Arterial inflammation in patients with HIV

Interferon-alpha, immune activation and immune dysfunction in treated HIV infection

Type I interferons (IFNs) exert anti-viral effects through the induction of numerous IFN-stimulated genes and an immunomodulatory effect on innate and adaptive immune responses. This is beneficial in controlling virus infections but prolonged IFN-α activity in persistent virus infections, such as HIV infection, may contribute to immune activation and have a detrimental effect on the function of monocytes and T and B lymphocytes. Activation of monocytes, associated with increased IFN-α activity, contributes to atherosclerotic vascular disease, brain disease and other ‘age-related diseases' in HIV patients treated with long-term antiretroviral therapy (ART). In HIV patients receiving ART, the anti-viral effects of IFN-α therapy have the potential to contribute to eradication of HIV infection while IFN-α inhibitor therapy is under investigation for the treatment of immune activation. The management of HIV patients receiving ART will be improved by understanding more about the opposing effects of IFN-α on HIV infection and disease and by developing methods to assess IFN-α activity in clinical practice.

HIV infection of macrophages is enhanced in the presence of increased expression of CD163 induced by substance P

Activation of NK1R by SP contributes to increased HIV-1 infection in macrophages. The scavenger receptor CD163 is expressed on cells of monocyte-macrophage origin. Our main goal was to determine if there is interplay among SP, CD163 expression, and HIV infection in macrophages. We showed that SP triggers intracellular calcium elevation and increased CD163 expression in human monocytes in a time- and concentration-dependent manner. The role of CD163 on HIV infection was examined by RT-PCR in sorted monocytes (CD163(low) and CD163(high)) and in macrophages having CD163 knocked down using siRNA. We found that the productivity of HIV infection was higher in CD163(high) cells. Additionally, in macrophages with CD163 expression knocked down, we found a significant decrease of HIV infection. Furthermore, Hb-Hp complexes, which function as an endogenous ligand for CD163, decreased HIV infection in macrophages in a dose-dependent manner. Thus, we demonstrate that SP induces higher levels of CD163 in monocytes and that high expression of CD163 is associated with increases HIV infection in macrophages. Thus, in addition to being a prognostic marker of HIV infection, the expression of CD163 on macrophages may be critical in HIV immunopathogenesis.

HDL redox activity is increased in HIV-infected men in association with macrophage activation and non-calcified coronary atherosclerotic plaque

BACKGROUND

HIV is associated with atherosclerosis and low high-density lipoprotein (HDL). With inflammation, HDL becomes dysfunctional. We previously showed that proinflammatory HDL has high HDL redox activity (HRA). In this study, we compare HRA in HIV-infected versus non-HIV-infected subjects and relate HRA to indices of macrophage activation and cardiovascular disease risk.

METHODS

102 HIV-infected subjects and 41 matched non-HIV controls without clinical cardiovascular disease underwent coronary CT angiography (CTA) and testing for immune/inflammatory biomarkers. The effect of purified HDL from each study subject on the oxidation rate of dihydrorhodamine-123 (DOR) was normalized to the DOR of pooled HDL from healthy subjects. The normalized ratio DOR subject/DOR pooled was used as a measure of HRA, with higher HRA suggesting dysfunctional HDL.

RESULTS

HRA was higher in HIV-infected versus non-HIV subjects (1.4 ±0.01 versus 1.3 ±0.01, P=0.03). In multivariate modelling for HRA among all subjects, HIV status remained positively related to HRA (P=0.02), even after controlling for traditional cardiovascular risk factors, comorbid conditions and immune activation. Among HIV-infected subjects, HRA correlated inversely with HDL (rho=-0.32, P=0.002) and log adiponectin (r=-0.28, P=0.006), and correlated positively with log sCD163 (r=0.24, P=0.02) - a monocyte/macrophage activation marker - and with the percentage of non-calcified coronary atherosclerotic plaque (r=0.29, P=0.03). sCD163 remained significantly associated with HRA in multivariate modelling among HIV-infected subjects (P=0.03).

CONCLUSIONS

These data demonstrate increased HRA among HIV-infected subjects versus matched non-HIV subjects with comparable HDL levels. In HIV-infected subjects, HRA relates to macrophage activation and to non-calcified coronary atherosclerotic plaque, which may be rupture-prone. Further studies are needed in HIV-infected patients to elucidate the interplay between immune activation, HDL function and CVD risk.

CLINICAL TRIAL REGISTRATION NUMBER

NCT 00455793.

Switch to raltegravir decreases soluble CD14 in virologically suppressed overweight women: the Women, Integrase and Fat Accumulation Trial

OBJECTIVES

Soluble CD14 (sCD14) is a monocyte activation marker associated with increased mortality in HIV infection. We assessed 48-week changes in sCD14 and other inflammatory biomarkers in virologically suppressed, HIV-infected women switching to raltegravir (RAL) from a protease inhibitor (PI) or nonnucleoside reverse transcriptase inhibitor (NNRTI).

METHODS

HIV-infected women with central adiposity and HIV-1 RNA < 50 HIV-1 RNA copies/mL continued their thymidine-sparing nucleoside reverse transcriptase inhibitor (NRTI) backbone and were randomized to switch to open-label RAL at week 0 (immediate) or 24 (delayed). In an exploratory analysis, inflammatory biomarkers were measured on stored fasting plasma.

