Endothelial and platelet function alterations in HIV-infected patients

Platelet and HIV Interactions and Their Contribution to Non-AIDS Comorbidities

Platelets are anucleate cytoplasmic cell fragments that circulate in the blood, where they are involved in regulating hemostasis. Beyond their normal physiologic role, platelets have emerged as versatile effectors of immune response. During an infection, cell surface receptors enable platelets to recognize viruses, resulting in their activation. Activated platelets release biologically active molecules that further trigger host immune responses to protect the body against infection. Their impact on the immune response is also associated with the recruitment of circulating leukocytes to the site of infection. They can also aggregate with leukocytes, including lymphocytes, monocytes, and neutrophils, to immobilize pathogens and prevent viral dissemination. Despite their host protective role, platelets have also been shown to be associated with various pathophysiological processes. In this review, we will summarize platelet and HIV interactions during infection. We will also highlight and discuss platelet and platelet-derived mediators, how they interact with immune cells, and the multifaceted responsibilities of platelets in HIV infection. Furthermore, we will give an overview of non-AIDS comorbidities linked to platelet dysfunction and the impact of antiretroviral therapy on platelet function.

Delayed circadian rhythms in older Africans living with human immunodeficiency virus (HIV)

The increasing number of people living with human immunodeficiency virus, HIV, (PLWH) have an elevated incidence of risk for noncommunicable comorbidities, the aetiology of which remains incompletely understood. While sleep disturbances are often reported in PLWH, it is unknown to what extent they relate to changes in the circadian and/or sleep homeostatic processes. We studied the relationship between sleep characteristics, circadian phase, and HIV status in older adults from the HAALSI (Health and Ageing in Africa: a Longitudinal Study of an INDEPTH Community in South Africa) subsample of the Agincourt Health and Demographic Surveillance System in South Africa (n = 187, 36 human immunodeficiency virus positive [HIV+], age: 66.7 ± 11.5 years, range 45-93 years), where HIV prevalence is high and (in contrast to the global north) does not associate significantly with potentially confounding behavioural differences. In participants with valid actigraphy data (n = 172), regression analyses adjusted for age and sex indicated that HIV+ participants had slightly later sleep onset (β = .16, p = .039), earlier sleep offset times (β = -.16, p = .049) and shorter total sleep times (β = -.20, p = .009) compared to the HIV negative (HIV-) participants. In a subset of participants (n = 51, 11 HIV+), we observed a later dim light melatonin onset (DLMO) in HIV+ (21:16 ± 01:47) than in HIV- (20:06 ± 00:58) participants (p = .006). This substantial difference remained when adjusted for age and sex (β = 1.21; p = .006). In 36 participants (6 HIV+) with DLMO and actigraphy data, median phase angle of entrainment was -6 min in the HIV+ group and +1 h 25 min in the HIV- group. DLMO time correlated with sleep offset (ρ = 0.47, p = .005) but not sleep onset (ρ = -0.086, p = .623). Collectively, our data suggest that the sleep phase occurred earlier than what would be biologically optimal among the HIV+ participants. This is the first report of a mistimed circadian phase in PLWH, which has important potential implications for their health and well-being, especially given the well-established relationships between circadian asynchrony and sleep deprivation with poorer health outcomes.

Pregnancy Related Venous Thromboembolism-Associated with HIV Infection and Antiretroviral Therapy

Human immunodeficiency virus (HIV) infection in pregnancy is associated with substantial morbidity and mortality. Improved access to effective antiretroviral therapy (ART) has shifted the spectrum of pregnancy-related complications among HIV-infected pregnant women. In addition to placental vascular complications and preterm delivery, increased rates of venous thromboembolism (VTE) have been described. HIV infection is characterized by immune activation, inflammation, and endothelial dysfunction, which contribute to the activation of coagulation and its prothrombotic consequences. Indeed, activated coagulation factors have been reported to be increased and natural anticoagulants reduced in HIV. Several mechanisms for this persistent prothrombotic balance on ART have been identified. These may include: co-infections, immune recovery, and loss of the gastrointestinal mucosal integrity with microbial translocation. In addition to the direct effects of HIV and ART, traditional venous and obstetric risk factors also contribute to the risk of VTE. A research priority has been to understand the mechanisms of VTE in HIV-infected pregnant women receiving suppressive ART and to translate this into HIV-specific thromboprophylaxis recommendations. Management requires a multidisciplinary approach and further studies are indicated to guide the prevention and management of pregnancy-associated VTE in this population. The current review describes the epidemiology, mechanisms, and management of VTE in HIV-infected women in pregnancy and the postpartum period.

Plasma CD16+ Extracellular Vesicles Associate with Carotid Artery Intima-Media Thickness in HIV+ Adults on Combination Antiretroviral Therapy

HIV-infected individuals have increased risk for cardiovascular disease (CVD) despite suppressive antiretroviral therapy (ART). This is likely a result of persistent immune activation and systemic inflammation. Extracellular vesicles (EVs) have emerged as critical mediators of intercellular communication and may drive inflammation contributing to CVD. EVs were characterized in plasma from 74 HIV-infected individuals on combination antiretroviral therapy (cART) and 64 HIV-uninfected controls with paired carotid intima-media thickness (cIMT) assessment. EVs were profiled with markers reflecting lymphoid, myeloid, and endothelial origin. Seventeen plasma inflammatory biomarkers were also assessed. Human umbilical vein endothelial cell (HUVEC) apoptosis was quantified after EV exposure. A significant correlation was observed in HIV-infected participants between cIMT and EVs expressing CD16, and the monocyte-related markers CD4, CD14, and CX3CR1 showed a similar but nonsignificant association with cIMT. No significant correlation between cIMT measurements from HIV-uninfected individuals and EVs was observed. Levels of serum amyloid A, C-reactive protein, and myeloperoxidase significantly correlated with CD14⁺, CD16⁺, and CX3CR1⁺ EVs. No correlation was noted between cIMT and soluble inflammatory markers. HUVECs showed increased necrosis after exposure to the EV-containing fraction of plasma derived from HIV-infected individuals compared to uninfected controls. Our study reveals that EVs expressing monocyte markers correlated with cIMT in HIV-infected individuals on cART. Moreover, EV fractions derived from HIV-infected individuals lead to greater endothelial cell death via necrotic pathways. Collectively, EVs have potential as biomarkers of and therapeutic targets in the pathogenesis of CVD in the setting of treated HIV disease. IMPORTANCE HIV-infected individuals have a 2-fold-increased risk of cardiovascular disease compared with the general population, yet the mechanisms underlying this comorbidity are unclear. Extracellular vesicles have emerged as important mediators in cell-cell communication and, given what we know of their biology, may drive inflammation contributing to cardiovascular disease in this vulnerable population.

