

SUMMARY

Current scientific evidence does not support the use of probiotics to alleviate inflammation in HIV infection. The potential effect of probiotic intervention in ART-treated PLHIV with high risk for inflammation remains to be investigated.

Cell-Associated HIV-1 Unspliced-to-Multiply-Spliced RNA Ratio at 12 Weeks of ART Predicts Immune Reconstitution on Therapy

Human immunodeficiency virus (HIV) infection is currently managed by antiretroviral drugs, which block virus replication and promote immune restoration. However, the latter effect is not universal, with a proportion of infected individuals failing to sufficiently reconstitute their immune function despite a successful virological response to antiretroviral therapy (ART).

Incomplete restoration of CD4⁺ T-cell counts on antiretroviral therapy (ART) is a major predictor of HIV-related morbidity and mortality. To understand the possible mechanisms behind this poor immunological response despite viral suppression, we longitudinally measured more than 50 virological and immunological biomarkers in a cohort of HIV-infected individuals at several time points during the first 96 weeks of virologically suppressive ART. No baseline virological or immunological marker was predictive of the degree of immune reconstitution. However, the cell-associated HIV-1 unspliced-to-multiply-spliced (US/MS) RNA ratio at 12 weeks of ART positively correlated with markers of CD4⁺ T-cell activation and apoptosis and negatively predicted both the absolute and relative CD4⁺ T-cell counts at 48 and 96 weeks. A higher US/MS RNA ratio may reflect the higher frequency of productively infected cells that could exert pressure on the immune system, contributing to persistent immune activation and apoptosis and subsequently to a poor immunological response to ART.

Mesenchymal stromal cells in human immunodeficiency virus-infected patients with discordant immune response: Early results of a phase I/II clinical trial

Between 15% and 30% of HIV‐infected subjects fail to increase their CD4⁺ T‐cell counts despite continuous viral suppression (immunological nonresponders [INRs]). These subjects have a higher morbidity and mortality rate, but there are no effective treatments to reverse this situation so far. This study used data from an interrupted phase I/II clinical trial to evaluate safety and immune recovery after INRs were given four infusions, at baseline and at weeks 4, 8, and 20, with human allogeneic mesenchymal stromal cells from adipose tissue (Ad‐MSCs). Based on the study design, the first 5 out of 15 INRs recruited received unblinded Ad‐MSC infusions. They had a median CD4⁺ nadir count of 16/μL (range, 2‐180) and CD4⁺ count of 253 cells per microliter (171‐412) at baseline after 109 (54‐237) months on antiretroviral treatment and 69 (52‐91) months of continuous undetectable plasma HIV‐RNA. After a year of follow‐up, an independent committee recommended the suspension of the study because no increase of CD4⁺ T‐cell counts or CD4⁺/CD8⁺ ratios was observed. There were also no significant changes in the phenotype of different immunological lymphocyte subsets, percentages of natural killer cells, regulatory T cells, and dendritic cells, the inflammatory parameters analyzed, and cellular associated HIV‐DNA in peripheral blood mononuclear cells. Furthermore, three subjects suffered venous thrombosis events directly related to the Ad‐MSC infusions in the arms where the infusions were performed. Although the current study is based on a small sample of participants, the findings suggest that allogeneic Ad‐MSC infusions are not effective to improve immune recovery in INR patients or to reduce immune activation or inflammation. ClinicalTrials.gov identifier: NCT0229004. EudraCT number: 2014‐000307‐26.

