Noncalcified coronary atherosclerotic plaque and immune activation in HIV-infected women

Influence of immune activation and inflammatory response on cardiovascular risk associated with the human immunodeficiency virus

Patients infected with the human immunodeficiency virus (HIV) have an increased cardiovascular risk. Although initially this increased risk was attributed to metabolic alterations associated with antiretroviral treatment, in recent years, the attention has been focused on the HIV disease itself. Inflammation, immune system activation, and endothelial dysfunction facilitated by HIV infection have been identified as key factors in the development and progression of atherosclerosis. In this review, we describe the epidemiology and pathogenesis of cardiovascular disease in patients with HIV infection and summarize the latest knowledge on the relationship between traditional and novel inflammatory, immune activation, and endothelial dysfunction biomarkers on the cardiovascular risk associated with HIV infection.

Sex, age, race and intervention type in clinical studies of HIV cure: a systematic review

This systematic review was undertaken to determine the extent to which adult subjects representing sex (female), race (nonwhite), and age (>50 years) categories are included in clinical studies of HIV curative interventions and thus, by extension, the potential for data to be analyzed that may shed light on the influence of such demographic variables on safety and/or efficacy. English-language publications retrieved from PubMed and from references of retrieved papers describing clinical studies of curative interventions were read and demographic, recruitment year, and intervention-type details were noted. Variables of interest included participation by sex, age, and race; changes in participation rates by recruitment year; and differences in participation by intervention type. Of 151 publications, 23% reported full demographic data of study enrollees, and only 6% reported conducting efficacy analyses by demographic variables. Included studies recruited participants from 1991 to 2011. No study conducted safety analyses by demographic variables. The representation of women, older people, and nonwhites did not reflect national or international burdens of HIV infection. Participation of demographic subgroups differed by intervention type and study location. Rates of participation of demographic groups of interest did not vary with time. Limited data suggest efficacy, particularly of early therapy initiation followed by treatment interruption, may vary by demographic variables, in this case sex. More data are needed to determine associations between demographic characteristics and safety/efficacy of curative interventions. Studies should be powered to conduct such analyses and cure-relevant measures should be standardized.

High-density lipoprotein-mediated cholesterol efflux capacity is improved by treatment with antiretroviral therapy in acute human immunodeficiency virus infection

Background

 Individuals infected with human immunodeficiency virus (HIV) have decreased high-density lipoprotein (HDL)-cholesterol and increased cardiovascular disease (CVD). Reverse cholesterol transport from macrophages may be inhibited by HIV and contribute to increased CVD. Human studies have not investigated longitudinal effects of HIV and antiretroviral therapy (ART) on cholesterol efflux.

Methods

 Subjects with acute HIV infection were randomized to ART or not. Cholesterol efflux capacity was determined ex vivo after exposure of murine macrophages to apolipoprotein B-depleted patient sera obtained at baseline and after 12 weeks.

Results

 After 12 weeks, HIV RNA decreased most in subjects randomized to ART. Available data on cholesterol demonstrated that efflux capacity from Abca1^+/+ macrophages was increased most by sera obtained from ART-treated subjects (20.5% ± 5.0% to 24.3 % ± 6.9%, baseline to 12 weeks, P = .007; ART group [n = 6] vs 18.0 % ± 3.9% to 19.1 % ± 2.9%, baseline to 12 weeks, P = .30; untreated group [n = 6] [P = .04 ART vs untreated group]). Change in HIV RNA was negatively associated with change in Abca1^+/+ macrophage cholesterol efflux (r = − 0.62, P = .03), and this finding remained significant (P = .03) after controlling for changes in HDL-cholesterol, CD4⁺ cells, and markers of monocyte or macrophage activation.

Conclusions

 In subjects acutely infected with HIV, ATP-binding cassette transporter A1-mediated cholesterol efflux was stimulated to a greater degree over time by apolipoprotein B-depleted serum from subjects randomized to ART. The improvement in cholesterol efflux capacity is independently related to reduction in viral load.