Comparative effects of 6-weeks progressive resistance exercise and moderate intensity aerobic exercise on CD4 count and weights of people living with HIV/AIDS in Alex-Ekwueme Federal University Teaching Hospital Ebonyi State

INTRODUCTION

The most significant clinical challenges in people living with HIV/AIDS (PLWHA) are decline in CD4+ T helper cells and abnormal weight reduction. Consequently, PLWHA who are on Anti-Retroviral Therapy (ART) or Highly Active Anti-Retroviral Therapy (HAART) are usually predisposed to coronary artery diseases due to abnormal weight gain (lipohypertrophy), though with improved and unstable Cluster of Differentiation 4 (CD4) counts.The main aim of this study was to compare the effects of 6 weeks progressive resistance exercise (PRE) and moderate intensity aerobic exercise (MIAE) on CD4 count, and weight of PLWHA in Alex-Ekwueme Federal University Teaching Hospital Ebonyi State.

METHOD

The study adopted quasi experimental research design. The population of the study was 60 Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome patients that attended HIV clinics at Alex-Ekwueme Federal University Teaching Hospital Abakaliki (AE-FUTHA) which formed 58 sample sizes for this study.Simple random sampling technique was adopted for the study and flow cytometry, Heel Densitometer (X-rite 331C), and Omron BF 400 were the instrument used for data collection of CD4 counts and weight respectively; and they are standardized hence not validated. Mean, standard deviation and Analysis of Co-variance (ANCOVA) were used to analyze the data obtained. The reliability coefficient obtained from the pilot study was 0.848 and 0.994 for CD4 and WEIGHT respectively.

RESULTS

The major findings revealed a significant difference after 6 weeks' PRE and MIAE on CD4 and Weight of PLWHA.

CONCLUSION

Health promotion policy maker's arm of the government and Healthcare givers should integrate and enforce the use of exercises either as a single regimen or combined exercises into the management plan of PLWHA for greater boost in absolute CD4 count bearing in mind that both have positive effects. Physiotherapist should be integrated in the managements of PLWHA for appropriate prescription and education of therapeutic exercises for body weight.

Severity, timeline, and management of complications after stereotactic brain biopsy

OBJECTIVE

The literature shows discrepancies in stereotactic brain biopsy complication rates, severities, and outcomes. Little is known about the timeline of postbiopsy complications. This study aimed to analyze 1) complications following brain biopsies, using a graded severity scale, and 2) a timeline of complication occurrence. The secondary objectives were to determine factors associated with an increased risk of complications and to assess complication-related management and extra costs.

METHODS

The authors retrospectively examined 1500 consecutive stereotactic brain biopsies performed in adult patients at their tertiary medical center between April 2009 and April 2019.

RESULTS

Three hundred eighty-one biopsies (25.4%) were followed by a complication, including 88.2% of asymptomatic hemorrhages. Symptomatic complications involved 3.0% of the biopsies, and 0.8% of the biopsies were fatal. The severity grading scale had a 97.6% interobserver reproducibility. Twenty-three (51.1%) of the 45 symptomatic complications occurred within the 1st hour following the biopsy, while 75.6% occurred within the first 6 hours. Age ≥ 65 years, second biopsy procedures, gadolinium-enhanced lesions, glioblastomas, and lymphomas were predictors of biopsy-related complications. Brainstem biopsy-targeted lesions and cerebral toxoplasmosis were predictive of mortality. Asymptomatic hemorrhage was associated with delayed (> 6 hours) symptomatic complications. Symptomatic complications led to extended hospitalization in 86.7% of patients. The average extra cost for management of a patient with postbiopsy symptomatic complication was $35,702.

CONCLUSIONS

Symptomatic complications from brain biopsies are infrequent but associated with substantial adverse effects and cost implications for the healthcare system. The use of a severity grading scale, as the authors propose in this article, helps to classify complications according to the therapeutic consequences and the patient's outcome. Because this study indicates that most complications occur within the first few hours following the biopsy, postbiopsy monitoring can be tailored accordingly. The authors therefore recommend systematic monitoring for 2 hours in the recovery unit and a CT scan 2 hours after the end of the biopsy procedure. In addition, they propose a modern algorithm for optimal postoperative management of patients undergoing stereotactic biopsy.

Evaluation of Platelet Activation by HIV Protease Inhibitors - The HIV-PLA II Study

Background

In the past, protease inhibitors (PIs) and the reverse transcriptase inhibitor abacavir were identified increasing the risk for thromboembolic complications and cardiovascular events (CVE) of HIV infected patients taking a combination antiretroviral therapy (cART). Results of the previous HIV-PLA I-study lead to the assumption that platelet activation could play a substantial role in increasing CVE risks.

Methods

The open label, monocentric HIV-PLA II-study investigated HIV-1-infected, therapy-naïve adults (n=45) starting with cART, consisting either of boosted PI (atazanavir, n= 6, darunavir, n=11), NNRTI (efavirenz, n=14) or integrase inhibitor (raltegravir, n=14), each plus tenofovir/emtricitabine co-medication. Main exclusion criteria were tobacco smoking, the intake of NSAIDs or abacavir or past CVE. Platelet adhesive molecule p-selectin (CD62P) and FITC anti-human Integrin α-IIb/Integrin β-3 (CD41/CD61) antibody (PAC-1) binding, monocyte CD11b/monocyte-associated CD41 expression and the endogenous thrombin potential (ETP) were assessed ex vivo-in vitro at baseline, weeks 4, 12 and 24. Therapy regimens were blinded to the investigators for laboratory and statistical analyses.

Results

CD11b and ETP showed no significant changes or differences between all study groups. In contrast, the mean + SD mean fluorescence units (MFI) of CD62P and PAC-1 increased significantly in patients taking PI, indicating an enhanced potential for thrombocyte activation and aggregation.

Conclusion

CD62P expression, detecting the ɑ-platelet degranulation of pro-inflammatory and pro-thrombotic factors and adhesive proteins, and PAC-1 expression, representing a marker for conformation changes of the GIIb/IIIa receptor, increased significantly in patients taking HIV protease inhibitors. The findings of this study revealed a yet unknown pathway of platelet activation, possibly contributing to the increased risk for CVE under HIV protease inhibitor containing cART.

Clinical Trial Registration No.

DRKS00000288.

