Biomarkers and HIV-associated cardiovascular disease

The Relationship Between Impaired Coronary Endothelial Function and Systemic Markers of Inflammation in People Living With HIV

BACKGROUND

People with HIV (PWH) are at an increased risk of cardiovascular disease, partially believed to be related to chronically elevated systemic inflammation. Abnormal systemic endothelial function (SEF) and coronary endothelial function (CEF) develop early in atherogenesis and predict adverse events. It is unknown whether abnormal CEF is related to systemic inflammation in PWH.

METHODS

In this substudy of a prior randomized controlled trial in PWH without prior clinical coronary artery disease suppressed on antiretroviral therapy with CEF as a primary end point (N = 82), we investigated the associations between baseline serum markers of inflammation and adhesion and baseline CEF, assessed by noninvasive MRI measures of percentage changes in coronary blood flow and cross-sectional area during isometric handgrip exercise, and SEF using brachial ultrasound for flow-mediated dilation. We also evaluated whether baseline marker levels were associated with CEF after 8 weeks in the placebo group (N = 40).

RESULTS

CEF measures were abnormal at baseline, based on trial entry criteria. A higher value of CEF was directly associated with levels of interleukin 10, whereas CEF at baseline was inversely associated with E-selectin. Worse CEF at 8 weeks was directly associated with baseline tumor necrosis factor alpha, intercellular adhesion molecule 1, C-reactive protein, interferon gamma and sICAM-3. SEF at baseline or 8 weeks was not associated with any baseline markers.

CONCLUSION

Coronary but not systemic endothelial dysfunction was significantly associated with select markers of inflammation and adhesion in PWH. Furthermore, CEF but not SEF at 8 weeks was associated with baseline levels of inflammation. Our findings suggest that abnormal CEF and systemic markers of inflammation are linked in PWH.

Maternal biomarkers of endothelial dysfunction and pregnancy outcomes in women with and without HIV in Botswana

BACKGROUND

Women living with HIV-1 (WLHIV) are at higher risk of having an adverse birth outcome, but the underlying mechanism(s) are unknown. We hypothesized that HIV-associated endothelial activation could adversely impact placental function and lead to impaired fetal growth or stillbirth.

METHODS

We used stored samples from WLHIV and HIV-negative women who had enrolled during pregnancy in the observational Botswana Tshipidi cohort. Written informed consent was obtained from the participants. We measured plasma levels of markers of endothelial activation (soluble vascular adhesion molecule 1 [VCAM-1], intercellular adhesion molecule 1 [ICAM-1] and E-selectin) from samples taken during pregnancy. We compared log10 biomarker levels by maternal HIV status and by the timing of ART initiation (ART prior to conception vs. during pregnancy; ART prior to sample collection vs. no ART prior to sampling) using t-tests and the Kruskal-Wallis rank test. We evaluated the association between these biomarkers and adverse birth outcomes (composite of stillbirth or small for gestational age [SGA]) using univariate and multivariate log-binomial regression controlling for maternal age (continuous) and timing of ART start. We also used generalized linear models (GLM) to evaluate the association between continuous birthweight (in grams) and gestational age (in weeks) and markers of endothelial dysfunction, adjusting for maternal age (continuous) and timing of ART relative to sample collection.

RESULTS

Specimens collected before delivery were available for 414 women (372 WLHIV and 42 HIV-negative women), with a median age of 28 years and median gestational age at sample collection of 30 weeks (range 26, 35 weeks). WLHIV had significantly higher median VCAM1 (p = 0.002) than HIV-negative women, but HIV-negative women had higher median ICAM1 (p = 0.01); e-Selectin levels did not differ by maternal HIV status. Women starting ART during pregnancy had higher log10 VCAM1 levels than those on ART before conception, regardless of whether the sample was collected before (p = 0.02) or after (p = 0.03) ART initiation. However, ICAM1 and e-Selectin did not differ significantly by ART status or ART timing. Ninety-eight women (91 WLHIV and 7 HIV-negative), or 9 (2%) and 89 (22%) included in this study, had a stillborn or SGA baby respectively. Univariate and adjusted analyses did not show significant associations between levels of any of the biomarkers with these adverse birth outcomes. However, lower birthweight (p = 0.03) and lower gestational age at delivery were associated e-Selectin and ICAM (p = 0.008), respectively.

CONCLUSION

Maternal HIV infection and lack of ART (or recent ART initiation) were associated with one marker of greater endothelial activation (VCAM-1), but not with other markers (ICAM-1 nor E-selectin) in pregnancy. e-Selectin was associated with lower birthweight and every unit increase in log ICAM-1 at delivery was associated with lower gestation age at delivery.

Cardiovascular disease and risk assessment in people living with HIV: Current practices and novel perspectives

Human immunodeficiency virus (HIV) infection represents a major cardiovascular risk factor, and the cumulative cardiovascular disease (CVD) burden among aging people living with HIV (PLWH) constitutes a leading cause of morbidity and mortality. To date, CVD risk assessment in PLWH remains challenging. Therefore, it is necessary to evaluate and stratify the cardiovascular risk in PLWH with appropriate screening and risk assessment tools and protocols to correctly identify which patients are at a higher risk for CVD and will benefit most from prevention measures and timely management. This review aims to accumulate the current evidence on the association between HIV infection and CVD, as well as the risk factors contributing to CVD in PLWH. Furthermore, considering the need for cardiovascular risk assessment in daily clinical practice, the purpose of this review is also to report the current practices and novel perspectives in cardiovascular risk assessment of PLWH and provide further insights into the development and implementation of appropriate CVD risk stratification and treatment strategies, particularly in countries with high HIV burden and limited resources.

Proinflammatory and cardiovascular biomarkers are associated with echocardiographic abnormalities in children with HIV taking antiretroviral therapy

OBJECTIVES

Children with perinatally acquired HIV (PHIV) and taking antiretroviral therapy (ART) have a high prevalence of subclinical cardiac disease. We hypothesized that cardiac disease may be a consequence of dysregulated systemic immune activation driven by HIV infection. We examined cardiovascular and proinflammatory biomarkers and their association with echocardiographic abnormalities in children with PHIV.

DESIGN

Cross-sectional analysis of soluble biomarkers from a prospective cohort of children aged 6-16 years with PHIV and age-matched HIV-uninfected comparison group.

METHODS

Cryopreserved plasma samples were used to measure seven soluble biomarkers using multiplex bead assay (Luminex). Multivariable logistic regression assessed how biomarker levels related to cardiac abnormalities.

RESULTS

A total of 406 children participated in this study (195 PHIV and 211 HIV-uninfected). Mean [standard deviation (SD)] ages of PHIV and HIV-uninfected participants were 10.7 (2.6) and 10.8 (2.8) years, respectively. Plasma levels of CRP, TNF-α, ST2, VCAM-1 and GDF-15 were significantly higher in the PHIV group compared with uninfected control ( P  < 0.001). Among children with PHIV, with one-unit representing one SD in biomarker level, a one-unit increase in CRP and GDF-15, was associated with increased odds of having left ventricular (LV) diastolic dysfunction [adjusted odds ratio (aOR), 1.49 (1.02-2.18; P  < 0.040)] and [aOR 1.71 (1.18-2.53; P  = 0.006)], respectively. Each one unit increase in GDF-15 was associated with increased odds of LV hypertrophy [aOR 1.84 (95% CI 1.10-3.10; P  < 0.021)].

CONCLUSION

Children with PHIV had higher levels of proinflammatory and cardiovascular biomarkers compared with HIV-uninfected children. Increased CRP and GDF-15 were associated with cardiac abnormalities in children with PHIV.

Effects and safety of Chinese herbal medicine on inflammatory biomarkers in cardiovascular diseases: A systematic review and meta-analysis of randomized controlled trials

Inflammation drives cardiovascular disease (CVD) in individuals with underlying chronic inflammatory diseases, including People with HIV (PWH), independently of dyslipidemia. Adjunctive treatments that lower inflammation may be useful to lower CVD risk in such populations. There is very little data on the efficacy of Chinese herbal medicine (CHM) in reducing inflammation in PWH to address its potential in reducing this CVD risk factor, therefore we evaluated its impact on inflammatory biomarkers relevant to CVD risk in the general population. Six English and Chinese databases were searched for studies investigating CHM’s effects on inflammatory biomarkers relevant to CVD from respective inceptions to February 2022. A systematic review and meta-analysis of randomized controlled trials (RCTs) were conducted and the most-frequently prescribed herbs were identified. Thirty-eight RCTs involving 4,047 participants were included. Greater than or equal to 50% of included studies had a low risk of bias in five domains (random sequence generation, detection, attrition, reporting and other bias) and 97% had a high risk of performance bias. CHM provided significant additive effects on attenuating relevant inflammatory indices including hs-CRP (SMD −2.05, 95% CI −2.55 to −1.54), IL-6 (SMD −1.14, 95% CI −1.63 to −0.66) and TNF-α levels (SMD −0.88, 95% CI −1.35 to −0.41), but no significant effects on hs-CRP were found between CHM and placebo when co-treating with Western drugs (MD 0.04, 95% CI −1.66 to 1.74). No severe adverse events were reported in CHM groups. The two most prevalent herbs present in formulae demonstrating reduction of at least one inflammatory biomarker were Dan shen (Salviae Miltiorrhizae Radix et Rhizoma) and Huang qi (Astragali Radix). CHM, in combination with standard anti-inflammatory medications, may depress inflammation and reduce the risk of inflammatory conditions such as CVD. Rigorously-conducted trials and adequate reporting are needed to provide more robust evidence supporting the use of CHM to reduce CVD risk in people with underlying chronic inflammation such as PWH.