RESULTS

Of the 37 evaluable subjects, 78% were non-White; the median age was 43 years, the median body mass index (BMI) was 32 kg/m(2) and the median CD4 count was 558 cells/μL. At baseline, biomarker values were similar between groups. After 24 weeks, median sCD14 significantly declined in subjects switching to RAL [-21% (P < 0.001) vs. PI/NNRTI -5% (P = 0.49); between-group P < 0.01]. After 48 weeks, immediate-switch subjects maintained this decline and delayed-switch subjects experienced a similar decline following the switch to RAL (-10%; within-group P < 0.01). Immediate-switch subjects also experienced an initial increase in tumour necrosis factor (TNF)-α that was neither maintained after 48 weeks nor seen in delayed-switch subjects. After adjustment for multiple testing, only declines in sCD14 remained significant.

CONCLUSIONS

In this randomized trial of women with central adiposity, a switch to RAL from a PI or NNRTI was associated with a statistically significant decline in sCD14. Further studies are needed to determine whether integrase inhibitors have improved monocyte activation profiles compared with PIs and/or NNRTIs, and whether measured differences between antiretroviral agents translate to demonstrable clinical benefit.

FDG-PET imaging in HIV infection and tuberculosis

The intersection and syndemic interaction between the human immunodeficiency virus (HIV) and tuberculosis (TB) epidemics have global prevalence with devastating morbidity and massive mortality. Using FDG-PET imaging it was shown that in HIV-infected individuals, involvement of the head and neck precedes that of the chest and of the abdomen. The sequence of lymph node involvement observed suggests the existence of a diffusible activation mediator that may be targeted via therapeutic intervention strategies. Furthermore, the degree of FDG uptake proved directly related to viral load and inversely related to CD4 cell count. Available data in acquired immune deficiency syndrome (AIDS)-defining cancers further suggest that FDG-PET/CT imaging may be useful for prognostication of cervical cancer and for identifying appropriate sites for biopsy, staging, and monitoring lymphoproliferative activity owing to HIV-associated Kaposi sarcoma and multicentric Castleman disease. Inversely, in HIV-associated lymphoma, FDG uptake in HIV-involved lymphoid tissue was shown to reduce the specificity of FDG-PET imaging findings, the effect of which in clinical practice warrants further investigation. In the latter setting, knowledge of viremia appears to be essential for FDG-PET image interpretation. Early HIV-associated neurocognitive disorder, formerly known as AIDS dementia complex, proved to be characterized by striatal hypermetabolism and progressive HIV-associated neurocognitive disorder or AIDS dementia complex by a decrease in subcortical and cortical metabolism. In lipodystrophic HIV-infected individuals, lipodystrophy proved associated with increased glucose uptake by adipose tissue, likely resulting from the metabolic stress of adipose tissue in response to highly active antiretroviral therapy. Furthermore, ongoing chronic low-grade infection in arteries of HIV-infected individuals could be depicted by FDG-PET/CT imaging. And there is promising data that FDG-PET/CT in HIV may serve as a new marker for the evaluation of thymic function in HIV-infected patients. In the setting of TB, FDG-PET has proven unable to differentiate malignancy from TB in patients presenting with solitary pulmonary nodules, including those suffering from HIV, and thus cannot be used as a tool to reduce futile biopsy or thoracotomy in these patients. In patients presenting with extrapulmonary TB, FDG-PET imaging was found to be significantly more efficient when compared with CT for the identification of more sites of involvement. Thus supporting that FDG-PET/CT can demonstrate lesion extent, serve as guide for biopsy with aspiration for culture, assist surgery planning and contribute to follow-up. Limited available data suggest that quantitative FDG-PET findings may allow for prediction or rapid assessment, at 4 months following treatment instigation, of response to antituberculostatics in TB-infected HIV patients. These results and more recent findings suggest a role for FDG-PET/CT imaging in the evaluation of therapeutic response in TB patients.

Effects of switching from efavirenz to raltegravir on endothelial function, bone mineral metabolism, inflammation, and renal function: a randomized, controlled trial

We performed a randomized controlled trial in 30 HIV-infected participants to either continue tenofovir/emtricitabine/efavirenz (Continuation Group) or switch to tenofovir/emtricitabine/raltegravir (Switch Group) for 24 weeks. There were no significant differences in the changes in flow-mediated dilation, 25(OH) vitamin D, or parathyroid hormone levels. Total cholesterol, high sensitivity C-reactive protein, serum alkaline phosphatase, sCD14 levels, and renal function significantly declined in the Switch Group compared with the Continuation Group; however, sCD163 levels significantly increased in the Switch Group. These findings suggest that raltegravir is not inherently more beneficial to endothelial function compared with efavirenz but may impact renal function and monocyte activation.

[Peripheral arterial disease and cardiovascular risk factors among patients infected with human immunodeficiency virus: a comparison between hospital out-patients and patients in a prison]

INTRODUCTION

Cardiovascular disease among human immunodeficiency virus (HIV) infected patients is more frequent than in the general population. Peripheral arterial disease measured by ankle-brachial index (ABI) and cardiovascular risk factors (CVRF) is not well known in all groups of HIV-infected patients.

METHODS

Transversal study of HIV-infected patients >45 years, seen as outpatients in hospital (HO) in 2008 and patients institutionalized in a prison in 2009. Cardiovascular risk factors, information on the HIV infection and healthy lifestyles were evaluated. ABI was measured at rest and was considered pathological when a value ≤ 0.9 or ≥ 1.3 was obtained.