T-cell activation, both pre- and post-HAART levels, correlates with carotid artery stiffness over 6.5 years among HIV-infected women in the WIHS

OBJECTIVE

T-cell activation is a major pathway driving HIV disease progression. Little is known regarding the impact of T-cell activation on HIV-associated atherosclerosis and cardiovascular disease, a common comorbidity in HIV infection. We hypothesized that T-cell activation will predict vascular stiffness, a measure of subclinical atherosclerosis.

DESIGN

Linear regression models evaluated the covariate-adjusted association of T-cell activation with vascular stiffness.

METHODS

CD38 and HLA-DR expression on CD4⁺ and CD8⁺ T cells was assessed by flow cytometry among 59 HIV-negative and 376 HIV-infected (185 hepatitis C coinfected) women in the Women's Interagency HIV Study. T-cell activation was defined by CD8⁺CD38⁺DR+ and CD4⁺CD3⁺8DR+. Multiple activation assessments over 6.5 years were averaged. In 140 women, T-cell activation was measured before and after highly active antiretroviral therapy (HAART) initiation. Carotid artery ultrasounds were completed a median of 6.5 years after last measurement of T-cell activation and carotid artery stiffness including distensibility and elasticity were calculated.

RESULTS

Percentages of CD4⁺ and CD8⁺ T-cell activation were significantly higher in HIV- infected compared with HIV-negative women. Among HIV-negative women, T-cell activation was not associated with carotid artery stiffness. Among HIV-infected women, higher CD4⁺ T-cell activation levels significantly predicted increased arterial stiffness independent of CD4⁺ cell count and HIV RNA. The association was stronger among HIV/hepatitis C-coinfected women compared with HIV-monoinfected women; however, the difference was not statistically significant (P for interaction >0.05). Pre- and post-HAART levels of CD4⁺ T-cell activation significantly predicted carotid artery stiffness.

CONCLUSIONS

Persistent T-cell activation, even after HAART initiation, can contribute to structural and/or functional vascular damage accelerating atherogenesis in HIV infection. These results need to be confirmed in a longitudinal prospective study.

Elevated levels of monocyte activation markers are associated with subclinical atherosclerosis in men with and those without HIV infection

BACKGROUND

Heightened immune activation among human immunodeficiency virus (HIV)-infected persons may contribute to atherosclerosis. We assessed associations of serologic markers of monocyte activation, soluble CD163 (sCD163) and soluble CD14 (sCD14), and monocyte chemoattractant protein 1 (CCL2) with subclinical atherosclerosis among men with and those without HIV infection in the Multicenter AIDS Cohort Study.

METHODS

We performed noncontrast computed tomography on 906 men (566 HIV-infected men and 340 HIV-uninfected men), 709 of whom also underwent coronary computed tomographic angiography. Associations between each biomarker and the prevalence of coronary plaque, the prevalence of stenosis of ≥50%, and the extent of plaque were assessed by logistic and linear regression, adjusting for age, race, HIV serostatus, and cardiovascular risk factors.

RESULTS

Levels of all biomarkers were higher among HIV-infected men, of whom 81% had undetectable HIV RNA, and were associated with lower CD4(+) T-cell counts. In the entire population and among HIV-infected men, higher biomarker levels were associated with a greater prevalence of coronary artery stenosis of ≥50%. Higher sCD163 levels were also associated with greater prevalences of coronary artery calcium, mixed plaque, and calcified plaque; higher CCL2 levels were associated with a greater extent of noncalcified plaque.

CONCLUSIONS

sCD163, sCD14, and CCL2 levels were elevated in treated HIV-infected men and associated with atherosclerosis. Monocyte activation may increase the risk for cardiovascular disease in individuals with HIV infection.