Interactions of HIV and Antiretroviral Therapy With Neutrophils and Platelets

Neutrophils are important components of the innate immune system that mediate pathogen defense by multiple processes including phagocytosis, release of proteolytic enzymes, production of reactive oxygen species, and neutrophil extracellular trap formation. Abnormalities of neutrophil count and function have been described in the setting of HIV infection, with the majority of antiretroviral agents (ARVs), excluding zidovudine, having been reported to correct neutropenia. Questions still remain, however, about their impact on neutrophil function, particularly the possibility of persistent neutrophil activation, which could predispose people living with HIV to chronic inflammatory disorders, even in the presence of virally-suppressive treatment. In this context, the effects of protease inhibitors and integrase strand transfer inhibitors, in particular, on neutrophil function remain poorly understood and deserve further study. Besides mediating hemostatic functions, platelets are increasingly recognized as critical role players in the immune response against infection. In the setting of HIV, these cells have been found to harbor the virus, even in the presence of antiretroviral therapy (ART) potentially promoting viral dissemination. While HIV-infected individuals often present with thrombocytopenia, they have also been reported to have increased platelet activation, as measured by an upregulation of expression of CD62P (P-selectin), CD40 ligand, glycoprotein IV, and RANTES. Despite ART-mediated viral suppression, HIV-infected individuals reportedly have sustained platelet activation and dysfunction. This, in turn, contributes to persistent immune activation and an inflammatory vascular environment, seemingly involving neutrophil-platelet-endothelium interactions that increase the risk for development of comorbidities such as cardiovascular disease (CVD) that has become the leading cause of morbidity and mortality in HIV-infected individuals on treatment, clearly underscoring the importance of unraveling the possible etiologic roles of ARVs. In this context, abacavir and ritonavir-boosted lopinavir and darunavir have all been linked to an increased risk of CVD. This narrative review is therefore focused primarily on the role of neutrophils and platelets in HIV transmission and disease, as well as on the effect of HIV and the most common ARVs on the numbers and functions of these cells, including neutrophil-platelet-endothelial interactions.

Differential Responsiveness of the Platelet Biomarkers, Systemic CD40 Ligand, CD62P, and Platelet-Derived Growth Factor-BB, to Virally-Suppressive Antiretroviral Therapy

Systemic biomarkers of inflammation, including cytokines and chemokines, are potentially useful in the management of both HIV infection and non-AIDS-defining disorders. However, relatively little is known about the utility of measurement of circulating biomarkers of platelet activation as a strategy to monitor the efficacy of combination antiretroviral therapy (cART), as well as the persistence of systemic inflammation following virally-suppressive therapy in HIV-infected persons. These issues have been addressed in the current study to which a cohort consisting of 199 HIV-infected participants was recruited, 100 of whom were cART-naïve and the remainder cART-treated and virally-suppressed. Fifteen healthy control participants were included for comparison. The study focused on the effects of cART on the responsiveness of three biomarkers of platelet activation, specifically soluble CD40 ligand (sCD40L), sCD62P (P-selectin), and platelet-derived growth factor-BB (PDGF-BB), measured using multiplex suspension bead array technology. Most prominently sCD40L in particular, as well as sCD62P, were significantly elevated in the cART-naïve group relative to both the cART-treated and healthy control groups. However, levels of PDGF-BB were of comparable magnitude in both the cART-naïve and -treated groups, and significantly higher than those of the control group. Although remaining somewhat higher in the virally-suppressed group relative to healthy control participants, these findings identify sCD40L, in particular, as a potential biomarker of successful cART, while PDGF-BB may be indicative of persistent low-level antigenemia.

HIV-1 Tat Protein Enters Dysfunctional Endothelial Cells via Integrins and Renders Them Permissive to Virus Replication

Previous work has shown that the Tat protein of Human Immunodeficiency Virus (HIV)-1 is released by acutely infected cells in a biologically active form and enters dendritic cells upon the binding of its arginine-glycine-aspartic acid (RGD) domain to the α5β1, αvβ3, and αvβ5 integrins. The up-regulation/activation of these integrins occurs in endothelial cells exposed to inflammatory cytokines that are increased in HIV-infected individuals, leading to endothelial cell dysfunction. Here, we show that inflammatory cytokine-activated endothelial cells selectively bind and rapidly take up nano-micromolar concentrations of Tat, as determined by flow cytometry. Protein oxidation and low temperatures reduce Tat entry, suggesting a conformation- and energy-dependent process. Consistently, Tat entry is competed out by RGD-Tat peptides or integrin natural ligands, and it is blocked by anti-α5β1, -αvβ3, and -αvβ5 antibodies. Moreover, modelling–docking calculations identify a low-energy Tat-αvβ3 integrin complex in which Tat makes contacts with both the αv and β3 chains. It is noteworthy that internalized Tat induces HIV replication in inflammatory cytokine-treated, but not untreated, endothelial cells. Thus, endothelial cell dysfunction driven by inflammatory cytokines renders the vascular system a target of Tat, which makes endothelial cells permissive to HIV replication, adding a further layer of complexity to functionally cure and/or eradicate HIV infection.

Pathomechanisms of HIV-Associated Cerebral Small Vessel Disease: A Comprehensive Clinical and Neuroimaging Protocol and Analysis Pipeline

Rationale: We provide an in-depth description of a comprehensive clinical, immunological, and neuroimaging study that includes a full image processing pipeline. This approach, although implemented in HIV infected individuals, can be used in the general population to assess cerebrovascular health.

Aims: In this longitudinal study, we seek to determine the effects of neuroinflammation due to HIV-1 infection on the pathomechanisms of cerebral small vessel disease (CSVD). The study focuses on the interaction of activated platelets, pro-inflammatory monocytes and endothelial cells and their impact on the neurovascular unit. The effects on the neurovascular unit are evaluated by a novel combination of imaging biomarkers.

Sample Size: We will enroll 110 HIV-infected individuals on stable combination anti-retroviral therapy for at least three months and an equal number of age-matched controls. We anticipate a drop-out rate of 20%.

Methods and Design: Subjects are followed for three years and evaluated by flow cytometric analysis of whole blood (to measure platelet activation, platelet monocyte complexes, and markers of monocyte activation), neuropsychological testing, and brain MRI at the baseline, 18- and 36-month time points. MRI imaging follows the recommended clinical small vessel imaging standards and adds several advanced sequences to obtain quantitative assessments of brain tissues including white matter microstructure, tissue susceptibility, and blood perfusion.

Discussion: The study provides further understanding of the underlying mechanisms of CSVD in chronic inflammatory disorders such as HIV infection. The longitudinal study design and comprehensive approach allows the investigation of quantitative changes in imaging metrics and their impact on cognitive performance.