Neutrophils promote T-cell activation through the regulated release of CD44-bound Galectin-9 from the cell surface during HIV infection

The interaction of neutrophils with T cells has been the subject of debate and controversies. Previous studies have suggested that neutrophils may suppress or activate T cells. Despite these studies, the interaction between neutrophils and T cells has remained a largely unexplored field. Here, based on our RNA sequencing (RNA-seq) analysis, we found that neutrophils have differential transcriptional and functional profiling depending on the CD4 T-cell count of the HIV-infected individual. In particular, we identified that neutrophils in healthy individuals express surface Galectin-9 (Gal-9), which is down-regulated upon activation, and is consistently down-regulated in HIV-infected individuals. However, down-regulation of Gal-9 was associated with CD4 T-cell count of patients. Unstimulated neutrophils express high levels of surface Gal-9 that is bound to CD44, and, upon stimulation, neutrophils depalmitoylate CD44 and induce its movement out of the lipid raft. This process causes the release of Gal-9 from the surface of neutrophils. In addition, we found that neutrophil-derived exogenous Gal-9 binds to cell surface CD44 on T cells, which promotes LCK activation and subsequently enhances T-cell activation. Furthermore, this process was regulated by glycolysis and can be inhibited by interleukin (IL)-10. Together, our data reveal a novel mechanism of Gal-9 shedding from the surface of neutrophils. This could explain elevated plasma Gal-9 levels in HIV-infected individuals as an underlying mechanism of the well-characterized chronic immune activation in HIV infection. This study provides a novel role for the Gal-9 shedding from neutrophils. We anticipate that our results will spark renewed investigation into the role of neutrophils in T-cell activation in other acute and chronic conditions, as well as improved strategies for modulating Gal-9 shedding.

This study shows that HIV-infected individuals have different neutrophil profiles depending on their CD4 T cell count. In particular, neutrophils express high levels of surface Gal-9 but this is shed upon stimulation; this exogenous Gal-9 binds to CD44 on T cells, which promotes LCK activation and subsequently enhances T cell activation.

Assessing Cardiovascular Risk in People Living with HIV: Current Tools and Limitations

PURPOSE OF REVIEW

To provide the current state of the development and application of cardiovascular disease (CVD) prediction tools in people living with HIV (PLWH).

RECENT FINDINGS

Several risk prediction models developed on the general population are available to predict CVD risk, the most notable being the US-based pooled cohort equations (PCE), the Framingham risk functions, and the Europe-based SCORE (Systematic COronary Risk Evaluation). In validation studies in cohorts of PLWH, these models generally underestimate CVD risk, especially in individuals who are younger, women, Black race, or predicted to be at low/intermediate risk. An HIV-specific CVD prediction model, the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) model, is available, but its performance is modest, especially in US-based cohorts. Enhancing CVD prediction with novel biomarkers of inflammation or coronary artery calcification is of interest but has not yet been evaluated in PLWH. Finally, studies on CVD risk prediction are lacking in diverse PLWH globally. While available risk models for CVD prediction in PLWH remain suboptimal, clinicians should remain vigilant of higher CVD risk in this population and should use any of these risk scores for risk stratification to guide preventive interventions. Focus on established traditional risk factors such as smoking remains critical in PLWH. Risk prediction functions tailored to PLWH in diverse settings will enhance clinicians' ability to deliver optimal preventive care.

Prevalence of Silent Atherosclerosis and Other Comorbidities in an Outpatient Cohort of Adults Living with HIV: Associations with HIV Parameters and Biomarkers

People living with HIV (PLWH) are at risk of noninfectious comorbidities. It is important to individualize those at higher risk. In a single-center cohort of PLWH, we performed a cross-sectional analysis of comorbidities, diagnosed according to standard procedures. The primary endpoint was the prevalence of subclinical carotid/coronary atherosclerosis. Secondary endpoints were its association with selected inflammatory/immune activation biomarkers and with other comorbidities. Associations were examined by using Chi-square or Fisher's exact test for categorical variables and Student or Wilcoxon tests for quantitative variables, and a stepwise multivariate logistical model was performed for further exploration. Among 790 participants [median age: 49.8 years (interquartile range, IQR: 44.5-55.6), 77.1% males, median CD4: 536/mm³ (IQR: 390-754), 83.6% with undetectable viral load], asymptomatic atherosclerosis was found in 26% and was associated in multivariate analysis with older age, longer known duration of infection, higher sCD14, and lower adiponectin levels. Hypertension was found in 33.5% of participants, diabetes in 19.4%, renal impairment in 14.6%, elevated low-density lipoprotein-cholesterol in 13.3%, elevated triglyceride/high-density lipoprotein (HDL)-cholesterol ratio in 6.6%, and osteoporosis in 7.9%. The presence of two or more comorbidities was found in 42.1% of participants and was associated in multivariate analysis with older age and longer exposure to antiretrovirals. Comorbidities were diversely associated with biomarkers: osteoporosis with higher IL-6, renal impairment with higher sCD14, hypertension with higher D-dimer, diabetes and elevated triglyceride/HDL-cholesterol ratio both with lower adiponectin and lower 25-hydroxyvitamin D. Asymptomatic atherosclerosis and multimorbidity were frequent in a cohort of middle-aged, well-controlled, PLWH and were associated with traditional and HIV-specific factors. Associations between morbidities and inflammatory/immune activation biomarkers were diverse.

Management of anticoagulation in patients with human immunodeficiency virus/acquired immunodeficiency virus

PURPOSE

Limited guidance is available to assist practitioners in managing complex human immunodeficiency virus (HIV) related pharmacotherapy. Management recommendations of oral anticoagulation (warfarin and direct oral anticoagulants [DOACs]) and highly active antiretroviral therapy (HAART) based on drug-drug interactions (DDI) studies and pharmacokinetic (PK) data are provided.

METHODS

Search of PubMed, EMBASE, and Google Scholar (01/1985 to 12/2018) using the terms "HIV," "DDI," and names of HAART. PK information and DDI screening were obtained from medication package inserts and drug information resources: Micromedex, Lexicomp, HIV-DDI Checker- University of Liverpool. All English literature on DDI or PK interactions was considered for inclusion. In the absence of data, PK principles were used to predict the likelihood of interactions.

RESULTS

No clinically significant DDI are expected to occur between DOACs and nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs), maraviroc, enfuvirtide, or integrase strand inhibitors (INSTIs) that do not include a pharmacologic booster. Potent cytochrome P (CYP) 450 enzyme inhibition by protease inhibitors (PIs) or pharmacologic boosters may lead to higher concentrations of the DOAC and potentially increase the risk of bleeding. CYP450 enzyme induction by non-nucleoside reverse transcriptase inhibitors (NNRTIs) may lower concentrations of DOACs, which may lead to treatment failure. Warfarin DDIs are variable, therefore close monitoring of the INR is recommended.

CONCLUSIONS

The potential for DDIs between HAART and oral anticoagulation exists based on PK profiles. Management of these interactions should involve careful selection based on patient characteristics and HAART and anticoagulants with a low potential for DDI should be selected.

The importance of advanced cytometry in defining new immune cell types and functions relevant for the immunopathogenesis of HIV infection

: In the last years, novel, exciting immunological findings of interest for HIV research and treatment were identified thanks to different cytometric approaches. The analysis of the phenotypes and functionality of cells belonging to the immune system could clarify their role in the immunopathogenesis of HIV infection, and to elaborate key concepts, relevant in the treatment of this disease. Important discoveries have been made concerning cells that are important for protective immunity like lymphocytes that display polyfunctionality, resident memory T cells, innate lymphoid cells, to mention a few. The complex phenotype of myeloid-derived suppressor cells has been investigated, and relevant changes have been reported during chronic and primary HIV infection, in correlation with changes in CD4 T-cell number, T-cell activation, and with advanced disease stage. The search for markers of HIV persistence present in latently infected cells, namely those molecules that are important for a functional or sterilizing cure, evidenced the role of follicular helper T cells, and opened a discussion on the meaning and use of different surface molecules not only in identifying such cells, but also in designing new strategies. Finally, advanced technologies based upon the simultaneous detection of HIV-RNA and proteins at the single cell level, as well as those based upon spectral cytometry or mass cytometry are now finding new actors and depicting a new scenario in the immunopathogenesis of the infection, that will allow to better design innovative therapies based upon novel drugs and vaccines.

