Immune activation and inflammation in HIV-1 infection: causes and consequences

HIV as a Cause of Immune Activation and Immunosenescence

Systemic immune activation has emerged as an essential component of the immunopathogenesis of HIV. It not only leads to faster disease progression, but also to accelerated decline of overall immune competence. HIV-associated immune activation is characterized by an increase in proinflammatory mediators, dysfunctional T regulatory cells, and a pattern of T-cell-senescent phenotypes similar to those seen in the elderly. These changes predispose HIV-infected persons to comorbid conditions that have been linked to immunosenescence and inflamm-ageing, such as atherosclerosis and cardiovascular disease, neurodegeneration, and cancer. In the antiretroviral treatment era, development of such non-AIDS-defining, age-related comorbidities is a major cause of morbidity and mortality. Treatment strategies aimed at curtailing persistent immune activation and inflammation may help prevent the development of these conditions. At present, the most effective strategy appears to be early antiretroviral treatment initiation. No other treatment interventions have been found effective in large-scale clinical trials, and no adjunctive treatment is currently recommended in international HIV treatment guidelines. This article reviews the role of systemic immune activation in the immunopathogenesis of HIV infection, its causes and the clinical implications linked to immunosenescence in adults, and the therapeutic interventions that have been investigated.

Chemokines and Chemokine Receptors: Accomplices for Human Immunodeficiency Virus Infection and Latency

Chemokines are small chemotactic cytokines that are involved in the regulation of immune cell migration. Multiple functional properties of chemokines, such as pro-inflammation, immune regulation, and promotion of cell growth, angiogenesis, and apoptosis, have been identified in many pathological and physiological contexts. Human immunodeficiency virus (HIV) infection is characterized by persistent inflammation and immune activation during both acute and chronic phases, and the "cytokine storm" is one of the hallmarks of HIV infection. Along with immune activation after HIV infection, an extensive range of chemokines and other cytokines are elevated, thereby generating the so-called "cytokine storm." In this review, the effects of the upregulated chemokines and chemokine receptors on the processes of HIV infection are discussed. The objective of this review was to focus on the main chemokines and chemokine receptors that have been found to be associated with HIV infection and latency. Elevated chemokines and chemokine receptors have been shown to play important roles in the HIV life cycle, disease progression, and HIV reservoir establishment. Thus, targeting these chemokines and receptors and the other proteins of related signaling pathways might provide novel therapeutic strategies, and the evidence indicates a promising future regarding the development of a functional cure for HIV.

The Canadian HIV and aging cohort study - determinants of increased risk of cardio-vascular diseases in HIV-infected individuals: rationale and study protocol

Background

With potent antiretroviral drugs, HIV infection is becoming a chronic disease. Emergence of comorbidities, particularly cardiovascular disease (CVD) has become a leading concern for patients living with the infection. We hypothesized that the chronic and persistent inflammation and immune activation associated with HIV disease leads to accelerated aging, characterized by CVD. This will translate into higher incidence rates of CVD in HIV infected participants, when compared to HIV negative participants, after adjustment for traditional CVD risk factors. When characterized further using cardiovascular imaging, biomarkers, immunological and genetic profiles, CVD associated with HIV will show different characteristics compared to CVD in HIV-negative individuals.

Methods/design

The Canadian HIV and Aging cohort is a prospective, controlled cohort study funded by the Canadian Institutes of Health Research. It will recruit patients living with HIV who are aged 40 years or older or have lived with HIV for 15 years or more. A control population, frequency matched for age, sex, and smoking status, will be recruited from the general population. Patients will attend study visits at baseline, year 1, 2, 5 and 8. At each study visit, data on complete medical and pharmaceutical history will be captured, along with anthropometric measures, a complete physical examination, routine blood tests and electrocardiogram. Consenting participants will also contribute blood samples to a research biobank. The primary outcome is incidence of a composite of: myocardial infarction, coronary revascularization, stroke, hospitalization for angina or congestive heart failure, revascularization or amputation for peripheral artery disease, or cardiovascular death. Preplanned secondary outcomes are all-cause mortality, incidence of the metabolic syndrome, incidence of type 2 diabetes, incidence of renal failure, incidence of abnormal bone mineral density and body fat distribution. Patients participating to the cohort will be eligible to be enrolled in four pre-planned sub-studies of cardiovascular imaging, glucose metabolism, immunological and genetic risk profile.

Discussion

The Canadian HIV and Aging Cohort will provide insights on pathophysiological pathways leading to premature CVD for patients living with HIV.

Electronic supplementary material

The online version of this article (10.1186/s12879-017-2692-2) contains supplementary material, which is available to authorized users.

Refining Current Scientific Priorities and Identifying New Scientific Gaps in HIV-Related Heart, Lung, Blood, and Sleep Research

The National Heart, Lung, and Blood Institute (NHLBI) AIDS Program's goal is to provide direction and support for research and training programs in areas of HIV-related heart, lung, blood, and sleep (HLBS) diseases. To better define NHLBI current HIV-related scientific priorities and with the goal of identifying new scientific priorities and gaps in HIV-related HLBS research, a wide group of investigators gathered for a scientific NHLBI HIV Working Group on December 14-15, 2015, in Bethesda, MD. The core objectives of the Working Group included discussions on: (1) HIV-related HLBS comorbidities in the antiretroviral era; (2) HIV cure; (3) HIV prevention; and (4) mechanisms to implement new scientific discoveries in an efficient and timely manner so as to have the most impact on people living with HIV. The 2015 Working Group represented an opportunity for the NHLBI to obtain expert advice on HIV/AIDS scientific priorities and approaches over the next decade.

The extent of B-cell activation and dysfunction preceding lymphoma development in HIV-positive people

OBJECTIVES

B-cell dysfunction and activation are thought to contribute to lymphoma development in HIV-positive people; however, the mechanisms are not well understood. We investigated levels of several markers of B-cell dysfunction [free light chain (FLC)-κ, FLC-λ, immunoglobulin G (IgG), IgA, IgM and IgD] prior to lymphoma diagnosis in HIV-positive people.

METHODS

A nested matched case-control study was carried out within the EuroSIDA cohort, including 73 HIV-positive people with lymphoma and 143 HIV-positive lymphoma-free controls. Markers of B-cell dysfunction were measured in prospectively stored serial plasma samples collected before the diagnosis of lymphoma (or selection date in controls). Marker levels ≤ 2 and > 2 years prior to diagnosis were investigated.

RESULTS

Two-fold higher levels of FLC-κ [odds ratio (OR) 1.84; 95% confidence interval (CI) 1.19, 2.84], FLC-λ (OR 2.15; 95% CI 1.34, 3.46), IgG (OR 3.05; 95% CI 1.41, 6.59) and IgM (OR 1.46; 95% CI 1.01, 2.11) were associated with increased risk of lymphoma > 2 years prior to diagnosis, but not ≤ 2 years prior. Despite significant associations > 2 years prior to diagnosis, the predictive accuracy of each marker was poor, with FLC-λ emerging as the strongest candidate with a c-statistic of 0.67 (95% CI 0.58, 0.76).

CONCLUSIONS

FLC-κ, FLC-λ and IgG levels were higher > 2 years before lymphoma diagnosis, suggesting that B-cell dysfunction occurs many years prior to lymphoma development. However, the predictive value of each marker was low and they are unlikely candidates for risk assessment for targeted intervention.

Brain Macrophages in Simian Immunodeficiency Virus-Infected, Antiretroviral-Suppressed Macaques: a Functional Latent Reservoir

A human immunodeficiency virus (HIV) infection cure requires an understanding of the cellular and anatomical sites harboring virus that contribute to viral rebound upon treatment interruption. Despite antiretroviral therapy (ART), HIV-associated neurocognitive disorders (HAND) are reported in HIV-infected individuals on ART. Biomarkers for macrophage activation and neuronal damage in cerebrospinal fluid (CSF) of HIV-infected individuals demonstrate continued effects of HIV in brain and suggest that the central nervous system (CNS) may serve as a viral reservoir. Using a simian immunodeficiency virus (SIV)/macaque model for HIV encephalitis and AIDS, we evaluated whether infected cells persist in brain despite ART. Eight SIV-infected pig-tailed macaques were virally suppressed with ART, and plasma and CSF viremia levels were analyzed longitudinally. To assess whether virus persisted in brain macrophages (BrMΦ) in these macaques, we used a macrophage quantitative viral outgrowth assay (MΦ-QVOA), PCR, and in situ hybridization (ISH) to measure the frequency of infected cells and the levels of viral RNA and DNA in brain. Viral RNA in brain tissue of suppressed macaques was undetectable, although viral DNA was detected in all animals. The MΦ-QVOA demonstrated that the majority of suppressed animals contained latently infected BrMΦ. We also showed that virus produced in the MΦ-QVOAs was replication competent, suggesting that latently infected BrMΦ are capable of reestablishing productive infection upon treatment interruption. This report provides the first confirmation of the presence of replication-competent SIV in BrMΦ of ART-suppressed macaques and suggests that the highly debated issue of viral latency in macrophages, at least in brain, has been addressed in SIV-infected macaques treated with ART.

Resting CD4⁺ T cells are currently the only cells that fit the definition of a latent reservoir. However, recent evidence suggests that HIV/SIV-infected macrophages persist despite ART. Markers of macrophage activation and neuronal damage are observed in the CSF of HIV-infected individuals and of SIV-infected macaques on suppressive ART regimens, suggesting that the CNS has continued virus infection and latent infection. A controversy exists as to whether brain macrophages represent a latent source of replication-competent virus capable of reestablishing infection upon treatment interruption. In this study, we demonstrated the presence of the latent macrophage reservoir in brains of SIV-infected ART-treated macaques and analyzed the reservoir using our established outgrowth assay to quantitate macrophages harboring replication-competent SIV genomes. Our results support the idea of the existence of other latent reservoirs in addition to resting CD4⁺ T cells and underscore the importance of macrophages in developing strategies to eradicate HIV.