RESULTS

We included 71 patients (mean age of 50.6 ± 6.9 years, 86% male), 32 HO and 39 in prison. The most prevalent CVRF was smoking (80.2%) followed by an altered lipid profile (63.3%). The evolution time of HIV infection was 13.1 ± 7.1 years. 74.6% of patients didn't follow a heart-healthy diet and 25% were sedentary. The ABI was low in 7 cases (9.8%) and ≥ 1.3 in one. Patients in prison were younger, the rate of smokers and of individuals with low HDL were higher, the time of evolution of the HIV infections was longer and they were less adherent to a heart-healthy diet than in HO, reaching in all cases statistical significance (P<.05).

CONCLUSIONS

In our study there is a high prevalence of altered ABI. The most common CVRF is smoking, followed by the alteration of lipids. Patients in prison are more likely to be smokers, to have low HDL and they are less adherence to a heart-healthy diet.

HIV infection and cardiovascular disease

AIMS

With the success of antiretroviral therapy (ART), non-human immunodeficiency virus (HIV)-related comorbidities like cardiovascular diseases (CVDs) are of increasing concern. We describe important recent research developments on the epidemiology of CVD in HIV infection, ART-related metabolic changes, and cardioprotective anti-inflammatory mechanisms, and summarize management strategies for CVD risk reduction.

METHODS AND RESULTS

We systematically identified and analysed systematic reviews and most cited literature published in the last 3 years and supplemented findings with selected evidence based on clinical expertise. Among HIV-infected individuals, the prevalence of CVD risk factors and the risk for CVD is higher compared with HIV negatives. Antiretroviral drugs may induce dyslipidaemia, reduce insulin sensitivity, and promote body fat redistribution that additionally contributes to CVD risk. Some antiretroviral drugs may increase risk for CVD events, but the absolute risk increase is moderate and has to be put into perspective with the massive HIV-related benefits. Sustained HIV suppression reduces systemic inflammatory markers and is associated with a moderate reduction in CVD events. Regular CVD risk assessment and counselling to stop smoking must be regularly done in all HIV-infected individuals. Statins are effective for the treatment of dyslipidaemia in HIV infection, but drug interactions with ART need to be considered.

CONCLUSION

Human immunodeficiency virus-infected individuals are at increased risk for CVD. Timely initiation of ART with consequent viral suppression is likely to reduce CVD events and to offset potential side effects from ART-induced metabolic changes. Reduction in smoking in HIV-infected individuals is a public health priority.

Metabolic disease in HIV infection

The treatment of metabolic disease is becoming an increasingly important component of the long-term management of patients with well controlled HIV on antiretroviral therapy (ART). Metabolic diseases probably develop at the intersection of traditional risk factors (such as obesity, tobacco use, and genetic predisposition) and HIV-specific and ART-specific contributors (including chronic inflammation and immune activation). This Review discusses present knowledge on adipose tissue dysfunction, insulin-glucose homoeostasis, lipid disturbances, and cardiovascular disease risk in people with HIV on ART. Although new antiretroviral drugs are believed to induce fewer short-term metabolic perturbations than do older drugs, the long-term effects of these drugs are not fully understood. Additionally, patients remain at increased risk of cardiovascular disease and other metabolic comorbidities. Research and treatment should focus on selection of ART that is both virologically effective and has minimum metabolic effects, minimisation of traditional risk factors for metabolic disease, and development of novel therapies to treat metabolic disease in patients with HIV, including use of anti-inflammatory and immunomodulatory drugs.

CD4 counts and mortality in virologically suppressed US veterans

We used the Veterans Health Administration (VA) HIV Clinical Case Registry (CCR) to evaluate the association between annual CD4 averages and all-cause mortality in HIV-infected veterans during their initial episode of suppressive highly active antiretroviral therapy (HAART). We observed 1083 deaths in 14 769 patients. Unadjusted mortality rates in the top and bottom CD4 quintiles differed significantly from the mid CD4 strata. Mortality in the top CD4 quintile (≥720 cells/mm(3)) was 14.1/1000 patient-years, 95% confidence interval (CI): 10.1-18.2, compared with 20.4 (CI: 15.5-25.3) in the next lower CD4 stratum (530-719 cells/mm(3)). This difference was significant in Cox proportional hazards model, controlling for demographics, hepatitis co-infections, low-level viremia, HAART adherence, and refill rates of individual antiretrovirals (HR: 1.4, CI: 1.13-1.73). Our results support early HAART initiation as advocated by the current US treatment guidelines for HIV infection.

Initiation of antiretroviral therapy at high CD4 cell counts: does it reduce the risk of cardiovascular disease?

PURPOSE OF REVIEW

Inflammation and immune activation associated with untreated HIV infection may increase the risk for cardiovascular disease (CVD) and are not entirely reversed by antiretroviral therapy (ART). Although older ART regimens were associated with drug-specific risks for CVD, this may not be true for modern ART. Thus, with regard to CVD risk, the net benefit of initiating ART at higher CD4 T-cell counts remains unclear.