The tetraspanin CD151 marks a unique population of activated human T cells

Tetraspanins are a family of proteins with an array of functions that are well studied in cancer biology, but their importance in immunology is underappreciated. Here we establish the tetraspanin CD151 as a unique marker of T-cell activation and, in extension, an indicator of elevated, systemic T-cell activity. Baseline CD151 expression found on a subset of T-cells was indicative of increased activation of the MAPK pathway. Following TCR/CD3 activation, CD151 expression was upregulated on the overall T-cell population, a quintessential feature of an activation marker. CD151+ T-cell frequencies in the spleen, an organ with increased immune activity, were twice as high as in paired peripheral blood samples. This CD151+ T-cell frequency increase was not paralleled by an increase of CD25 or CD38, demonstrating that CD151 expression is regulated independently of other T-cell activation markers. CD151+ T-cells were also more likely to express preformed granzyme B, suggesting that CD151+ T cells are pro-inflammatory. To this end, HIV-1 patients on antiretroviral therapy who are reported to exhibit chronically elevated levels of immune activity, had significantly higher CD4+CD151+ T-cell frequencies than healthy controls, raising the possibility that proinflammatory CD151+ T cells could contribute to the premature immunological aging phenotype observed in these patients.

Definition of Immunological Nonresponse to Antiretroviral Therapy: A Systematic Review

BACKGROUND

Terms and criteria to classify people living with HIV on antiretroviral therapy who fail to achieve satisfactory CD4 T-cell counts are heterogeneous, and need revision and summarization.

METHODS

We performed a systematic review of PubMed original research articles containing a set of predefined terms, published in English between January 2009 and September 2018. The search retrieved initially 1360 studies, of which 103 were eligible. The representative terminology and criteria were extracted and analyzed.

RESULTS

Twenty-two terms and 73 criteria to define the condition were identified. The most frequent term was "immunological nonresponders" and the most frequent criterion was "CD4 T-cell count <350 cells/µL after ≥24 months of virologic suppression." Most criteria use CD4+ T-cell counts as a surrogate, either as an absolute value or as a change after a defined period of time [corrected]. Distinct values and time points were used. Only 9 of the 73 criteria were used by more than one independent research team. Herein we propose 2 criteria that could help to reach a consensus.

CONCLUSIONS

The high disparity in terms and criteria here reported precludes data aggregation and progression of the knowledge on this condition, because it renders impossible to compare data from different studies. This review will foster the discussion of terms and criteria to achieve a consensual definition.

Incomplete immune reconstitution in HIV/AIDS patients on antiretroviral therapy: Challenges of immunological non-responders

The morbidity and mortality of HIV type-1 (HIV-1)-related diseases were dramatically diminished by the grounds of the introduction of potent antiretroviral therapy, which induces persistent suppression of HIV-1 replication and gradual recovery of CD4⁺ T-cell counts. However, ∼10-40% of HIV-1-infected individuals fail to achieve normalization of CD4⁺ T-cell counts despite persistent virological suppression. These patients are referred to as "inadequate immunological responders," "immunodiscordant responders," or "immunological non-responders (INRs)" who show severe immunological dysfunction. Indeed, INRs are at an increased risk of clinical progression to AIDS and non-AIDS events and present higher rates of mortality than HIV-1-infected individuals with adequate immune reconstitution. To date, the underlying mechanism of incomplete immune reconstitution in HIV-1-infected patients has not been fully elucidated. In light of this limitation, it is of substantial practical significance to deeply understand the mechanism of immune reconstitution and design effective individualized treatment strategies. Therefore, in this review, we aim to highlight the mechanism and risk factors of incomplete immune reconstitution and strategies to intervene.

CD4 rate of increase is preferred to CD4 threshold for predicting outcomes among virologically suppressed HIV-infected adults on antiretroviral therapy

Objectives

Immune non-responders (INR) have poor CD4 recovery and are associated with increased risk of serious events despite antiretroviral therapy (ART). A clinically relevant definition for INR is lacking.

Methods

We conducted a retrospective analysis of three large cohorts: Infectious Disease Clinic at the Atlanta Veterans Affairs Medical Center, the US Military HIV Natural History Study and Infectious Disease Program of the Grady Health System in Atlanta, Georgia. Two-stage modeling and joint model (JM) approaches were used to evaluate the association between CD4 (or CD4/CD8 ratio) slope within two years since ART initiation and a composite endpoint (AIDS, serious non-AIDS events and death) after two years of ART. We compared the predictive capacity of four CD4 count metrics (estimated CD4 slope, estimated CD4/CD8 ratio slope during two years following ART initiation and CD4 at 1 and 2 years following ART initiation) using Cox regression models.