Extracellular Vesicle-Related Thrombosis in Viral Infection

Although the outcomes of viral infectious diseases are remarkably varied, most infections cause acute diseases after a short period. Novel coronavirus disease 2019, which recently spread worldwide, is no exception. Extracellular vesicles (EVs) are small circulating membrane-enclosed entities shed from the cell surface in response to cell activation or apoptosis. EVs transport various kinds of bioactive molecules between cells, including functional RNAs, such as viral RNAs and proteins. Therefore, when EVs are at high levels, changes in cell activation, inflammation, angioplasty and transportation suggest that EVs are associated with various diseases. Clinical research on EVs includes studies on the coagulatory system. In particular, abnormal enhancement of the coagulatory system through EVs can cause thrombosis. In this review, we address the functions of EVs, thrombosis, and their involvement in viral infection.

Protocol paper: Stepped wedge cluster randomized trial translating the ABCS into optimizing cardiovascular care for people living with HIV

People living with HIV (PWH) are at higher risk for cardiovascular disease (CVD) and stroke in comparison to their non-infected counterparts. The ABCS (aspirin-blood pressure control-cholesterol control-smoking cessation) reduce atherosclerotic (ASCVD) risk in the general population, but little is known regarding strategies for promoting the ABCS among PWH. Guided by the Consolidated Framework for Implementation Research (CFIR), we designed multilevel implementation strategies that target PWH and their clinicians to promote appropriate use of the ABCS based on a 10-year estimated ASCVD risk. Implementation strategies include patient coaching, automated texting, peer phone support, academic detailing and audit and feedback for the patient's clinician. We are evaluating implementation through a stepped wedge cluster randomized trial based on the Reach-Effectiveness-Adoption-Maintenance/Qualitative-Evaluation-for-Systematic-Translation (RE-AIM/QuEST) mixed methods framework that integrates quantitative and qualitative assessments. The primary outcome is change in ASCVD risk. Findings will have important implications regarding strategies for reducing ASCVD risk among PWH.

Biomarkers of Inflammation Correlate With Clinical Scoring Indices in Human Immunodeficiency Virus-Infected Kenyans

Background

In high-income countries, inflammation has been associated with increased morbidity and mortality in human immunodeficiency virus (HIV)-infected individuals despite treatment with antiretroviral therapy (ART). However, these findings may not be generalizable to low-income settings.

Methods

In this cross-sectional study, multivariable linear regression was used to compare 28 inflammatory biomarker levels in HIV-infected and -uninfected participants. Correlations between biomarkers and Veterans Aging Cohort Study (VACS) index, Fibrosis-4 (FIB-4) score, and Framingham risk score were assessed.

Results

Plasma samples from 304 Kenyans were analyzed. Compared to HIV-uninfected controls, virologically suppressed HIV-infected participants had higher levels of CCL5, CXCL10, fatty acid binding protein (FABP) 2, fas ligand (FASLG), matrix metalloproteinase (MMP) 1, MMP7, soluble CD14 (sCD14), and soluble CD163 (sCD163) and lower MMP9 (P < .01). CD4+/HLA-DR+CD38+ (ρ = 0.32; P < .001), sCD14 (ρ = 0.25; P = .004), and sCD163 (ρ = 0.24; P = .006) were correlated with the VACS index. FABP2 was positively correlated (ρ = 0.29; P = .002), whereas MMP1 (ρ = -.32; P < .001) and MMP2 (ρ = -0.28; P = .002) were inversely correlated with the FIB-4 score.

Conclusions

Differences in biomarker levels exist between well-controlled HIV-infected participants on ART and uninfected controls. Some biomarkers are correlated to scoring indices predictive of morbidity and mortality. These biomarkers could serve as prognostic indicators and inform therapeutic development.

Changes in Inflammation but Not in T-Cell Activation Precede Non-AIDS-Defining Events in a Case-Control Study of Patients on Long-term Antiretroviral Therapy

Background

We examined changes in soluble inflammatory cytokines and T-cell activation after antiretroviral therapy (ART) initiation in an AIDS Clinical Trials Group (ACTG) nested case-control study.

Methods

Cases were 143 human immunodeficiency virus (HIV)-infected adults who developed a non-AIDS event; 315 controls remained event-free. Specimens were tested pre-ART, year 1 post-ART, and at the visit preceding the event. Conditional logistic regression evaluated the associations of biomarker changes with non-AIDS events.

Results

Inflammatory and most activation biomarkers declined from pre-ART to year 1 for cases and controls. Subsequently, inflammatory biomarkers remained mostly stable in controls but not cases. Cellular activation markers generally declined for both cases and controls between year 1 and the pre-event sampling. Controls with greater pre-ART RNA levels or lower CD4+ levels had higher biomarker levels while also experiencing greater biomarker declines in the first year of ART. Changes in biomarkers to year 1 showed no significant associations with non-AIDS events. Cases, however, had significantly greater increases in all plasma biomarkers (but not cellular activation) from year 1 to the visit preceding the event.

Conclusions

Inflammation increases prior to non-AIDS events in treated HIV-infected adults. These biomarker changes may reflect subclinical disease processes or other alterations in the inflammatory environment that causally contribute to disease.

Clinical Trials Registration

NCT00001137.

Brachial Artery Echogenicity and Grayscale Texture Changes in HIV-Infected Individuals Receiving Low-Dose Methotrexate

Objective- We evaluated the biological effects of low-dose methotrexate on 3 novel brachial artery grayscale ultrasound measures that may indicate subclinical arterial injury. Approach and Results- Exploratory analysis from a clinical trial of people with HIV infection at increased cardiovascular disease risk who were randomly assigned to low-dose methotrexate (target dose 15 mg/wk) or placebo. Brachial artery ultrasound grayscale median, gray level difference statistic texture-contrast (GLDS-CON), and gray level texture entropy were measured at baseline and after 24 weeks of intervention. Findings from the intention-to-treat (N=148) and adequately-dosed (N=118) populations were consistent, so the adequately-dosed population results are presented. Participants were a median (Q1, Q3) age of 54 (50, 60) years. After 24 weeks, the low-dose methotrexate intervention was associated with a 25.4% (-18.1, 58.6; P=0.007) increase in GLDS-CON compared with 1.3% (-29.1, 44.7; P=0.97) with placebo ( P=0.05) and a 0.10 u (-0.06, 0.23; P=0.026) increase in entropy compared with 0.02 u (-0.11, 0.14; P=0.54) with placebo ( P=0.14). At week 24, changes in CD4+ T cells correlated inversely with changes in GLDS-CON (ρ=-0.20; P=0.031), and entropy (ρ=-0.21; P=0.023). Changes in D-dimer levels, but no other inflammatory biomarkers, also correlated inversely with changes in GLDS-CON (ρ=-0.23; P=0.014) and entropy (ρ=-0.26; P=0.005). Conclusions- Brachial artery GLDS-CON and entropy increased after 24 weeks of low-dose methotrexate, though the latter was not significantly different from placebo. Grayscale changes were associated with decreases in CD4+ T-cell and D-dimer concentrations and may indicate favorable arterial structure changes.

Evolving understanding of cardiovascular, cerebrovascular and peripheral arterial disease in people living with HIV and role of novel biomarkers. A study of the Spanish CoRIS cohort, 2004-2015

Objectives

To analyze the incidence rates (IR) and spectrum of vascular events in people living with HIV (PLWH) in Spain from 2004 to 2015. Serial measurements of different plasma cardiovascular biomarkers were assessed in relation to disease development.

Methods

Longitudinal study in a nationwide contemporary multicenter cohort of PLWH. A nested case-control study was performed to evaluate the predictive value of cardiovascular biomarkers. Additive generalized and Cox mixed models were used for the analyses.