The Role of Defensins in HIV Pathogenesis

Profound loss of CD4⁺ T cells, progressive impairment of the immune system, inflammation, and sustained immune activation are the characteristics of human immunodeficiency virus-1 (HIV-1) infection. Innate immune responses respond immediately from the day of HIV infection, and a thorough understanding of the interaction between several innate immune cells and HIV-1 is essential to determine to what extent those cells play a crucial role in controlling HIV-1 in vivo. Defensins, divided into the three subfamilies α-, β-, and θ-defensins based on structure and disulfide linkages, comprise a critical component of the innate immune response and exhibit anti-HIV-1 activities and immunomodulatory capabilities. In humans, only α- and β-defensins are expressed in various tissues and have broad impacts on HIV-1 transmission, replication, and disease progression. θ-defensins have been identified as functional peptides in Old World monkeys, but not in humans. Instead, θ-defensins exist only as pseudogenes in humans, chimpanzees, and gorillas. The use of the synthetic θ-defensin peptide “retrocyclin” as an antiviral therapy was shown to be promising, and further research into the development of defensin-based HIV-1 therapeutics is needed. This review focuses on the role of defensins in HIV-1 pathogenesis and highlights future research efforts that warrant investigation.

Monocytes Phenotype and Cytokine Production in Human Immunodeficiency Virus-1 Infected Patients Receiving a Modified Vaccinia Ankara-Based HIV-1 Vaccine: Relationship to CD300 Molecules Expression

A modified vaccinia Ankara-based HIV-1 vaccine clade B (MVA-B) has been tested for safety and immunogenicity in low-risk human immunodeficiency virus (HIV)-uninfected individuals and as a therapeutic vaccine in HIV-1-infected individuals on combined antiretroviral therapy (cART). As a therapeutic vaccine, MVA-B was safe and broadly immunogenic; however, patients still showed a viral rebound upon treatment interruption. Monocytes are an important part of the viral reservoir and several studies suggest that they are partly responsible for the chronic inflammation observed in cART-treated HIV-infected people. The CD300 family of receptors has an important role in several diseases, including viral infections. Monocytes express CD300a, c, e, and f molecules and lipopolysaccharide (LPS) and other stimuli regulate their expression. However, the expression and function of CD300 receptors on monocytes in HIV infection is still unknown. In this work, we investigated for the first time the expression of CD300 molecules and the cytokine production in response to LPS on monocytes from HIV-1-infected patients before and after vaccination with MVA-B. Our results showed that CD300 receptors expression on monocytes from HIV-1-infected patients correlates with markers of HIV infection progression and immune inflammation. Specifically, we observed a positive correlation between the expression of CD300e and CD300f receptors on monocytes with the number of CD4+ T cells of HIV-1-infected patients before vaccination. We also saw a positive correlation between the expression of the inhibitory receptor CD300f and the expression of CD163 on monocytes from HIV-1-infected individuals before and after vaccination. In addition, monocytes exhibited a higher cytokine production in response to LPS after vaccination, almost at the same levels of monocytes from healthy donors. Furthermore, we also described a correlation in the expression of CD300e and CD300f receptors with TNF-α production in response to LPS, only in monocytes of HIV-1-infected patients before vaccination. Altogether, our results describe the impact of HIV-1 and of the MVA-B vaccine in cytokine production and monocytes phenotype.

Vaginal progesterone to reduce preterm birth among HIV-infected pregnant women in Zambia: a feasibility study protocol

Background

Women infected with HIV have a risk of preterm birth (PTB) that is twice that among uninfected women, and treatment with antiretroviral therapy (ART) may further increase this risk. Progesterone supplementation reduces the risk of preterm delivery in women who have a shortened cervix in the midtrimester. We propose to study the feasibility of a trial of vaginal progesterone (VP) to prevent PTB among HIV-infected women receiving ART in pregnancy. Given low adherence among women self-administering vaginal study product in recent microbicide trials, we plan to investigate whether adequate adherence to VP can be achieved prior to launching a full-scale efficacy trial.

Methods and design

One hundred forty HIV-infected pregnant women in Lusaka, Zambia, will be randomly allocated to daily self-administration of either VP or matched placebo, starting between 20 and 24 gestational weeks. The primary outcome will be adherence, defined as the proportion of participants who achieve at least 80% use of study product, assessed objectively with a validated dye stain assay that confirms vaginal insertion of returned single-use applicators. Secondary outcomes will be study uptake, retention, and preliminary efficacy. We will concurrently perform semi-structured interviews with participants enrolled in the study and with women who decline enrollment to assess the acceptability of VP to prevent PTB and of enrollment to a randomized controlled trial.

Discussion

We hypothesize that VP could prevent PTB among women receiving ART in pregnancy. In preparation for a trial to test this hypothesis, we plan to assess whether participants will be adherent to study product and protocol.

Trial registration

ClinicalTrial.gov, NCT02970552.

Immune markers, diurnal blood pressure profile and cardiac function in virologically suppressed HIV-infected patients

PURPOSE

Non-dipping nocturnal blood pressure (BP) pattern has been reported prevalent among HIV-infected patients and is associated with adverse cardiovascular outcomes. The aims of this observational study were to identify predictors of nocturnal BP decline, and to explore whether diurnal BP profile is associated with alterations in cardiac structure and function.

MATERIALS AND METHODS

A total of 108 treated HIV-infected patients with suppressed viremia underwent ambulatory BP measurement, 51 of these patients also underwent echocardiography.

RESULTS

Non-dipping nocturnal BP pattern was present in 51% of the patients. Decreased nocturnal decline in systolic BP (SBP) correlated with lower CD4 count (r_sp = 0.21, p = 0.032) and lower CD4/CD8 ratio (r_sp = 0.26, p = 0.008). In multivariate linear regression analyses, lower BMI (p = 0.015) and CD4/CD8 ratio <0.4 (p = 0.010) remained independent predictors of nocturnal decline in SBP. Nocturnal decline in SBP correlated with impaired diastolic function, e' (r = 0.28, p = 0.049) as did nadir CD4 count (r_sp = 0.38, p = 0.006). In multivariate linear regression analyses, nadir CD4 count <100 cells/μL (p = 0.037) and age (p < 0.001) remained independent predictors of e'.

CONCLUSIONS

Compromised immune status may contribute to attenuated diurnal BP profile as well as impaired diastolic function in well-treated HIV infection.

The investigation of CD4+T-cell functions in primary HIV infection with antiretroviral therapy

Human immunodeficiency virus (HIV) infection leads to reduced CD4T-cell counts and immune dysfunction. Initiation of antiretroviral therapy (ART) in HIV primary infection has been recommended to achieve an optimal clinical outcome, but a comprehensive study on restoration of CD4T-cell function in primary HIV-infected individuals with ART still needs to be eluciated. We investigated longitudinal changes in the CD4T-cell counts, phenotypes, and functions in HIV-infected individuals with early ART (initiated within 6 months after HIV infection) or later ART (initiated more than 12 months after HIV infection). Patients from early ART and later ART groups had received ART for at least 1 year. Individuals with early ART had more CD4T cells, a faster rate of CD4T-cell recovery than those receiving later ART; the levels of CD4T-cell activation and senescence were lower in early ART compared to those with later ART (P = .031; P = .016), but the activation was higher than normal controls (NC) (P = .001); thymic emigrant function was more upregulated in early ART than in later ART (P = .015), but still lower than NC (P = .027); proliferative capacity and interferon-γ secretion of CD4T cells were significantly decreased in primary infection (P < .001; P = .029), and early ART restored these CD4T-cell functions, there is no difference with NC, later ART could partially restore the functions of CD4T cells, but it remained lower than that of NC (P = .005; P = .019). Early ART could better improve CD4T-cell function.

The impact of diabetes on CD4 recovery in persons with HIV in an urban clinic in the United States

The purpose of this study was to exam the impact of type 2 diabetes mellitus (T2DM) on CD4 cell count trends in adults with HIV. In a longitudinal retrospective study in an urban primary care HIV clinic in the southeastern United States from 2010 to 2012, patients with HIV medical charts were audited to obtain their CD4 cell count, diabetes status, weight, and demographic information. Rates of increase of CD4 T cell count (i.e. slopes) were obtained using a linear mixed-effects model. Most of the HIV-T2DM cohort (n = 262) and HIV-only cohort (n = 2399) were African American (76%) and male (77%). The CD4 T cell counts were consistently higher in the HIV-T2DM cohort ( p < .0001). The mean rate of CD4 T cell count increase (mean ± SE) was 63 ± 9 cells/µl/year in HIV-T2DM African American women and 28 ± 7 cells/µl/year in HIV-T2DM African American men ( p = 0.003). In the multivariable slope analysis, the CD4 T cell count increase was significantly faster for HIV-T2DM African American women than for all other patients (mean difference = 30/cells/µl/year, 95% CI: 13-47; p < 0.001). Gender, race/ethnicity, and the diagnosis of diabetes influenced the recovery of CD4 cell counts.

Contribution of Oxidative Stress to Non-AIDS Events in HIV-Infected Patients

OBJECTIVE

Recognition of potentially modifiable mechanisms implicated in the pathogenesis of non-AIDS events (NAEs) might help improve outcomes of HIV-infected individuals. HIV infection has been associated with increased oxidative stress. We assessed the association between F2-isoprostanes and serious NAEs, and whether they improve the predictive performance of inflammation and coagulation biomarkers.

METHODS

Prospective multicenter cohort. Individuals who had an incident serious NAE and 2 sex- and age-matched participants with no events were selected. Measurement of F2-isoprostanes, highly sensitive C-reactive protein, interleukin-6, D-dimer, sCD14, sCD40, sCD163, and neopterin levels was performed in successive plasma samples collected from cohort inclusion.