Results

We included 2,422 patients. Mean CD4 slope (±standard error) during two years of ART was 102 ± 2 cells/μl/year (95% confidence interval: 98–106 cells/μl/year), this increase was uniform among the three cohorts (p = 0.80). There were 267 composite events after two years on ART. Using the JM approach, a CD4 slope ≥100 cells/μL/year or CD4/CD8 ratio slope >0.1 higher rate per year were associated with lower composite endpoint rates (adjusted hazard ratio [HR] = 0.80, p = 0.04 and HR = 0.75 p<0.01, respectively). All four CD4 metrics showed modest predictive capacity.

Conclusions

Using a complex JM approach, CD4 slope and CD4/CD8 ratio slope the first two years after ART initiation were associated with lower rates of the composite outcome. Moreover, the uniformity observed in the mean CD4 slope regardless of the cohort suggests a common CD4 response pattern independent of age or CD4 nadir. Given the consistency observed with CD4 slope, availability and ease of interpretation, this study provides strong rationale for using CD4 gains <100 cells/μl/year to identify patients at risk for adverse events.

Genetic and clinical predictors of CD4 lymphocyte recovery during suppressive antiretroviral therapy: Whole exome sequencing and antiretroviral therapy response phenotypes

Increase of peripheral blood CD4 lymphocyte counts is a key goal of combined antiretroviral therapy (cART); most, but not all, recipients respond adequately and promptly. A small number of studies have examined specific genetic factors associated with the extent of CD4 recovery. We report a genome-wide examination of factors that predict CD4 recovery in HIV-infected women. We identified women in in a cohort study who were on cART with viral load below 400 copies, and drew racially and ethnically matched samples of those with good CD4 response over 2 years or poor response. We analyzed the exomes of those women employing next generation sequencing for genes associated with CD4 recovery after controlling for non-genetic factors identified through forward stepwise selection as important. We studied 48 women with good CD4 recovery and 42 with poor CD4 recovery during virologically-suppressive cART. Stepwise logistic regression selected only age as a statistically significant (p<0.05) non-genetic predictor of response type (each additional year of age reduced the odds of good recovery by 11% (OR = 0.89, CI = 0.84–0.96, p = 0.0009). After adjustment for age and genomic estimates of race and ethnicity, 41 genes harbored variations associated with CD4 recovery group (p≤0.001); 5 of these have been previously reported to be associated with HIV infection, 4 genes would likely influence CD4 homeostasis, and 13 genes either had known functions or were members of product families that had functions for which interactions with HIV or effects on lymphocyte homeostasis were biologically plausible. Greater age was the strongest acquired factor that predicted poor CD4 cell recovery. Sequence variations spanning 41 genes were independently predictive of CD4 recovery. Many of these genes have functions that impact the cell cycle, apoptosis, lymphocyte migration, or have known interactions with HIV. These findings may help inform new hypotheses related to responses to HIV therapy and CD4 lymphocyte homeostasis.

Thymic Function as a Predictor of Immune Recovery in Chronically HIV-Infected Patients Initiating Antiretroviral Therapy