RECENT FINDINGS

In addition to the well established risk of coronary heart disease, emerging evidence now suggests that chronic HIV infection is associated with higher risk of ischemic stroke, heart failure, and arrhythmias. These epidemiologic studies have associated immunodeficiency and active viral replication with higher CVD risk. Novel methods of imaging subclinical vascular disease continue to implicate inflammation and immune activation as likely mediators of CVD among patients with HIV. Newer generation protease inhibitors, chemokine receptor 5 antagonists, and integrase inhibitors do not appear to be associated with the adverse cardiometabolic risks of older drugs.

SUMMARY

Recent evidence suggests that treating HIV infection with ART may reduce the risk of CVD, even at higher CD4 T-cell counts; however, the definitive answer to this question will come from clinical trials and long-term observational studies.

Reduced CD14 expression on classical monocytes and vascular endothelial adhesion markers independently associate with carotid artery intima media thickness in chronically HIV-1 infected adults on virologically suppressive anti-retroviral therapy

HIV infection causes systemic immune inflammation, and increases the risk for cardiovascular (CVD) disease even among those on virologically suppressive anti-retroviral treatment (ART). We performed a biostatistical analysis and screen of candidate cellular and plasma biomarkers for association with carotid artery intima-media thickness (CIMT), independent of traditional CVD risk factors such as age, gender, systolic blood pressure (SBP), lipid levels, smoking and diabetes. We conducted a multi-stage analysis based on a cross-sectional study of CVD risk in HIV-infected subjects age >45 years on ART for >6 months. The goal of this analysis was to identify candidate cellular and plasma biomarkers of CIMT in HIV-1 infected adults. We further sought to determine if these candidate biomarkers were independent of traditional CVD risk factors previously identified in HIV negative adults. High-resolution B-mode ultrasound images of the right common carotid common artery (CCA) were obtained. Plasma soluble inflammatory mediators, cytokines and chemokines were detected. Monocytes were defined by CD14/CD16 expression, and CD8+ T-cell activation by CD38/HLA-DR expression. Subjects were a median of 49.5 years old, 87% male, had a CIMT of 0.73 mm, FRS of 6%, a median viral load of 48 copies/mL, and CD4+ T cell count of 479 cells/μL. Soluble VCAM-1, and expansion of CD14dimCD16- monocytes each associated with higher CIMT independently of age and SBP. These factors are distinct components of a shared atherogenic process; 1) vascular endothelial molecular expression and 2) vascular monocytes that enter into the vascular endothelium and promote atherosclerotic plaque.

Immune mechanisms in hypertension and vascular injury

Over the last 20 years it has become recognized that low-grade inflammation plays a role in cardiovascular disease. More recently, participation of the innate and the adaptive immune response in mechanisms that contribute to inflammation in cardiovascular disease has been reported in atherosclerosis and hypertension. Different subsets of lymphocytes and their cytokines are involved in vascular remodelling in hypertension, chronic kidney disease and heart disease. Effector T-cells include Th1 (interferon-γ-producing) and Th2 (interleukin-4 producing) lymphocytes, as well as Th17 (which produce interleukin-17) and T-suppressor lymphocytes such as T(reg)-cells (regulatory T-cells), which express the transcription factor Foxp3 (forkhead box P3) and participate respectively as pro- and anti-inflammatory cells. Pro-inflammatory T-lymphocytes participate in mechanisms of cardiovascular disease in part by mediating the effects of angiotensin II and mineralocorticoids. Involvement of immune mechanisms in cardiac, vascular and renal changes in hypertension has been demonstrated in many experimental models, an example being the Dahl-salt sensitive rat and the spontaneously hypertensive rat. How activation of immunity is triggered remains unknown, but neo-antigens could be generated by elevated blood pressure through damage-associated molecular pattern receptors or other mechanisms. Once activated, Th1 cells may contribute to blood pressure elevation by affecting the kidney, vascular remodelling of blood vessels directly via the effects of the cytokines produced or through their effects on perivascular fat. T(reg)-cells protect from blood pressure elevation by acting upon similar targets. Recent data suggests that participation of these mechanisms that have been demonstrated already in murine models also occurs in humans. These novel findings may open the way for new therapeutic approaches to improve outcomes in hypertension and cardiovascular disease in humans.

Rosuvastatin treatment reduces markers of monocyte activation in HIV-infected subjects on antiretroviral therapy

BACKGROUND

Statins, or 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, have anti-inflammatory effects that are independent of their lipid-lowering properties. Despite suppressive antiretroviral therapy (ART), elevated levels of immune activation and inflammation often persist.

METHODS

The Stopping Atherosclerosis and Treating Unhealthy Bone With Rosuvastatin in HIV (SATURN-HIV) trial is a randomized, double-blind, placebo-controlled study, designed to investigate the effects of rosuvastatin (10 mg/daily) on markers of cardiovascular disease risk in ART-treated human immunodeficiency virus (HIV)-infected subjects. A preplanned analysis was to assess changes in markers of immune activation at week 24. Subjects with low-density lipoprotein cholesterol <130 mg/dL and heightened immune activation (%CD8(+)CD38(+)HLA-DR(+) ≥19%, or plasma high-sensitivity C-reactive protein ≥2 mg/L) were randomized to receive rosuvastatin or placebo. We measured plasma (soluble CD14 and CD163) and cellular markers of monocyte activation (proportions of monocyte subsets and tissue factor expression) and T-cell activation (expression of CD38, HLA-DR, and PD1).