Inflammatory co-morbidities in HIV+ individuals: learning lessons from healthy ageing

Increased life expectancy due to improved efficacy of cART has uncovered an increased risk of age-related morbidities in HIV+ individuals and catalyzed significant research into mechanisms driving these diseases. HIV infection increases the risk of non-communicable diseases common in the aged, including cardiovascular disease, neurocognitive decline, non-AIDS malignancies, osteoporosis, and frailty. These observations suggest that HIV accelerates immunological ageing, and there are many immunological similarities with the aged, including shortened telomeres, accumulation of senescent T cells and altered monocyte phenotype/function. However, the most critical similarity between HIV+ individuals and the elderly, which most likely underpins the heightened risk of non-communicable diseases, is chronic inflammation and associated immune activation. Here, we review the similarities between HIV+ individuals and the aged regarding the pathogenesis of inflammatory diseases, the current evidence for mechanisms driving these processes and discuss current and potential therapeutic strategies for addressing inflammatory co-morbidity in HIV+ infection.

HIV infection and cardiovascular disease in women

Background

HIV infection is associated with increased risk of cardiovascular disease (CVD) in men. Whether HIV is an independent risk factor for CVD in women has not yet been established.

Methods and Results

We analyzed data from the Veterans Aging Cohort Study on 2187 women (32% HIV infected [HIV⁺]) who were free of CVD at baseline. Participants were followed from their first clinical encounter on or after April 01, 2003 until a CVD event, death, or the last follow‐up date (December 31, 2009). The primary outcome was CVD (acute myocardial infarction [AMI], unstable angina, ischemic stroke, and heart failure). CVD events were defined using clinical data, International Classification of Diseases, Ninth Revision, Clinical Modification codes, and/or death certificate data. We used Cox proportional hazards models to assess the association between HIV and incident CVD, adjusting for age, race/ethnicity, lipids, smoking, blood pressure, diabetes, renal disease, obesity, hepatitis C, and substance use/abuse. Median follow‐up time was 6.0 years. Mean age at baseline of HIV⁺ and HIV uninfected (HIV⁻) women was 44.0 versus 43.2 years (P<0.05). Median time to CVD event was 3.1 versus 3.7 years (P=0.11). There were 86 incident CVD events (53%, HIV⁺): AMI, 13%; unstable angina, 8%; ischemic stroke, 22%; and heart failure, 57%. Incident CVD/1000 person‐years was significantly higher among HIV⁺ (13.5; 95% confidence interval [CI]=10.1, 18.1) than HIV⁻ women (5.3; 95% CI=3.9, 7.3; P<0.001). HIV⁺ women had an increased risk of CVD, compared to HIV⁻ (hazard ratio=2.8; 95% CI=1.7, 4.6; P<0.001).

Conclusions

HIV is associated with an increased risk of CVD in women.

The importance of monocytes and macrophages in HIV pathogenesis, treatment, and cure

Monocytes and macrophages play critical roles in HIV transmission, viral spread early in infection, and as a reservoir of virus throughout infection. There has been a recent resurgence of interest in the biology of monocyte subsets and macrophages and their role in HIV pathogenesis, partly fuelled by efforts to understand difficulties in achieving HIV eradication. This article examines the importance of monocyte subsets and tissue macrophages in HIV pathogenesis. Additionally, we will review the role of monocytes and macrophages in the development of serious non-AIDS events including cardiovascular disease and neurocognitive impairment, their significance in viral persistence, and how these cells represent an important obstacle to achieving HIV eradication.

2013 American College of Cardiology/American Heart Association and 2004 Adult Treatment Panel III cholesterol guidelines applied to HIV-infected patients with/without subclinical high-risk coronary plaque

BACKGROUND

The 2013 American College of Cardiology/American Heart Association (ACC/AHA) cholesterol guidelines are being applied to HIV-infected patients but have not been validated in this at-risk population, which is known to have a high prevalence of subclinical high-risk morphology (HRM) coronary atherosclerotic plaque.

OBJECTIVE

To compare recommendations for statins among HIV-infected subjects with/without HRM coronary plaque according to 2013 ACC/AHA versus 2004 Adult Treatment Panel III guidelines.

METHODS/DESIGN

Data from 108 HIV-infected subjects without known cardiovascular disease (CVD) or lipid-lowering treatment who underwent contrast-enhanced computed tomography angiography were analyzed. Recommendations for statin therapy according to 2013 versus 2004 guidelines were assessed among those with/without HRM coronary plaque.