RESULTS

Biomarkers were measured in 78 participants developing serious NAEs or death, and 151 subjects with no events. Adjusted levels of F2-isoprostanes, and also of highly sensitive C-reactive protein, sCD14, and D-dimer were higher in individuals who developed serious NAEs, including or not non-AIDS deaths. The same results were observed when only samples collected since the time of achieving virological suppression were analyzed. The additive incorporation of each biomarker, ending with F2-isoprostanes, in an adjusted model was associated with a graded and significant increase in the quality of model fitting, and 94% sensitivity, 33% specificity, and 0.77 accuracy to predict serious NAEs including non-AIDS-related death.

CONCLUSION

Oxidative stress is associated with a higher risk of serious NAEs, including non-AIDS deaths. This effect is independent and additive to biomarkers of inflammation, monocyte activation, and coagulation. Our results suggest that oxidative stress should be included among mechanisms to deal with to improve prognosis of HIV-infected individuals.

Increasing procaspase 8 expression using repurposed drugs to induce HIV infected cell death in ex vivo patient cells

HIV persists because a reservoir of latently infected CD4 T cells do not express viral proteins and are indistinguishable from uninfected cells. One approach to HIV cure suggests that reactivating HIV will activate cytotoxic pathways; yet when tested in vivo, reactivating cells do not die sufficiently to reduce cell-associated HIV DNA levels. We recently showed that following reactivation from latency, HIV infected cells generate the HIV specific cytotoxic protein Casp8p41 which is produced by HIV protease cleaving procaspase 8. However, cell death is prevented, possibly due to low procaspase 8 expression. Here, we tested whether increasing procaspase 8 levels in CD4 T cells will produce more Casp8p41 following HIV reactivation, causing more reactivated cells to die. Screening 1277 FDA approved drugs identified 168 that increased procaspase 8 expression by at least 1.7-fold. Of these 30 were tested for anti-HIV effects in an acute HIV_IIIb infection model, and 9 drugs at physiologic relevant levels significantly reduced cell-associated HIV DNA. Primary CD4 T cells from ART suppressed HIV patients were treated with one of these 9 drugs and reactivated with αCD3/αCD28. Four drugs significantly increased Casp8p41 levels following HIV reactivation, and decreased total cell associated HIV DNA levels (flurbiprofen: p = 0.014; doxycycline: p = 0.044; indomethacin: p = 0.025; bezafibrate: P = 0.018) without effecting the viability of uninfected cells. Thus procaspase 8 levels can be increased pharmacologically and, in the context of HIV reactivation, increase Casp8p41 causing death of reactivating cells and decreased HIV DNA levels. Future studies will be required to define the clinical utility of this or similar approaches.

Immune Activation by Mycobacterium tuberculosis in HIV-Infected and -Uninfected Subjects

INTRODUCTION

This study investigates the influence of Mycobacterium tuberculosis infection on immune activation biomarkers, both in HIV-infected and -uninfected subjects.

METHODS

Forty-eight treatment-naive HIV-infected patients and 74 HIV-uninfected subjects were recruited and divided into groups according to their M. tuberculosis infection status: latent tuberculosis infection (LTBI), active tuberculosis (TB), and no evidence of M. tuberculosis infection. The expression of cellular markers CD38 and HLA-DR on circulating CD8 T lymphocytes and the plasmatic levels of soluble markers interleukin-6, sCD14, and D-Dimer were measured and compared between groups. The HIV-infected patients with no evidence of M. tuberculosis or with LTBI who initiated antiretroviral treatment were tested again for these biomarkers once viral suppression was reached.

RESULTS

In both HIV-infected and -uninfected groups, patients with TB had higher levels of immune activation markers than subjects with LTBI and with no evidence of M. tuberculosis. Among the HIV-uninfected subjects, no significant difference in biomarker level was found between those presenting LTBI and those with no evidence of M. tuberculosis. The effect of LTBI on activation biomarkers in the HIV-infected groups was inconclusive because of the small number of individuals in the HIV+/LTBI group. sCD14 and D-Dimer levels were significantly higher in the TB-only group than in the HIV-only group.

DISCUSSION

Although TB is associated with an increase in biomarkers of immune activation, the effect of LTBI is less evident. Further investigation is warranted, and according to our results, soluble markers may offer greater sensitivity for the evaluation of M. tuberculosis-associated immune activation than cellular markers.

Elevated Spontaneous Interferon-γ Secretion in Human Immunodeficiency Virus-Infected Persons

Immune activation in human immunodeficiency virus (HIV) is a well described phenomenon. We found that HIV patients have higher secretion of interferon (IFN)-γ compared with non-HIV subjects, as measured by the “nil” value in the QuantiFERON-TB Gold test, even when viral loads are low. This may reflect ongoing immune activation, even with optimal HIV management.

Low Bone Mineral Density in Vertically HIV-infected Children and Adolescents: Risk Factors and the Role of T-cell Activation and Senescence

BACKGROUND

Our aim was to determine the prevalence and risk factors associated with low bone mineral density (BMD) in vertically HIV-infected patients and to investigate whether low BMD is related to immune activation and senescence induced by HIV infection.

METHODS

A cross-sectional study was performed in 98 vertically HIV-infected patients. BMD was measured by dual-energy radiograph absorptiometry at lumbar spine. Height adjustment of BMD Z score was performed using height-for-age Z score. T-cell immune activation and senescence were analyzed in a subgroup of 54 patients by flow cytometry.

RESULTS

Median age was 15.9 years, 71.4% were Caucasian, 99% received antiretroviral therapy and 80.6% had undetectable viral load. Low BMD (BMD Z score ≤ -2) was present in 15.3% of cases, but after height adjustment in 4.1% of cases. Height-adjusted BMD Z score was positively correlated with body mass index Z score, CD4/CD8 ratio and nadir CD4, and inversely with duration of severe immunosuppression and parathyroid hormone values. In the multivariate model including age, gender, ethnicity, encephalopathy, Tanner stage, nadir CD4, duration of viral suppression, CD4 count, CD4/CD8 ratio, body mass index, cumulative duration of antiretroviral therapy, tenofovir and protease inhibitors exposure, nadir CD4 was independently associated to height-adjusted BMD Z score. No association was found between height-adjusted BMD Z score and T-cell activation or senescence.

CONCLUSIONS

The prevalence of low BMD in vertically HIV-infected patients was low after height adjustment. Nadir CD4, but not T-cell activation or senescence, was an independent predictor for low BMD. Larger and prospective studies are needed to achieve better knowledge of the pathogenesis of low BMD in vertical HIV infection.

The Role of Caveolin 1 in HIV Infection and Pathogenesis

Caveolin 1 (Cav-1) is a major component of the caveolae structure and is expressed in a variety of cell types including macrophages, which are susceptible to human immunodeficiency virus (HIV) infection. Caveolae structures are present in abundance in mechanically stressed cells such as endothelial cells and adipocytes. HIV infection induces dysfunction of these cells and promotes pathogenesis. Cav-1 and the caveolae structure are believed to be involved in multiple cellular processes that include signal transduction, lipid regulation, endocytosis, transcytosis, and mechanoprotection. Such a broad biological role of Cav-1/caveolae is bound to have functional cross relationships with several molecular pathways including HIV replication and viral-induced pathogenesis. The current review covers the relationship of Cav-1 and HIV in respect to viral replication, persistence, and the potential role in pathogenesis.

PKC-δ isoform plays a crucial role in Tat-TLR4 signalling pathway to activate NF-κB and CXCL8 production

HIV-1 Tat protein induces the production of CXCL8 chemokine in a TLR4/MD2 and PKC dependent manner. The objective of this study was to understand whether these two pathways were distinct or constituted a single common pathway, and to determine the nature of the PKC isoforms involved and their interrelation with the activation of NF-κB and CXCL8 gene product expression. Here, we show that Tat-induced CXCL8 production is essentially dependent on the activation of PKC delta isoform, as shown a) by the capacity of PKC delta dominant negative (DN), and Rottlerin, a selective PKC delta pharmacological inhibitor, to inhibit Tat-induced CXCL8 production and b) by the ability of the constitutively active (CAT) isoform of PKC delta to induce CXCL8 production in a HEK cell line in the absence of Tat stimulation. The finding that comparable amounts of CXCL8 were produced following stimulation with either Tat protein, PKC-delta CAT transfection, or both, argue for the implication of one common pathway where PKC delta is activated downstream of TLR4 recruitment and leads to the activation of NF-κB. Altogether, our results underline the crucial role of PKC delta isoform in activating gene expression of CXCL8, a cytokine largely implicated in the physiopathology of HIV-1 infection.

Pathophysiology of CD4+ T-Cell Depletion in HIV-1 and HIV-2 Infections

The hall mark of human immunodeficiency virus (HIV) infection is a gradual loss of CD4+ T-cells and imbalance in CD4+ T-cell homeostasis, with progressive impairment of immunity that leads ultimately to death. HIV infection in humans is caused by two related yet distinct viruses: HIV-1 and HIV-2. HIV-2 is typically less virulent than HIV-1 and permits the host to mount a more effective and sustained T-cell immunity. Although both infections manifest the same clinical spectrum, the much lower rate of CD4+ T-cell decline and slower progression of disease in HIV-2 infected individuals have grabbed the attention of several researchers. Here, we review the most recent findings on the differential rate of decline of CD4+ T-cell in HIV-1 and HIV-2 infections and provide plausible reasons for the observed differences between the two groups.

Frailty and physical function in older HIV-infected adults

Background and Objectives

HIV patients have seen accelerated ageing. Our objective was to determine the prevalence of frailty, to evaluate factors associated with frailty and to evaluate physical function in older HIV-infected adults.

Design

this was a cross-sectional study.