RESULTS

After 24 weeks of rosuvastatin, we found significant decreases in plasma levels of soluble CD14 (-13.4% vs 1.2%, P = .002) and in proportions of tissue factor-positive patrolling (CD14(Dim)CD16(+)) monocytes (-38.8% vs -11.9%, P = .04) in rosuvastatin-treated vs placebo-treated subjects. These findings were independent of the lipid-lowering effect and the use of protease inhibitors. Rosuvastatin did not lead to any changes in levels of T-cell activation.

CONCLUSIONS

Rosuvastatin treatment effectively lowered markers of monocyte activation in HIV-infected subjects on antiretroviral therapy.

CLINICAL TRIALS REGISTRATION

NCT01218802.

Cardiovascular disease and HIV infection

The emergence of chronic disease complications in controlled HIV disease has changed the landscape of HIV clinical care. HIV infection confers an increased cardiovascular disease risk, which is thought to be due to a complex interplay of mechanistic factors. While traditional cardiovascular risk factors likely play a role, recent evidence suggests that HIV-associated inflammation and immune activation are important mediators of cardiovascular risk. It is unclear whether established preventative interventions for the general population are applicable to HIV-infected patients, and the need to translate mechanistic knowledge into HIV-specific clinical interventions represents an important priority. Developing strategies to prevent cardiovascular disease in HIV-infected individuals calls for a multidisciplinary approach and represents an opportunity to exert a major public health impact in an at-risk population.

[Association between inflammatory markers and microbial translocation in patients with human immunodeficiency virus infection taking antiretroviral treatment]

BACKGROUND AND OBJECTIVE

Inflammatory biomarkers are increased in patients with human immunodeficiency virus (HIV) infection. Antiretroviral treatment (ART) improves some parameters but do not normalize them. The aim of this study is to determine those factors (including microbial translocation) associated with higher inflammation in HIV treated patients.

PATIENTS AND METHODS

Transversal observational study.

INCLUSION CRITERIA

HIV patients receiving ART with an HIV viral load (VL)<400 copies/mL. Selection of patients: consecutively between November 2011 and January 2012. Main variable: plasma levels of interleukin 6 (IL-6) and tumour necrosis factor α (TNF-α). Main explanatory variable: microbial translocation markers (16S ribosomal DNA and sCD14). Patients with IL-6 or TNF-α levels above percentile 75 (group 1) were compared with the rest of patients (group 2). Odds ratio (OR) were determined.

RESULTS

Eighty-one patients were included (73% male, median age 45 years, 48% stage C). Twenty-six percent had chronic hepatitis C. Median CD4 cell was 493/mm(3) and 30% had detectable HIV VL. 16S ribosomal DNA was detected in 21% of patients. Factors associated with the higher levels of inflammatory markers were 16S ribosomal DNA (OR 77, P<.0001), sCD14 levels (P<.0001) and history of cardiovascular disease (OR 15, P<.01). In multivariate analysis, associations remained for 16S ribosomal DNA (OR 62, P<.0001) and previous cardiovascular disease (OR 25, P<.01).

CONCLUSIONS

In patients with HIV infection receiving treatment, the higher levels of inflammatory markers are associated with microbial translocation and past cardiovascular events.

Dyslipidemia, atherosclerosis and cardiovascular disease: an increasingly important triad in an aging population living with HIV

As a result of major advances in the management of HIV over the last two decades, patients living with HIV are now encountering comorbidities commonly associated with aging. Cardiovascular disease is the leading cause of death worldwide. As the population living with HIV ages, understanding cardiovascular disease in the setting of HIV is of increasing importance. This review examines the complex interplay between cardiovascular disease, HIV infection and the drugs used to treat it, with particular emphasis on the contribution of dyslipidemia.

Symmetric ambulatory arterial stiffness index and 24-h pulse pressure in HIV infection: results of a nationwide cross-sectional study

OBJECTIVE

HIV infection has been associated with increased cardiovascular risk. Twenty-four-hour ambulatory blood pressure (BP) is a more accurate and prognostically relevant measure of an individual's BP load than office BP, and the ambulatory BP-derived ambulatory arterial stiffness index (AASI) and symmetric AASI (s-AASI) are established cardiovascular risk factors.

METHODS

In the setting of the HIV and HYpertension (HIV-HY) study, an Italian nationwide survey on high BP in HIV infection, 100 HIV-infected patients with high-normal BP or untreated hypertension (72% men, age 48 ± 10 years, BP 142/91 ± 12/7 mmHg) and 325 HIV-negative individuals with comparable age, sex distribution, and office BP (68% men, age 48 ± 10 years, BP 141/90 ± 11/8 mmHg) underwent 24-h ambulatory BP monitoring.

RESULTS

Despite having similar office BP, HIV-infected individuals had higher 24-h SBP (130.6 ± 14 vs. 126.4 ± 10 mmHg) and pulse pressure (49.1 ± 9 vs. 45.9 ± 7 mmHg, both P < 0.001), and a lower day-night reduction of mean arterial pressure (14.3 ± 9 vs. 16.3 ± 7%, P = 0.025). Both s-AASI and AASI were significantly higher in HIV patients (s-AASI, 0.22 ± 0.18 vs. 0.11 ± 0.15; AASI, 0.46 ± 0.22 vs. 0.29 ± 0.17; both P <0.001). In a multivariate regression, s-AASI was independently predicted by HIV infection (β = 0.252, P <0.001), age, female sex, and 24-h SBP. In HIV patients, s-AASI had an inverse relation with CD4 cell count (Spearman's ρ -0.24, P = 0.027).