RESULTS

Among all subjects, 10-year atherosclerotic cardiovascular disease (ASCVD) risk score was 3.3% (1.6, 6.6), yet 36% of subjects had HRM coronary plaque. Among those with HRM coronary plaque, statins would be recommended for 26% by 2013 guidelines versus 10% by 2004 guidelines (P = 0.04). Conversely, among those without HRM coronary plaque, statins would be recommended for 19% by 2013 guidelines versus 7% by 2004 guidelines (P = 0.005). In multivariate modeling, while 10-year ASCVD risk score related to HRM coronary plaque burden (P = 0.02), so too did other factors not incorporated into 2013 guidelines.

CONCLUSION

The 2013 ACC/AHA cholesterol guidelines recommend statin therapy for a higher percentage of subjects with and without HRM coronary plaque relative to 2004 guidelines. However, even by 2013 guidelines, statin therapy would not be recommended for the majority (74%) of HIV-infected subjects with subclinical HRM coronary plaque. Outcome studies are needed to determine the utility of new statin recommendations and the contribution of HRM coronary plaque to CVD events among HIV-infected subjects.

Cardiovascular disease associated with the human immunodeficiency virus: an update

OPINION STATEMENT

With the advent of increasingly available antiretroviral therapy (ART), the life expectancy of HIV-infected persons is increasing. As they age, HIV-infected persons have increased propensity to typical diseases of aging including cardiovascular disease and accelerated atherosclerosis. The pathogenesis of HIV-associated atherosclerosis is complex and involves a state of chronic inflammation, exposure to traditional risk factors, and metabolic side effects of ART. Treatment of HIV-associated atherosclerosis should include special attention to drug-drug interactions and is best accomplished by a multidisciplinary team experienced in the care of HIV-infected persons.

The role of T cells in the development of cardiovascular disease in HIV-infected patients

Cardiovascular disease (CVD) is highly prevalent in HIV-infected patients. Besides the classical cardiovascular risk factors, HIV related factors play a role, such as immune activation and treatment with highly active antiretroviral therapy (HAART). The resulting T cell activation is regarded as one of the driving forces behind this accelerated atherogenesis. Interventions, such as early treatment and anti-inflammatory therapy, decreasing T cell activation might lead to a lower incidence of CVD in future HIV infected patients. This review specifically explores the role of T cells in the development of atherosclerosis in HIV-infected patients.

Sex-based differences in HIV type 1 pathogenesis

Human immunodeficiency virus (HIV) remains a global infectious diseases threat that disproportionally affects women. Beyond social and political factors, biological and genetic differences have been identified that lead to differential disease courses and outcomes in men and women. Following HIV type 1 (HIV-1) seroconversion, women have up to 40% lower HIV loads and higher CD4(+) T-cell counts than men. However, at the same level of viremia, progression to AIDS is faster in women. After adjustment for viral load, HIV-positive women also display increased levels of generalized immune activation and experience the consequences of elevated inflammatory activity more frequently than men. Part of these observations are linked to sex-based differences in innate immunity, in which the differential ability of plasmacytoid dendritic cells to produce interferon α following stimulation of Toll-like receptor 7 and upregulation of interferon-stimulated genes play a central role. Here, we review the current knowledge and remaining gaps therein regarding sex-based differences in HIV-1 pathogenesis.

Preventing Heart Failure in Inflammatory and Immune Disorders

Patients with chronic inflammatory diseases are at increased risk for heart failure due to ischemic heart disease and other causes including heart failure with preserved ejection fraction. Using rheumatoid arthritis and treated HIV infection as two prototypical examples, we review the epidemiology and potential therapies to prevent heart failure in these populations. Particular focus is given to anti-inflammatory therapies including statins and biologic disease modifying drugs. There is also limited evidence for lifestyle changes and blockade of the renin-angiotensin-aldosterone system. We conclude by proposing how a strategy for heart failure prevention, such as the model tested in the Screening To Prevent Heart Failure (STOP-HF) trial, may be adapted to chronic inflammatory disease.