An Outlook on the Impact of HIV Infection and Highly Active Antiretroviral Therapy on the Cardiovascular System - A Review

HIV has been related to various cardiovascular pathologies in both adults and children. Highly active antiretroviral therapy (HAART) has been effective in subduing viral replication and improving immunity thereby reducing the effects of HIV both in AIDS and other chronic diseases related to the virus. Complications related to HAART have been reported with metabolic disorders and cardiac effects seen based on the therapy. HIV and HAART have shown to have direct effects on the cardiovascular system, and more public awareness and medical knowledge are required on this subject. This literature review tries to shed some light on the role of HIV and HAART in the cardiovascular manifestations seen in HIV-infected individuals.

Effects of gut microbial metabolite trimethylamine N-oxide (TMAO) on platelets and endothelial cells

Thrombotic events result from different pathologies and are the underlying causes of severe diseases like stroke or myocardial infarction. Recent basic research now revealed a link between food uptake, food conversion and gut metabolism. Gut microbial production of trimethylamine N-oxide (TMAO) from dietary nutrients like choline, lecithin and L-carnitine was associated with the development of cardiovascular diseases. Within this review we give a systematic overview about the influence of TMAO on blood components like platelets and endothelial cells which both are involved as key players in thrombotic processes. In summary, a mechanistic correlation between the gut microbiome, TMAO and cardiovascular diseases becomes obvious and emphasizes to the significance of the intestinal microbiome.

Increased levels of reactive oxygen species in platelets and platelet-derived microparticles and the risk of respiratory failure in HIV/AIDS patients

Respiratory failure (RF) is the main cause of hospital admission in HIV/AIDS patients. This study assessed comorbidities and laboratory parameters in HIV/AIDS inpatients with RF (N = 58) in relation to those without RF (N = 36). Tuberculosis showed a huge relative risk and platelet counts were slightly higher in HIV/AIDS inpatients with RF. A flow cytometry assay for reactive oxygen species (ROS) showed lower levels in platelets of these patients in relation to the healthy subjects. However, when stimulated with adrenaline, ROS levels increased in platelets and platelet-derived microparticles of HIV/AIDS inpatients, which may increase the risk of RF during HIV and tuberculosis (HIV-TB) coinfection.

Endothelial dysfunction and carotid atherosclerosis in Malawian adults: A cross-sectional study

Background and objective

In sub-Saharan Africa, data on prevalence, risk factors and pathobiology of carotid atherosclerosis are scarce. We aimed to investigate the relationship between biomarkers of endothelial dysfunction and carotid atherosclerosis.

Methods

Carotid ultrasound was performed in 66 patients. Plasma concentration of ICAM-1, PAI-1, VEGF, and soluble thrombomodulin were measured by ELISA. A univariable logistic regression analysis was performed to study the relationship between carotid atherosclerosis, biomarkers of endothelial dysfunction, and various demographic and clinical parameters of the participants.

Results

The mean age of the participants was 58.7 years (95% CI: 54.4-63.1). Carotid atherosclerosis was diagnosed in 39.4% (95% CI: 27.6-52.2). In the univariable logistic regression, the following factors were associated with carotid atherosclerosis: age > 45 years (OR = 12.0, 95% CI: 1.4-98.8, p = .02), hypertension (OR = 3.8, 95% CI: 1.2-12.1, p = .02), and high-level of soluble thrombomodulin (OR = 3.4, 95% CI: 1.2-10.0, p = .02).

Conclusions

There is an association between high levels of soluble thrombomodulin and carotid atherosclerosis in Malawian adults. Further studies with a larger sample size are needed to confirm our findings in other African populations.

Comparison of pathological clotting using haematological, functional and morphological investigations in HIV-positive and HIV-negative patients with deep vein thrombosis

BACKGROUND

Patients infected with the human immunodeficiency virus (HIV) are more prone to systemic inflammation and pathological clotting, and many may develop deep vein thrombosis (DVT) as a result of this dysregulated inflammatory profile. Coagulation tests are not routinely performed unless there is a specific reason.

METHODS

We recruited ten healthy control subjects, 35 HIV negative patients with deep vein thrombosis (HIV negative-DVT), and 13 HIV patients with DVT (HIV positive-DVT) on the primary antiretroviral therapy (ARV) regimen-emtricitabine, tenofovir and efavirenz. Serum inflammatory markers, haematological results, viscoelastic properties using thromboelastography (TEG) and scanning electron microscopy (SEM) of whole blood (WB) were used to compare the groups.

RESULTS

The DVT patients (HIV positive and HIV negative) had raised inflammatory markers. The HIV positive-DVT group had anaemia in keeping with anaemia of chronic disorders. DVT patients had a hypercoagulable profile on the TEG but no significant difference between HIV negative-DVT and HIV positive-DVT groups. The TEG analysis compared well and supported our ultrastructural results. Scanning electron microscopy of DVT patient's red blood cells (RBCs) and platelets demonstrated inflammatory changes including abnormal cell shapes, irregular membranes and microparticle formation. All the ultrastructural changes were more prominent in the HIV positive-DVT patients.

CONCLUSIONS

Although there were trends that HIV-positive patients were more hypercoagulable on functional tests (viscoelastic profile) compared to HIV-negative patients, there were no significant differences between the 2 groups. The sample size was, however, small in number. Morphologically there were inflammatory changes in patients with DVT. These ultrastructural changes, specifically with regard to platelets, appear more pronounced in HIV-positive patients which may contribute to increased risk for hypercoagulability and deep vein thrombosis.

Brief Report: Higher Levels of Angiopoietin-1 Are Associated With Early and Sustained Viral Suppression in Children Living With Vertically Acquired HIV

BACKGROUND

Systemic inflammation, platelet dysfunction, and endothelial activation persist in people living with HIV despite sustained virologic suppression (SVS) with combined antiretroviral therapy (cART) and may lead to complications such as atherosclerosis and cardiovascular disease. Angiopoietin-1 (Ang-1) is a key regulator of angiogenesis and endothelial activation and has been studied as an objective biomarker in disease states such as atherosclerosis, sepsis, and severe malaria.

SETTING

Eight pediatric HIV care centers across Canada.

METHODS

Cross-sectional study of 61 children living with vertically acquired HIV on cART with undetectable RNA viral load. Plasma levels of Ang-1 were measured by ELISA and analyzed in relation to clinical characteristics abstracted from medical records.

RESULTS

Ang-1 levels were directly correlated with clinical indices of virologic control: cumulative proportion of life on effective cART (ρ = +0.35, P = 0.0078) and cumulative proportion of life with SVS (ρ = +0.36, P = 0.0049). Furthermore, higher Ang-1 levels were associated with younger age at SVS (ρ = -0.56, P < 0.0001). These associations remained statistically significant in multivariable linear regression models adjusting for potential confounders (P < 0.05 for all associations).

CONCLUSIONS

Early effective cART and SVS were associated with higher Ang-1 levels in children living with vertically acquired HIV-1.