CONCLUSION

Individuals with HIV infection and borderline or definite hypertension have higher symmetric AASI and 24-h systolic and pulse pressures than HIV-uninfected controls matched by office BP. High ambulatory BP may play a role in the HIV-related increase in cardiovascular risk.

Chronic HIV disease and activation of the coagulation system

With current effective antiretroviral treatment, the spectrum of morbidity and mortality during chronic HIV disease has shifted away from AIDS defining clinical events. Persistent abnormalities in coagulation appear to contribute to excess risk for a broad spectrum of non-AIDS defining complications, including, but not limited to, venous and arterial thrombotic disease. Mechanisms specific to HIV disease, antiretroviral therapy, and lifestyle or behavioral factors contribute to a pro-coagulant state, in part, through increased tissue factor activity coupled with a paradoxical decline in the anti-coagulant response. Alterations in coagulation biology in the context of HIV disease appear to be largely a consequence of persistent systemic immune activation, micro- and macro-vascular disease, and, potentially, impaired hepatic synthesis of coagulation factors. The clinical consequences of HIV-related changes in coagulation biology, the degree to which they are unique to HIV disease, and whether they can be mitigated through adjunct treatments, remains a focus of current research.

Expression of substance P, neurokinin-1 receptor and immune markers in the brains of individuals with HIV-associated neuropathology

The tachykinin neuropeptide substance P (SP) has an important signaling role in both the nervous and the immune systems. Two naturally occurring variants of the neurokinin-1 receptor (NK1R) mediate the effects of SP, full-length receptor (NK1R-F) and a truncated form (NK1R-T) that lacks 96 amino acid residues at the C-terminus. We previously reported decreased expression of the NK1R-F in the CNS of HIV-positive individuals in comparison to HIV-negative control subjects. There were no differences in the expression of the NK1R-T in the same groups. In the current study, we quantified the expressions of SP precursor mRNA preprotachykinin (TAC1), NK1R (full and truncated forms), viral load (HIV-gag) and several proinflammatory and immune markers (CD4, CCR5, CXCR4, fractalkine, IL-6, IL-10, CCL2, CCL20 and CD163) in the frontal cortex of autopsied brains from HIV-1-positive individuals with or without HIV-associated neuropathology. The expressions of SP and, to lesser extent, NK1R-F were decreased while the expressions of CXCR4, CCR5 and CCL2 were increased in CNS of individuals with HIV-associated neuropathology. There was no change in HIV loads associated with neuropathology; however, we found a positive correlation between viral loads and the expression of haptoglobin-hemoglobin scavenger receptor CD163. An analysis of CSF from corresponding samples demonstrated an increase in proinflammatory markers (CCL2 MIP-1α and MIP-1β) associated with neuropathology. Although our data confirm the overall inflammatory nature of HIV-associated neuropathology, we observed a decrease in the expression of SP and NK1R-F, which is also associated with other forms of neuroinflammation.

A literature review on cardiovascular risk in human immunodeficiency virus-infected patients: implications for clinical management

Introduction

In recent years, there has been growing concern about an increasing rate of cardiovascular diseases in human immunodeficiency virus-infected patients, which could be associated with side effects of highly active antiretroviral therapy. It is likely that the metabolic disorders related to anti-human immunodeficiency virus treatment will eventually translate into a increased cardiovascular risk in patients submitted to such regimens.

Objective

To evaluate if human immunodeficiency virus-infected patients receiving highly active antiretroviral therapy are at higher risk of cardiovascular diseases than human immunodeficiency virus infected patients not receiving highly active antiretroviral therapy, or the general population.

Research design and methods

We conducted a computer-based search in representative databases, and also performed manual tracking of citations in selected articles.

Result

The available evidence suggests an excess risk of cardiovascular events in human immunodeficiency virus-infected persons compared to non-human immunodeficiency virus infected individuals. The use of highly active antiretroviral therapy is associated with increased levels of total cholesterol, triglycerides, low-density lipoprotein and morphological signs of cardiovascular diseases. Some evidence suggested that human immunodeficiency virus-infected individuals on highly active antiretroviral therapy regimens are at increased risk of dyslipidemia, ischemic heart disease, and myocardial infarction, particularly if the highly active antiretroviral therapy regimen contains a protease inhibitor.

Conclusion

Physicians must weigh the cardiovascular risk against potential benefits when prescribing highly active antiretroviral therapy. Careful cardiac screening is warranted for patients who are being evaluated for, or who are receiving highly active antiretroviral therapy regimens, particularly for those with known underlying cardiovascular risk factors. A better understanding of the molecular mechanisms responsible for increased risk of cardiovascular diseases in human immunodeficiency virus-infected patients will lead to the discovery of new drugs that will reduce cardiovascular risk in human immunodeficiency virus-infected patients receiving highly active antiretroviral therapy.

Perivascular fat, inflammation, and cardiovascular risk in HIV-infected patients on antiretroviral therapy

BACKGROUND

HIV-infection is characterized by chronic immune activation that persists despite effective antiretroviral therapy (ART) and is associated with elevated cardiovascular risk. Whether specific perivascular fat depots are associated with inflammation in HIV is unknown.