Frailty in people aging with human immunodeficiency virus (HIV) infection

The increasing life spans of people infected with human immunodeficiency virus (HIV) reflect enormous treatment successes and present new challenges related to aging. Even with suppression of viral loads and immune reconstitution, HIV-positive individuals exhibit excess vulnerability to multiple health problems that are not AIDS-defining. With the accumulation of multiple health problems, it is likely that many people aging with treated HIV infection may be identified as frail. Studies of frailty in people with HIV are currently limited but suggest that frailty might be feasible and useful as an integrative marker of multisystem vulnerability, for organizing care and for comprehensively measuring the impact of illness and treatment on overall health status. This review explains how frailty has been conceptualized and measured in the general population, critically reviews emerging data on frailty in people with HIV infection, and explores how the concept of frailty might inform HIV research and care.

Severity of cardiovascular disease outcomes among patients with HIV is related to markers of inflammation and coagulation

Background

In the general population, raised levels of inflammatory markers are stronger predictors of fatal than nonfatal cardiovascular disease (CVD) events. People with HIV have elevated levels of interleukin‐6 (IL‐6), high‐sensitivity C‐reactive protein (hsCRP), and D‐dimer; HIV‐induced activation of inflammatory and coagulation pathways may be responsible for their greater risk of CVD. Whether the enhanced inflammation and coagulation associated with HIV is associated with more fatal CVD events has not been investigated.

Methods and Results

Biomarkers were measured at baseline for 9764 patients with HIV and no history of CVD. Of these patients, we focus on the 288 that experienced either a fatal (n=74) or nonfatal (n=214) CVD event over a median of 5 years. Odds ratios (ORs) (fatal versus nonfatal CVD) (95% confidence intervals [CIs]) associated with a doubling of IL‐6, D‐dimer, hsCRP, and a 1‐unit increase in an IL‐6 and D‐dimer score, measured a median of 2.6 years before the event, were 1.39 (1.07 to 1.79), 1.40 (1.10 to 1.78), 1.09 (0.93 to 1.28), and 1.51 (1.15 to 1.97), respectively. Of the 214 patients with nonfatal CVD, 23 died during follow‐up. Hazard ratios (95% CI) for all‐cause mortality were 1.72 (1.28 to 2.31), 1.73 (1.27 to 2.36), 1.44 (1.15 to 1.80), and 1.88 (1.39 to 2.55), respectively, for IL‐6, D‐dimer, hsCRP, and the IL‐6 and D‐dimer score.

Conclusions

Higher IL‐6 and D‐dimer levels reflecting enhanced inflammation and coagulation associated with HIV are associated with a greater risk of fatal CVD and a greater risk of death after a nonfatal CVD event.

Clinical Trial Registration

URL: http://www.clinicaltrial.gov Unique identifier: SMART: NCT00027352, ESPRIT: NCT00004978, SILCAAT: NCT00013611.

Monocyte-activation phenotypes are associated with biomarkers of inflammation and coagulation in chronic HIV infection

BACKGROUND

Soluble biomarkers of inflammation predict non-AIDS related morbidity and mortality among human immunodeficiency virus (HIV)-infected persons. Exploring associations between plasma biomarkers and cellular phenotypes may identify sources of excess inflammation.

METHODS

Plasma biomarkers (interleukin 6 [IL-6] level, D-dimer level, high-sensitivity C-reactive protein [hsCRP] level, soluble CD14 [sCD14] level, and soluble CD163 [sCD163] level) were measured from cryopreserved samples from the Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy (SUN Study). We performed immunophenotyping of peripheral blood mononuclear cells for markers of T-cell and monocyte activation, maturation, and migration. We evaluated associations between cellular phenotypes and soluble biomarkers by Spearman rank correlation and multivariate linear regression.