Poor immunological responders (PIR) are HIV-infected patients with virologic suppression upon antiretroviral therapy (ART) but persistently low CD4⁺ T cell counts. Early identification of PIR is important given their higher morbimortality compared to adequate immune responders (AIR). In this study, 33 patients severely lymphopenic at ART onset, were followed for at least 36 months, and classified as PIR or AIR using cluster analysis grounded on their CD4⁺ T cell count trajectories. Based on a variety of immunological parameters, we built predictive models of PIR/AIR outcome using logistic regression. All PIR had CD4⁺ T cell counts consistently below 500 cells/μL, while all AIR reached this threshold. AIR showed a higher percentage of recent thymic emigrants among CD4⁺ T cells; higher numbers of sj-TRECs and greater sj/β TREC ratios; and significant increases in thymic volume from baseline to 12 months of ART. We identified mathematical models that correctly predicted PIR/AIR outcome after 36 months of therapy in 77-87% of the cases, based on observations made until 2-6 months after ART onset. This study highlights the importance of thymic activity in the immune recovery of severely lymphopenic patients, and may help to select the patients that will benefit from closer follow-up or novel therapeutic approaches.

A systematic review and cost-effectiveness analyses of the new World Health Organization guidelines for the treatment of HIV-positive adults in India

Background

The World Health Organization (WHO) in 2013 has revised its guidelines on antiretroviral therapy (ART) treatment for human immunodeficiency virus (HIV)-positive adults and further updated it in 2016. Based on the WHO recommendations, in May 2017, National AIDS Control Organisation, India recommended initiation of ART treatment for all people living with HIV, regardless of CD4 count, clinical stage, age, or population. This systematic review aims to assess the clinical effectiveness and cost implication of the new guidelines for India.

Methods

A systematic and comprehensive literature search on PubMed, OvidSP, Cochrane Library, and Google Scholar was carried out. Studies reporting either acquired immunodeficiency syndrome (AIDS) or mortality or both as outcome variables were selected. A meta-analysis of the available studies was carried out. The risk ratio was calculated to assess the reduction in AIDS or mortality or both. Cost-effectiveness analysis using health technology principles evaluating the lives saved in terms of incremental cost-effectiveness ratio and cost per quality-adjusted life years gained was carried out.

Results

Nine eligible studies were included for the meta-analysis. For India, the pooled relative risk of AIDS or mortality or both being 0.84 (95% confidence interval [CI], 0.76-0.92) and 0.78 (95% CI, 0.68-0.89) for ART initiation at CD4 count of ≤350 vs CD4 count of ≤500 and at CD4 count of ≤500 vs CD4 count > 500 cells/mm³, respectively. The incremental cost for per additional life saved is US$ 2592 and US$ 2357 for ART initiation at ≤500 and > 500 CD4 count, respectively.

Conclusion

The adoption of the new WHO guidelines is beneficial with substantial reduction in AIDS or mortality or both. This study suggests that adopting new WHO guidelines is cost-effective for India.

Safety of monitoring antiretroviral therapy response in HIV-1 infection using CD4+ T cell count at long-term intervals

The latest Brazilian guideline recommended the reduction of routine CD4+ T cell counts for the monitoring of patients with human immunodeficiency virus type 1 (HIV-1) under combination antiretroviral therapy (cART). The aim of this study was to evaluate the safety of monitoring response to cART in HIV-1 infection using routine viral load at shorter intervals and CD4+ T cell count at longer intervals. CD4+ T cell counts and HIV-1 viral load were evaluated in 1,906 HIV-1-infected patients under cART during a three-year follow-up. Patients were stratified as sustained, non-sustained and non-responders. The proportion of patients who showed a CD4+ T > 350cells/µL at study entry among those with sustained, non-sustained and non-responders to cART and who remained with values above this threshold during follow-up was 94.1%, 81.8% and 71.9%, respectively. HIV-1-infected patients who are sustained virologic responders and have initial CD4+ T cell counts > 350cells/µL showed a higher chance of maintaining the counts of these cells above this threshold during follow-up than those presenting CD4+ T ≤ 350cells/µL (OR = 39.9; 95%CI: 26.5-60.2; p < 0.001). This study showed that HIV-1-infected patients who had sustained virologic response and initial CD4+ T > 350cells/µL were more likely to maintain CD4+ T cell counts above this threshold during the next three-year follow-up. This result underscores that the evaluation of CD4+ T cell counts in longer intervals does not impair the safety of monitoring cART response when routine viral load assessment is performed in HIV-1-infected patients with sustained virologic response.