METHODS

In a cross-sectional study, epicardial (EAT) and thoracic periaortic (TAT) adipose tissue volumes were measured by computed tomography in 100 HIV-infected adults, on stable ART, with LDL-cholesterol ≤130 mg/dL and evidence of heightened T-cell activation (CD8+CD38+HLA-DR+ ≥19%) or increased inflammation (high sensitivity C-reactive protein ≥2 mg/L).

RESULTS

Overall, 77% were males and 70% African American. Mean (standard deviation) age and body mass index were 47 (10) years and 28 (6.4) kg/m(2), respectively. All subjects had HIV-1 RNA <1000 copies/mL with mean (standard deviation) CD4+ T cell count of 665 (280) cells/μL; 50% were on a protease inhibitor. EAT and TAT were correlated with each other (r = 0.766, p < 0.0001). Both were associated with metabolic syndrome, atherogenic lipid profile, insulin resistance, total and central body fat, serum biomarkers of inflammation, and soluble CD163, but not with cellular immune activation markers. In multivariable models that adjusted for age, sex, and other measures of adiposity, both perivascular fat depots were independently associated with the presence of coronary calcium.

CONCLUSIONS

Perivascular fat is associated with soluble CD163, biomarkers of inflammation, insulin resistance, and subclinical atherosclerosis in this population of virologically suppressed HIV-infected patients on ART. The association of perivascular fat with coronary artery calcification appears to be independent of other measures of adiposity.

Feasibility of simultaneous PET/MR of the carotid artery: first clinical experience and comparison to PET/CT

The study aimed at comparing PET/MR to PET/CT for imaging the carotid arteries in patients with known increased risk of atherosclerosis. Six HIV-positive men underwent sequential PET/MR and PET/CT of the carotid arteries after injection of 400 MBq of (18)F-FDG. PET/MR was performed a median of 131 min after injection. Subsequently,PET/CT was performed. Regions of interest (ROI) were drawn slice by slice to include the carotid arteries and standardized uptake values (SUV) were calculated from both datasets independently. Quantitative comparison of (18)F-FDG uptake revealed a high congruence between PET data acquired using the PET/MR system compared to the PET/CT system. The mean difference for SUVmean was -0.18 (p < 0.001) and -0.14 for SUVmax (p < 0.001) indicating a small but significant bias towards lower values using the PET/MR system. The 95% limits of agreement were -0.55 to 0.20 for SUVmean and -0.93 to 0.65 for SUVmax. The image quality of the PET/MR allowed for delineation of the carotid vessel wall. The correlations between (18)F-FDG uptake from ROI including both vessel wall and vessel lumen to ROI including only the wall were strong (r = 0.98 for SUVmean and r = 1.00 for SUVmax) indicating that the luminal (18)F-FDG content had minimal influence on the values. The study shows for the first time that simultaneous PET/MR of the carotid arteries is feasible in patients with increased risk of atherosclerosis. Quantification of (18)F-FDG uptake correlated well between PET/MR and PET/CT despite difference in method of PET attenuation correction, reconstruction algorithm, and detector technology.

Monocyte/macrophages and their role in HIV neuropathogenesis

Neurological sequelae of human immunodeficiency virus (HIV) infection have been and remain a significant problem. Monocytes and macrophages in humans and monkeys are susceptible to infection by HIV and simian immunodeficiency virus (SIV), and are considered to be a main mechanism by which the central nervous system (CNS) is infected. Within the infected CNS, perivascular macrophages and, in some cases, parenchymal microglia are infected as are multinucleated giant cells when present. While neurons are not themselves directly infected, neuronal damage occurs within the infected CNS. Despite the success of antiretroviral therapy (ART) in limiting virus in plasma to non-detectable levels, neurological deficits persist. This review discusses the continued neurological dysfunctions that persist in the era of ART, focusing on the roles of monocyte and macrophage as targets of continued viral infection and as agents of pathogenesis in what appears to be emergent macrophage-mediated disease resulting from long-term HIV infection of the host. Data discussed include the biology of monocyte/macrophage activation with HIV and SIV infection, traffic of cells into and out of the CNS with infection, macrophage-associated biomarkers of CNS and cardiac disease, the role of antiretroviral therapy on these cells and CNS disease, as well as the need for effective adjunctive therapies targeting monocytes and macrophages.

Elevated sCD163 in plasma but not cerebrospinal fluid is a marker of neurocognitive impairment in HIV infection

OBJECTIVE

Here we evaluated whether neurocognitive disorders in HIV-infected individuals on effective antiretroviral therapy (ART) are associated with persistent monocyte activation as indexed by levels of soluble CD163 (sCD163), shed by monocyte/macrophages.

DESIGN

Chronically, HIV-infected individuals were examined at two consecutive visits median [interquartile range (IQR)] 16 (7-32) months apart. All patients were on ART and durably virologically suppressed (plasma HIV RNA <50 copies/ml) at all visits. Thirty-four age-matched HIV-seronegative patients were used as controls.

METHODS

A global deficit score (GDS) was calculated based on comprehensive neuropsychological assessment according to standard methods. Neuropsychological and medical data were used to assign neurocognitive status according to published guidelines for HIV-associated neurocognitive disorders (HAND) as follows: neuropsychologically normal (NP-nml), asymptomatic neuropsychological impairment (ANI) and minor neurocognitive disorder (MND). sCD163 in plasma and cerebrospinal fluid was measured using ELISA.

