Human immunodeficiency virus (HIV) infects human arterial smooth muscle cells in vivo and in vitro: implications for the pathogenesis of HIV-mediated vascular disease

Association of HIV Infection and Incident Abdominal Aortic Aneurysm Among 143 001 Veterans

BACKGROUND

People with HIV (PWH) have an increased risk of cardiovascular disease. Previous cross-sectional data suggest there is a higher prevalence of abdominal aortic aneurysm (AAA) in PWH than in those without HIV. Whether PWH have an increased risk of incident AAA compared with those without HIV is unknown.

METHODS

We analyzed data among participants without prevalent AAA from the Veterans Aging Cohort Study, a prospective, observational, longitudinal cohort of veterans with HIV matched 1:2 with veterans without HIV infection. We calculated AAA rates by HIV status and assessed the association between HIV infection and incident AAA using Cox proportional hazards models. We defined AAA using the International Classification of Diseases, 9th or 10th revision, or Current Procedural Terminology codes and adjusted all models for demographic characteristics, cardiovascular disease risk factors, and substance use. Secondary analyses examined the association between time-varying CD4+ T-cell count or HIV viral load and incident AAA.

RESULTS

Among 143 001 participants (43 766 with HIV), over a median follow-up of 8.7 years, there were 2431 incident AAA events (26.4% among PWH). Rates of incident AAA per 1000 person-years were similar among PWH (2.0 [95% CI, 1.9-2.2]) and people without HIV (2.2 [95% CI, 2.1-2.3]). There was no evidence that HIV infection increased the risk of incident AAA compared with no HIV infection (adjusted hazard ratio, 1.02 [95% CI, 0.92-1.13]). In adjusted analyses with time-varying CD4+ T-cell counts or HIV viral load, PWH with CD4+ T-cell counts <200 cells/mm3 (adjusted hazard ratio, 1.29 [95% CI, 1.02-1.65]) or HIV viral load ≥500 copies/mL (adjusted hazard ratio, 1.29 [95% CI, 1.09-1.52]) had an increased risk of AAA compared with those without HIV.

CONCLUSIONS

HIV infection is associated with an increased risk of AAA among those with low CD4+ T-cell counts or elevated HIV viral load over time.

HIV and Drug Use: A Tale of Synergy in Pulmonary Vascular Disease Development

Over the past two decades, with the advent and adoption of highly active anti-retroviral therapy, HIV-1 infection, a once fatal and acute illness, has transformed into a chronic disease with people living with HIV (PWH) experiencing increased rates of cardio-pulmonary vascular diseases including life-threatening pulmonary hypertension. Moreover, the chronic consequences of tobacco, alcohol, and drug use are increasingly seen in older PWH. Drug use, specifically, can have pathologic effects on the cardiovascular health of these individuals. The "double hit" of drug use and HIV may increase the risk of HIV-associated pulmonary arterial hypertension (HIV-PAH) and potentiate right heart failure in this population. This article explores the epidemiology and pathophysiology of PAH associated with HIV and recreational drug use and describes the proposed mechanisms by which HIV and drug use, together, can cause pulmonary vascular remodeling and cardiopulmonary hemodynamic compromise. In addition to detailing the proposed cellular and signaling pathways involved in the development of PAH, this article proposes areas ripe for future research, including the influence of gut dysbiosis and cellular senescence on the pathobiology of HIV-PAH. © 2023 American Physiological Society. Compr Physiol 13:4659-4683, 2023.

Prevalence of Microorganisms in Atherosclerotic Plaques of Coronary Arteries: A Systematic Review and Meta-Analysis

Background

In this systematic review and meta-analysis, the existence of pathogens in atherosclerotic plaques of coronary arteries was investigated in coronary arteries diseases (CAD) patients.

Methods

This study was designed and implemented up to 31 August 2020. The findings present according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) checklist. Two independent reviewers (I.RJ and S.H) performed a comprehensive search on four different English databases including PubMed, ISI, Scopus, and Embase. In order to assess the quality of the articles, a checklist prepared by The Joanna Briggs Institute (JBI) was used.

Results

Finally, 44 studies were selected. The prevalence of different microorganisms in coronary arteries were as follows: Aggregatibacter actinomycetemcomitans (46.2%), Campylobacter rectus (43.0%), Chlamydia pneumonia (42.8%), Cytomegalovirus (29.1%), Helicobacter pylori (18.9%), Herpes simplex virus type 1 (5.9%), Porphyromonas gingivalis (42.6%), Prevotella intermedia (47.6%), Tannerella forsythia (43.7%), and Treponema denticola (32.9%).

Conclusion

Based on the result of this meta-analysis, Prevotella intermedia and Aggregatibacter actinomycetemcomitans are the most common microorganisms in atherosclerotic plaques of coronary arteries and may have an important role in the development of atherosclerosis.

Association between inflammation and coagulation biomarkers and carotid atherosclerosis among treated people with HIV

Background

Atherosclerotic cardiovascular disease (CVD) is a common cause of morbidity among people with human immunodeficiency virus (PWH) who initiate antiretroviral therapy (ART). Little is known about the roles of inflammation in atherosclerotic CVD among PWH.

Methods

This cross-sectional evaluation included 178 PWH between 40 and 70 years on stable (>3 months) ART who were derived from the ongoing, prospective cohort for Comparative HIV and Aging Research in Taizhou (CHART), China, from February 2017 to August 2018. Carotid intima-media thickness (cIMT) ≥1 mm was considered as cIMT thickening indicative of atherosclerotic CVD. Plasma inflammation and coagulation biomarkers were quantified by a multiplex bead cytokine assay for 27 cytokines and enzyme-linked immunosorbent assay (ELISA) for soluble CD14 and D-dimer, respectively. We performed a series of multiparametric analyses of biomarkers and developed a composite score for atherosclerotic CVD assessment among PWH.

Results

Of 178 PWH, 53 (30.9%) had cIMT thickening. In multivariable logistic analysis adjusting for CVD and human immunodeficiency virus-specific risk factors, interleukin (IL)-4 (odds ratio [OR] = 19.0; 95% confidence interval [CI], 1.6–226.5), IL-7 (OR = 16.7; 95% CI, 1.8–151.7), IL-10 (OR = 11.9; 95% CI, 2.0–72.1), and D-dimer (OR = 3.1; 95% CI, 1.0–10.1) were significantly associated with cIMT thickening. We also developed a composite score incorporating markers (IL-7, IL-10, D-dimer, and hypertension) that accurately evaluated atherosclerotic CVD.

Conclusions

The associations of IL-4, IL-7, IL-10, and D-dimer with atherosclerosis underscores research needs to further understand the inflammatory mechanisms in the pathogenesis of atherosclerosis CVD among treated PWH. The composite score for atherosclerotic CVD assessment could be useful for risk stratification in PWH.

Pannexin-1 channel opening is critical for COVID-19 pathogenesis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly rampaged worldwide, causing a pandemic of coronavirus disease (COVID -19), but the biology of SARS-CoV-2 remains under investigation. We demonstrate that both SARS-CoV-2 spike protein and human coronavirus 229E (hCoV-229E) or its purified S protein, one of the main viruses responsible for the common cold, induce the transient opening of Pannexin-1 (Panx-1) channels in human lung epithelial cells. However, the Panx-1 channel opening induced by SARS-CoV-2 is greater and more prolonged than hCoV-229E/S protein, resulting in an enhanced ATP, PGE₂, and IL-1β release. Analysis of lung lavages and tissues indicate that Panx-1 mRNA expression is associated with increased ATP, PGE₂, and IL-1β levels. Panx-1 channel opening induced by SARS-CoV-2 spike protein is angiotensin-converting enzyme 2 (ACE-2), endocytosis, and furin dependent. Overall, we demonstrated that Panx-1 channel is a critical contributor to SARS-CoV-2 infection and should be considered as an alternative therapy.