Influence of antiretroviral therapy and cardiovascular disease on the immature platelet fraction in patients living with HIV

Cardiovascular disease is an important contributor to morbidity and mortality in people living with HIV . The immature platelet fraction (IPF) is increased in HIV-negative patients with cardiovascular disease and evidence suggests that an enlarged IPF is associated with adverse cardiovascular events. In this multi-center observational study, we aimed to investigate how the IPF in people living with HIV is influenced by antiretroviral therapy and cardiovascular disease. Subjects without cardiovascular disease that received antiretroviral therapy showed a smaller IPF accompanied by lower D-dimer and C-reactive protein (CRP) levels compared to therapy-naïve subjects (mean IPF: 2.9% vs. 3.9%, p = .016; median D-dimer: 252 µg/L vs. 623 µg/L, p < .001; median CRP: 0.2 mg/dL vs. 0.5 mg/dL, p = .004). No significant differences for the IPF, D-dimer or CRP were found between subjects on antiretroviral therapy with documented cardiovascular disease and therapy-naïve subjects. In conclusion, we observed a reduction in the IPF among subjects on therapy only in the absence of cardiovascular disease. In contrast, subjects receiving therapy that had documented cardiovascular disease showed an IPF comparable to therapy-naïve subjects. Future studies are needed to investigate if an enlarged IPF may serve as a biomarker in predicting adverse cardiovascular events in people living with HIV.

Circulating CD40 ligand, Dickkopf-1 and P-selectin in HIV-infected patients

OBJECTIVES

The aim of this study was to evaluate the circulating levels of CD40 ligand (CD40 L), Dickkopf-1 (DKK-1) and P-selectin, their relationships and their contributions to cardiovascular risk in subjects with HIV infection.

METHODS

The study population included 80 HIV-infected patients, 14 (17.5%) of whom had diabetes mellitus (DM) and 32 (40.0%) of whom had arterial hypertension (AH). The HIV-infected patients were compared with a control group with similar demographic and clinical features. CD40L, DKK-1 and P-selectin levels were measured using an enzyme-linked immunosorbent assay.

RESULTS

The HIV-infected patients showed higher levels of all the cardiovascular disease (CVD) markers. Both serum CD40L and DKK-1 were significantly higher in HIV-infected patients than in the HIV-negative controls (P < 0.001), while soluble P-selectin showed no significant between-group difference (P = 0.133), reflecting the role of HIV infection in CVD. In the HIV-infected group, patients with DM showed lower levels of CD40L and DKK-1 in comparison with the nondiabetic patients and patients with AH (P < 0.05, with Bonferroni correction). In contrast, patients with AH showed higher levels of CD40L and DKK-1 in comparison to patients without DM or AH (P < 0.05, with Bonferroni correction). Patients with AH showed higher levels of CD40L and DKK-1 than patients with DM (P < 0.05, with Bonferroni correction).

CONCLUSIONS

In this study, we found that HIV-infected patients displayed significantly higher circulating levels of both CD40L and DKK-1, which were linearly and directly correlated, when compared to HIV-negative patients. The presence of diabetes was associated with lower levels of both CD40L and DKK-1, whereas the presence of hypertension was associated with higher levels of CD40L.

Mechanisms of Cardiovascular Disease in the Setting of HIV Infection

Although the initial reports of increased cardiovascular (CV) disease in the setting of advanced AIDS were reported approximately 30 years ago, advances in antiretroviral therapy and immediate initiation of therapy on diagnosis have transformed what was once a deadly infectious disease into a chronic health condition. Accordingly, the types of CV diseases occurring in HIV have shifted from pericardial effusions and dilated cardiomyopathy to atherosclerosis and heart failure. The underlying pathophysiology of HIV-associated CV disease remains poorly understood, partly because of the rapidly evolving nature of HIV treatment and because clinical endpoints take many years to develop. The gut plays an important role in the early pathogenesis of HIV infection as HIV preferentially infects CD4+ T cells, 80% of which are located in gut mucosa. The loss of these T cells damages gut mucosa resulting in increased gut permeability and microbial translocation, which incites chronic inflammation and immune activation. Antiretroviral therapy does not cure HIV infection and immune abnormalities persist. These abnormalities correlate with mortality and CV events. The effects of antiretroviral therapy on CV risk are complex; treatment reduces inflammation and other markers of CV risk but induces lipid abnormalities, most commonly hypertriglyceridemia. On a molecular level, monocytes/macrophages, platelet reactivity, and immune cell activation, which play a role in the general population, may be heightened in the setting of HIV and contribute to HIV-associated atherosclerosis. Chronic inflammation represents an inviting therapeutic target in HIV, as it does in uninfected persons with atherosclerosis.

The HIV protease inhibitor, ritonavir, dysregulates human platelet function in vitro

There are 37 million people globally infected with the Human Immunodeficiency Virus (HIV). People living with HIV can achieve nearly normal lifespans due to the use of antiretroviral drugs (ARVs). However, people living with HIV experience chronic inflammation and increased risk for cardiovascular diseases (CVD) relative to uninfected people. While the cause for this risk is unclear, some ARVs have been associated with CVD, and it is speculated that some ARVs potentiate inflammation in infected individuals. Platelets are a critical link between inflammation and the development and progression of CVD, but the effects of ARVs on platelets are largely understudied. In this study, we examined the effects of ARVs on human platelet function in vitro. Our data show that the ARV ritonavir, a protease inhibitor, severely altered human platelet lipid mediator production (prostaglandin E2 and thromboxane) in both resting and activated platelets. Further characterization revealed that ritonavir altered measures of platelet hemostatic and thrombotic function that included significantly decreased platelet spreading, increased platelet aggregation, and trended toward increased clot strength. These data provide proof-of-principle that ARVs can directly dysregulate human platelets, possibly contributing to inflammation-related comorbidities. These data may provide mechanistic insight into the factors contributing to increased risk of CVD in people living with HIV, and may help guide future development of new HIV agents and ARV regimens that mitigate platelet dysregulation by ARVs.