Results

9,712 PLWH and 48,341 person-years of follow-up were analysed. During 2004–2015, 147 persons developed 154 vascular events; 80 (54.42%) coronary-related; 65 (44.22%) cerebrovascular-related, and 9 (6.12%) peripheral arterial disease. The 2004–2015 IR (95% confidence interval) of vascular events was 3.17 (2.69–3.71) x1,000 person-years; 1.64 (1.30–2.05) for coronary events; 1.34 (1.03–1.70) for cerebrovascular events; and 0.19 (0.09–0.35) for peripheral arterial disease (p<0.001). IR of vascular events gradually increased from 0.37 (0.12–0.85) x1,000 patient-years in the stratum 25-34-years to 19.65 (6.38–45.85) x1,000 patient-years in the stratum 75-84-years. Compared to the general population, there was a higher incidence of acute myocardial infarction (AMI) in men (sIR ratio 1.29 [95% CI 1.16–1.42]), of cerebrovascular events in women (sIR ratio 2.44 [95% CI 1.68–3.19]), and of both types of events specifically among the younger age-strata. CD4 count (hazard ratio 0.80, [95% CI, 0.79–0.81]), age (1.86 [1.47–2.34] for 45–65 years and 3.44 [2.37–4.97] for >65 years) and vascular event (1.81 [1.12–2.94]) were associated with total mortality. Adjusted levels of intercellular-adhesion-molecule (sICAM), pro-b-type-natriuretic-peptide (pro-BNP) and marginally sCD14, were higher among patients who subsequently developed vascular events.

Conclusion

Vascular events in PLWH do preferentially occur in the older age-strata, they are associated with increased mortality and, compared to the general population, the excess risk occurs at younger ages. Peripheral arterial disease is unusual. Vascular events are preceded by increased levels of sICAM, pro-BNP and, marginally, sCD14.

Effects of HIV-1 gp120 and TAT-derived microvesicles on endothelial cell function

The aims of this study were twofold. The first was to determine if human immunodeficiency virus (HIV)-1 glycoprotein (gp) 120 and transactivator of transcription (Tat) stimulate the release of endothelial microvesicles (EMVs). The second was to determine whether viral protein-induced EMVs are deleterious to endothelial cell function (inducing endothelial cell inflammation, oxidative stress, senescence and increasing apoptotic susceptibility). Human aortic endothelial cells (HAECs) were treated with recombinant HIV-1 proteins Bal gp120 (R5), Lav gp120 (X4), or Tat. EMVs released in response to each viral protein were isolated and quantified. Fresh HAECs were treated with EMVs generated under control conditions and from each of the viral protein conditions for 24 h. EMV release was higher (P < 0.05) in HAECs treated with R5 (141 ± 21 MV/µl)_, X4 (132 ± 20 MV/µl), and Tat (130 ± 20 MV/µl) compared with control (61 ± 13 MV/µl). Viral protein EMVs induced significantly higher endothelial cell release of proinflammatory cytokines and expression of cell adhesion molecules than control. Reactive oxygen species production was more pronounced (P < 0.05) in the R5-, X4- and Tat-EMV-treated cells. In addition, viral protein-stimulated EMVs significantly augmented endothelial cell senescence and apoptotic susceptibility. Concomitant with these functional changes, viral protein-stimulated EMVs disrupted cell expression of micro-RNAs 34a, 126, 146a, 181b, 221, and miR-Let-7a (P < 0.05). These results demonstrate that HIV-1 gp120 and Tat stimulate microvesicle release from endothelial cells, and these microvesicles confer pathological effects on endothelial cells by inducing inflammation, oxidative stress, and senescence as well as enhancing susceptibility to apoptosis. Viral protein-generated EMVs may contribute to the increased risk of vascular disease in patients with HIV-1. NEW & NOTEWORTHY Human immunodeficiency virus (HIV)-1-related proteins glycoprotein (gp) 120 and transactivator of transcription (Tat)-mediated endothelial damage and dysfunction are poorly understood. Endothelial microvesicles (EMVs) serve as indicators and potent mediators of endothelial dysfunction. In the present study we determined if HIV-1 R5- and X4-tropic gp120 and Tat stimulate EMV release in vitro and if viral protein-induced EMVs are deleterious to endothelial cell function. gp120 and Tat induced a marked increase in EMV release. Viral protein-induced EMVs significantly increased endothelial cell inflammation, oxidative stress, senescence, and apoptotic susceptibility in vitro. gp120- and Tat-derived EMVs promote a proinflammatory, pro-oxidative, prosenescent, and proapoptotic endothelial phenotype and may contribute to the endothelial damage and dysfunction associated with gp120 and Tat.

HIV and cardiovascular diseases risk: exploring the interplay between T-cell activation, coagulation, monocyte subsets, and lipid subclass alterations

Although rollout of combined antiretroviral treatment (cART) has blunted human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) onset, there is increased development of cardiovascular diseases (CVDs) in HIV-infected individuals. While most HIV-infected individuals on cART achieve viral suppression, this may not necessarily result in complete immunological recovery. This study therefore evaluated T-cell-mediated changes and coagulation markers in HIV-positive individuals to ascertain their potential to increase CVD risk. Eighty participants were recruited (Worcester, South Africa), and fasted blood was collected to evaluate: 1) immune activation (CD38 expression on CD4⁺ and CD8⁺ T cells) and thrombus formation [tissue factor (CD142)] on CD4⁺ and CD8⁺ T cells; 2) monocyte subpopulations (nonclassical, intermediate, and classical); and 3) classical regulatory T (Treg) cells with activation markers [glycoprotein A repetitions predominant (GARP) and special AT-rich sequence-binding protein 1 (SATB-1)]. High- and low-density lipoprotein subclasses (Lipoprint) were also determined. This study revealed four key findings for HIV-positive patients: 1) coexpression of the CD142 coagulation marker together with immune activation on both CD4⁺ and CD8⁺ T cells during chronic infection stages; 2) Treg cell activation and upregulated GARP and SATB-1 contributing to Treg dysfunction in chronic HIV; 3) proatherogenic monocyte subset expansion with significant correlation between T-cell activation and macrophage activation (marker: CD163); and 4) significant correlation between immune activation and lipid subclasses, revealing crucial changes that can be missed by traditional lipid marker assessments (LDL and HDL). These data also implicate lipopolysaccharide-binding protein as a crucial link between immune activation, lipid alterations, and increased CVD risk. NEW & NOTEWORTHY With combined antiretroviral treatment rollout, HIV-AIDS patients are increasingly associated with cardiovascular diseases onset. This study demonstrated the significant interplay between adaptive immune cell activation and monocyte/macrophage markers in especially HIV-positive individuals with virological failure and on second line treatment. Our data also show a unique link between immune activation and lipid subclass alterations, revealing important changes that can be missed by traditional lipid marker assessments (e.g., LDL and HDL).

Plasma glycomics predict cardiovascular disease in patients with ART-controlled HIV infections

Despite effective control of HIV infection with antiretroviral drugs, individuals with HIV have high incidences of secondary diseases. These sequelae, such as cardiovascular disease (CVD), are poorly understood and represent a major health burden. To date, predictive biomarkers of HIV-associated secondary disease have been elusive, making preventative clinical management essentially impossible. Here, we applied a newly developed and easy to deploy, multitarget, and high-throughput glycomic analysis to banked HIV+ human plasma samples to determine whether the glycome may include biomarkers that predict future HIV-associated cardiovascular events or CVD diagnoses. Using 324 patient samples, we identified a glycomic fingerprint that was predictive of future CVD events but independent of CD4 counts, diabetes, age, and birth sex, suggesting that the plasma glycome may serve as a biomarker for specific HIV-associated sequelae. Our findings constitute the discovery of novel glycan biomarkers that could classify patients with HIV with elevated risk for CVD and reveal the untapped prognostic potential of the plasma glycome in human disease.-Oswald, D. M., Sim, E. S., Baker, C., Farhan, O., Debanne, S. M., Morris, N. J., Rodriguez, B. G., Jones, M. B., Cobb, B. A. Plasma glycomics predict cardiovascular disease in patients with ART-controlled HIV infections.

Cardiac and inflammatory biomarkers in perinatally HIV-infected and HIV-exposed uninfected children

OBJECTIVES

To compare distributions of serum cardiac and inflammatory biomarkers between perinatally HIV-infected (PHIV) and perinatally HIV-exposed uninfected (PHEU) children, to evaluate their associations with echocardiographic measures, and among PHIV youth, with antiretroviral therapy (ART) and HIV disease severity measures.

DESIGN

Cross-sectional analysis of temporally paired serum samples for biomarkers and echocardiograms in a prospective multicenter cohort study of PHIV and PHEU youth.

METHODS

Serum samples were analyzed among 402 youth in the PHACS Adolescent Master Protocol (AMP) for high-sensitivity cardiac troponin-T (hs-cTnT, a cardiomyocyte injury marker), N-terminal-pro-brain natriuretic peptide (NT-proBNP, a myocardial stress marker), and inflammatory markers [high-sensitivity C-reactive protein, interleukin (IL)-1, IL-6, IL-8, IL-10, IL-18, tumor necrosis factor-α (TNF-α), and soluble TNF receptor II (sTNF-RII)]. Echocardiograms were centrally measured and parameters converted to z cores to account for differences in age and body size.