Cardio-ankle vascular index of increased arterial wall stiffness is associated with neurocognitive impairment in well-controlled HIV

OBJECTIVES

HIV-associated neurocognitive disorders (HAND) remain prevalent in people living with HIV (PLWH) despite widespread use of combined antiretroviral therapy (ART). Vascular disease contributes to the pathogenesis of HAND, but traditional vascular risk factors do not fully explain the relation between vascular disease and HAND. A more direct measure of vascular dysfunction is needed. This cross-sectional study tested whether the cardio-ankle vascular index (CAVI), a novel method to assess arterial stiffness, is associated with HAND among PLWH.

METHODS

Participants included 75 non-diabetic adults with well-controlled HIV from an outpatient HIV clinic. We assessed the relation between CAVI and neurocognitive impairment (NCI). The latter was primarily characterized by the Frascati criteria and secondarily (post hoc) using the Global Deficit Score (GDS). Logistic regression models tested whether high CAVI (≥ 8) was independently associated with NCI when controlling for potential confounders.

RESULTS

Participants (M_age  = 45.6 ± 8.3 years; 30.1% male) had few traditional cardiovascular disease (CVD) risk factors (hypertension, n = 7; dyslipidaemia, n = 34; body mass index ≥ 25 kg/m² , n = 12; smoking history, n = 13; 2.2% mean 10-year risk of CVD or stroke). Twelve (16%) participants had high CAVI, which was independently associated with meeting Frascati criteria for NCI [n = 39, odds ratio (OR) = 7.6, p = 0.04], accounting for age, education, gender, income, CD4 nadir, recent CD4 and traditional CVD risk factors. High CAVI was also associated with NCI as reflected by higher GDS (OR = 17.4, p = 0.02).

CONCLUSIONS

Cardio-ankle vascular index is a promising measure of vascular dysfunction that may be independently associated with NCI in relatively healthy PLWH. Larger studies should test the utility of CAVI in predicting NCI/decline in PLWH.

The magnitude of hypertension and associated factors among clients on highly active antiretroviral treatment in Southern Ethiopia, 2020: A hospital-based cross-sectional study

INTRODUCTION

Following the introduction of Highly Active Anti Retro Viral Treatment (HAART), the survival of people living with HIV/AIDS (PLHIV) has improved. However, hypertension remains a major challenge for people living with HIV. Very little effort has been made to examine the magnitude of hypertension and its contributing factors among clients receiving HAART, particularly in southern Ethiopia. Hence, the current study aimed at determining the frequency of Hypertension and associated factors among clients receiving HAART at Wachemo University Nigist Eleni Mohammed Memorial Referral Hospital, southern Ethiopia, 2020.

METHODS

A hospital-based cross-sectional study took place from January 20- March 20, 2020. A systematic sampling technique was employed in the selection of 397 clients. Interviewer administered pretested structured questionnaire was used for data collection. Blood pressure and anthropometric parameters of PLHIV were measured. The data was encoded and entered using Epi Data Version 3.1 and exported to SPSS version 23 for analysis. Then bivariable and multivariable logistic regression analyses were used to identify associated factors. Adjusted Odds Ratio (AOR) with 95% CI was used to present the estimated effect size and declare the presence of statistically significant association respectively.

RESULTS

The magnitude of hypertension among clients on HAART was 11.0% 95% CI [7.93, 14.04]. Being on HAART for at least 60 months (AOR: 2.57, 95% CI: 1.24-5.21), being on TDF/3TC/EFV combination (AOR: 4.61, 95% CI: 2.52-8.3), and high alcohol consumption (AOR: 4.31, 95% CI: 1.84-10.02) were identified as significant predictors of hypertension among clients on HAART.

CONCLUSION AND RECOMMENDATION

The magnitude of hypertension in the study area was in a considerable state to plan and implement intervention measures. For those clients who have received TDF/3TC/EFV and TDF/3TC/NVP and those who have been on HAART for 60 months, a strong emphasis should be placed on planning a strict follow-up. A concerted effort among health care providers is needed through counseling and education to discourage the habit of high alcohol consumption among clients.

Cardiac Catheterization Procedures in Patients with HIV: A Retrospective Analysis

With the advent of effective antiretroviral therapies, there has been a decrease in HIV-related mortality, but an increase in non-AIDS-related comorbidities including cardiovascular disease (CVD). We sought to investigate current status of cardiac catheterization (CC) procedures in people with HIV (PWH). This is a retrospective study done at a University Hospital in South Florida between 2017 and 2019. Medical records from 985 PWH indicated that CC was performed in 1.9% of the cases. Of the PWH who underwent CC, 68% were found to have obstructive coronary artery disease (CAD). Among obstructive CAD cases, PCI was performed in 77% and CABG in 21% of cases; 26% had a repeat procedure and 11% died from non-cardiac causes. When comparing PWH who had CC to those who did not, there was a significantly higher rate of statin use (63% vs. 25%, p < 0.015) and a higher prevalence of low ejection fraction (38% vs. 11%, p = 0.004) among those patients who underwent CC. However, there was no significant difference in the prevalence of hypertension (p = 0.13), HbA1c levels (p = 0.32), CD4 count (p = 0.45) nor in undetectable viral load status (p = 0.75) after controlling for age, sex and BMI. Despite the finding of traditional CVD risk factors among PWH, there were no differences in HIV-related factors among patients requiring CC, supporting the importance of optimization of traditional CVD risk factors in this population.

Thrombocytopenia in Virus Infections

Thrombocytopenia, which signifies a low platelet count usually below 150 × 10⁹/L, is a common finding following or during many viral infections. In clinical medicine, mild thrombocytopenia, combined with lymphopenia in a patient with signs and symptoms of an infectious disease, raises the suspicion of a viral infection. This phenomenon is classically attributed to platelet consumption due to inflammation-induced coagulation, sequestration from the circulation by phagocytosis and hypersplenism, and impaired platelet production due to defective megakaryopoiesis or cytokine-induced myelosuppression. All these mechanisms, while plausible and supported by substantial evidence, regard platelets as passive bystanders during viral infection. However, platelets are increasingly recognized as active players in the (antiviral) immune response and have been shown to interact with cells of the innate and adaptive immune system as well as directly with viruses. These findings can be of interest both for understanding the pathogenesis of viral infectious diseases and predicting outcome. In this review, we will summarize and discuss the literature currently available on various mechanisms within the relationship between thrombocytopenia and virus infections.

Bilateral limb gangrene in an HIV patient due to vasculopathy: Managing the dual challenge of psychosocial issues and an uncommon medical condition

Patients with human immunodeficiency virus (HIV) have been reported to experience a spectrum of homeostatic dysregulation and resulting manifestations in their vascular system. This may be due to either disruption in the coagulation-anticoagulation pathways or due to damage to vessels from either HIV or other opportunistic infections. However, gangrene in an HIV-infected patient is an uncommon phenomenon. We herein report a case of a 30-year-old female, who had been taking antiretrovirals irregularly for 10 years, developing bilateral limb gangrene during her hospitalization for cryptococcal meningitis. Unfortunately, her condition continued to deteriorate and her attendants took her from the hospital against medical advice, with her death soon after. We illustrate how several biopsychosocial factors came together here to result in poor outcomes. To note, peripheral arterial disease (PAD) in HIV can rapidly lead to critical limb ischemia, resulting in limb gangrene. Aggravating risk factors for the same include smoking, poor glycemic control, and/or low CD4 T-cell count (<200 cells/mm³). General practitioners should be aware that HIV patients are far more prone to PAD than the normal population. Early recognition of at-risk patients, both medically and psychosocially, by family physicians is thus critical.