HIV-associated cardiovascular disease: importance of platelet activation and cardiac fibrosis in the setting of specific antiretroviral therapies

HIV infection is a risk factor for cardiovascular disease (CVD). This risk is accentuated by certain combination antiretroviral therapies (cARTs), independent of their effects on lipid metabolism and insulin sensitivity. We sought to define potential mechanisms for this association through systematic review of clinical and preclinical studies of CVD in the setting of HIV/cART from the English language literature from 1989 to March 2018. We used PubMed, Web of Knowledge and Google Scholar, and conference abstracts for the years 2015-March 2018. We uncovered three themes: (1) a critical role for the HIV protease inhibitor (PI) ritonavir and certain other PI-based regimens. (2) The importance of platelet activation. Virtually all PIs, and one nucleoside reverse transcriptase inhibitor, abacavir, activate platelets, but a role for this phenomenon in clinical CVD risk may require additional postactivation processes, including: release of platelet transforming growth factor-β1; induction of oxidative stress with production of reactive oxygen species from vascular cells; suppression of extracellular matrix autophagy; and/or sustained proinflammatory signalling, leading to cardiac fibrosis and dysfunction. Cardiac fibrosis may underlie an apparent shift in the character of HIV-linked CVD over the past decade from primarily left ventricular systolic to diastolic dysfunction, possibly driven by cART. (3) Recognition of the need for novel interventions. Switching from cART regimens based on PIs to contemporary antiretroviral agents such as the integrase strand transfer inhibitors, which have not been linked to clinical CVD, may not mitigate CVD risk assumed under prior cART. In conclusion, attention to the effects of specific antiretroviral drugs on platelet activation and related profibrotic signalling pathways should help: guide selection of appropriate anti-HIV therapy; assist in evaluation of CVD risk related to novel antiretrovirals; and direct appropriate interventions.

HIV and myocarditis

PURPOSE OF REVIEW

The purpose of this article is to review the literature on HIV and myocarditis and HIV-associated heart failure.

RECENT FINDINGS

Currently, 17 million people are receiving antiretroviral therapy (ART) globally. There is a decrease in mortality from HIV in the last decade with increased survival in those receiving ART. HIV-associated cardiac failure is on the increase, with more cases of diastolic dysfunction reported in the ART era. The pathophysiology of HIV-associated myocarditis is multifactorial. Cardiovascular magnetic resonance (CMR), through tissue characterization, demonstrates increased native T1 values which reflect both increased myocardial inflammation and fibrosis in HIV infection.

SUMMARY

HIV-associated myocarditis is common and may be an important cause of HIV-associated cardiac failure. CMR is an important imaging modality for the study of myocardial inflammation.

Cardiovascular Disease in the Setting of Human Immunodeficiency Virus Infection

Background:

Since the introduction of Antiretroviral Therapy (ART), the life expectancy and health quality for patients infected with Human Immunodeficiency Virus (HIV) have significant-ly improved. Nevertheless, as a result of not only the deleterious effects of the virus itself and pro-longed ART, but also the effects of aging, cardiovascular diseases have emerged as one of the most common causes of death among these patients.

Objective:

The purpose of this review is to explore the new insights on the spectrum of Cardiovascu-lar Disease (CVD) in HIV infection, with emphasis on the factors that contribute to the atherosclerot-ic process and its role in the development of acute coronary syndrome in the setting of infection.

Methods:

A literature search using PubMed, ScienceDirect and Web of Science was performed. Ar-ticles up to Mar, 2017, were selected for inclusion. The search was conducted using MeSH terms, with the following key terms: [human immunodeficiency virus AND (cardiovascular disease OR coronary heart disease) AND (antiretroviral therapy AND (cardiovascular disease OR coronary heart disease))].

Results:

Clinical cardiovascular disease tends to appear approximately 10 years before in infected in-dividuals, when compared to the general population. The pathogenesis behind the cardiovascular, HIV-associated complications is complex and multifactorial, involving traditional CVD risk factors, as well as factors associated with the virus itself - immune activation and chronic inflammation – and the metabolic disorders related to ART regimens.

Conclusion:

Determining the cardiovascular risk among HIV-infected patients, as well as targeting and treating conditions that predispose to CVD, are now emerging concerns among physicians.

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

Background

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

Methods

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

Results

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

Conclusion

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

HIV status and type of coronary stent placed in patients presenting with ST-elevation myocardial infarction

BACKGROUND

Drug-eluting stents (DES) outperform bare-metal stents (BMS) in reducing target vessel revascularization following a percutaneous coronary intervention (PCI). Little is known about the types of stents placed in HIV-positive patients presenting with ST-segment elevation myocardial infarctions (STEMIs).

METHODS

We used the 2003-2013 National Inpatient Sample to identify adults of 18 years or older presenting with STEMI. We evaluated differences in stent type placed following STEMIs on the basis of HIV status. Temporal trends in the use of PCI, DES, and BMS were studied on the basis of HIV status.

RESULTS

Of 1 695 947 patients with STEMI, 5887 (0.3%) were HIV-positive patients. Following STEMIs, HIV-positive patients were equally likely to have PCI compared with HIV-negative patients [adjusted odds ratio (AOR): 1.04, 95% confidence interval (CI): 0.89-1.21, P=0.63]. However, HIV-positive patients were less likely to have DES (AOR: 0.83, 95% CI: 0.73-0.94, P=0.003) and more likely to have BMS (AOR: 1.26, 95% CI: 1.11-1.45, P=0.001). Over the 11-year period observed, there were increases in PCI following STEMIs in both HIV-positive and HIV-negative patients (all Ptrend<0.001). There were significant increases in the use of DES in HIV-negative patients [adjusted odds ratio (AOR) per year: 1.07, 95% CI: 1.06-1.09, Ptrend<0.001] and significant decreases in the use of BMS (AOR per year: 0.93, 95% CI: 0.92-0.94, Ptrend<0.001). Significant trends showing changed practice patterns in the use of DES and BMS among HIV-positive patients were not observed.

CONCLUSION

Over a decade, there were significant increases in the use of PCI following STEMIs in both HIV-negative and HIV-positive patients. Although HIV-positive patients presenting with STEMIs were as likely as HIV-negative patients to undergo PCI, they were less likely to be treated with DES and more likely to receive BMS. Highlighting these observations will hopefully bring renewed attention to best practices for all STEMI patients.

Effect of aspirin treatment on abacavir-associated platelet hyperreactivity in HIV-infected patients

BACKGROUND

Ischemic cardiovascular events are a relevant cause of morbidity and mortality in HIV-infected patients. Use of abacavir (ABC), a nucleoside analog reverse transcriptase inhibitor, has been associated with increased risk of myocardial infarction (MI) and with platelet hyperreactivity. We explored whether low-dose aspirin reduces in vivo platelet activation and platelet hyperreactivity induced by ABC in HIV-infected subjects.

METHODS AND RESULTS

In a randomized, placebo-controlled, cross-over study forty HIV-infected patients with ABC-associated platelet hyperreactivity, defined by a score based on laboratory variables reflecting in vivo platelet activation and ex vivo platelet hyperresponsiveness, were randomized to aspirin 100 mg daily for 15 days with subsequent cross-over to placebo for additional 15 days or placebo for 15 days with subsequent cross-over to aspirin for further 15 days. In vivo and ex vivo platelet activation markers were measured at day 15 and 30. One group of healthy subjects, one of untreated HIV infected-patients and one treated without ABC, were studied concomitantly. Serum TxB₂ and urinary 11-dehydro-TxB₂ were decreased by aspirin in ABC-treated patients, but not as much as in healthy controls. Aspirin therapy reduced significantly platelet hyperreactivity (score: from 9.3, 95% CIs 8.7 to 10.0, to 7.5, 6.9 to 8.0), however without bringing it back to the levels of healthy controls (score: 4.6, 95% CIs 3.6 to 5.6).