RESULTS

Compared with PHEU (N = 156), PHIV youth (N = 246) more often had detectable hs-cTnT and higher levels of sTNF-RII and IL-18. Higher inflammatory biomarkers were generally associated with higher left ventricular (LV) wall stress and lower LV function and LV mass in the two groups. Among PHIV youth, the biomarkers were more strongly associated with current rather than historical immunologic and virologic status.

CONCLUSION

PHEU and PHIV have modest, significant differences in serum levels of specific inflammatory and active myocardial injury biomarkers. Higher biomarker levels were associated with lower LV mass and shifts in LV structure. Further study is warranted on the longitudinal role of cardiac and inflammatory biomarkers for targeting interventions among PHIV and PHEU youth.

Triad of the Ischemic Cardiovascular Disease in People Living with HIV? Association Between Risk Factors, HIV Infection, and Use of Antiretroviral Therapy

PURPOSE OF REVIEW

This review is focused on cardiovascular risk factors in HIV-infected people.

RECENT FINDINGS

Antiretroviral therapy (ART) has significantly increased the life expectancy of HIV-infected people. Thus, this population has experienced non-HIV-related diseases, mainly cardiovascular diseases. Thus, in our review, we intend to understand the cardiovascular risk factors that trigger this situation. We have demonstrated that both ART and traditional cardiovascular risk factors contribute to the development of cardiovascular disease in HIV-infected people. Thus, it becomes important to stratify the risk factors to reduce this scenario.

HIV disease is associated with increased biomarkers of endothelial dysfunction despite viral suppression on long-term antiretroviral therapy in Botswana

Background

Untreated HIV infection is associated with increased biomarkers of endothelial dysfunction. However, the predictors and degree of endothelial dysfunction among virally suppressed HIV–infected adults on long–term antiretroviral therapy (ART) have not been well studied in sub– Saharan Africa (SSA).

Methods

We enrolled 112 HIV–infected adults with virological suppression on long–term ART and 84 HIV–uninfected controls in Botswana. We measured plasma levels of markers of endothelial injury [soluble vascular adhesion molecule 1 (VCAM–1), intercellular adhesion molecule 1 (ICAM–1) and E–selectin] and plasma levels of biomarkers of inflammation [interleukin 6 (IL–6)] and monocyte activation (sCD163). Baseline traditional cardiovascular disease (CVD) risk factors and bilateral common carotid intima–media thickness (cIMT) were also available for all participants. We assessed whether HIV status (despite virological suppression on ART) was associated with biomarkers of endothelial dysfunction after controlling for traditional CVD risk factors in linear regression models. We additionally assessed the association between IL–6, sCD163 and cIMT with endothelial dysfunction in separate multivariate linear regression models, controlling for cIMT, among virally suppressed HIV–infected participants only.

Results

In multivariate analysis, HIV infection was significantly associated with increased VCAM–1 (p < 0.01) and ICAM–1 (p = 0.03) but not E–selectin (p = 0.74) levels. Within the HIV–positive group, higher sCD163 levels were associated with decreased ICAM–1 and E–selectin (p < 0.01 and p = 0.01, respectively) but not VCAM–1 (p = 0.13) levels. IL–6 was not associated with any of the biomarkers of endothelial dysfunction.

Conclusion

HIV disease was associated with biomarkers of endothelial dysfunction among virally suppressed adults in Botswana on long–term ART after controlling for traditional CVD risk factors. Future work should explore the clinical impact of persistent endothelial dysfunction following longterm HIV viral suppression on the risk of CVD clinical endpoints among HIV–infected patients in this setting.

Circulating metabolomic profile can predict dyslipidemia in HIV patients undergoing antiretroviral therapy

BACKGROUND AND AIMS

Dyslipidemia in HIV-infected patients is unique and pathophysiologically associated with host factors, HIV itself and the use of antiretroviral therapy (ART). The use of nuclear magnetic resonance spectroscopy (NMR) provides additional data to conventional lipid measurements concerning the number of lipoprotein subclasses and particle sizes.

METHODS

To investigate the ability of lipoprotein profile, we used a circulating metabolomic approach in a cohort of 103 ART-naive HIV-infected patients, who were initiating non-nucleoside analogue transcriptase inhibitor (NNRTI)-based ART, and we subsequently followed up these patients for 36 months. Univariate and multivariate analyses were performed to evaluate the predictive power of NMR spectroscopy.

RESULTS

VLDL-metabolism (including VLDL lipid concentrations, sizes, and particle numbers), total triglycerides and lactate levels resulted in good classifiers of dyslipidemia (AUC 0.903). Total particles/HDL-P ratio was significantly higher in ART-associated dyslipidemia compared to ART-normolipidemia (p = 0.001). Large VLDL-Ps were positively associated with both LDL-triglycerides (ρ 0.682, p < 0.001) and lactate concentrations (ρ 0.416, p < 0.001), the last one a marker of mitochondrial low oxidative capacity.

CONCLUSIONS

Our data suggest that circulating metabolites have better predictive values for HIV/ART-related dyslipidemia onset than do the biochemical markers associated with conventional lipid measurements. NMR identifies changes in VLDL-P, lactate and LDL-TG as potential clinical markers of baseline HIV-dyslipidemia predisposition. Differences in circulating metabolomics, especially differences in particle size, are indicators of important derangements of mitochondrial function that are linked to ART-related dyslipidemia.

The involvement of plasmacytoid cells in HIV infection and pathogenesis

Plasmacytoid dendritic cells (pDCs) are a unique dendritic cell subset that are specialized in type I interferon (IFN) production. pDCs are key players in the antiviral immune response and serve as bridge between innate and adaptive immunity. Although pDCs do not represent the main reservoir of the Human Immunodeficiency Virus (HIV), they are a crucial subset in HIV infection as they influence viral transmission, target cell infection and antigen presentation. pDCs act as inflammatory and immunosuppressive cells, thus contributing to HIV disease progression. This review provides a state of art analysis of the interactions between HIV and pDCs and their potential roles in HIV transmission, chronic immune activation and immunosuppression. A thorough understanding of the roles of pDCs in HIV infection will help to improve therapeutic strategies to fight HIV infection, and will further increase our knowledge on this important immune cell subset.

Dyslipidemia, chronic inflammation, and subclinical atherosclerosis in children and adolescents infected with HIV: The PositHIVe Health Study

HIV-infected children and adolescents may be at risk for cardiovascular disease due to chronic inflammation and exacerbation of risk factors. The aim of this study was as follows: 1) compare cardiovascular risk factors, chronic inflammation, and carotid intima-media thickness (IMTc) between the HIV and control groups; 2) determine the association of HIV and antiretroviral (ART) regimens with cardiovascular risk factors, chronic inflammation, and IMTc; and 3) identify variables associated with elevated IMTc. Cross-sectional analysis of 130 children and adolescents, 8-15 years of age, divided into HIV-infected (n = 65) and healthy control (n = 65) participants. Body fat, blood pressure, glycemia, insulin, and glycated hemoglobin, total cholesterol and fractions (LDL-C and HDL-C), triglycerides, C-reactive protein (CRP), interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), and the IMTc were measured. The results showed HIV-infected children and adolescents had higher levels of glycemia (87.9 vs. 75.9 mg.dL-1, p< 0.001), LDL-c (94.7 vs. 79.5 mg.dL-1, p = 0.010), triglycerides (101.2 vs. 61.6 mg.dL-1, p< 0.001), CRP (1.6 vs. 1.0 mg.L-1, p = 0.007), IL-6 (1.42 vs. 0.01 pg.mL-1, p< 0.001), TNF-α (0.49 vs. 0.01 pg.mL-1, p< 0.001), mean IMTc (0.526 vs. 0.499 mm, p = 0.009), and lower HDL-c (53.7 vs. 69.4 mg.dL-1, p< 0.001) compared to controls. Systolic blood pressure (β = 0.006, p = 0.004) and TNF-α (β = -0.033, p = 0.029) accounted for 16% of IMTc variability in HIV-infected children and adolescents. In patients using protease inhibitors-based ART, male gender (β = -0.186, p = 0.008), trunk body fat (β = -0.011, p = 0.006), glucose (β = 0.005, p = 0.046), and IL-6 (β = 0.017, p = 0.039) accounted for 28% of IMTc variability. HIV-infected children and adolescents may be at risk for premature atherosclerosis due to chronic inflammation and dyslipidemia. Interventions with the potential to improve lipid profile, mitigate inflammation, and reduce cardiovascular risk are needed.