HIV Associated Risk Factors for Ischemic Stroke and Future Perspectives

Although retroviral therapy (ART) has changed the HIV infection from a fatal event to a chronic disease, treated HIV patients demonstrate high prevalence of HIV associated comorbidities including cardio/cerebrovascular diseases. The incidence of stroke in HIV infected subjects is three times higher than that of uninfected controls. Several clinical and postmortem studies have documented the higher incidence of ischemic stroke in HIV infected patients. The etiology of stroke in HIV infected patients remains unknown; however, several factors such as coagulopathies, opportunistic infections, vascular abnormalities, atherosclerosis and diabetes can contribute to the pathogenesis of stroke. In addition, chronic administration of ART contributes to the increased risk of stroke in HIV infected patients. Concurrently, experimental studies in murine model of ischemic stroke demonstrated that HIV infection worsens stroke outcome, increases blood brain barrier permeability and increases neuroinflammation. Additionally, residual HIV viral proteins, such as Trans-Activator of Transcription, glycoprotein 120 and Negative regulatory factor, contribute to the pathogenesis. This review presents comprehensive information detailing the risk factors contributing to ischemic stroke in HIV infected patients. It also outlines experimental evidence demonstrating the impact of HIV infection on stroke outcomes, in addition to possible novel therapeutic approaches to improve these outcomes.

HIV-1 Tat: Role in Bystander Toxicity

HIV Tat protein is a critical protein that plays multiple roles in HIV pathogenesis. While its role as the transactivator of HIV transcription is well-established, other non-viral replication-associated functions have been described in several HIV-comorbidities even in the current antiretroviral therapy (ART) era. HIV Tat protein is produced and released into the extracellular space from cells with active HIV replication or from latently HIV-infected cells into neighboring uninfected cells even in the absence of active HIV replication and viral production due to effective ART. Neighboring uninfected and HIV-infected cells can take up the released Tat resulting in the upregulation of inflammatory genes and activation of pathways that leads to cytotoxicity observed in several comorbidities such as HIV associated neurocognitive disorder (HAND), HIV associated cardiovascular impairment, and accelerated aging. Thus, understanding how Tat modulates host and viral response is important in designing novel therapeutic approaches to target the chronic inflammatory effects of soluble viral proteins in HIV infection.

Subclinical Atherosclerosis Imaging in People Living with HIV

In many, but not all studies, people living with HIV (PLWH) have an increased risk of coronary artery disease (CAD) events compared to the general population. This has generated considerable interest in the early, non-invasive detection of asymptomatic (subclinical) atherosclerosis in PLWH. Ultrasound studies assessing carotid artery intima-media thickness (CIMT) have tended to show a somewhat greater thickness in HIV+ compared to HIV-, likely due to an increased prevalence of cardiovascular (CV) risk factors in PLWH. Coronary artery calcification (CAC) determination by non-contrast computed tomography (CT) seems promising to predict CV events but is limited to the detection of calcified plaque. Coronary CT angiography (CCTA) detects calcified and non-calcified plaque and predicts CAD better than either CAC or CIMT. A normal CCTA predicts survival free of CV events over a very long time-span. Research imaging techniques, including black-blood magnetic resonance imaging of the vessel wall and 18F-fluorodeoxyglucose positron emission tomography for the assessment of arterial inflammation have provided insights into the prevalence of HIV-vasculopathy and associated risk factors, but their clinical applicability remains limited. Therefore, CCTA currently appears as the most promising cardiac imaging modality in PLWH for the evaluation of suspected CAD, particularly in patients <50 years, in whom most atherosclerotic coronary lesions are non-calcified.

Comparative Assessment of the Magnitude of Hyperlipidemia in HIV-Infected Patients Receiving Lopinavir/r- and Atazanavir/r-Based Antiretroviral Drugs

OBJECTIVE

To assess prevalence of hyperlipidemia in patients receiving lopinavir boosted with ritonavir (LPV/r) and atazanavir boosted with ritonavir (ATV/r) antiretroviral drugs.

METHODS

HIV-infected patients (300) were recruited in the study between December 2015 and April 2016. Lipid profile including triglycerides (TG), high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol (LDL-C) were assessed.

RESULTS

Prevalence of derangement in TG was 71.0% in patients using LPV/r compared to 44% in those using ATV/r ( P = .01). Use of LPV/r was independently associated with increased total cholesterol (TC; P = .001) and TG ( P = .0003). Females had raised levels of TC compared to males ( P = .00008). Body mass index of ≥ 25 kg/m2 was also associated with raised TC ( P = .002) and LDL-C ( P = .006).

CONCLUSION

LPV/r was significantly associated with lipid derangements, indicating the need to regularly monitor lipid profile in patients using LPV/r.

Dysregulation of Neuronal Cholesterol Homeostasis upon Exposure to HIV-1 Tat and Cocaine Revealed by RNA-Sequencing

HIV-1 Tat protein is released from HIV-1-infected cells and can enter non-permissive cells including neurons. Tat disrupts neuronal homeostasis and may contribute to the neuropathogenesis in people living with HIV (PLWH). The use of cocaine by PLWH exacerbates neuronal dysfunction. Here, we examined the mechanisms by which Tat and cocaine facilitate alterations in neuronal homeostatic processes. Bioinformatic interrogation of the results from RNA deep sequencing of rat hippocampal neurons exposed to Tat alone indicated the dysregulation of several genes involved in lipid and cholesterol metabolism. Following exposure to Tat and cocaine, the activation of cholesterol biosynthesis genes led to increased levels of free cholesterol and cholesteryl esters in rat neurons. Results from lipid metabolism arrays validated upregulation of several processes implicated in the biogenesis of β-amyloid and Alzheimer’s disease (AD), including sterol o-acyltransferase 1/acetyl-coenzyme A acyltransferase 1 (SOAT1/ACAT1), sortilin-related receptor L1 (SORL1) and low-density lipoprotein receptor-related protein 12 (LRP12). Further studies in Tat-treated primary neuronal cultures and brain tissues from HIV-1 transgenic mice as well as SIV-infected macaques confirmed elevated levels of SOAT1/ACAT 1 proteins. Our results offer novel insights into the molecular events involved in HIV and cocaine-mediated neuronal dysfunction that may also contribute to neuropathogenic events associated with the development of AD.

Mitochondrial dysfunction in human immunodeficiency virus-1 transgenic mouse cardiac myocytes

The pathophysiology of human immunodeficiency virus (HIV)-associated cardiomyopathy remains uncertain. We used HIV-1 transgenic (Tg26) mice to explore mechanisms by which HIV-related proteins impacted on myocyte function. Compared to adult ventricular myocytes isolated from nontransgenic (wild type [WT]) littermates, Tg26 myocytes had similar mitochondrial membrane potential (ΔΨ _m ) under normoxic conditions but lower Δ Ψ _m after hypoxia/reoxygenation (H/R). In addition, Δ Ψ _m in Tg26 myocytes failed to recover after Ca ²⁺ challenge. Functionally, mitochondrial Ca ²⁺ uptake was severely impaired in Tg26 myocytes. Basal and maximal oxygen consumption rates (OCR) were lower in normoxic Tg26 myocytes, and further reduced after H/R. Complex I subunit and ATP levels were lower in Tg26 hearts. Post-H/R, mitochondrial superoxide (O ₂ ^•- ) levels were higher in Tg26 compared to WT myocytes. Overexpression of B-cell lymphoma 2-associated athanogene 3 (BAG3) reduced O ₂ ^•- levels in hypoxic WT and Tg26 myocytes back to normal. Under normoxic conditions, single myocyte contraction dynamics were similar between WT and Tg26 myocytes. Post-H/R and in the presence of isoproterenol, myocyte contraction amplitudes were lower in Tg26 myocytes. BAG3 overexpression restored Tg26 myocyte contraction amplitudes to those measured in WT myocytes post-H/R. Coimmunoprecipitation experiments demonstrated physical association of BAG3 and the HIV protein Tat. We conclude: (a) Under basal conditions, mitochondrial Ca ²⁺ uptake, OCR, and ATP levels were lower in Tg26 myocytes; (b) post-H/R, Δ Ψ _m was lower, mitochondrial O ₂ ^•- levels were higher, and contraction amplitudes were reduced in Tg26 myocytes; and (c) BAG3 overexpression decreased O ₂ ^•- levels and restored contraction amplitudes to normal in Tg26 myocytes post-H/R in the presence of isoproterenol.