CONCLUSION

Aspirin reduces ABC-induced in vivo platelet activation and platelet hyperreactivity in HIV-infected patients, however without normalizing them. Whether the observed reduction of platelet activation is sufficient to prevent cardiovascular events requires a prospective trial.

Platelet function and cardiovascular risk in adult HIV-infected patients on HAART: a protocol for a systematic review and meta-analysis

INTRODUCTION

The incidence of cardiovascular disease (CVD) is now at least threefold higher in HIV-infected patients as compared with the general population. Although platelet activation and reactivity are implicated in the development of CVDs in HIV-infected patients, its precise role remains inconclusive. We aim to assess the association between platelet activation and selected cardiovascular risk factors in HIV-1-infected individuals on highly active antiretroviral treatment (HAART).

METHODS

This will be a systematic review and meta-analysis of published studies evaluating the association between platelet activation and CVD risk factors in HAART-treated adults. The search strategy will include medical subject headings words for MEDLINE, and this will be adapted to Embase search headings (Emtree) terms for the EMBASE database. The search will cover literature published between 1 January 1996 to 30 April 2017. Studies will be independently screened by two reviewers using predefined criteria. Relevant eligible full texts will be screened; data will be extracted, and a qualitative synthesis will be conducted. Data extraction will be performed using Review Manager V.5.3. To assess the quality and strengths of evidence across selected studies, the Grading of Recommendations Assessment Development and Evaluation approach will be used. The Cochran's Q statistic and the I² statistics will be used to analyse statistical heterogeneity between studies. If included studies show high levels of homogeneity, a random effects meta-analysis will be performed using R statistical software.

ETHICS AND DISSEMINATION

This will be a review of existing studies and will not require ethical approval. The findings will be disseminated through peer-reviewed publication and presented at local and international conferences. An emerging patient management dilemma is that of the increased incidence of CVD in people living with HIV on HAART. This review may inform treatment and cardiovascular risk stratification of HIV-infected patients at increased risk of developing CVD.

PROSPERO REGISTRATION NUMBER

CRD42017062393.

Cardiovascular toxicity of abacavir: a clinical controversy in need of a pharmacological explanation

: There is a long-lasting controversy surrounding an association between abacavir (ABC) and an increased risk of cardiovascular disease in HIV-positive patients. Although differing in their specifics, a number of published cohort studies and clinical trials support such an association, usually relating it to recent exposure to the drug, independently of traditional predisposing factors. However, other clinical trials have failed to reveal such a relation and have pointed to methodological differences to explain discrepancies. Significantly, the controversy has been fueled by the lack of a credible mechanism of action to justify the putative detrimental actions of ABC. There is a myriad of contradictory clinical indicators which are not clearly compatible with known profiles of either vascular physiopathology or pharmacological interference. However, basic research has recently hinted at altered homeostatic mechanisms, though this requires clinical validation. In particular, recurrent evidence - both clinical and experimental - relates ABC with vascular inflammation, a leading contributor to the atherosclerotic plaque and thrombosis. ABC's chemical structure is very close to that of endogenous purines (ATP, ADP and AMP), major paracrine signaling molecules capable of triggering prothrombotic and proinflammatory vascular programs. Other proposed mechanisms are a competitive inhibition of guanylyl cyclase in platelets and a subsequent decrease in cyclic guanosine monophosphate (cGMP). The present review aims to shed light on this complex subject by summarizing and critically evaluating all the available clinical data regarding a relationship between ABC and cardiovascular disease, and to put forward potential pharmacological explanations compatible with both the clinical scenario and experimental findings.

Virus–Platelet Associations

Virus–platelet interplay is complex. Diverse virus types have been shown to associate with numerous distinct platelet receptors. This association can benefit the virus or the host, and thus the platelet is somewhat of a renegade. Evidence is accumulating to suggest that viruses are capable of entering platelets. For at least one type of RNA virus (dengue virus), the platelet has the necessary post-translational and packaging machinery required for production of replicative viral progeny. As a facilitator of immunity, the platelet also participates in eradicating the virus by direct and indirect mechanisms involving presentation of the pathogen to the innate and adaptive immune systems, thus enhancing inflammation by release of cytokines and other agonists. Virus-induced thrombocytopenia is caused by tangential imbalance of thrombopoeisis, autoimmunity, and loss of platelet function and integrity.

Efavirenz Causes Oxidative Stress, Endoplasmic Reticulum Stress, and Autophagy in Endothelial Cells

The non-nucleoside reverse transcriptase inhibitor efavirenz is a widely prescribed antiretroviral drug used in combined antiretroviral therapy. Despite being an essential and life-saving medication, the required lifelong use of HIV drugs has been associated with a variety of adverse effects, including disturbances in lipid metabolism and increased cardiovascular risk. Efavirenz belongs to those HIV drugs for which cardiovascular and endothelial dysfunctions have been reported. It is here shown that elevated concentrations of efavirenz can inhibit endothelial meshwork formation on extracellular matrix gels by normal and immortalized human umbilical vein cells. This inhibition was associated with an increase in oxidative stress markers, endoplasmic reticulum (ER) stress markers, and autophagy. Induction of ER stress occurred at pharmacologically relevant concentrations of efavirenz and resulted in reduced proliferation and cell viability of endothelial cells, which worsened in the presence of elevated efavirenz concentrations. In combination with the HIV protease inhibitor nelfinavir, both oxidative stress and ER stress became elevated in endothelial cells. These data indicate that pharmacologically relevant concentrations of efavirenz can impair cell viability of endothelial cells and that these effects may be aggravated by either elevated concentrations of efavirenz or by a combined use of efavirenz with other oxidative stress-inducing medications.

Role of Autophagy in HIV Pathogenesis and Drug Abuse

Autophagy is a highly regulated process in which excessive cytoplasmic materials are captured and degraded during deprivation conditions. The unique nature of autophagy that clears invasive microorganisms has made it an important cellular defense mechanism in a variety of clinical situations. In recent years, it has become increasingly clear that autophagy is extensively involved in the pathology of HIV-1. To ensure survival of the virus, HIV-1 viral proteins modulate and utilize the autophagy pathway so that biosynthesis of the virus is maximized. At the same time, the abuse of illicit drugs such as methamphetamine, cocaine, morphine, and alcohol is thought to be a significant risk factor for the acquirement and progression of HIV-1. During drug-induced toxicity, autophagic activity has been proved to be altered in various cell types. Here, we review the current literature on the interaction between autophagy, HIV-1, and drug abuse and discuss the complex role of autophagy during HIV-1 pathogenesis in co-exposure to illicit drugs.