Changes in inflammatory/cardiac markers of HIV positive patients

HIV replication promotes atherogenesis and participates in the immune response to the virus, thereby influencing the inflammatory profile. These changes may, in turn, contribute to the risk of cardiovascular diseases with involvement of platelets. However, adenine nucleotides and nucleosides involved in thromboregulation and modulation of immune response may therefore be affected by these alterations.

OBJECTIVES

This study sought to evaluate the profile of pro and anti-inflammatory cytokines (IL-10, IL-6, IL-17, TNF, IL-4, IL-2 and IFN-gamma), cardiac markers (troponin, CK, CK MB, LDH, CRP) in HIV-positive patients and assess the in vitro effect of antiretroviral therapy on the activities of ectonucleotidases (E-NTPDase and E-5'-nucleotidase) in human platelets.

DESIGN AND METHODS

Blood samples were obtained from ten HIV positive patients at the Infectious Disease Clinic of the University Hospital of Santa Maria, Brazil and ten HIV negative individuals (control group) for this study.

RESULTS

The results revealed that there were significant (P < 0.05) increases in serum levels of IL-6 and IFN-gamma with no significant (P > 0.05) changes in the serum levels of the cardiac markers investigated (CK, CK-MB, troponin, LDH and CRP). In addition, the ectonucleotidases (E-NTPDase and E-5'-nucleotidase) activities were not altered (P > 0.05) in human platelets when incubated with different antiretroviral drugs in vitro.

CONCLUSIONS

The results of this study suggest that, despite successful treatment, a proinflammatory state is not altered in HIV patients, and that antiretroviral therapy per se does not change the purinergic profile.

Sex and gender differences in HIV-1 infection

The major burden of the human immunodeficiency (HIV) type 1 pandemic is nowadays carried by women from sub-Saharan Africa. Differences in the manifestations of HIV-1 infection between women and men have been long reported, and might be due to both socio-economic (gender) and biological (sex) factors. Several studies have shown that women are more susceptible to HIV-1 acquisition than men. Following HIV-1 infection, women have lower viral loads during acute infection and exhibit stronger antiviral responses than men, which may contribute to differences in the size of viral reservoirs. Oestrogen receptor signalling could represent an important mediator of sex differences in HIV-1 reservoir size and may represent a potential therapeutic target. Furthermore, immune activation, a hallmark of HIV-1 infection, is generally higher in women than in men and could be a central mechanism in the sex difference observed in the speed of HIV-1 disease progression. Here, we review the literature regarding sex-based differences in HIV-1 infection and discuss how a better understanding of the underlying mechanisms could improve preventive and therapeutic strategies.

Activation, senescence and inflammation markers in HIV patients: association with renal function

OBJECTIVES

To assess the association among immune activation, immune senescence, inflammation biomarkers and renal function measured by estimated glomerular filtration rate (eGFR) at inclusion and its evolution over a 3-year follow-up in HIV-infected patients with undetectable viral load.

DESIGN

The Chronic Immune Activation and Senescence (CIADIS) substudy consecutively included patients between October 2011 and May 2013 enrolled in the ANRS CO3 Aquitaine observational cohort.

METHODS

Biomarkers of T-cell activation, differentiation and senescence were summarized in a cellular-CIADIS weighted score and inflammation biomarkers in a soluble-CIADIS weighted score using principal component analysis. Logistic regression and linear mixed models were used to determine the association between the CIADIS weighted scores and confirmed eGFR less than 60 ml/min per 1.73 m, and evolution of eGFR, respectively.

RESULTS

Of 756 patients with an undetectable viral load, 76% were men, and median age was 51 years (Interquartile range: 45-57 years). In multivariable analysis, the soluble-CIADIS weighted score was independently associated with a confirmed eGFR less than 60 [odds ratio = 1.4; 95% confidence interval (CI) 1.1-1.8] but the cellular-CIADIS weighted score was not (odds ratio = 1.2; 95% CI 1.0-1.5). Only in patients with a confirmed eGFR less than 60 ml/min per 1.73 m at inclusion, a higher soluble-CIADIS weighted score (increased inflammation) was associated with a steeper decrease of renal function of -2.3 (ml/min per 1.73 m) per year (95% CI -3.6 to -1.0).

CONCLUSION

At inclusion, soluble-CIADIS weighted score was independently associated with a confirmed eGFR less than 60 ml/min per 1.73 m. The soluble-CIADIS weighted score was associated with a decrease of eGFR evolution during a 3-year follow-up only in patients with a confirmed eGFR less than 60 ml/min per 1.73 m.

Stimulation of PBMC and Monocyte-Derived Macrophages via Toll-Like Receptor Activates Innate Immune Pathways in HIV-Infected Patients on Virally Suppressive Combination Antiretroviral Therapy

In HIV-infected, combination antiretroviral therapy (cART)-treated patients, immune activation and microbial translocation persist and associate with inadequate CD4 recovery and morbidity/mortality. We analyzed whether alterations in the toll-like receptor (TLR) pathway could be responsible for the immune hyperactivation seen in these patients. PBMC/monocyte-derived macrophages (MDMs) of 28 HIV+ untreated and 35 cART-treated patients with HIV-RNA < 40 cp/mL [20 Full Responders (FRs): CD4 ≥ 350; 15 Immunological Non-Responders (INRs): CD4 < 350], as well as of 16 healthy controls were stimulated with a panel of TLR agonists. We measured: CD4/CD8/CD14/CD38/HLA-DR/Ki67/AnnexinV/CD69/TLR4/8 (Flow Cytometry); PBMC expression of 84 TLR pathway genes (qPCR); PBMC/MDM cytokine release (Multiplex); and plasma lipopolysaccharide (LPS)/sCD14 (LAL/ELISA). PBMC/MDM from cART patients responded weakly to LPS stimulation but released high amounts of pro-inflammatory cytokines. MDM from these patients were characterized by a reduced expression of HLA-DR+ MDM and failed to expand activated HLA-DR+ CD38+ T-lymphocytes. PBMC/MDM from cART patients responded more robustly to ssRNA stimulation; this resulted in a significant expansion of activated CD38 + CD8 and the release of amounts of pro-inflammatory cytokines comparable to those seen in untreated viremic patients. Despite greater constitutive TLR pathway gene expression, PBMC from INRs seemed to upregulate only type I IFN genes following TLR stimulation, whereas PBMC from full responders showed a broader response. Systemic exposure to microbial antigens drives immune activation during cART by triggering TLRs. Bacterial stimulation modifies MDM function/pro-inflammatory profile in cART patients without affecting T-lymphocytes; this suggests translocating bacteria as selective stimulus to chronic innate activation during cART. High constitutive TLR activation is seen in patients lacking CD4 recovery, suggesting an exhausted immune milieu, anergic to further antigen encounters.

HIV-1 and hijacking of the host immune system: the current scenario

Human immunodeficiency virus (HIV) infection is a major health burden across the world which leads to the development of acquired immune deficiency syndrome (AIDS). This review article discusses the prevalence of HIV, its major routes of transmission, natural immunity, and evasion from the host immune system. HIV is mostly prevalent in Sub-Saharan Africa and low income countries. It is mostly transmitted by sharing syringe needles, blood transfusion, and sexual routes. The host immune system is categorized into three main types; the innate, the adaptive, and the intrinsic immune system. Regarding the innate immune system against HIV, the key players are mucosal membrane, dendritic cells (DCs), complement system, interferon, and host Micro RNAs. The major components of the adaptive immune system exploited by HIV are T cells mainly CD4+ T cells and B cells. The intrinsic immune system confronted by HIV involves (apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G) APOBEC3G, tripartite motif 5-α (TRIM5a), terherin, and (SAM-domain HD-domain containing protein) SAMHD1. HIV-1 efficiently interacts with the host immune system, exploits the host machinery, successfully replicates and transmits from one cell to another. Further research is required to explore evasion strategies of HIV to develop novel therapeutic approaches against HIV.

Left ventricle thrombus after tranexamic acid for spine surgery in an HIV-positive patient

BACKGROUND CONTEXT

Our case highlights the underappreciated thrombotic risks of tranexamic acid (TXA) use in non-cardiac surgery and emphasizes the need to elucidate these risks with appropriate clinical trials.

PURPOSE

The use of TXA in non-cardiac surgery has significantly expanded in the past 5 years, especially after the 2010 publication of the CRASH-2 Trial. We submit a case with the intent to highlight the thrombotic risk of TXA use during non-cardiac surgery and discuss the need for careful risk stratification before the use of TXA in this context.

STUDY DESIGN

A 66-year-old man with long-standing HIV infection, hypertension, and no history of coronary artery disease (CAD) presented for revision spinal fusion surgery with the use of TXA is presented.

METHODS

To limit perioperative blood loss, the case patient received TXA intraoperatively. His operative course was uneventful.