Role of pre-stroke immunity in ischemic stroke mechanism among patients with HIV

Individuals with HIV are at a higher risk of stroke compared to uninfected populations. The role of HIV-related immunosuppression in stroke mechanism is uncertain. Our aim is to test the hypothesis that stroke mechanisms among HIV+ individuals vary according to preceding CD4 counts. We carried out a retrospective chart review of inpatient admissions for ICD-9 defined ischemic events (TIA or stroke) in HIV+ individuals from 2002 to 2016 at a tertiary care center. Stroke mechanisms were ascertained based on radiographic and clinical presentation, and adjudicated by the treating team and confirmed separately by a vascular neurologist. Vascular risk factors, use of antiretroviral drugs (ARVs), nadir CD4 and current CD4 counts (cells/mm³) were captured to build logistic regressions and generalized linear models to calculate the odds ratios (OR) and beta estimates with their respective 95% confidence intervals. We found that among 115 cases (median age 52, 64% men), stroke mechanisms were 22% due to large artery atherosclerosis (LAA), 17% small artery disease, 16% infectious, 8% cardioembolic, 21% cryptogenic, and 16% other etiologies. The median nadir CD4-count was 153 (IQR 22-274), and 312 (IQR 88-518) at the time of stroke, and 53% were on ARVs. LAA was more common with longer HIV infection (OR 1.1 per year, 1.0-1.2) and nadir CD4 counts <200 (OR 6.7, 1.4-31.9). Stroke due to LAA was associated with higher CD4 count the year prior to stroke (B = 0.009, P = 0.06 for the interaction) independent of CD4 nadir <200 (B = 1.88, P = 0.035). We concluded that in this sample, LAA was the most frequent stroke mechanism among HIV+ individuals with nadir CD4 < 200 but higher CD4 counts near the time of stroke. Determining the association between pre-stroke immune status and stroke mechanisms may allow a targeted approach to stroke prevention.

Aging, Health, and Quality of Life for Older People Living With HIV in Sub-Saharan Africa: A Review and Proposed Conceptual Framework

OBJECTIVE

The number of people living with HIV (PLWH) over 50 years old in sub-Saharan Africa is predicted to triple in the coming decades, to 6-10 million. Yet, there is a paucity of data on the determinants of health and quality of life for older PLWH in the region.

METHODS

A review was undertaken to describe the impact of HIV infection on aging for PLWH in sub-Saharan Africa.

RESULTS

We (a) summarize the pathophysiology and epidemiology of aging with HIV in resource-rich settings, and (b) describe how these relationships might differ in sub-Saharan Africa, (c) propose a conceptual framework to describe determinants of quality of life for older PLWH, and (d) suggest priority research areas needed to ensure long-term gains in quality of life for PLWH in the region.

CONCLUSIONS

Differences in traditional, lifestyle, and envirnomental risk factors, as well as unique features of HIV epidemiology and care delivery appear to substantially alter the contribution of HIV to aging in sub-Saharan Africa. Meanwhile, unique preferences and conceptualizations of quality of life will require novel measurement and intervention tools. An expanded research and public health infrastructure is needed to ensure that gains made in HIV prevention and treamtent are translated into long-term benefits in this region.

Dysregulation of mitochondrial bioenergetics and quality control by HIV-1 Tat in cardiomyocytes

Cardiovascular disease remains a leading cause of morbidity and mortality in HIV-positive patients, even in those whose viral loads are well controlled with antiretroviral therapy. However, the underlying molecular events responsible for the development of cardiac disease in the setting of HIV remain unknown. The HIV-encoded Tat protein plays a critical role in the activation of HIV gene expression and profoundly impacts homeostasis in both HIV-infected cells and uninfected cells that have taken up released Tat via a bystander effect. Since cardiomyocyte function, including excitation-contraction coupling, greatly depends on energy provided by the mitochondria, in this study, we performed a series of experiments to assess the impact of Tat on mitochondrial function and bioenergetics pathways in a primary cell culture model derived from neonatal rat ventricular cardiomyocytes (NRVCs). Our results show that the presence of Tat in cardiomyocytes is accompanied by a decrease in oxidative phosphorylation, a decline in the levels of ATP, and an accumulation of reactive oxygen species (ROS). Tat impairs the uptake of mitochondrial Ca²⁺ ([Ca²⁺ ]_m ) and the electrophysiological activity of cardiomyocytes. Tat also affects the protein clearance pathway and autophagy in cardiomyocytes under stress due to hypoxia-reoxygenation conditions. A reduction in the level of ubiquitin along with dysregulated degradation of autophagy proteins including SQSTM1/p62 and a reduction of LC3 II were detected in cardiomyocytes harboring Tat. These results suggest that, by targeting mitochondria and protein quality control, Tat significantly impacts bioenergetics and autophagy resulting in dysregulation of cardiomyocyte health and homeostasis.

Non-communicable diseases and related risk behaviors among men and women living with HIV in Cambodia: findings from a cross-sectional study

BACKGROUND

There is a growing concern for an increasing burden of non-communicable diseases (NCDs) in people living with HIV. This concern is evident especially in developing countries where dietary and lifestyle risk factors associated with NCDs are becoming more prominent. This study explored the prevalence of diabetes mellitus, hypertension, and hyperlipidemia and related risk factors in men and women living with HIV in Cambodia.

METHODS

This cross-sectional study was conducted among 510 adult people living with HIV randomly selected from one city and four provinces in Cambodia. A structured questionnaire was used to collect data on socio-demographic characteristics, health behaviors, medical history, and antiretroviral therapy (ART). Anthropometric and biological measurements were performed. Descriptive statistics were used to calculate proportions and means of the measured variables. An independent Student's t-test was used for continuous variables. Chi square test or Fisher's exact test was used for categorical variables to explore gender differences.

RESULTS

Prevalence of diabetes mellitus, hypertension, and hyperlipidemia was 9.4, 15.1, and 33.7%, respectively. The prevalence of hyperlipidemia was significantly higher among men compared to women. Mean systolic and diastolic blood pressures were also significantly higher among men. Regarding risk factors, 17.3% of participants were overweight, and 4.1% were obese. Tobacco and alcohol use was common, particularly among men. Fruit and vegetable consumption was considerably low among both men and women. Physical activity levels were also low. About 40% of participants reported having a job that involved mostly sitting or standing; 46.3% reported engaging in moderate activities; and 11.8% reported engaging in vigorous activities during leisure time. A significantly higher proportion of men compared to women engaged in vigorous activities both at work and during leisure time.

CONCLUSIONS

The prevalence of diabetes mellitus, hypertension, and hyperlipidemia among men and women living with HIV in Cambodia is considerably high. Related risk factors were also common. Given the comorbidity of NCDs and HIV, policy and programmatic interventions are required, including integration of NCD screening into HIV programs. Distinctions in the levels of diseases and in health behaviors between men and women suggest that interventions need to be tailor-made and gender-specific, targeting their respective diseases and behaviors.

Effect of Cocaine on Pulmonary Vascular Remodeling and Hemodynamics in Human Immunodeficiency Virus-Transgenic Rats

Human immunodeficiency virus (HIV)-related pulmonary arterial hypertension has been found to be more prevalent in intravenous drug users. Our earlier cell-culture findings reported down-regulation of bone morphogenetic protein receptors (BMPRs) in combination with enhanced proliferation of human pulmonary arterial smooth muscle cells (PASMCs) in the presence of HIV-Trans-activator of transcription (Tat) and cocaine compared with either treatment alone. Here, we report physiologic evidence of significant increases in mean pulmonary arterial pressure in HIV-transgenic (Tg) rats intraperitoneally administered 40 mg/kg body weight cocaine (HIV-cocaine group) once daily for 21 days when compared with HIV-Tg rats given saline (HIV group) or wild-type (WT) Fischer 334 rats treated with (WT-cocaine group) and without cocaine (WT group). In addition, right ventricle systolic pressure was also found to be significantly higher in the HIV-cocaine rats compared with the WT group. Significant down-regulation in protein expression of BMPR-2 and BMPR-1B was observed in total lung extract from HIV-cocaine rats compared with the other three groups. Furthermore, the PASMCs isolated from HIV-cocaine rats demonstrated a higher level of proliferation and lower levels of apoptosis compared with cells isolated from other rat groups. Interestingly, corroborating our earlier cell-culture findings, we observed higher expression of BMPR-2 and BMPR-1B messenger RNA and significantly lower levels of BMPR-2 and BMPR-1B protein in HIV-cocaine PASMCs compared with cells isolated from all other groups. In conclusion, our findings support an additive effect of cocaine and HIV on smooth muscle dysfunction, resulting in enhanced pulmonary vascular remodeling with associated elevation of mean pulmonary arterial pressure and right ventricle systolic pressure in HIV-Tg rats exposed to cocaine.