Persistent platelet activation and apoptosis in virologically suppressed HIV-infected individuals

Cardiovascular diseases and thrombotic events became major clinical problems in the combined antiretroviral therapy (cART) era. Although the precise mechanisms behind these clinical problems have not been fully elucidated, a persistent pro-inflammatory state plays a central role. As platelets play important roles on both, thrombus formation and inflammatory/immune response, we aimed at investigating platelet function in HIV-infected subjects virologically controlled through cART. We evaluate parameters of activation, mitochondrial function and activation of apoptosis pathways in platelets from 30 HIV-infected individuals under stable cART and 36 healthy volunteers. Despite viral control achieved through cART, HIV-infected individuals exhibited increased platelet activation as indicated by P-selectin expression and platelet spreading when adhered on fibrinogen-coated surfaces. Platelets from HIV-infected subjects also exhibited mitochondrial dysfunction and activation of apoptosis pathways. Finally, thrombin stimuli induced lower levels of P-selectin translocation and RANTES secretion, but not TXA2 synthesis, in platelets from HIV-infected individuals compared to control; and labeling of platelet alpha granules showed reduced granule content in platelets from HIV-infected individuals when compared to healthy subjects. In summary, platelets derived from HIV-infected individuals under stable cART exhibit a phenotype of increased activation, activation of the intrinsic pathway of apoptosis and undermined granule secretion in response to thrombin.

HIV-Infected Subjects With Poor CD4 T-Cell Recovery Despite Effective Therapy Express High Levels of OX40 and α4β7 on CD4 T-Cells Prior Therapy Initiation

Background

HIV-infected subjects with suboptimal CD4 restoration despite suppressive combined antiretroviral treatment (cART) (immunodiscordant subjects) have been classically characterized after a variable period of time under cART. Recently, we have reported that an increased frequency of proliferating CD4 T-cells in these subjects is already present before the cART onset. The potential contribution of peripheral compensatory homeostatic proliferation (HP) is yet unknown. We aimed to analyze the expression of HP-related cellular markers on CD4 T-cells of immunodiscordant subjects before cART.

Methods

We analyzed the expression of OX40 and α4β7 on peripheral CD4 T-cells from immunodiscordant and control subjects (n = 21 each group) before cART initiation, and also on available follow-up samples (after 24 month of suppressive cART). Additionally, we tested the expression of these markers in an in vitro system for the study of human HP processes.

Results

Immunodiscordant subjects showed increased levels of OX40 and α4β7 on CD4 T-cells before cART initiation. While the cART tended to reduce these levels, immunodiscordant subjects still maintained comparatively higher levels of OX40 and α4β7 after 24 months under suppressive cART. These HP-related markers were upregulated in vitro during the human HP, especially during the fast HP.

Conclusion

Our results are compatible with exacerbated HP processes in immunodiscordant subjects, already before the cART onset.

Platelets in Immune Response to Virus and Immunopathology of Viral Infections

Platelets are essential effector cells in hemostasis. Aside from their role in coagulation, platelets are now recognized as major inflammatory cells with key roles in the innate and adaptive arms of the immune system. Activated platelets have key thromboinflammatory functions linking coagulation to immune responses in various infections, including in response to virus. Recent studies have revealed that platelets exhibit several pattern recognition receptors (PRR) including those from the toll-like receptor, NOD-like receptor, and C-type lectin receptor family and are first-line sentinels in detecting and responding to pathogens in the vasculature. Here, we review the main mechanisms of platelets interaction with viruses, including their ability to sustain viral infection and replication, their expression of specialized PRR, and activation of thromboinflammatory responses against viruses. Finally, we discuss the role of platelet-derived mediators and platelet interaction with vascular and immune cells in protective and pathophysiologic responses to dengue, influenza, and human immunodeficiency virus 1 infections.