RESULTS

GDS-impaired patients had higher plasma sCD163 than those who were not impaired [median (IQR) 1401 ng/ml (1057-2258) versus 955 ng/ml (586-1313); Wilcoxon P=0.028]. Patients with MND (N=6) had significantly higher plasma sCD163 than ANI (P=0.04) or NP-nml (P=0.02). Whereas plasma sCD163 levels dropped in patients who were stably GDS-unimpaired after the first visit (P<0.032), levels remained elevated in those who remained GDS-impaired (P=0.50).

INTERPRETATION

These findings are consistent with persistent monocyte/macrophage activation in neurophysiologically impaired HIV-infected individuals despite virally suppressive ART. Overall, these observations underscore the significance of monocyte/macrophage immune responses in HIV, persistent monocyte activation in HAND and the value of sCD163, as a plasma marker of neurocognitive impairment.

Soluble CD163 does not predict first-time myocardial infarction in patients infected with human immunodeficiency virus: a nested case-control study

BACKGROUND

Soluble CD163 (sCD163) has been associated with arterial inflammation and non-calcified plaques in human immunodeficiency virus (HIV)-infected individuals and has therefore been suggested as a predictive biomarker of myocardial infarction (MI).

METHODS

We conducted a nested case-control study of 55 cases with first-time MI and 182 controls matched for age, duration of antiretroviral therapy (ART), gender, smoking, and no known cardiovascular disease. All patients had four available plasma samples, 1: Before initiation of antiretroviral therapy (ART), 2: Three months after ART, 3: One year before the case's MI, and 4: The last sample available before the case's MI. We used conditional logistic regression to estimate the association of sCD163 with first-time MI.

RESULTS

The two groups had similar HIV-parameters and cardiovascular risk factors were equally distributed. There was no significant association between sCD163 and MI neither in samples obtained one year before (OR 1.05, CI 95% 0.85 - 1.29, p = 0.66) nor two months before (OR 1.20, CI 95% 0.98-1.47 p = 0.08).

CONCLUSION

sCD163 did not prove to be a useful biomarker for prediction of first-time MI in a HIV-infected population.

Increased coronary atherosclerotic plaque vulnerability by coronary computed tomography angiography in HIV-infected men

OBJECTIVE

Among HIV-infected patients, high rates of myocardial infarction (MI) and sudden cardiac death have been observed. Exploring potential underlying mechanisms, we used multidetector spiral coronary computed tomography angiography (coronary CTA) to compare atherosclerotic plaque morphology in HIV-infected patients and non-HIV-infected controls.

METHODS

Coronary atherosclerotic plaques visualized by CTA in HIV-infected (101) and non-HIV-infected (41) men without clinically apparent heart disease matched on cardiovascular risk factors were analyzed for three vulnerability features: low attenuation, positive remodeling, and spotty calcification.

RESULTS

Ninety-five percent of HIV-infected patients were receiving ART (median duration 7.9 years) and had well controlled disease (median CD4 cell count, 473 cells/μl; median HIV RNA <50 copies/ml). Age and traditional cardiovascular risk factors were similar in HIV-infected patients and controls. Among the HIV-infected (versus control) group, there was a higher prevalence of patients with at least one: low attenuation plaque (22.8 versus 7.3%, P = 0.02), positively remodeled plaque (49.5 versus 31.7%, P = 0.05) and high-risk 3-feature plaque (7.9 versus 0%, P = 0.02). Moreover, patients in the HIV-infected (versus control) group demonstrated a higher number of low attenuation plaques (P = 0.01) and positively remodeled plaques (P = 0.03) per patient.

CONCLUSION

Our data demonstrate an increased prevalence of vulnerable plaque features among relatively young HIV-infected patients. Differences in coronary atherosclerotic plaque morphology - namely, increased vulnerable plaque among HIV-infected patients - are here for the first time reported and may contribute to increased rates of MI and sudden cardiac death in this population.

Effects of smoking on non-AIDS-related morbidity in HIV-infected patients

Tobacco smoking has many adverse health consequences. Patients with human immunodeficiency virus (HIV) infection smoke at very high rates, and many of the comorbidities associated with smoking in the general population are more prevalent in this population. It is likely that a combination of higher smoking rates along with an altered response to cigarette smoke throughout the body in persons with HIV infection leads to increased rates of the known conditions related to smoking. Several AIDS-defining conditions associated with smoking have been reviewed elsewhere. This review aims to summarize the data on non-AIDS-related health consequences of smoking in the HIV-infected population and explore evidence for the potential compounding effects on chronic systemic inflammation due to HIV infection and smoking.

Increased coronary atherosclerosis and immune activation in HIV-1 elite controllers

HIV-1 elite controllers spontaneously maintain suppressed levels of viremia, but exhibit significant immune activation. We investigated coronary atherosclerosis by coronary computed tomography angiography (CTA) in elite controllers, nonelite controller, chronically HIV-1 infected, antiretroviral therapy (ART)-treated patients with undetectable viral load ('chronic HIV'), and HIV-negative controls. Prevalence of atherosclerosis (78 vs. 42%, P < 0.05) and markers of immune activation were increased in elite controllers compared with HIV-negative controls. sCD163, a monocyte activation marker, was increased in elite controllers compared with chronic HIV-1 (P < 0.05) and compared with HIV-negative controls (P < 0.05). These data suggest a significant degree of coronary atherosclerosis and monocyte activation among elite controllers.