White matter hyperintensities in relation to cognition in HIV-infected men with sustained suppressed viral load on combination antiretroviral therapy

OBJECTIVES

The objective of this study was to assess whether HIV-infected patients on long-term successful combination antiretroviral therapy (cART) have more extensive white matter hyperintensities (WMH) of presumed vascular origin compared with uninfected controls and whether these intensities are associated with cognitive impairment. Furthermore, we explored potential determinants of increased WMH load long-term suppressed HIV infection.

DESIGN

A cross-sectional comparison of WMH in an observational cohort.

METHODS

Clinical, cognitive, and MRI data were collected from 103 middle-aged, aviremic HIV-infected men on cART, and 70 HIV-uninfected, otherwise similar controls. In the MRI data, WMH load was quantified by automated approaches and qualitatively reviewed by an experienced neuroradiologist using the Fazekas scale.

RESULTS

HIV-infected men had an increased WMH load. Among HIV-infected patients, increased WMH load was independently associated with older age, higher DBP, higher D-dimer levels, and longer time spent with a CD4 cell count below 500 cells/μl. HIV-associated cognitive deficits were associated with increased WMH load.

CONCLUSIONS

WMH are more extensive and associated with cognitive deficits in middle-aged, aviremic cART-treated HIV-infected men. The extent of WMH load was associated with both cardiovascular risk factors and past immune deficiency. As cognitive impairment in these same patients is also associated with these risk factors, this may suggest that in the setting of HIV, WMH, and cognitive deficits share a common cause. This supports the importance of optimizing cardiovascular risk management, and early, effective treatment of HIV infection.

Metalloproteinases and Brain Arterial Remodeling Among Individuals With and Those Without HIV Infection

BACKGROUND

 This study tests the hypothesis that increased elastolytic activity is associated differentially with dolichoectasia in individuals with and those without human immunodeficiency virus (HIV) infection.

METHODS

 Large arteries from 84 autopsied brains from HIV-positive individuals and 78 autopsied brains from HIV-negative individuals were stained for metalloproteinase 2 (MMP-2), MMP-3, MMP-9, tissue inhibitor of metalloproteinases 1 (TIMP-1), TIMP-2, CD68, and caspase 3. Average pixel intensity was automatically obtained and categorized as high, moderate, or low. Dolichoectasia was defined as a lumen to wall ratio ≥95th percentile.

RESULTS

 High MMP-9 staining alone (P = .001) or coexistent with low TIMP-2 staining was associated with dolichoectasia only in HIV-negative individuals (P = <.001). In HIV-positive individuals, MMP-9 was associated with dolichoectasia only when coexpressed with caspase 3 (P = .01). Thinning of the media was associated with CD68 staining (P = <.001) in HIV-negative individuals, while caspase 3 was associated with a thinner media only in HIV-positive individuals (P = .01). Media thickness modified the association between lumen to wall ratio and MMP expression.

CONCLUSIONS

 A role for MMP/TIMP balance in dolichoectasia appears more prominent in HIV-negative individuals, while apoptosis, mediated by caspase 3, is the most important determinant of media thinning in HIV-infected individuals. Furthermore, apoptosis and media thickness appear to mediate the effects of MMP in the HIV-infected population.

HIV Infection Itself May Not Be Associated With Subclinical Coronary Artery Disease Among African Americans Without Cardiovascular Symptoms

Background

The key objectives of this study were to examine whether HIV infection itself is associated with subclinical coronary atherosclerosis and the potential contributions of cocaine use and antiretroviral therapies (ARTs) to subclinical coronary artery disease (CAD) in HIV‐infected persons.

Methods and Results

Between June 2004 and February 2015, 1429 African American (AA) adults with/without HIV infection in Baltimore, Maryland, were enrolled in an observational study of the effects of HIV infection, exposure to ART, and cocaine use on subclinical CAD. The prevalence of subclinical coronary atherosclerosis was 30.0% in HIV‐uninfected and 33.7% in HIV‐infected (P=0.17). Stratified analyses revealed that compared to HIV‐uninfected, HIV‐infected ART naïve were at significantly lower risk for subclinical coronary atherosclerosis, whereas HIV‐infected long‐term ART users (≥36 months) were at significantly higher risk. Thus, an overall nonsignificant association between subclinical coronary atherosclerosis and HIV was found. Furthermore, compared to those who were ART naïve, long‐term ART users (≥36 months) were at significantly higher risk for subclinical coronary atherosclerosis in chronic cocaine users, but not in those who never used cocaine. Cocaine use was independently associated with subclinical coronary atherosclerosis.

Conclusions

Overall, HIV infection, per se, was not associated with subclinical coronary atherosclerosis in this population. Cocaine use was prevalent in both HIV‐infected and ‐uninfected individuals and itself was associated with subclinical disease. In addition, cocaine significantly elevated the risk for ART‐associated subclinical coronary atherosclerosis. Treating cocaine addiction must be a high priority for managing HIV disease and preventing HIV/ART‐associated subclinical and clinical CAD in individuals with HIV infection.

HIV infection and arterial stiffness among older-adults taking antiretroviral therapy in rural Uganda

HIV infection is associated with arterial stiffness, but no studies have assessed this relationship in sub-Saharan Africa. We enrolled 205 participants over 40 years old in Uganda: 105 on antiretroviral therapy for a median of 7 years, and a random sample of 100 age and sex-matched HIV-uninfected controls from the clinic catchment area. The prevalence of arterial stiffness (ankle brachial index  > 1.2) was 33%, 18%, 19% and 2% in HIV+ men, HIV- men, HIV+ women, and HIV- women. In multivariable models adjusted for cardiovascular risk factors, HIV+ individuals had over double the prevalence of arterial stiffness (adjusted prevalence ratio 2.86, 95% confidence interval 1.41-5.79, P = 0.003).

Evidence for a vascular microbiome and its role in vessel health and disease

PURPOSE OF REVIEW

We have summarized available evidence for and against the presence of a vascular microbiome. Studies that have attempted to detect bacteria and viruses in blood vessels in both health and disease are critiqued in an attempt to explain contrary results that may be due to variations in methodology.

RECENT FINDINGS

Many studies have demonstrated the presence of both bacteria and viruses within diseased blood vessels. Evidence is most compelling in atherosclerosis; however, recent reports have raised questions about the potential role of microbes in nonatherosclerotic aortic aneurysms and vasculitis. Preliminary evidence also suggests that apparently normal vessels may harbor microbes. With the exception of certain viral infections (e.g. hepatitis C virus, HIV, Epstein-Barr virus, and cytomegalovirus) and infectious endocarditis, systemic vasculitides have not been convincingly associated with infectious agents. However, emerging data suggest that different communities of microbes may be present in noninflammatory and inflammatory large-vessel diseases. Whether variations in vascular microbial communities are the cause or a secondary result (epiphenomena) of vessel injury remains to be determined.

SUMMARY

Blood vessels may not be sterile. Future studies of microbes in vessel health and disease may provide important insights into disease pathogenesis and suggest new therapies for diseases now considered to be idiopathic and refractory.