Cost-Effectiveness of Peer- Versus Venue-Based Approaches for Detecting Undiagnosed HIV Among Heterosexuals in High-Risk New York City Neighborhoods

INTRODUCTION

We used a computer simulation of HIV progression and transmission to evaluate the cost-effectiveness of a scale-up of 3 strategies to seek out and test individuals with undiagnosed HIV in New York City (NYC).

SETTING

Hypothetical NYC population.

METHODS

We incorporated the observed effects and costs of the 3 "seek and test" strategies in a computer simulation of HIV in NYC, comparing a scenario in which the strategies were scaled up with a 1-year implementation or a long-term implementation with a counterfactual scenario with no scale-up. The simulation combined a deterministic compartmental model of HIV transmission with a stochastic microsimulation of HIV progression, calibrated to NYC epidemiological data from 2003 to 2015. The 3 approaches were respondent-driven sampling (RDS) with anonymous HIV testing ("RDS-A"), RDS with a 2-session confidential HIV testing approach ("RDS-C"), and venue-based sampling ("VBS").

RESULTS

RDS-A was the most cost-effective strategy tested. When implemented for only 1 year and then stopped thereafter, using a societal perspective, the cost per quality-adjusted life-year (QALY) gained versus no intervention was $812/QALY, $18,110/QALY, and $20,362/QALY for RDS-A, RDS-C, and VBS, respectively. When interventions were implemented long term, the cost per QALY gained versus no intervention was cost-saving, $31,773/QALY, and $35,148/QALY for RDS-A, RDS-C, and VBS, respectively. When compared with RDS-A, the incremental cost-effectiveness ratios for both VBS and RDS-C were dominated.

CONCLUSIONS

The expansion of the RDS-A strategy would substantially reduce HIV-related deaths and new HIV infections in NYC, and would be either cost-saving or have favorable cost-effectiveness.

Atherosclerotic Cardiovascular Disease and Anti-Retroviral Therapy

In the current era of available therapy for human immunodeficiency virus (HIV), life expectancy for persons living with HIV (PLWH) nears that of the general population. Atherosclerotic cardiovascular disease (ASCVD) has become a particular burden for PLWH and society at large. PLWH have historically been shown to have an excess of cardiovascular risk and subsequent events when compared to the general population. Potential explanations include the increased prevalence of traditional risk factors, direct inflammatory and immunological effects from the HIV virus itself, and metabolic adverse effects of anti-retroviral therapy (ART). Over the past few years, there has been building evidence that chronic inflammation and immune activation independent of virologic suppression contribute significantly to excess ASCVD risk. Although independent agents and combination therapies have varying metabolic effects, the evidence from major randomized controlled trials (RCTs) supports the benefits of early initiation of ART. In this review, we will discuss the epidemiology of ASCVD in HIV-infected patients compared with the general population, give an overview of potential pathogenesis of high-risk plaque in HIV-infected patients, discuss different metabolic effects of individual anti-retrovirals, and discuss the limitations in current screening models for assessing cardiovascular disease (CVD) risk and future directions for treatment.

Quantitative angiographic characterisation of coronary artery disease in patients with human immunodeficiency virus (HIV) infection undergoing percutaneous coronary intervention

AIMS

Patients with human immunodeficiency virus (HIV) infection have an increased risk of acute myocardial infarction (MI), and 6.5-15% of mortality in this population is attributable to cardiovascular disease. However, the angiographic pattern of coronary artery disease (CAD) in patients with HIV undergoing percutaneous coronary intervention (PCI) remains unknown. We sought to assess and describe the angiographic features and burden of CAD in patients with HIV as compared to those without HIV infection.