RESULTS

Participants' (n = 670) median age was 41 years, 88% were prescribed antiretroviral therapy, 72% had a plasma HIV RNA load of <400 copies/mL, and the median CD4(+) T-lymphocyte count was 471 cells/µL. After adjustment, CD14(++)CD16(+) monocytes were associated with higher levels of IL-6, hsCRP, and sCD163; associations with IL-6 and hsCRP persisted in persons with suppressed HIV replication. While CCR5(+) monocytes positively associated with D-dimer levels, CCR2(+) monocytes were inversely associated with hsCRP levels.

CONCLUSIONS

Plasma inflammatory biomarkers that predict morbidity and mortality were strongly associated with monocyte activation and migration, modestly associated with T-cell maturation, and not associated with CD8(+) T-cell activation phenotypes. These findings suggest that strategies to control monocyte activation warrant further investigation.

Metabolic and body composition effects of newer antiretrovirals in HIV-infected patients

In the absence of a cure, HIV-infected patients are being successfully treated with antiretroviral therapies (ART) and living longer. Indeed, an increasing number of HIV-infected patients are living beyond the age of 50 years, and in that regard, the use of ART has transformed HIV into a chronic medical condition. As more HIV-infected patients are virologically controlled and living longer, the trajectory of disease morbidity has shifted, however, primarily from opportunistic infections and immune dysfunction to metabolic complications. Evidence suggests that HIV-infected patients acquire significant metabolic risks, including lipodystrophic changes, subclinical atherosclerosis, and insulin resistance. The etiology of these metabolic complications specifically in HIV-infected patients is not entirely clear but may be related to a complex interaction between long-term consequences of infection and HIV itself, chronic use of antiretrovirals, and underlying inflammatory processes. Previous classes of ART, such as protease inhibitors (PIs) and reverse transcriptase inhibitors, have been implicated in altering fat redistribution and lipid and glucose homeostasis. Advances in drug development have introduced newer ART with strategies to target novel mechanisms of action and improve patient adherence with multi-class drug combinations. In this review, we will focus on these newer classes of ART, including selected entry inhibitors, integrase inhibitors, and multi-class drug combinations, and two newer PIs, and the potential of these newer agents to cause metabolic complications in HIV-infected patients. Taken together, further reduction of morbidity in HIV-infected patients will require increasing awareness of the deleterious metabolic complications of ART with subsequent management to mitigate these risks.

Soluble CD14 is independently associated with coronary calcification and extent of subclinical vascular disease in treated HIV infection

OBJECTIVE

To use multimodality imaging to explore the relationship of biomarkers of inflammation, T-cell activation and monocyte activation with coronary calcification and subclinical vascular disease in a population of HIV-infected patients on antiretroviral therapy (ART).

DESIGN

Cross-sectional.

METHODS

A panel of soluble and cellular biomarkers of inflammation and immune activation was measured in 147 HIV-infected adults on ART with HIV RNA less than 1000 copies/ml and low-density lipoprotein cholesterol (LDL-C) 130  mg/dl or less. We examined the relationship of biomarkers to coronary calcium (CAC) score and multiple ultrasound measures of subclinical vascular disease.

RESULTS

Overall, median (interquartile range, IQR) age was 46 (40-53) years; three-quarters of participants were male and two-thirds African-American. Median 10-year Framingham risk score was 6%. Participants with CAC more than 0 were older, less likely to be African-American and had higher current and lower nadir CD4 T-cell counts. Most biomarkers were similar between those with and without CAC; however, soluble CD14 was independently associated with CAC after adjustment for traditional risk factors. Among those with a CAC score of zero, T-cell activation and systemic inflammation correlated with carotid intima-media thickness and brachial hyperemic velocity, respectively. Compared with normal participants and those with CAC only, participants with increasing degrees of subclinical vascular disease had higher levels of sCD14, hs-CRP and fibrinogen (all P<0.05).

CONCLUSION

Soluble CD14 is independently associated with coronary artery calcification, and, among those with detectable calcium, predicts the extent of subclinical disease in other vascular beds. Future studies should investigate the utility of multimodality imaging to characterize vascular disease phenotypes in this population.