Setting

outpatient clinics of two public university hospitals in Madrid (Spain).

Methods

frailty was defined according to the criteria of Fried: shrinking, weakness, poor endurance and energy, slowness and low physical activity level, being frail those who met at least three criteria, prefrail one or two criteria and robust when they met no criteria. Physical function was assessed using standardised methods.

Results

we evaluated 117 HIV-infected patients. Mean age was 61.3 ([standard deviation] 6.87) years. All patients were on antiretroviral therapy. Median current CD4+ T-cell count was 638 (144-1871) cells/μl, and median CD4/CD8 ratio was 0.79 (0.00-3.62). The prevalence of frailty was 15.4%, and that of prefrailty was 52.1%. In the multivariate analyses depressive symptoms (OR [95% CI], 9.20 [2.17-39.05]) and CD4/CD8 ratio (OR 0.11 [0.02-0.61]) were associated with frailty. Even though 100% of the patients were able to walk and perform basic activities of daily life independently, functional impairment was high (20% slow gait and 55% Short Physical Performance Battery ≤9).

Conclusions

HIV-infected patients aged ≥55 years have a high prevalence of frailty and a high burden of functional impairment. Optimal management of this population requires close collaboration between infectious diseases specialists and geriatricians.

Effect of Liver Disease on Hepatic Transporter Expression and Function

Liver disease can alter the disposition of xenobiotics and endogenous substances. Regulatory agencies such as the Food and Drug Administration and the European Medicines Evaluation Agency recommend, if possible, studying the effect of liver disease on drugs under development to guide specific dose recommendations in these patients. Although extensive research has been conducted to characterize the effect of liver disease on drug-metabolizing enzymes, emerging data have implicated that the expression and function of hepatobiliary transport proteins also are altered in liver disease. This review summarizes recent developments in the field, which may have implications for understanding altered disposition, safety, and efficacy of new and existing drugs. A brief review of liver physiology and hepatic transporter localization/function is provided. Then, the expression and function of hepatic transporters in cholestasis, hepatitis C infection, hepatocellular carcinoma, human immunodeficiency virus infection, nonalcoholic fatty liver disease and nonalcoholic steatohepatitis, and primary biliary cirrhosis are reviewed. In the absence of clinical data, nonclinical information in animal models is presented. This review aims to advance the understanding of altered expression and function of hepatic transporters in liver disease and the implications of such changes on drug disposition.

Emphysema is associated with thoracic vertebral bone attenuation on chest CT scan in HIV-infected individuals

BACKGROUND

Age-related chronic diseases are prevalent in HIV-infected persons in the antiretroviral therapy (ART) era. Bone mineral density (BMD) loss and emphysema have separately been shown to occur at a younger age and with lesser risk exposure in HIV-infected compared to HIV-uninfected individuals. In non-HIV infected smokers, emphysema has been shown to independently predict low BMD. We hypothesized that emphysema would independently associate with thoracic vertebral bone attenuation, a surrogate for bone mineral density, in HIV-infected individuals.

METHODS

Clinical, pulmonary function, and radiographic data were analyzed for 164 individuals from the University of Pittsburgh's HIV Lung Research Center cohort. Chest CT scans were used to quantify emphysema and compute Hounsfield Unit (HU) attenuation of the 4th, 7th, and 10th thoracic vertebrae. The association between mean HU attenuation values across the three vertebrae and radiographic emphysema, age, sex, body mass index (BMI), steroid use, viral load, CD4 count, and forced expiratory volume in the first second (FEV1) was assessed by univariate and multivariate analyses.

RESULTS

In univariate analysis, mean HU attenuation decreased with increasing age (p<0.001), pack years (p = 0.047), and percent emphysema (p<0.001). In a multivariable model, including pack years, age, sex, ART and steroid use, greater emphysema was independently associated with this surrogate marker of BMD in HIV-infected individuals (p = 0.034).

CONCLUSIONS

The association of emphysema with thoracic bone attenuation in HIV-infected individuals is consistent with previous reports in non-HIV infected smokers. These findings suggest that emphysema should be considered a potential marker of osteoporosis risk in HIV-infected individuals.

The Effect of Antiretroviral Naïve HIV-1 Infection on the Ability of Natural Killer Cells to Produce IFN-γ upon Exposure to Plasmodium falciparum-Infected Erythrocytes

Background

In sub-Saharan Africa, intense perennial Plasmodium species transmission coincides with areas of high prevalence of the human immunodeficiency virus type 1 (HIV) infection. This implies that antiretroviral naïve HIV-infected people living within these regions are repeatedly exposed to Plasmodium species infection and consequently malaria. Natural killer (NK) cells are known to contribute to malaria immunity through the production of IFN-γ after exposure to Plasmodium falciparum-infected erythrocytes (infected red blood cells [iRBC]). However, in antiretroviral naïve HIV-1 infection, these functions could be impaired. In this study we assess the ability of NK cells from antiretroviral naïve HIV-1-infected people to respond to iRBC.

Method

Magnetically sorted NK cells from antiretroviral naïve HIV-1-infected people were tested for their ability to respond to iRBC following in vitro coculture. NK cell IFN-γ production after coculture was measured through multiparametric flow cytometry analysis.

Results

Our data show a significant reduction (p = 0.03) in IFN-γ production by NK cells from antiretroviral naïve HIV-1-infected people after coculture with iRBCs. This was in contrast to the NK cell response from healthy controls, which demonstrated elevated IFN-γ production. NK cell IFN-γ production from untreated HIV-1-infected participants correlated inversely with the viral load (r = −0.5, p = 0.02) and positively with total helper CD4⁺ T-cell count (r = 0.4, p = 0.04). Thus, antiretroviral naïve HIV-1 infection can dampen NK cell-mediated immunity to P. falciparum infection in malaria-intense regions. This could in effect escalate morbidity and mortality in people chronically infected with HIV-1.

Total HIV-1 DNA, a Marker of Viral Reservoir Dynamics with Clinical Implications

HIV-1 DNA persists in infected cells despite combined antiretroviral therapy (cART), forming viral reservoirs. Recent trials of strategies targeting latent HIV reservoirs have rekindled hopes of curing HIV infection, and reliable markers are thus needed to evaluate viral reservoirs. Total HIV DNA quantification is simple, standardized, sensitive, and reproducible. Total HIV DNA load influences the course of the infection and is therefore clinically relevant. In particular, it is predictive of progression to AIDS and death, independently of HIV RNA load and the CD4 cell count. Baseline total HIV DNA load is predictive of the response to cART. It declines during cART but remains quantifiable, at a level that reflects both the history of infection (HIV RNA zenith, CD4 cell count nadir) and treatment efficacy (residual viremia, cumulative viremia, immune restoration, immune cell activation). Total HIV DNA load in blood is also predictive of the presence and severity of some HIV-1-associated end-organ disorders. It can be useful to guide individual treatment, notably, therapeutic de-escalation. Although it does not distinguish between replication-competent and -defective latent viruses, the total HIV DNA load in blood, tissues, and cells provides insights into HIV pathogenesis, probably because all viral forms participate in host cell activation and HIV pathogenesis. Total HIV DNA is thus a biomarker of HIV reservoirs, which can be defined as all infected cells and tissues containing all forms of HIV persistence that participate in pathogenesis. This participation may occur through the production of new virions, creating new cycles of infection and disseminating infected cells; maintenance or amplification of reservoirs by homeostatic cell proliferation; and viral transcription and synthesis of viral proteins without new virion production. These proteins can induce immune activation, thus participating in the vicious circle of HIV pathogenesis.

South African Breast Cancer and HIV Outcomes Study: Methods and Baseline Assessment

Purpose

In low- and middle-income, HIV-endemic regions of sub-Saharan Africa, morbidity and mortality from the common epithelial cancers of the developed world are rising. Even among HIV-infected individuals, access to antiretroviral therapy has enhanced life expectancy, shifting the distribution of cancer diagnoses toward non–AIDS-defining malignancies, including breast cancer. Building on our prior research, we recently initiated the South African Breast Cancer and HIV Outcomes study.

Methods

We will recruit a cohort of 3,000 women newly diagnosed with breast cancer at hospitals in high (average, 20%) HIV prevalence areas, in Johannesburg, Durban, Pietermaritzburg, and Empangeni. At baseline, we will collect information on demographic, behavioral, clinical, and other factors related to access to health care. Every 3 months in year 1 and every 6 months thereafter, we will collect interview and chart data on treatment, symptoms, cancer progression, comorbidities, and other factors.

We will compare survival rates of HIV-infected and uninfected women with newly diagnosed breast cancer and their likelihood of receiving suboptimal anticancer therapy. We will identify determinants of suboptimal therapy and context-specific modifiable factors that future interventions can target to improve outcomes. We will explore molecular mechanisms underlying potentially aggressive breast cancer in both HIV-infected and uninfected patients, as well as the roles of pathogens, states of immune activation, and inflammation in disease progression.

Conclusion

Our goals are to contribute to development of evidence-based guidelines for the management of breast cancer in HIV-positive women and to improve outcomes for all patients with breast cancer in resource-constrained settings.

Role of Natural Killer Cells in HIV-Associated Malignancies

Now in its fourth decade, the burden of HIV disease still persists, despite significant milestone achievements in HIV prevention, diagnosis, treatment, care, and support. Even with long-term use of currently available antiretroviral therapies (ARTs), eradication of HIV remains elusive and now poses a unique set of challenges for the HIV-infected individual. The occurrence of HIV-associated non-AIDS-related comorbidities outside the scope of AIDS-defining illnesses, in particular non-AIDS-defining cancers, is much greater than the age-matched uninfected population. The underlying mechanism is now recognized in part to be related to the immune dysregulated and inflammatory status characteristic of HIV infection that persists despite ART. Natural killer (NK) cells are multifunctional effector immune cells that play a critical role in shaping the innate immune responses to viral infections and cancer. NK cells can modulate the adaptive immune response via their role in dendritic cell (DC) maturation, removal of immature tolerogenic DCs, and their ability to produce immunoregulatory cytokines. NK cells are therefore poised as attractive therapeutic targets that can be harnessed to control or clear both HIV and HIV-associated malignancies. To date, features of the tumor microenvironment and the evolution of NK-cell function among individuals with HIV-related malignancies remain unclear and may be distinct from malignancies observed in uninfected persons. This review intends to uncouple anti-HIV and antitumor NK-cell features that can be manipulated to halt the evolution of HIV disease and HIV-associated malignancies and serve as potential preventative and curative immunotherapeutic options.