START or SMART? Timing of Antiretroviral Therapy Initiation and Cardiovascular Risk for People With Human Immunodeficiency Virus Infection

The Initiation of Antiretroviral Therapy in Early Asymptomatic HIV Infection (START) study has reinforced the benefits of early initiation of antiretroviral therapy (ART). However, a notable secondary finding from that study was that immediate initiation of ART did not prevent cardiovascular disease (CVD) events (0.17 vs 0.20 events/1000 person-years, P = .65). This result appears to contradict a body of evidence, most notably from the Strategies for Management of Antiretroviral Therapy (SMART) study, which reported a 70% increased hazard of cardiovascular events for those deferring or interrupting treatment. Thus, an important unresolved question is whether the timing of ART impacts CVD risk. In this review, published data on relationships between timing of ART and CVD risk are reviewed. The data support a role for ART in mitigating CVD risk at lower CD4 counts, but data also suggests that, among those initiating therapy early, ART alone appears to suboptimally mitigate CVD risk. Additional interventions to address CVD risk among human immunodeficiency virus-infected populations are likely to be needed.

Brain large artery inflammation associated with HIV and large artery remodeling

OBJECTIVE

To test the hypothesis that brain arteries from HIV+ cases have a greater degree of inflammation than brain arteries from HIV- cases, and that inflammation is associated with brain arterial remodeling.

DESIGN

Case-control study, cross-sectional.

METHODS

Brain arteries from 162 autopsy cases (84 with HIV) were systematically analyzed for thickness of the intima, media, and adventitia, and atherosclerosis and dolichoectasia. Inflammation was assessed with CD68 immunohistochemistry, and measured with a semiquantitative score reflecting the number and location (i.e., arterial layer) of activated macrophages infiltrating the arterial wall. Latent varicella zoster virus (VZV) was assessed with anti-VZV gene 63 product immunohistochemistry. Demographic and clinical variables were available in all cases, and longitudinal data about CD4 cell counts were available among cases with HIV. Multilevel generalized linear models were used to test the association between inflammation and HIV.

RESULTS

Arteries from HIV+ cases had a higher inflammation score (B = 0.36, P = 0.05) compared with arteries from HIV- cases, although the association was attenuated after controlling for demographic variables, vascular risk factors, and latent VZV (B = 0.20, P = 0.18). Although intimal inflammation was similar in cases with and without HIV, adventitial inflammation was associated with HIV. Intimal inflammation was associated with intracranial atherosclerosis independent of HIV status, but adventitial inflammation was associated with HIV-associated dolichoectasia in arteries with a thin media.

CONCLUSIONS

Adventitial inflammation is associated with HIV and dolichoectasia independent of intracranial atherosclerosis. This suggests that differential inflammatory responses may play a role in intracranial atherosclerosis and dolichoectasia.

HIV inhibits endothelial reverse cholesterol transport through impacting subcellular Caveolin-1 trafficking

Background

Human immunodeficiency virus (HIV) infection leads to decreased reverse cholesterol transport (RCT) in macrophages, and Nef mediated down-regulation and redistribution of ATP-binding cassette transporter A1 (ABCA1) are identified as key factors for this effect. This may partially explain the increased risk of atherosclerosis in HIV infected individuals. Since endothelial dysfunction is key in the initial stages of atherosclerosis, we sought to determine whether RCT was affected in human aortic endothelial cells (HAECs).

Results

We found that apoA-I does not significantly stimulate cholesterol efflux in HAECs while cholesterol efflux to high-density lipoprotein (HDL) was dramatically reduced in HAECs co-cultured with HIV infected cells. Studies with wild type and Nef defective HIV revealed no significant differences suggesting that multiple factors are working perhaps in concert with Nef to affect cholesterol efflux to HDL from HAECs. Interestingly, treating HAECs with recombinant Nef showed similar effect in HDL mediated cholesterol efflux as observed in HAECs co-cultured with HIV infected cells. Using a detergent-free based subcellular fractionation approach, we demonstrated that exposure of HAECs to HIV infected cells or Nef alone disrupts caveolin 1 (Cav-1) subcellular trafficking upon HDL stimulation. Moreover, Nef significantly enhanced tyrosine 14 phosphorylation of Cav-1 which may have an impact on recycling of Cav-1 and caveolae.

Conclusion

These results suggest that HIV interferes with cholesterol efflux by HDL in HAECs through the disruption of Cav-1s’ cellular distribution and that multiple factors are involved, possibly including Nef, for the inhibition of HDL mediated cholesterol efflux and alteration of cellular distribution of Cav-1.

Electronic supplementary material

The online version of this article (doi:10.1186/s12977-015-0188-y) contains supplementary material, which is available to authorized users.

Infection and Atherosclerosis Development

Atherosclerosis is a chronic disease hallmarked by chronic inflammation, endothelial dysfunction and lipid accumulation in the vasculature. Although lipid modification and deposition are thought to be a major source of the continuous inflammatory stimulus, a large body of evidence suggests that infectious agents may contribute to atherosclerotic processes. This could occur by either direct effects through infection of vascular cells and/or through indirect effects by induction of cytokine and acute phase reactant proteins by infection at other sites. Multiple bacterial and viral pathogens have been associated with atherosclerosis by seroepidemiological studies, identification of the infectious agent in human atherosclerotic tissue, and experimental studies demonstrating an acceleration of atherosclerosis following infection in animal models of atherosclerosis. This review will focus on those infectious agents for which biological plausibility has been demonstrated in animal models and on the challenges of proving a role of infection in human atherosclerotic disease.

Surgical repair of descending thoracic and thoracoabdominal aortic aneurysms in patients with human immunodeficiency virus infection: a 10-patient series

BACKGROUND

Major surgery in patients with human immunodeficiency virus (HIV) infection increases the risk of complications such as cardiovascular morbidity and opportunistic infections.

METHODS

This study reports our experience with open surgical repair of 10 descending thoracic and thoracoabdominal aortic aneurysms in patients with HIV.

RESULTS

Seven were men, and their median age was 49 years. All patients were controlled with highly active antiretroviral therapy (mean CD4+: 613/mm(3)). Three patients died (1 preoperatively, 1 after rupture, and 1 after elective surgery). No patient had spinal cord ischemia or infectious complications, either early or after a median follow-up of 29 months. Bacteriologic and histologic analyses did not determine any specific etiology for the aneurysms.

CONCLUSIONS

Surgical repair of descending thoracic and thoracoabdominal aortic aneurysms in patients with HIV infection is feasible and may not lead to remote infectious complications.

Stimulating high impact HIV-related cardiovascular research: recommendations from a multidisciplinary NHLBI Working Group on HIV-related heart, lung, and blood disease

The clinical challenges confronting patients with human immunodeficiency virus (HIV) have shifted from acquired immunodeficiency syndrome (AIDS)-related illnesses to chronic diseases, such as coronary artery disease, chronic lung disease, and chronic anemia. With the growing burden of HIV-related heart, lung, and blood (HLB) disease, the National Heart, Lung, and Blood Institute (NHLBI) recognizes it must stimulate and support HIV-related HLB research. Because HIV offers a natural, accelerated model of common pathological processes, such as inflammation, HIV-related HLB research may yield important breakthroughs for all patients with HLB disease. This paper summarizes the cardiovascular recommendations of an NHLBI Working Group, Advancing HIV/AIDS Research in Heart, Lung, and Blood Diseases, charged with identifying scientific priorities in HIV-related HLB disease and developing recommendations to promote multidisciplinary collaboration among HIV and HLB investigators. The working group included multidisciplinary sessions, as well as HLB breakout sessions for discussion of disease-specific issues, with common themes about scientific priorities and strategies to stimulate HLB research emerging in all 3 groups.