RESULTS

During the first 12 hours postoperatively the patient was noted to have persistent tachycardia and ST-elevation on electrocardiogram. Echocardiography showed a new apical wall motion abnormality and a left ventricle thrombus; cardiac catheterization confirmed two-vessel CAD, treated with a bare-metal stent and anticoagulation.

CONCLUSIONS

The thrombotic risks of TXA use in non-cardiac surgery have yet to be adequately studied in clinical trials. Hence, TXA use in this context is still an area of uncertainty, and its thrombogenic risks have yet to be studied as a primary outcome in any large prospective trial to date. Patients with any hypercoagulable risk factors, including HIV infection or any prior thrombotic history in which TXA use is being considered, should prompt a discussion among the perioperative physicians involved.

Atorvastatin restricts HIV replication in CD4+ T cells by upregulation of p21

OBJECTIVE

Antigen persistence due to HIV is a major source of inflammation and substantial immune activation, both of which are linked to accelerated aging. This illustrates the need to reduce immune activation in these patients and subsequently decrease the risk of cardiovascular diseases and other non-AIDS-defining comorbidities.

METHODS

CD4 T cells were infected with HIV-1 isolates in the presence or absence of atorvastatin (0.25 to 1 μg/ml) for 24-48 h. Atorvastatin-induced anti-inflammatory functions and anti-viral replication were measured in vitro.

RESULTS

Atorvastatin, a lipid-lowering medication, exerted a broad spectrum of anti-inflammatory functions by reducing T-cell immune activation markers (e.g. CD38, HLA-DR and Ki67), lowering HIV-1 co-receptor CCR-5, and decreasing proliferative capabilities of CD4 T cells in vitro. In contrast, atorvastatin expanded regulatory T cells (Tregs) and upregulated the expression of T-cell immunoglobulin and ITIM domain (TIGIT), which enhanced the suppressive activity of Tregs. Furthermore, atorvastatin upregulated the cyclin-dependent kinase inhibitor p21, which is also known as cip-1 and waf-1, in the CD4 T cells. Upregulation of p21 in CD4 T cells rendered them less susceptible to HIV-1 infection and replication whereas siRNA-mediated p21 depletion and/or p21 selective inhibitor rescued viral replication. Interestingly, atorvastatin reduced HIV infection in both rested and phytohemagglutinin-activated CD4 T cells in vitro. Finally, atorvastatin mediated p21 upregulation occurred via mevalonate pathway, but independent of p53.

CONCLUSION

The results demonstrate a novel mechanism by which atorvastatin induced resistance of CD4 T cells to HIV-1 infection via p21 upregulation and suggest that statins may hold particular promise for some HIV-infected individuals.

HIV-associated neurocognitive disorders: the relationship of HIV infection with physical and social comorbidities

The prevalence of HIV (human immunodeficiency virus) associated neurocognitive disorders (HAND) will undoubtedly increase with the improved longevity of HIV-infected persons. HIV infection, itself, as well as multiple physiologic and psychosocial factors can contribute to cognitive impairment and neurologic complications. These comorbidities confound the diagnosis, assessment, and interventions for neurocognitive disorders. In this review, we discuss the role of several key comorbid factors that may contribute significantly to the development and progression of HIV-related neurocognitive impairment, as well as the current status of diagnostic strategies aimed at identifying HIV-infected individuals with impaired cognition and future research priorities and challenges.

Dendritic cells in progression and pathology of HIV infection

Although the major targets of HIV infection are CD4⁺ T cells, dendritic cells (DCs) represent a crucial subset in HIV infection because they influence viral transmission and target cell infection and presentation of HIV antigens. DCs are potent antigen-presenting cells that can modulate antiviral immune responses. Through secretion of inflammatory cytokines and interferons (IFNs), DCs also alter T cell proliferation and differentiation, participating in the immune dysregulation characteristic of chronic HIV infection. Their wide distribution in close proximity with the mucosal epithelia makes them one of the first cell types to encounter HIV during sexual transmission. We discuss here the multiple roles that DCs play at different stages of HIV infection, emphasizing their relevance to HIV pathology and progression.

Dendritic cell dysregulation during HIV-1 infection

Dendritic cells (DCs) are a diverse subset of innate immune cells that are key regulators of the host response to human immunodeficiency virus-1 (HIV-1) infection. HIV-1 directly and indirectly modulates DC function to hinder the formation of effective antiviral immunity and fuel immune activation. This review focuses upon the differential dysregulation of myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) at various stages of HIV-1 infection providing insights into pathogenesis. HIV-1 evades innate immune sensing by mDCs resulting in suboptimal maturation, lending to poor generation of antiviral adaptive responses and contributing to T-regulatory cell (Treg) development. Dependent upon the stage of HIV-1 infection, mDC function is altered in response to Toll-like receptor ligands, which further hinders adaptive immunity and limits feasibility of therapeutic vaccine strategies. pDC interactions with HIV-1 are pleotropic, modulating immune responses on an axis between immunostimulatory and immunosuppressive. pDCs promote immune activation through an altered phenotype of persistent type I interferon secretion and weak antigen presentation capacity. Conversely, HIV-1 stimulates secretion of indolemine 2,3 dioxygenase (IDO) by pDCs resulting in Treg induction. An improved understanding of the roles and underlying mechanisms of DC dysfunction will be valuable to the development of therapeutics to enhance HIV-specific adaptive responses and to dampen immune activation.

Decreases in inflammatory and coagulation biomarkers levels in HIV-infected patients switching from enfuvirtide to raltegravir: ANRS 138 substudy

Stored plasma specimens from 164 participants in the ANRS 138 trial were analyzed to determine interleukin 6 (IL-6), high-sensitivity C-reactive protein (hsCRP), and D-dimer levels at baseline and weeks 24 and 48. These virologically suppressed, treatment-experienced patients were randomly assigned to undergo an immediate switch (IS) or a deferred switch (DS; at week 24) from an enfuvirtide-based antiretroviral therapy (ART) regimen to a raltegravir-based regimen. At week 24, a significant decrease from baseline was observed in the IS arm, compared with the DS arm, for IL-6 level (-30% vs +10%; P < .002), hsCRP level (-46% vs +15%; P < .0001), and D-dimer level (-40% vs +6%; P < .0001). At week 48, there was a reproducible decrease in levels of all biomarkers in the DS arm.

Interventions to address chronic disease and HIV: strategies to promote exercise and nutrition among HIV-infected individuals

Food insecurity, micronutrient deficits, dyslipidemia, insulin resistance, obesity, cardiovascular disease, and bone disorders complicate the treatment of HIV infection. Nutrition and exercise interventions can be effective in ameliorating these symptoms that are associated with HIV and antiretroviral therapy (ART). In this literature review, we examine the most recent nutrition and exercise interventions for HIV-infected patients. Macronutrient supplementation can be useful in treating malnutrition and wasting. Multivitamin (vitamin B complex, vitamin C, and vitamin E) supplements and vitamin D may improve quality of life and decrease morbidity and mortality. Nutritional counseling and exercise interventions are effective for treating obesity, fat redistribution, and metabolic abnormalities. Physical activity interventions improve body composition, strength, and fitness in HIV-infected individuals. Taken collectively, the evidence suggests that a proactive approach to nutrition and physical activity guidance and interventions can improve outcomes and help abrogate the adverse metabolic, cardiovascular, and psychological consequences of HIV and its treatments.

Effect of darunavir on lipid profile in HIV-infected patients

Highly active antiretroviral therapy regimens, consisting of a ritonavir-boosted protease inhibitor (PI) and 2 nucleoside reverse transcriptase inhibitors, are established first-line regimens for HIV-infected patients. However, a common adverse effect in patients receiving PIs is dyslipidemia, characterized by increases in plasma levels of triglycerides, low-density lipoprotein cholesterol, and total cholesterol (TC). These lipid changes, as well as other well-described risk factors, may predispose patients to the development of cardiovascular disease, an important comorbidity, especially as the lifespan of HIV-infected patients has increased dramatically in recent years. Among PIs, ritonavir-boosted atazanavir (ATV/r) and, more recently, ritonavir-boosted darunavir (DRV/r) have demonstrated potent antiviral efficacy with more favorable lipid profiles than other PIs. This review provides an overview of the lipid effects of DRV/r. Studies with DRV/r in healthy volunteers and in both treatment-naïve and -experienced patients have demonstrated that changes in tri-glycerides and TC are comparable to those seen with ATV/r.

Changes in cardiovascular biomarkers in HIV-infected patients switching from ritonavir-boosted protease inhibitors to raltegravir

BACKGROUND

: Switching from boosted protease inhibitors (PI/r) to raltegravir (RAL) results in a better plasma lipid profile than continuing PI/r. Whether this strategy affects plasma biomarkers associated with atherosclerosis is unknown.