HIV Infection and Compromised Mucosal Immunity: Oral Manifestations and Systemic Inflammation

Mucosal surfaces account for the vast majority of HIV transmission. In adults, HIV transmission occurs mainly by vaginal and rectal routes but rarely via oral route. By contrast, pediatric HIV infections could be as the result of oral route by breastfeeding. As such mucosal surfaces play a crucial role in HIV acquisition, and spread of the virus depends on its ability to cross a mucosal barrier. HIV selectively infects, depletes, and/or dysregulates multiple arms of the human immune system particularly at the mucosal sites and causes substantial irreversible damage to the mucosal barriers. This leads to microbial products translocation and subsequently hyper-immune activation. Although introduction of antiretroviral therapy (ART) has led to significant reduction in morbidity and mortality of HIV-infected patients, viral replication persists. As a result, antigen presence and immune activation are linked to “inflammaging” that attributes to a pro-inflammatory environment and the accelerated aging process in HIV patients. HIV infection is also associated with the prevalence of oral mucosal infections and dysregulation of oral microbiota, both of which may compromise the oral mucosal immunity of HIV-infected individuals. In addition, impaired oral immunity in HIV infection may predispose the patients to periodontal diseases that are associated with systemic inflammation and increased risk of cardiovascular diseases. The purpose of this review is to examine existing evidence regarding the role of innate and cellular components of the oral cavity in HIV infection and how HIV infection may drive systemic hyper-immune activation in these patients. We will also discuss current knowledge on HIV oral transmission, HIV immunosenescence in relation to the oral mucosal alterations during the course of HIV infection and periodontal disease. Finally, we discuss oral manifestations associated with HIV infection and how HIV infection and ART influence the oral microbiome. Therefore, unraveling how HIV compromises the integrity of the oral mucosal tissues and innate immune components of the oral cavity and its association with induction of chronic inflammation are critical for the development of effective preventive interventions and therapeutic strategies.

HIV Infection and Compromised Mucosal Immunity: Oral Manifestations and Systemic Inflammation

Mucosal surfaces account for the vast majority of HIV transmission. In adults, HIV transmission occurs mainly by vaginal and rectal routes but rarely via oral route. By contrast, pediatric HIV infections could be as the result of oral route by breastfeeding. As such mucosal surfaces play a crucial role in HIV acquisition, and spread of the virus depends on its ability to cross a mucosal barrier. HIV selectively infects, depletes, and/or dysregulates multiple arms of the human immune system particularly at the mucosal sites and causes substantial irreversible damage to the mucosal barriers. This leads to microbial products translocation and subsequently hyper-immune activation. Although introduction of antiretroviral therapy (ART) has led to significant reduction in morbidity and mortality of HIV-infected patients, viral replication persists. As a result, antigen presence and immune activation are linked to "inflammaging" that attributes to a pro-inflammatory environment and the accelerated aging process in HIV patients. HIV infection is also associated with the prevalence of oral mucosal infections and dysregulation of oral microbiota, both of which may compromise the oral mucosal immunity of HIV-infected individuals. In addition, impaired oral immunity in HIV infection may predispose the patients to periodontal diseases that are associated with systemic inflammation and increased risk of cardiovascular diseases. The purpose of this review is to examine existing evidence regarding the role of innate and cellular components of the oral cavity in HIV infection and how HIV infection may drive systemic hyper-immune activation in these patients. We will also discuss current knowledge on HIV oral transmission, HIV immunosenescence in relation to the oral mucosal alterations during the course of HIV infection and periodontal disease. Finally, we discuss oral manifestations associated with HIV infection and how HIV infection and ART influence the oral microbiome. Therefore, unraveling how HIV compromises the integrity of the oral mucosal tissues and innate immune components of the oral cavity and its association with induction of chronic inflammation are critical for the development of effective preventive interventions and therapeutic strategies.

Impact of endotoxin on the expression of drug transporters in the placenta of HIV-1 transgenic (HIV-Tg) rats

BACKGROUND

Inflammatory responses in HIV (+) patients may be exacerbated due to reports of subclinical endotoxemia and existing immune dysregulation. As inflammation has been reported to mediate changes in the expression of transporters, this could be potentiated in pregnant HIV (+) women. Similar to humans, the HIV-Tg rat model develops immune dysregulation and chronic AIDS-like conditions. Our objective was to examine the expression of placental drug transporters in HIV-Tg rats in response to low-dose endotoxin.

METHODS

Pregnant HIV-Tg rats or wild-type littermates (WT) were treated with low dose bacterial endotoxin 0.1mg/kg (n=8) or 0.25mg/kg (n=4-6) on GD18 and placentas were harvested 18h later. Placental and hepatic expression of transporters and cytokines were examined using qRT-PCR and Western blotting.

RESULTS

As compared to WT, endotoxin administration increased the hepatic and placental expression of IL-6 and TNF-α to a greater extent in HIV-Tg rats (p<0.05). The placental mRNA and protein expression of Abcb1a and Slco2b1 was significantly decreased in endotoxin-treated HIV-Tg but not WT rats and downregulation of Slco4a1 mRNA was more pronounced in the HIV-Tg group (p<0.05). These changes significantly correlated with the placental expression of pro-inflammatory cytokines. Abcc3 mRNA expression was increased in the placenta of endotoxin treated WT rats only, while placental expression of Abcc1, Abcc2 and Abcc4 was not significantly affected in both WT and HIV rats. Endotoxin imposed a pronounced downregulation in the hepatic expression of Abcb1a, Abcc2, Abcc4, Abcg2, Slco1a1, Slco1b2 and Slc29a1 in both HIV-Tg and WT rats; however, Abcb1b expression was increased in HIV but not WT rats.

CONCLUSION

Our results indicate that low-dose endotoxin resulted in an augmented inflammatory response in HIV-Tg rats accompanied with significant changes in the placental expression of several drug transporters. Our data suggests that subclinical endotoxemia and other co-existing infections may alter the placental transfer of drugs in the HIV population.

Skin advanced glycation end products in HIV infection are increased and predictive of development of cardiovascular events

OBJECTIVE

HIV-1 infection is associated with an increased cardiovascular disease (CVD) risk. Advanced glycation end products are formed as stable markers of glycaemic and oxidative stress. Skin autofluorescence (SAF) as marker of accumulated advanced glycation end products is increased and predictive of CVD events in diabetes mellitus, chronic kidney disease (CKD), and preexisting CVD. We determined SAF levels in HIV-1 infected patients, testing the hypothesis that SAF predicts CVD events in HIV infection.

DESIGN

Single-centre prospective cohort study.

METHODS

In 2010-2011, SAF was measured in 91 patients. Development of CVD events was monitored during a median follow-up of 4.8 years. SAF values of the patients were expressed as a ratio (rSAF) to expected SAF levels in age-matched healthy volunteers.

RESULTS

Seventy-nine men and 12 women were included, mean age 47 years; 81 patients were on combination antiretroviral therapy. With a mean rSAF of 1.155, SAF levels in patients were 15.5% higher than predicted for their age (95% confidence interval, 10.0-20.0; P < 0.001). In multivariate regression analysis, rSAF was associated with nadir CD4 cell count less than 200 cells/μl (β -0.274; P = 0.01), smoking (β 0.240; P = 0.03), and men who have sex with men (MSM) (β 0.202; P = 0.07). CVD events occurred in six patients (7%). In Cox regression analysis including age, SAF, smoking, diabetes, hypertension and CKD, SAF (P = 0.01), and (Wet Medisch-wetenschappelijk Onderzoek met mensen; WMO) CKD (P = 0.03) remained as independent predictors of CVD events.

CONCLUSION

SAF is increased in HIV-infected patients, and related with smoking, low nadir CD4 cell count, and MSM. Larger studies are needed to confirm whether SAF is an independent predictor of CVD events.

IFN-γ Attenuates Spontaneous Lymphocyte Proliferation by Fuelling Regulatory T Cells in HIV-1-Infected Patients

HIV infection is characterized by a high degree of immune activation. It has an impact on CD4 cell count and populations' distribution and function. T regulatory cells (Tregs) were found to play a controversial role in the course of infection because of their beneficial effect on the degree of immune activation and unfavorable influence on the antigen-specific responses. The goal of the present work was to study the relationship among interferon-γ (IFN-γ), spontaneous lymphocyte proliferation, and regulatory T cells in HIV patients receiving therapy. Three lymphocyte populations, isolated after a stepwise magnetic separation from 17 individuals, were investigated-peripheral blood lymphocytes, CD4⁺CD45RA^- (CD4⁺TM), and CD4⁺CD45RA^-CD25^- (TMCD25depl.) cells. The spontaneous, phytohemagglutinin (PHA) and HIV-1p24Ag-stimulated IFN-γ production and the spontaneous lymphocyte proliferation were evaluated. The potential of Tregs to establish a productive infection was determined by measurement of free HIV-1p24 antigen. Two types of constellations among subsets were found. In the first one (in 11 subjects), the spontaneous INF-γ inversely correlated with the spontaneous proliferation in all fractions (r = -0.9, p < 0.001). Conversely, in the second group (six subjects), no associations between the selected parameters were observed. The overall increase in p24-stimulated IFN-γ from TMCD25depl. cells was weak. Four samples: one in Tregs and three in TMCD25depl. cells were positive for the free p24 antigen. No association with the CD4⁺ T cell count, percentage of Tregs, and stage of infection was determined. In conclusion, our results demonstrate that IFN-γ could impact the proliferative capacity of non-Treg cells by fuelling Tregs. Furthermore, Tregs may control the spontaneous lymphocyte proliferation, but are less powerful in the suppression of Ag-specific IFN-γ production from non-Treg lymphocytes. The direct viral influence on Treg functions should be also considered.