Acute Spontaneous Coronary Artery Thrombosis as Initial Presentation of HIV Infection in a Young Man

Introduction. The presentation of acute coronary syndrome (ACS) in young HIV patients may be atypical with different pathophysiological and clinical features. Acute coronary thrombosis, as a presentation of acute coronary syndrome in young patients with HIV, raises diagnostic and treatment challenges. Case Presentation. We describe a case of a 33-year-old African man, without traditional atherosclerotic risk factors, who presented with chest pain of acute onset. Emergent coronary angiography revealed extensive thrombus in the left anterior descending coronary artery with no evidence of atherosclerosis in this or other coronary vessels. Plaque and/or thrombus prolapse through the stent was noted following percutaneous coronary intervention (PCI). Resolution of chest pain and improvement in ST-segment elevation was noted after the procedure. A diagnosis of HIV infection was made during the workup for HIV infection. Conclusion. In young patients without traditional risk factors, HIV infection is a possible etiological factor for spontaneous coronary artery thrombosis. Percutaneous coronary intervention in patients with this presentation may be compounded with atherothrombotic complications. The likely pathophysiological pathway is superficial endothelial cell denudation as a result of chronic inflammation and immune activation.

Vascular smooth muscle cells contribute to APOL1-induced podocyte injury in HIV milieu

Clinical reports have demonstrated that higher rates of non-diabetic glomerulosclerosis in African Americans can be attributed to two coding sequence variants (G1 and G2) in the APOL1 gene; however, the underlying mechanism is still unknown. Kidney biopsy data suggest enhanced expression of APOL1/APOL1 variants (Vs) in smooth muscle cells (SMCs) of renal vasculature. Since APOL1 is a secretory protein of relatively low molecular weight (41kDa), SMCs may be a contributory endocrine/paracrine source of APOL1 wild type (WT)/APOL1Vs in the glomerular capillary perfusate percolating podocytes. In the present study, we tested the hypothesis that an HIV milieu stimulated secretion of APOL1 and its risk variants by arterial SMCs contributes to podocyte injury. Human umbilical artery smooth muscle cells (HSMCs)-treated with conditioned media (CM) of HIV-infected peripheral mononuclear cells (PBMC/HIV-CM), CM of HIV-infected U939 cells, or recombinant IFN-γ displayed enhanced expression of APOL1. Podocytes co-cultured in trans-wells with HSMCs-over expressing APOL1WT showed induction of injury; however, podocytes co-cultured with HSMC-over expressing either APOL1G1 or APOL1G2 showed several folds greater injury when compared to HSMC-over expressing APOL1WT. Conditioned media collected from HSMC-over-expressing APOL1G1/APOL1G2 (HSMC/APOL1G1-CM or HSMC/APOL1G2-CM) also displayed higher percentages of injured podocytes in the form of swollen cells, leaky lysosomes, loss of viability, and enhanced sensitivity to adverse host factors when compared to HSMC/APOL1WT-CM. Notably, HSMC/APOL1WT-CM promoted podocyte injury only at a significantly higher concentrations compared to HSMC/APOL1G1/G2-CM. We conclude that HSMCs could serve as an endocrine/paracrine source of APOL1Vs, which mediate accelerated podocyte injury in HIV milieu.

HIV-associated large-vessel vasculopathy: a review of the current and emerging clinicopathological spectrum in vascular surgical practice

An established relationship exists between human immunodeficiency virus (HIV) and the vascular system, which is characterised by clinical expressions of aneurysmal and occlusive disease that emanate from a common pathological process. The exact pathogenesis is currently unknown; attempts to implicate opportunistic pathogens have been futile. Theories converge on leucocytoclastic vasculitis with the vaso vasora as the vasculopathic epicentre. It is thought that the virus itself or viral proteins trigger the release of inflammatory mediators that cause endothelial dysfunction and smooth muscle proliferation leading to vascular injury and thrombosis. The beneficial effects of highly active anti-retroviral therapy alter the natural history of the disease profile and promote longevity but are negated by cardiovascular complications. Atherosclerosis is an emerging challenge. Presently patients are managed by standard surgical protocols because of non-existent universal surgical interventional guidelines. Clinical response to treatment is variable and often compounded by complications of graft occlusion, sepsis and poor wound healing. The clinical, imaging and pathological observations position HIV-associated large-vessel vasculopathy as a unique entity. This review highlights the spectrum of HIV-associated large-vessel aneurysmal, occlusive and atherosclerotic disease in vascular surgical practice.

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.

Magnitude and risk factors of non-communicable diseases among people living with HIV in Tanzania: a cross sectional study from Mbeya and Dar es Salaam regions

Background

HIV and Non communicable diseases (NCDs) are major problem of public health importance in developing countries. This study was conducted to explore and establish information on the magnitude, distribution of NCDs risk factors among people living with HIV (PLWHIV) which is scarce in Tanzania.

Method

A cross sectional study was conducted to PLWHIV from 12 care and treatment clinics in Dar es Salaam and Mbeya regions from October 2011 to February 2012. Data on demographic characteristics, NCD risk factors including behavioral, biochemical tests and physical measurements was collected from PLWHIV.

Results

Of 754 PLWHIV recruited, 671(89.0%) consented to participate in the study and 354/671(52.8%) were on antiretroviral therapy (ART). The following NCD risk factors: raised blood levels of low density lipoprotein (61.3% vs 38.7%, p < 0.001) total cholesterol (TC) (71.6% vs 28.4%, p < 0.001) and triglyceride (67.0% vs 33.0%, p = 0.001) as well as overweight/obesity (61.1% vs 38.9%, p = 0.010), abnormal waist circumference (61.7% vs 38.3%, p < 0.001) and being aged >40 years (63.3% vs 36.7%, p < 0.001) were more prevalent among PLWHIV on ART than ART naïve. The prevalence of Diabetes mellitus among PLWHIV was 4.2% and was slightly high among those ART naïve (4.7% vs 3.7%). The prevalence of hypertension was 26.2% and was high among those on ART (30.0% vs 21.9%, p = 0.010). Being aged >40 years (AOR = 2.52, 95% CI 1.37-4.63), abnormal waist circumference (AOR = 2.37 95% CI 1.13-5.00), overweight/obesity (AOR = 2.71, 95% CI 1.26-5.84) and male sex (AOR = 1.17, 1.02-4.20) were the predictors of hypertension among patients on ART while raised TC (AOR = 1.47 (1.01-2.21) and being aged >40 years (AOR = 3.42, 95% CI 2.06-5.70) were predictors for hypertension among ART naïve patients.

Conclusion

This study has revealed that the magnitude of NCD risk factors is significantly higher among PLWHIV on ART than those not on ART. Initiating and strengthening of interventions for minimizing preventable NCD risks should be considered when initiating ART among PLWHIV. Regular monitoring of NCD risk factors is of paramount importance among ART patients.

Development of imaging techniques to study the pathogenesis of biosafety level 2/3 infectious agents

Despite significant advances in microbiology and molecular biology over the last decades, several infectious diseases remain global concerns, resulting in the death of millions of people worldwide each year. According to the Center for Disease Control (CDC) in 2012, there were 34 million people infected with HIV, 8.7 million new cases of tuberculosis, 500 million cases of hepatitis, and 50-100 million people infected with dengue. Several of these pathogens, despite high incidence, do not have reliable clinical detection methods. New or improved protocols have been generated to enhance detection and quantitation of several pathogens using high-end microscopy (light, confocal, and STORM microscopy) and imaging software. In the current manuscript, we discuss these approaches and the theories behind these methodologies. Thus, advances in imaging techniques will open new possibilities to discover therapeutic interventions to reduce or eliminate the devastating consequences of infectious diseases.

The CXCL12/CXCR4 chemokine ligand/receptor axis in cardiovascular disease

The chemokine receptor CXCR4 and its ligand CXCL12 play an important homeostatic function by mediating the homing of progenitor cells in the bone marrow and regulating their mobilization into peripheral tissues upon injury or stress. Although the CXCL12/CXCR4 interaction has long been regarded as a monogamous relation, the identification of the pro-inflammatory chemokine macrophage migration inhibitory factor (MIF) as an important second ligand for CXCR4, and of CXCR7 as an alternative receptor for CXCL12, has undermined this interpretation and has considerably complicated the understanding of CXCL12/CXCR4 signaling and associated biological functions. This review aims to provide insight into the current concept of the CXCL12/CXCR4 axis in myocardial infarction (MI) and its underlying pathologies such as atherosclerosis and injury-induced vascular restenosis. It will discuss main findings from in vitro studies, animal experiments and large-scale genome-wide association studies. The importance of the CXCL12/CXCR4 axis in progenitor cell homing and mobilization will be addressed, as will be the function of CXCR4 in different cell types involved in atherosclerosis. Finally, a potential translation of current knowledge on CXCR4 into future therapeutical application will be discussed.