METHODS

: We assessed 48-week changes in fasting lipids and several biomarkers including serum high-sensitivity C-reactive protein (hsCRP), monocyte chemoattractant protein 1 (MCP-1), osteoprotegerin, interleukin (IL) 6, IL-10, tumor necrosis factor alpha (TNF-α), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin and P-selectin, adiponectin, insulin, and D-dimer in otherwise healthy, virologically suppressed HIV-infected patients treated with PI/r who randomly switched from PI/r to RAL or continued with PI/r in the SPIRAL trial. Biomarkers and lipids at baseline and 48-week changes between both study arms were compared. Correlations between changes in biomarkers and changes in lipids were also evaluated.

RESULTS

: Of 273 patients initiating study drugs in the SPIRAL trial, 233 (119 RAL, 114 PI/r) remained on allocated therapy for 48 weeks and had sera available for the purpose of this substudy. Triglycerides (-28%, P < 0.0001), total (-14%, P < 0.0001), low-density lipoprotein (-9%, P = 0.0069), and high-density lipoprotein (-10%, P = 0.0017) cholesterol decreased in RAL relative to the PI/r group. Among biomarkers, hsCRP (-40%, P < 0.0001), MCP-1 (-20%, P = 0.0003), osteoprotegerin (-13%, P = 0.0024), IL-6 (-46%,P < 0.0001), TNF-α (-27%, P = 0.0011), insulin (-26%, P < 0.0001), and D-dimer (-8%, P = 0.0187) decreased in RAL relative to PI/r group, whereas IL-10 (+1%, P = 0.7773), ICAM-1 (-6%, P = 0.1255), VCAM-1(0%, P = 0.8671), E-selectin (-9%, P = 0.2174), P-selectin (-6%, P = 0.3865), and adiponectin (+8%, P = 0.2028) remained unchanged. Biomarkers and lipids changes at 48 weeks were weakly correlated.

CONCLUSION

: Switching from PI/r to RAL induced significant changes in several cardiovascular biomarkers that were not completely explained by lipid changes.

Inflammation, coagulation and cardiovascular disease in HIV-infected individuals

Background

The SMART study was a trial of intermittent use of antiretroviral therapy (ART) (drug conservation [DC]) versus continuous use of ART (viral suppression [VS]) as a strategy to reduce toxicities, including cardiovascular disease (CVD) risk. We studied the predictive value of high sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6) and D-dimer with CVD morbidity and mortality in HIV-infected patients who were enrolled in SMART beyond other measured CVD risk factors.

Methods

A blood sample was available in 5098 participants who were enrolled in the SMART study for the measurement of IL-6, hsCRP and D-dimer. Hazard ratios (HR) with 95% CI for CVD events were estimated for each quartile (Q) for each biomarker vs the 1^st quartile and for 1 SD higher levels. For both treatment groups combined, unadjusted and adjusted HRs were determined using Cox regression models.

Results

There were 252 participants who had a CVD event over a median follow-up of 29 months. Adjusted HRs (95% CI) for CVD for Q4 vs Q1 were 4.65 (2.61, 8.29), 2.10 (1.40, 3.16), and 2.14 (1.38, 3.33) for IL-6, hsCRP and D-dimer, respectively. Associations were similar for the DC and VS treatment groups (interaction p-values were >0.30). The addition of the three biomarkers to a model that included baseline covariates significantly improved model fit (p<0.001). Area under the curve (AUC) estimates improved with inclusion of the three biomarkers in a model that included baseline covariates corresponding to other CVD risk factors and HIV factors (0.741 to 0.771; p<0.001 for difference).

Conclusions

In HIV-infected individuals, IL-6, hsCRP and D-dimer are associated with an increased risk of CVD independent of other CVD risk factors. Further research is needed to determine whether these biomarkers can be used to improve CVD risk prediction among HIV positive individuals.

[HIV infection and chronic inflammation: is the bacterial translocation the underlying cause?]

Currently, non-AIDS comorbidities (cardiovascular disease, non-AIDS-related cancers, liver disease, osteoporosis, etc.) have become an important cause of morbimortality in patients with human immunodeficiency virus type 1 (HIV-1) infection. The elevation of plasma markers of inflammation has been associated with the development of cardiovascular disease and death from all causes. Therefore, there is great interest in elucidating the underlying causes responsible for this persistent inflammatory status. The intestinal barrier disruption associated with HIV-1 infection may favor the passage of gut microbial products into the blood, resulting in immune stimulation. In this article we review the pathogenesis of bacterial translocation and its relevance to HIV-1 infection.

Cardiovascular disease in patients with HIV

The introduction of combination antiretroviral therapy (cART) has substantially decreased mortality among the HIV-infected population. In this setting, cardiovascular disease (CVD) has become a leading cause of morbidity and mortality. Compared with the general population, higher rates of myocardial infarction as well as a high prevalence of subclinical coronary atherosclerosis have been found in the HIV-infected population. It has been suggested that in HIV-infected patients, the atherosclerotic burden is not based solely on traditional cardiovascular risk factors. The interplay of other mechanisms such as chronic inflammation, effects of cART or immune activation after initiation of cART may predispose to accelerated and increased risk of CVD. Effective treatment are available today to reduce CVD in at-risk patients, and therefore early detection of subclinical coronary atherosclerosis is important. However, the mechanisms behind the development of CVD in HIV-infected patients may limit the usefulness of the traditional noninvasive screening tools for CVD used in the general population. This review will focus on the different plausible mechanisms behind the increased risk of CVD and the noninvasive methods by which atherosclerosis may be assessed in the HIV-infected population.

Plasmacytoid dendritic cells in HIV infection

Plasmacytoid dendritic cells (pDCs) are innate immune cells that are specialized to produce interferon-alpha (IFNα) and participate in activating adaptive immune responses. Although IFNα inhibits HIV-1 (HIV) replication in vitro, pDCs may act as inflammatory and immunosuppressive dendritic cells (DCs) rather than classical antigen-presenting cells during chronic HIV infection in vivo, contributing more to HIV pathogenesis than to protection. Improved understanding of HIV-pDC interactions may yield potential new avenues of discovery to prevent HIV transmission, to blunt chronic immune activation and exhaustion, and to enhance beneficial adaptive immune responses. In this chapter we discuss pDC biology, including pDC development from progenitors, trafficking and localization of pDCs in the body, and signaling pathways involved in pDC activation. We focus on the role of pDCs in HIV transmission, chronic disease progression and immune activation, and immunosuppression through regulatory T cell development. Lastly, we discuss potential future directions for the field which are needed to strengthen our current understanding of the role of pDCs in HIV transmission and pathogenesis.

Metabolic abnormalities and viral replication are associated with biomarkers of vascular dysfunction in HIV-infected children

OBJECTIVES

HIV-infected children may be at risk for premature cardiovascular disease. We compared levels of biomarkers of vascular dysfunction in HIV-infected children (with and without hyperlipidaemia) with those in HIV-exposed, uninfected (HEU) children enrolled in the Pediatric HIV/AIDS Cohort Study (PHACS), and determined factors associated with these biomarkers.

METHODS

A prospective cohort study was carried out. Biomarkers of inflammation [C-reactive protein (CRP), interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP1)], coagulant dysfunction (fibrinogen and P-selectin), endothelial dysfunction [soluble intracellular cell adhesion molecule-1 (sICAM), soluble vascular cell adhesion molecule-1 (sVCAM) and E-selectin], and metabolic dysfunction (adiponectin) were measured in 226 HIV-infected and 140 HEU children. Anthropometry, body composition, lipids, glucose, insulin, HIV disease severity, and antiretroviral therapy were recorded.

RESULTS

The median ages of the children were 12.3 years in the HIV-infected group and 10.1 years in the HEU group. Body mass index (BMI) z-scores, waist and hip circumferences, and percentage body fat were lower in the HIV-infected children. Total and non-high-density lipoprotein (HDL) cholesterol and triglycerides were higher in HIV-infected children. HIV-infected children also had higher MCP-1, fibrinogen, sICAM and sVCAM levels. In multivariable analyses in the HIV-infected children alone, BMI z-score was associated with higher CRP and fibrinogen, but lower MCP-1 and sVCAM. Unfavourable lipid profiles were positively associated with IL-6, MCP-1, fibrinogen, and P- and E-selectin, whereas increased HIV viral load was associated with markers of inflammation (MCP-1 and CRP) and endothelial dysfunction (sICAM and sVCAM).

CONCLUSIONS

HIV-infected children have higher levels of biomarkers of vascular dysfunction than do HEU children. Risk factors associated with higher biomarkers include unfavourable lipid levels and active HIV replication.