Integrative Analysis of Immunological Data to Explore Chronic Immune T-Cell Activation in Successfully Treated HIV Patients

OBJECTIVES

To unravel the complex relationships between cytomegalovirus-induced-, autoimmune-induced responses, microbial translocation and chronic immune activation (CIA) in successfully treated HIV-infected patients and to explore the mediating role of alpha-interferon in these processes.

DESIGN

Cross-sectional study nested in the ANRS CO3 Aquitaine Cohort, a prospective hospital-based cohort of HIV-1-infected patients in South-Western France.

METHODS

Patients initiated antiretroviral therapy between 2005 and 2008 and were treated with sustained virological suppression for at least two years. CIA was defined by the percentage of HLA-DR+/CD38+ among CD8+T-cells. Integrative analyses were performed using structural equation modelling (SEM).

RESULTS

The main analysis was performed in 57 HLA-A*0201 positive patients, due to availability of percentages of actin-, vimentin-, lamin-specific CD8+T-cells (HLA-A2-restricted tests) to further characterize autoimmune response. Cytomegalovirus-induced response was assessed by Quantiferon and pp-65 ELISPOT. SEM revealed a direct effect of cytomegalovirus-induced response on CIA (standardized estimate βstd = 0.56, p-value = 0.0004). The effect of autoimmune-induced response on CIA was indirect through alpha-interferon pathway, assessed by expression levels of 5 alpha-interferon-stimulated genes ADAR, ISG15, IFIT1, Mx1 and OAS1 (effect of autoimmune response on alpha-interferon: βstd = 0.36, p-value = 0.0401; effect of alpha-interferon on CIA: βstd = 0.39, p-value = 0.0044). There was no direct effect of autoimmune-induced response on CIA (p-value = 0.3169). Microbial translocation as measured by 16SrDNA and sCD14 in plasma was not associated with CIA. Results were consistent in 142 patients in whom cytomegalovirus and auto-immunity responses were measured by Quantiferon and anti-nuclear antibodies, respectively. All analyses performed in HLA-A*0201 positive patients and in the overall population revealed a significant effect of IFN-α latent variable on CIA.

CONCLUSION

The role of cytomegalovirus-induced response on CIA was confirmed as well as the involvement of alpha-interferon on CIA. The indirect effect of auto-immunity response on CIA revealed through the alpha-interferon pathway requires further investigation to confirm the potential role of auto-immunity for CIA in HIV-infected patients.

Lung microbiome in human immunodeficiency virus infection

The lung microbiome plays a significant role in normal lung function and disease. Because microbial colonization is likely influenced by immunodeficiency, one would speculate that infection with human immunodeficiency virus (HIV) alters the lung microbiome. Furthermore, how this alteration might impact pulmonary complications now seen in HIV-infected patients on antiretroviral therapy (ART), which has shifted from opportunistic infections to diseases associated with chronic inflammation, is not known. There have been limited publications on the lung microbiome in HIV infection, many of them emanating from the Lung HIV Microbiome Project. Current evidence suggests that the lung microbiome in healthy HIV-infected individuals with preserved CD4 counts is similar to uninfected individuals. However, in individuals with more advanced disease, there is an altered alveolar microbiome characterized by a loss of richness and evenness (alpha diversity) within individuals. Furthermore, as a group the taxa making up the HIV-infected and uninfected lung microbiome are different (differences in beta diversity), and the HIV-infected population is more spread out (greater dispersion) than the uninfected population. These differences decline with ART, but even after effective therapy the alveolar microbiome in HIV-infected individuals contains increased amounts of signature bacteria, some of which have previously been associated with chronic lung inflammation. Furthermore, more recent investigations into the lung virome in HIV infection suggest that perturbations in lung viral communities also exist in HIV infection, and that these too are associated with evidence of lung inflammation. Thus, it is likely both microbiome and virome alterations in HIV infection contribute to lung inflammation in these individuals, which has important implications on the changing spectrum of pulmonary complications in patients living with HIV.

Impairment of CCR6+ and CXCR3+ Th Cell Migration in HIV-1 Infection Is Rescued by Modulating Actin Polymerization

CD4+ T cell repopulation of the gut is rarely achieved in HIV-1-infected individuals who are receiving clinically effective antiretroviral therapy. Alterations in the integrity of the mucosal barrier have been indicated as a cause for chronic immune activation and disease progression. In this study, we present evidence that persistent immune activation causes impairment of lymphocytes to respond to chemotactic stimuli, thus preventing their trafficking from the blood stream to peripheral organs. CCR6+ and CXCR3+ Th cells accumulate in the blood of aviremic HIV-1-infected patients on long-term antiretroviral therapy, and their frequency in the circulation positively correlates to levels of soluble CD14 in plasma, a marker of chronic immune activation. Th cells show an impaired response to chemotactic stimuli both in humans and in the pathogenic model of SIV infection, and this defect is due to hyperactivation of cofilin and inefficient actin polymerization. Taking advantage of a murine model of chronic immune activation, we demonstrate that cytoskeleton remodeling, induced by okadaic acid, restores lymphocyte migration in response to chemokines, both in vitro and in vivo. This study calls for novel pharmacological approaches in those pathological conditions characterized by persistent immune activation and loss of trafficking of T cell subsets to niches that sustain their maturation and activities.

Effect of Antiretroviral Therapy on the Memory and Activation Profiles of B Cells in HIV-Infected African Women

Human immunodeficiency virus infection induces a wide range of effects in B cells, including skewed memory cell differentiation, compromised B cell function, and hypergammaglobulinemia. However, data on the extent to which these B cell abnormalities can be reversed by antiretroviral therapy (ART) are limited. To investigate the effect of ART on B cells, the activation (CD86) and differentiation (IgD, CD27, and CD38) profiles of B cells were measured longitudinally in 19 HIV-infected individuals before (median, 2 mo) and after ART initiation (median, 12 mo) and compared with 19 age-matched HIV-uninfected individuals using flow cytometry. Twelve months of ART restored the typical distribution of B cell subsets, increasing the proportion of naive B cells (CD27^-IgD⁺CD38^-) and concomitantly decreasing the immature transitional (CD27^-IgD⁺CD38⁺), unswitched memory (CD27⁺IgD⁺CD38^-), switched memory (CD27⁺IgD^-CD38^- or CD27^-IgD^-CD38^-), and plasmablast (CD27⁺IgD^-CD38^high) subsets. However, B cell activation was only partially normalized post-ART, with the frequency of activated B cells (CD86⁺CD40⁺) reduced compared with pre-ART levels (p = 0.0001), but remaining significantly higher compared with HIV-uninfected individuals (p = 0.0001). Interestingly, unlike for T cell activation profiles, the extent of B cell activation prior to ART did not correlate with HIV plasma viral load, but positively associated with plasma sCD14 levels (p = 0.01, r = 0.58). Overall, ART partially normalizes the skewed B cell profiles induced by HIV, with some activation persisting. Understanding the effects of HIV on B cell dysfunction and restoration following ART may provide important insights into the mechanisms of HIV pathogenesis.

Intensive statin regimens for reducing risk of cardiovascular diseases among human immunodeficiency virus-infected population: A nation-wide longitudinal cohort study 2000-2011

OBJECTIVE

This study evaluated the risk of cardiovascular diseases (CVD) in a statin-treated HIV-infected population and the effects of intensive statin regimens (i.e., high-dose or potency) on CVD risks.

METHODS

945 HIV-infected patients newly on statin treatment (144, 15.7% with CVD history) were identified from Taiwan's national HIV cohort. Using the median of the first year cumulative statin dosage as a cut-off point, patients were classified into either a high-dose or low-dose group. Patients were also classified as high-potency (i.e., atorvastatin) or low-potency (i.e., pravastatin) statin users. CVD, including ischemic stroke, coronary artery diseases, and heart failure, were identified after statin use to the end of 2011. Cox hazards regression was applied to assess the time-to-event hazards of CVD in association with intensive statin regimens.

RESULTS

In the HIV-infected population with CVD history, the high-dose group had a lower CVD risk compared to that of the low-dose group (hazard ratio [HR]: 0.88, 95% confidence interval [CI]: 0.39-1.99). The high-potency group showed a lower CVD risk compared to that of the low-potency group (HR: 0.42, 95% CI: 0.06-3.13). For those without CVD history, the corresponding figures were HR: 0.64 (95% CI: 0.30-1.35) and HR: 0.67 (95% CI: 0.16-2.87). The event rate of new-onset diabetes in high-dose statin group was higher than that in low-dose statin group (15.28% vs. 8.33%), while no muscle complications (i.e., myalgia, myositis, rhabdomyolysis) and dementia were observed in statin users.

CONCLUSIONS

There appears a trend showing a lower CVD risk in HIV patients receiving intensive statin therapy.

Multiplex assay reliability and long-term intra-individual variation of serologic inflammatory biomarkers

BACKGROUND

Circulating cytokines, chemokines, and soluble cytokine receptors can serve as biomarkers of inflammation and immune dysregulation. Good reliability of multiplex platforms, which allow for simultaneous, comprehensive biomarker assessment, is critical for their utility in epidemiologic studies. We examined the reliability of the Meso-Scale Discovery (MSD) platform to simultaneously quantitate 15 cytokines and chemokines and the Luminex platform (R&D Systems) to quantitate 5 soluble receptors and 2 chemokines and cytokines and evaluated long-term within-person correlation of these biomarkers.