HIV protease inhibitor exposure predicts cerebral small vessel disease

OBJECTIVE

HIV-associated neurocognitive disorders (HANDs) remain prevalent in patients who receive HAART and may be associated with cumulative exposure to antiretroviral medications and other factors. We proposed that chronic toxic effects of antiretroviral drugs could contribute to cerebral small vessel disease (CSVD), which might be one of the key underpinnings of HAND.

DESIGN

Clinicopathological cross-sectional study of HIV-infected adults in the California NeuroAIDS Tissue Network.

METHODS

We employed multivariable logistic regression methods to determine associations between HAART exposure (protease inhibitor-based, nonprotease inhibitor-based, or no HAART) and CSVD occurrence (standard histopathology: moderate/severe, mild, or absent). We also associated HAND (relative to normal cognition) with CSVD, HIV-related neuropathologic changes, older age at death (≥50 years), sex, or hepatitis C virus infection.

RESULTS

We found that both mild and moderate/severe CSVD were associated with protease inhibitor-based HAART exposure after adjusting for diabetes mellitus [odds ratio (OR) 2.8 (95% confidence interval, CI 1.03-7.9) and 2.6 (95% CI 1.03-6.7), respectively, n = 134]. Moderate/severe CSVD was associated with diabetes after adjusting for HAART exposure [OR 7.4 (95% CI 1.6-70.7), n = 134]. Notably, HAND was associated with mild CSVD [OR 4.8 (95% CI 1.1-21.2), n = 63], which remained statistically significant after adjusting for vessel mineralization, HIV encephalitis, microglial nodular lesions, white matter lesions, or older age.

CONCLUSION

Protease inhibitor-based HAART exposure may increase the risk of CSVD and thereby neurocognitive impairment in HIV-infected adults. Apart from the possible direct toxicity to cerebral small vessels, protease inhibitor-based HAART may contribute indirectly to CSVD by inducing metabolic abnormalities.

Subclinical atherosclerosis and markers of immune activation in HIV-infected children and adolescents: the CaroVIH Study

BACKGROUND

HIV-infected adults display increased cardiovascular disease, probably driven by inflammation and immune activation. These relationships have not been addressed in vertically HIV-infected children and adolescents, a population at very high risk for long-term non-AIDS complications.

METHODS

Carotid intima media thickness (IMT) was measured in a cohort of HIV-infected children and adolescents and healthy controls. C-reactive protein and markers of immune activation (CD38⁺HLA-DR⁺) and immune senescence (CD28⁻CD57⁺) were determined.

RESULTS

One hundred fifty HIV-infected patients and 150 controls were included, 64.8% female. IMT was thicker in HIV-infected patients (0.434 mm ± 0.025 vs. 0.424 mm ± 0.018, P < 0.001). After adjustment by age, sex, body mass index, and smoking status, HIV infection was independently associated with thicker IMT (odds ratio, 2.28; 95% confidence interval: 1.25 to 4.13; P = 0.007). Among HIV-related variables, a low CD4 nadir was related to an increased IMT. Although HIV-infected subjects presented higher frequencies of activated CD4⁺ and CD8⁺ T cells (P = 0.002 and P = 0.087, respectively), no relation was found between IMT and inflammation, immune activation, or senescence.

CONCLUSIONS

Structural changes of the vasculature present early in vertically HIV-infected subjects as well as immune activation and senescence. These patients should be carefully monitored for the prompt detection and early treatment of cardiovascular disease.

The CCR5 chemokine receptor mediates vasoconstriction and stimulates intimal hyperplasia in human vessels in vitro

AIMS

The chemokine receptor CCR5 and its inflammatory ligands have been linked to atherosclerosis, an accelerated form of which occurs in saphenous vein graft disease. We investigated the function of vascular smooth muscle CCR5 in human coronary artery and saphenous vein, vascular tissues susceptible to atherosclerosis, and vasospasm.

METHODS AND RESULTS

CCR5 ligands were vasoconstrictors in saphenous vein and coronary artery. In vein, constrictor responses to CCL4 were completely blocked by CCR5 antagonists, including maraviroc. CCR5 antagonists prevented the development of a neointima after 14 days in cultured saphenous vein. CCR5 and its ligands were expressed in normal and diseased coronary artery and saphenous vein and localized to medial and intimal smooth muscle, endothelial, and inflammatory cells. [(125)I]-CCL4 bound to venous smooth muscle with KD = 1.15 ± 0.26 nmol/L and density of 22 ± 9 fmol mg(-1) protein.

CONCLUSIONS

Our data support a potential role for CCR5 in vasoconstriction and neointimal formation in vitro and imply that CCR5 chemokines may contribute to vascular remodelling and augmented vascular tone in human coronary artery and vein graft disease. The repurposing of maraviroc for the treatment of cardiovascular disease warrants further investigation.

A quantitative perspective to the study of brain arterial remodeling of donors with and without HIV in the Brain Arterial Remodeling Study (BARS)

Mechanisms underlying brain arterial remodeling are uncertain. We tested the hypothesis that arterial size and location are important determinants of arterial characteristics. We collected large and penetrating brain arteries from cadavers with and without HIV. Morphometric characterization was obtained from digital images using color-based thresholding. The association of arterial size and location with lumen diameter, media and adventitia area, media proportion, a wall thickness, wall-to-lumen ratio and stenosis was obtained with multilevel mixed models and a P value ≤ 0.05 was considered significant. We included 336 brains, in which 2279 large arteries and 1488 penetrating arteries were identified. We found that arterial size was significantly associated with all arterial characteristics studied of large and penetrating arteries with exception of arterial stenosis in large arteries. After adjusting for size, an independent association was found between lumen diameters, media and adventitia thickness with artery locations. Arterial stenosis was also associated with artery location in both large and penetrating arteries. In summary, significant effects of size and/or location were found in arterial characteristics typically used to define arterial remodeling. Brain arterial remodeling characteristics differ across arterial sizes and location, and these differences should be controlled for in future studies of brain arterial remodeling.

Vitamin D deficiency is associated with the development of subclinical coronary artery disease in African Americans with HIV infection: a preliminary study

BACKGROUND

Premature coronary artery disease (CAD) is a major concern in human immunodeficiency virus (HIV)-infected African Americans. The objectives of the study were to estimate the incidence of subclinical CAD, defined by the presence of coronary plaque and/or calcification on cardiac computed tomography (CT), and to identify the associated risk factors in this vulnerable population.

SUBJECTS AND METHODS

Between August 2003 and September 2010, 188 HIV-infected African Americans without known, or symptoms of, CAD underwent cardiac CT. The subset without demonstrable disease underwent a second cardiac CT approximately 2 years later. The incidence of disease over that period and the effects of antiretroviral treatment and other known and hypothesized risk factors were investigated.

RESULTS

Sixty-nine of these 188 African Americans had evidence of subclinical disease on the initial cardiac CT, confirming prior high prevalence reports. A second cardiac CT was performed on 119 African Americans without disease approximately 2 years later. The total person-years of follow-up was 284.4. Subclinical CAD was detected in 14 of these, yielding an overall incidence of 4.92/100 person-years (95% confidence interval, 2.69-8.26). Among the factors investigated, only male sex and vitamin D deficiency were independently associated with the development of subclinical CAD. The study did not find significant associations between CD4 count, HIV viral load, antiretroviral treatment use, or cocaine use and the incidence of subclinical CAD.

CONCLUSIONS

The incidence of subclinical CAD in African Americans with HIV infection is provocatively high. Larger studies are warranted to confirm the role of vitamin D deficiency in the development of CAD in HIV-infected African Americans.