METHODS AND RESULTS

This is a retrospective, single-centre study comparing 93 patients with HIV infection who underwent PCI between 2003 and 2011 with 93 control patients without HIV infection matched for age (±3 years), gender, diabetes, and year of PCI (±2 years). Quantitative coronary angiography (QCA) was performed for all treated lesions at baseline and following PCI in both groups. One-year clinical outcomes post PCI were also analysed and compared. The mean age for both study populations was 57 years; patients with HIV were more likely to present with ST-segment elevation myocardial infarction (STEMI). Patients had a similar extent of CAD as measured by the presence of multivessel disease as well as SYNTAX score; however, patients with HIV were more likely to have lesions in the proximal segment of the respective coronary artery. While both groups mostly displayed none/mild calcified lesions, HIV+ patients had longer and fewer stenotic lesions. Clinical outcomes at one year were similar.

CONCLUSIONS

While HIV+ patients were more likely to present with STEMI, detailed coronary angiographic analysis revealed less complex lesions and favourable anatomy. This paradox may suggest alterations in genesis and progression of atherosclerosis in this clinical setting.

Multiphenotype association study of patients randomized to initiate antiretroviral regimens in AIDS Clinical Trials Group protocol A5202

Supplemental Digital Content is available in the text.

Background

High-throughput approaches are increasingly being used to identify genetic associations across multiple phenotypes simultaneously. Here, we describe a pilot analysis that considered multiple on-treatment laboratory phenotypes from antiretroviral therapy-naive patients who were randomized to initiate antiretroviral regimens in a prospective clinical trial, AIDS Clinical Trials Group protocol A5202.

Participants and methods

From among 5 9545 294 polymorphisms imputed genome-wide, we analyzed 2544, including 2124 annotated in the PharmGKB, and 420 previously associated with traits in the GWAS Catalog. We derived 774 phenotypes on the basis of context from six variables: plasma atazanavir (ATV) pharmacokinetics, plasma efavirenz (EFV) pharmacokinetics, change in the CD4+ T-cell count, HIV-1 RNA suppression, fasting low-density lipoprotein-cholesterol, and fasting triglycerides. Permutation testing assessed the likelihood of associations being by chance alone. Pleiotropy was assessed for polymorphisms with the lowest P-values.

Results

This analysis included 1181 patients. At P less than 1.5×10⁻⁴, most associations were not by chance alone. Polymorphisms with the lowest P-values for EFV pharmacokinetics (CYPB26 rs3745274), low-density lipoprotein -cholesterol (APOE rs7412), and triglyceride (APOA5 rs651821) phenotypes had been associated previously with those traits in previous studies. The association between triglycerides and rs651821 was present with ATV-containing regimens, but not with EFV-containing regimens. Polymorphisms with the lowest P-values for ATV pharmacokinetics, CD4 T-cell count, and HIV-1 RNA phenotypes had not been reported previously to be associated with that trait.

Conclusion

Using data from a prospective HIV clinical trial, we identified expected genetic associations, potentially novel associations, and at least one context-dependent association. This study supports high-throughput strategies that simultaneously explore multiple phenotypes from clinical trials’ datasets for genetic associations.

Inside Out: HIV, the Gut Microbiome, and the Mucosal Immune System

The components of the human gut microbiome have been found to influence a broad array of pathologic conditions ranging from heart disease to diabetes and even to cancer. HIV infection upsets the delicate balance in the normal host-microbe interaction both through alterations in the taxonomic composition of gut microbial communities as well as through disruption of the normal host response mechanisms. In this article we review the current methods of gut microbiome analysis and the resulting data regarding how HIV infection might change the balance of commensal bacteria in the gut. Additionally, we cover the various effects gut microbes have on host immune homeostasis and the preliminary but intriguing data on how HIV disrupts those mechanisms. Finally, we briefly describe some of the important biomolecules produced by gut microbiota and the role that they may play in maintaining host immune homeostasis with and without HIV infection.

Plasma IP-10 Is Increased in Immunological NonResponders and Associated With Activated Regulatory T Cells and Persisting Low CD4 Counts

OBJECTIVE

To explore immune mechanisms and identify biomarkers associated with an inadequate immune recovery in patients with HIV with efficient antiretroviral therapy.