METHODS

The detectability and reliability of these assay systems were assessed using the same external controls across plates and archived sera from 250 HIV^- men in the Multicenter AIDS Cohort Study. Using up to four visits per person from 1984 to 2009, age-adjusted intraclass correlation coefficients (ICC) of biomarkers with >80% detectability (CCL11, CXCL8, CXCL10, CCL2, CCL4, CCL13, CCL17, CXCL13, IL-10, IL-12p70, IL-6, TNF-α, BAFF, sCD14, sCD27, sgp130, sIL-2Rα, and sTNF-R2) were obtained using linear mixed models.

RESULTS

Most biomarkers were detectable in 80% of control samples; IFN-γ, GM-CSF, and IL-2 were undetectable in >20% of samples. Among the HIV-uninfected men, most biomarkers showed fair to strong within-person correlation (ICC>0.40) up to 15years. The ICC for CXCL8 was good in the short term but decreased with increasing time between visits, becoming lower (ICC<0.40) after 8years.

CONCLUSIONS

These multiplexed assays showed acceptable reliability for use in epidemiologic research, despite some technical variability and limitations in cytokine quantitation. Most biomarkers displayed moderate-to-excellent intra-individual variability over the long term, suggesting their utility in prospective studies investigating etiologic associations with diverse chronic conditions.

Immune Activation and Bacterial Translocation: A Link between Impaired Immune Recovery and Frequent Visceral Leishmaniasis Relapses in HIV-Infected Patients

The maintenance of chronic immune activation due to leishmaniasis or even due to microbial translocation is associated with immunosenescence and may contribute to frequent relapses. Our aim was to investigate whether patients with HIV-associated visceral leishmaniasis (VL/HIV) who experience a single episode of VL have different immunological behaviors in comparison to those who experience frequent relapses. VL/HIV patients were allocated to non-relapsing (NR, n = 6) and relapsing (R, n = 11) groups and were followed from the active phase of VL up to 12 months post-treatment (mpt). The patients were receiving highly active antiretroviral therapy (HAART) and secondary prophylaxis after VL therapy. During active VL, the two groups were similar in all immunological parameters, including the parasite load. At 6 and 12 mpt, the NR group showed a significant gain of CD4⁺ T cells, a reduction of lymphocyte activation, and lower soluble CD14 and anti-Leishmania IgG3 levels compared to the R group. The viral load remained low, without correlation with the activation. The two groups showed elevated but similar percentages of senescent T cells. These findings suggest a decreased ability of the R group to downmodulate immune activation compared to the NR group. Such functional impairment of the effector response may be a useful indicator for predicting clinical prognosis and recommending starting or stopping secondary prophylaxis.

Maternal systemic or cord blood inflammation is associated with birth anthropometry in a Tanzanian prospective cohort

OBJECTIVES

HIV infection is associated with chronic systemic inflammation, with or without antiretroviral therapy. Consequences for foetal growth are not understood, particularly in settings where multiple maternal infections and malnutrition are common. The study was designed to examine maternal systemic circulating and umbilical cord blood cytokine concentrations in relation to birth anthropometry in a Tanzanian prospective cohort.

METHODS

A 9-plex panel of maternal plasma cytokines in HIV-positive (n = 44) and HIV-negative (n = 70) mothers and the same cytokines in umbilical cord blood collected at delivery was assayed. Linear regression modelled associations between maternal or cord blood cytokines and birth anthropometry.

RESULTS

Health indicators (haemoglobin, mid-upper-arm circumference, body mass index) in HIV-positive mothers without considerable immunosuppression did not differ from HIV-negative women. Despite this, HIV-exposed infants had lower birthweight and length. Subgroup analyses indicated that HIV management using HAART was associated with lower plasma TNF-α, as were longer durations of any antiretroviral therapy (≥2 months). Greater maternal plasma TNF-α was associated with earlier delivery (-1.7 weeks, P = 0.039) and lower birthweights (-287 g; P = 0.020), while greater umbilical cord TNF-α (-1.43 cm; P = 0.036) and IL-12p70 (-2.4 cm; P = 0.008) were associated with shorter birth length. Birthweight was inversely associated with cord IL-12p70 (-723 g; P = 0.001) and IFN-γ (-482 g, P = 0.007). Maternal cytokines during pregnancy did not correlate with umbilical cord cytokines at delivery.

CONCLUSIONS

Systemic inflammation identified in maternal plasma or umbilical cord blood was associated with poorer birth anthropometrics in HIV-exposed and HIV-unexposed infants. Controlling maternal and/or foetal systemic inflammation may improve birth anthropometry.

Lung function, inflammation and cardiovascular mortality in Africans

BACKGROUND

The link between impaired lung function and cardiovascular outcome is well established in European and American populations. It is possible that this association may be driven by a systemic spillover of inflammation occurring within the lungs. As several studies have found an increased level of inflammatory markers in African populations, we aimed to establish the contribution of lung function in predicting all-cause and cardiovascular mortality in Africans, whilst taking inflammatory markers into account.

DESIGN

We followed 1442 black South Africans from the North West Province participating in the South African leg of the Prospective Urban and Rural Epidemiology (PURE) study, over a five-year period. Spirometry, cardiovascular and metabolic measures were performed, and cardiovascular mortality as well as all-cause mortality used as endpoints.

RESULTS

In univariate Cox regression models, both forced expiratory volume in 1-s (FEV₁ ) and forced vital capacity (FVC) predicted all-cause (P = 0·022; P < 0·001) and cardiovascular mortality (P = 0·004; P < 0·001). In multivariate adjusted standardized Cox regression analyses, only FVC predicted cardiovascular mortality independent of several covariates (hazard ratio, 0·57 [0·35-0·94]), including C-reactive protein (CRP). When CRP was replaced by interleukin-6 in the model, the significance of FVC was lost (hazard ratio, 0·85 [0·55-1·30]).

CONCLUSION

FVC, but not FEV₁ , is a strong predictor of both all-cause and CV mortality in black South Africans, which may be mediated by inflammation.

Immune activation during acute HIV infection and the impact of early antiretroviral therapy

PURPOSE OF REVIEW

The purpose of this review is to outline recent data pertaining to mechanisms of immune activation in acute infection and describe new developments that seek to determine if early antiretroviral treatment can mitigate chronic immune activation.

RECENT FINDINGS

Following the detection of HIV RNA, highly activated CD8 T cells expand and peak approximately 2 weeks following peak viral load whereas levels of proinflammatory soluble markers coincide with a rise in viral load. Immune activation during acute infection is driven by many factors including pyroptosis, replicative capacity of the infecting virus, and loss of Th17 cells within the gut. Early antiretroviral therapy (ART), particularly if initiated in Fiebig I (HIV IgM-), preserved mucosal CD4 T cells, possibly preventing the release of microbial products associated with immune activation. Viral reservoirs were restricted by the early initiation of ART, and heightened systemic immune activation was partially prevented compared with chronic HIV infection. A strong correlation was found between the size of the viral reservoir and cellular immune activation.

SUMMARY

The timing of immune activation during acute infection occurs shortly after exposure. Recent studies demonstrated that ART mitigates inflammatory responses, preserves CD4 T cells, and limits reservoir seeding if provided early in acute HIV infection.

Immune activation and immune aging in HIV infection

PURPOSE OF REVIEW

The development of serious non-AIDS-related pathologies typically associated with aging, and the premature immune aging that characterizes HIV-1-infected patients, even with suppressive antiretroviral therapy, have raised increasing concerns in recent years. Deciphering the causes of these phenomena is key for our understanding of HIV pathogenesis and for the clinical care of patients living with the virus.

RECENT FINDINGS

An important basis for the immune parallels between HIV infection and aging lies in the exhaustion of the lymphopoietic capacity of infected individuals, which eventually affects all compartments of the immune system. The alleged cause for these immune alterations, and the onset of age-related comorbidities, is the systemic chronic immune activation that is established in patients. However, there is a multiplicity of contributors to this immune activation.

SUMMARY

Our understanding of the precise link between immune activation and aging in HIV infection is complicated by the influence of coinfections and life style factors. Developing rational interventions to reduce the hyper-inflammatory status of HIV-1-infected patients requires a clearer delineation of the factors contributing to the increased levels of systemic immune activation.

CD4 T-Cell Responses in Primary HIV Infection: Interrelationship with Immune Activation and Virus Burden

Early events during primary HIV infection (PHI) are thought to influence disease outcome. Although a growing body of evidence suggests a beneficial role of HIV-specific CD4 help in HIV infection, it is unclear how early viral replication, systemic immune activation, and antiretroviral therapy (ART) may shape CD4 T-cell responses during PHI, and whether HIV-specific CD4 responses contribute to the high immune activation observed in PHI. Twenty-seven patients with early PHI were included in a prospective longitudinal study and 12 of them received ART after enrollment. Fresh peripheral blood mononuclear cells were used for measurement of ex vivo T-cell activation and of cytokine-producing CD4 T-cells following stimulation with PMA/ionomycin or HIV-1-gag-p24 antigen. Patients were segregated based on CD8 T-cell activation level (i.e., % HLA-DR⁺CD38⁺ CD8 T-cells) at baseline (BL). Patients with lower immune activation exhibited higher frequency of bulk CD4 T-cells producing IFN-γ or IL-17 and higher effector-to-regulatory cell ratios. No differences were found in HIV-specific CD4 T-cell frequencies. In contrast, segregation of patients based on plasma viral load (pVL) revealed that patients with higher pVL showed higher cytokine-producing HIV-specific CD4 responses. Of note, the frequency of IFN-γ⁺ HIV-specific CD4 T cells significantly diminished between BL and month 6 only in ART-treated patients. However, early treatment initiation was associated with better maintenance of HIV-specific IFN-γ⁺ CD4 T-cells. These data suggest that HIV-specific CD4 responses do not fuel systemic T-cell activation and are driven by viral replication but not able to contribute to its control in the early phase of infection. Moreover, our data also suggest a benefit of early treatment for the maintenance of HIV-specific CD4 T-cell help.

HIV Suppression Restores the Lung Mucosal CD4+ T-Cell Viral Immune Response and Resolves CD8+ T-Cell Alveolitis in Patients at Risk for HIV-Associated Chronic Obstructive Pulmonary Disease

BACKGROUND

Lung CD4⁺ T-cell depletion and dysfunction, CD8⁺ T-cell alveolitis, smoking, and poor control of human immunodeficiency virus (HIV) are features of HIV-associated chronic obstructive pulmonary disease (COPD), but these changes have not been evaluated in smokers at risk for COPD. We evaluated the impact of viral suppression following initiation of antiretroviral therapy (ART) on HIV-specific immunity and the balance of the CD4⁺ T-cell to CD8⁺ T-cell ratio in the lung.

METHODS

Using flow cytometry, we assessed the T-cell immune response in lung and blood specimens obtained from 12 actively smoking HIV-positive patients before ART initiation and after ART-associated viral suppression.

RESULTS

HIV suppression resulted in enhanced lung and systemic HIV-specific CD4⁺ T-cell immune responses without significant changes in CD8⁺ T-cell responses. We observed an increase in lung ratios of CD4⁺ T cells to CD8⁺ T cells and CD4⁺ T-cell frequencies, decreased CD8⁺ T-cell numbers, and resolution of CD8⁺ T-cell alveolitis after ART in 9 of 12 individuals. Viral suppression reduced Fas receptor and programmed death 1 expression in lung CD4⁺ T cells, correlating with enhanced effector function and reduced susceptibility to apoptosis. HIV suppression rescued peripheral but not lung HIV-specific CD4⁺ T-cell proliferation, resulting in augmented effector multifunction.

DISCUSSION

Together, our results demonstrate that HIV suppression restores lung mucosal HIV-specific CD4⁺ T-cell multifunctional immunity and balance in the ratio of CD4⁺ T cells to CD8⁺ T cells, often resolving CD8⁺ T-cell alveolitis in active smokers. Peripheral expansion and redistribution of CD4⁺ T cells and increased resistance to apoptosis are 2 mechanisms contributing to immunologic improvement following viral suppression in patients at risk for HIV-associated COPD.

Low CD4/CD8 Ratio Is Associated with Non AIDS-Defining Cancers in Patients on Antiretroviral Therapy: ANRS CO8 (Aproco/Copilote) Prospective Cohort Study

Objectives

To study the association between CD4/CD8 ratio and morbidity in HIV-infected patients on antiretroviral therapy (ART).

Methods

The APROCO/COPILOTE cohort enrolled patients initiating a protease inhibitor-containing ART in 1997–1999. The association between occurrence of first non AIDS-defining severe events (NADE) and time-dependent measures of immune restoration was assessed by 4 Cox models with different definitions of restoration, CD4+ cell counts (CD4), CD4/CD8 ratio, both CD4 and CD4/CD8 ratio, or a composite variable (CD4< 500/mm³, CD4 > 500/mm³ and CD4/CD8 ratio < 1, CD4 > 500/mm³ and CD4/CD8 ratio > 1). Models adjusted on baseline characteristics and time-dependent viral load were compared using Akaike Information Criterion.

Results

We included 1227 patients. Median duration of follow-up was 9.2 years (IQR: 4.2–11.4). Median CD4 was 530/mm³ at 9 years. Median CD4/CD8 ratio was 0.3 (IQR: 0.2–0.5) at baseline and 0.6 (IQR: 0.4–0.9) after 9 years. Incidence of first NADE was 7.4/100 person-years, the most common being bacterial infections (21%), cardiovascular events (14%) and cancers (10%). For both bacterial infections and cardiovascular events, the CD4/CD8 ratio did not add predictive information to the CD4 cell count. However, low CD4/CD8 ratio was the best predictor of non-AIDS cancers (adjusted HR = 2.13 for CD4/CD8 < 0.5; 95% CI = 1.32–3.44).

Conclusions

CD4/CD8 ratio remains < 1 in most HIV-infected patients despite long-term CD4+ cell counts restoration on ART. A CD4/CD8 ratio < 0.5 could identify patients who require a more intensive strategy of cancer prevention or screening.

Divergent Annexin A1 expression in periphery and gut is associated with systemic immune activation and impaired gut immune response during SIV infection

HIV-1 disease progression is paradoxically characterized by systemic chronic immune activation and gut mucosal immune dysfunction, which is not fully defined. Annexin A1 (ANXA1), an inflammation modulator, is a potential link between systemic inflammation and gut immune dysfunction during the simian immunodeficiency virus (SIV) infection. Gene expression of ANXA1 and cytokines were assessed in therapy-naïve rhesus macaques during early and chronic stages of SIV infection and compared with SIV-negative controls. ANXA1 expression was suppressed in the gut but systemically increased during early infection. Conversely, ANXA1 expression increased in both compartments during chronic infection. ANXA1 expression in peripheral blood was positively correlated with HLA-DR+CD4+ and CD8+ T-cell frequencies, and negatively associated with the expression of pro-inflammatory cytokines and CCR5. In contrast, the gut mucosa presented an anergic cytokine profile in relation to ANXA1 expression. In vitro stimulations with ANXA1 peptide resulted in decreased inflammatory response in PBMC but increased activation of gut lymphocytes. Our findings suggest that ANXA1 signaling is dysfunctional in SIV infection, and may contribute to chronic inflammation in periphery and with immune dysfunction in the gut mucosa. Thus, ANXA1 signaling may be a novel therapeutic target for the resolution of immune dysfunction in HIV infection.

Elevated CD8 T-cell counts and virological failure in HIV-infected patients after combination antiretroviral therapy

Elevated CD8 counts with combination antiretroviral therapy (cART) initiation may be an early warning indicator for future treatment failure. Thus, we investigated whether elevated CD8 counts were associated with virological failure (VF) in the first 4 years of cART in Asian HIV-infected patients in a multicenter regional cohort.We included patients from the TREAT Asia HIV Observational Database (TAHOD). Patients were included in the analysis if they started cART between 1996 and 2013 with at least one CD8 measurement within 6 months prior to cART initiation and at least one CD8 and viral load (VL) measurement beyond 6 months after starting cART. We defined VF as VL ≥400 copies/mL after 6 months on cART. Elevated CD8 was defined as CD8 ≥1200 cells/μL. Time to VF was modeled using Cox regression analysis, stratified by site.In total, 2475 patients from 19 sites were included in this analysis, of whom 665 (27%) experienced VF in the first 4 years of cART. The overall rate of VF was 12.95 per 100 person-years. In the multivariate model, the most recent elevated CD8 was significantly associated with a greater hazard of VF (HR = 1.35, 95% CI 1.14-1.61; P = 0.001). However, the sensitivity analysis showed that time-lagged CD8 measured at least 6 months prior to our virological endpoint was not statistically significant (P = 0.420).This study indicates that the relationship between the most recent CD8 count and VF was possibly due to the CD8 cells reacting to the increase in VL rather than causing the VL increase itself. However, CD8 levels may be a useful indicator for VF in HIV-infected patients after starting cART.

The CD4/CD8 Ratio is Inversely Associated with Carotid Intima-Media Thickness Progression in Human Immunodeficiency Virus-Infected Patients on Antiretroviral Treatment

Inversion of the CD4/CD8 ratio (<1) has been identified as a surrogate marker of immunosenescence and an independent predictor of AIDS events in HIV-infected patients and mortality in the general population. We aimed to assess the association between the CD4/CD8 ratio and carotid intima-media thickness (cIMT) progression in treated HIV-infected patients as a marker of coronary heart disease. A longitudinal study was conducted during 3 years in 96 virally suppressed HIV-infected patients receiving antiretroviral treatment (ART). We analyzed the associations between the CD4/CD8 ratio, cardiovascular risk factors, and antiretroviral treatment (ART) and progression of subclinical atherosclerosis assessed using cIMT at baseline and after 3 years. Finally, 96 patients completed the study. Seventy six (79.1%) patients were male, aged 44 ± 10 years; 39 (40.6%) were on treatment with protease inhibitors; 49 (51.04%) with nonnucleoside reverse transcriptase inhibitors, 6 (6.25%) with integrase inhibitors, 3 (3.12%) with maraviroc, and 2 (2.08%) just with nucleoside reverse transcriptase inhibitors. The mean of ART exposition was 6.9 ± 5.9 years. Twenty six (27%) patients had family history of ischemic heart disease, 51 (53.12%) were smokers, 12 (12.5%) were hypertensive, 4 (4.16%) had type 2 diabetes, 23 (23.9%) had dyslipidemia, and 31 (32.3%) were infected with hepatitis C virus. Baseline cIMT was significantly associated with age (rho = 0.497; p < .001), basal glucemia (rho = 0.323; p = .001), triglycerides (rho = 0.232; p = .023), Framingham risk score (rho = 0.324; p = .001), CD4/CD8 ratio (rho = -0.176; p = .05), and dyslipidemia (0.72 ± 0.16 mm vs. 0.63 ± 0.11 mm; p = .029). In multivariable analysis where cardiovascular risk factor and ART were included, cIMT progression was inversely associated with CD4/CD8 ratio [odds ratio (OR) = 0.283; confidence interval (95% CI) 0.099-0.809; p = .019]. In conclusion, the inversion of CD4/CD8 ratio in treated HIV-infected patients is independently associated with cIMT progression, a marker of coronary heart disease. Therefore, it might be clinically useful as predictor of cardiovascular events.