DESIGN

A cross-sectional study of 67 HIV-infected patients on antiretroviral therapy for ≥24 months with HIV RNA ≤20 copies per milliliter; 41 were defined as immunological nonresponders (INR) (CD4 < 400 cells per microliter) and 26 as immunological responders (CD4 > 600 cells per microliter). CD4 counts were also registered 2 years after inclusion.

METHODS

Cytokines, soluble markers of microbial translocation, and tryptophan catabolites were measured in plasma by multiplex assay, ELISA, or mass spectrometry. T-cell activation, differentiation, and regulatory T cells (Tregs) were analyzed by flow cytometry in 2 subgroups with comparable nadir CD4 counts.

RESULTS

Plasma interferon-inducible protein-10 (IP-10) levels were higher (P < 0.05), the T cells were more activated (CD38HLA-DR) (P < 0.05), the naive/effector memory T-cell ratio was lower (P < 0.01) and the proportion of resting Tregs (CD4CD45RAFoxP3) was reduced (P < 0.001) in INR patients compared with immunological responders. INR patients with CD4 counts ≤300 cells per microliter also demonstrated a higher fraction of activated Tregs (aTreg) (CD4CD147CD25) (P < 0.05). In the INR group, the aTreg percentages correlated with plasma IP-10 levels and inversely with CD4 counts (both P < 0.01). IP-10 levels (P < 0.05) and kynurenine/tryptophan ratio (P < 0.01) were negatively associated with the CD4 count 2 years after inclusion.

CONCLUSION

Patients with HIV with inadequate CD4 responses had higher levels of IP-10, more activated and differentiated T-cell phenotypes, as well as aTreg, compared with patients with satisfactory CD4 gain. High IP-10 levels were also associated with lower CD4 counts after 2 years.

Impaired Upregulation of the Costimulatory Molecules, CD27 and CD28, on CD4+ T Cells from HIV Patients Receiving ART Is Associated with Poor Proliferative Responses

HIV patients beginning antiretroviral therapy (ART) with advanced immunodeficiency often retain low CD4⁺ T cell counts despite virological control. We examined proliferative responses and upregulation of costimulatory molecules, following anti-CD3 stimulation, in HIV patients with persistent CD4⁺ T cell deficiency on ART. Aviremic HIV patients with nadir CD4⁺ T cell counts <100 cells/μL and who had received ART for a median time of 7 (range 1-11) years were categorized into those achieving low (<350 cells/μL; n = 13) or normal (>500 cells/μL; n = 20) CD4⁺ T cell counts. Ten healthy controls were also recruited. CD4⁺ T cell proliferation (Ki67) and upregulation of costimulatory molecules (CD27 and CD28) after anti-CD3 stimulation were assessed by flow cytometry. Results were related to proportions of CD4⁺ T cells expressing markers of T cell senescence (CD57), activation (HLA-DR), and apoptotic potential (Fas). Expression of CD27 and/or CD28 on uncultured CD4⁺ T cells was similar in patients with normal CD4⁺ T cell counts and healthy controls, but lower in patients with low CD4⁺ T cell counts. Proportions of CD4⁺ T cells expressing CD27 and/or CD28 correlated inversely with CD4⁺ T cell expression of CD57, HLA-DR, and Fas. After anti-CD3 stimulation, induction of CD27^hiCD28^hi expression was independent of CD4⁺ T cell counts, but lower in HIV patients than in healthy controls. Induction of CD27^hiCD28^hi expression correlated with induction of Ki67 expression in total, naïve, and CD31⁺ naïve CD4⁺ T cells from patients. In HIV patients responding to ART, impaired induction of CD27 and CD28 on CD4⁺ T cells after stimulation with anti-CD3 is associated with poor proliferative responses as well as greater CD4⁺ T cell activation and immunosenescence.