Abacavir has no prothrombotic effect on platelets in vitro

OBJECTIVES

HIV patients exposed to abacavir have an increased risk of myocardial infarction, with contradictory results in the literature. The aim of our study was to determine whether abacavir has a direct effect on platelet activation and aggregation using platelets from healthy donors and from HIV-infected patients under therapy with an undetectable viral load.

METHODS

Platelet-rich plasma (PRP) or whole blood from healthy donors was treated with abacavir (5 or 10 μg/mL) or its active metabolite carbovir diphosphate. Experiments were also performed using blood of HIV-infected patients (n = 10) with an undetectable viral load. Platelet aggregation was performed on PRP by turbidimetry and under high shear conditions at 4000 s^-1. Platelet procoagulant potential was analysed by measuring thrombin generation by thrombinography.

RESULTS

Abacavir and carbovir diphosphate significantly increased the aggregation of platelets from healthy donors induced by collagen at 2 μg/mL (P = 0.002), but not at 0.5 μg/mL. No effect of abacavir or carbovir diphosphate was observed on platelet aggregation induced by other physiological agonists or by high shear stress, or on thrombin generation. Pretreatment of blood from HIV-infected patients with abacavir produced similar results.

CONCLUSIONS

Our results suggest that abacavir does not significantly influence platelet activation in vitro when incubated with platelets from healthy donors or from HIV-infected patients. It is, however, not excluded that a synergistic effect with other drugs could promote platelet activation and thereby play a role in the pathogenesis of myocardial infarction.

Human immunodeficiency virus-associated heart failure in sub-Saharan Africa: evolution in the epidemiology, pathophysiology, and clinical manifestations in the antiretroviral era

The survival of patients with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) who have access to highly active antiretroviral therapy (ART) has dramatically increased in recent times. This review focuses on HIV‐associated heart failure in sub‐Saharan Africa (SSA). In HIV infected persons, heart failure may be related to pathology of the pericardium, the myocardium, the valves, the conduction system, or the coronary and pulmonary vasculature. HIV‐associated heart failure can be because of direct consequences of HIV infection, autoimmune reactions, pro‐inflammatory cytokines, opportunistic infections (OIs) or neoplasms, use of ART or therapy for OIs and presence of traditional cardiovascular risk factors. Myocardial involvement includes diastolic dysfunction, asymptomatic left ventricular dysfunction, cardiomyopathy, myocarditis, fibrosis, and steatosis. Pericardial diseases include pericarditis, pericardial effusions (rarely causing tamponade), pericardial constriction, and effusive‐constrictive syndromes. Coronary artery disease is commonly reported in industrial nations, although its prevalence is thought to be low in HIV‐infected persons from SSA.

SIV/SHIV Infection Triggers Vascular Inflammation, Diminished Expression of Krüppel-like Factor 2 and Endothelial Dysfunction

BACKGROUND

Human immunodeficiency virus (HIV) infection is associated with increased risk of thromboembolic and cardiovascular comorbid conditions. Although systemic inflammation is linked to cardiovascular risk, direct evidence of vascular inflammation and endothelial dysfunction is lacking.

METHODS

We examined by immunofluorescence microscopy thoracic aortas from 16 simian immunodeficiency virus (SIV)- or simian-human immunodeficiency virus (SHIV)-infected and 16 uninfected rhesus macaques.

RESULTS

Focal endothelial proliferation and subendothelial inflammatory cells were found in sections of all infected animals, compared with minimal changes in sections from the 16 uninfected controls. In the infected animals, we detected increased endothelial levels of bacterial 16s ribosomal DNA as well as increased subendothelial accumulation of CD68(+) monocytes/macrophages (P< .001) and CD8(+) T lymphocytes (P< .001). Endothelial dysfunction was manifested by decreased levels of endothelial nitric oxide synthase (P< .005) and Krüppel-like factor 2 (KLF2) (P< .005). KLF2 expression was decreased in primary human aortic endothelial cells exposed to bacterial lipopolysaccharide or to oxidized low-density lipoprotein in vitro, and this could be prevented by simvastatin.

CONCLUSIONS

SIV and SHIV infection lead to endothelial inflammation, dysfunction, and decreased KLF2 expression reflecting early atherosclerotic changes. Translocated bacterial components and lipid oxidation products may induce endothelial dysfunction in HIV infection that could be prevented by statin treatment.

Aspirin in the 21st century-common mechanisms of disease and their modulation by aspirin: a report from the 2015 scientific conference of the international aspirin foundation, 28 August, London, UK

Professor Peter Rothwell of Oxford University chaired the annual Scientific Conference of the International Aspirin Foundation in London on 28 August 2015. It took the form of four sessions. Aspirin has more than one action in its effects on disease. Its acetylation of cyclooxygenase 2 (COX-2) in platelets leads to the blockade of pro-inflammatory chemicals and generation of anti-inflammatory mediators and increase in nitrous oxide (NO) production, which helps to preserve arterial endothelium. But platelets are not its only target. There is now evidence that aspirin has a direct antitumour effect on intestinal mucosal cells that block their potential transformation into cancer cells. Randomised placebo-controlled trials (RCTs) in people with histories of colorectal neoplasia have shown that aspirin reduces the risk of recurrent adenomas and reduces long-term cancer incidence in patients with Lynch syndrome. Among women given aspirin for cardiovascular disease, there were fewer cancers than in those given placebo. Epidemiological evidence has suggested that aspirin treatment after cancer is diagnosed reduces the incidence of metastases and prolongs survival, and long-term studies of anticancer treatment with aspirin are under way to confirm this. Apart from cancer studies, aspirin use is now firmly established as treatment for antiphospholipid syndrome (Hughes syndrome) and is being used to prevent and treat the heightened risk of cardiovascular disease in diabetes mellitus and in patients with HIV.

Cardiovascular disease associated with human immunodeficiency virus: a review

The cardiovascular manifestations of human immunodeficiency virus (HIV) infection have changed significantly following the introduction of highly active antiretroviral therapy (HAART) regimens. On one hand, HAART has altered the course of HIV disease, with longer survival of HIV-infected patients, and cardiovascular complications of HIV infection such as myocarditis have been reduced. On the other hand, HAART is associated with an increase in the prevalence of both peripheral and coronary arterial disease. As longevity increases in HIV-infected individuals, long-term effects, such as cardiovascular disease, are emerging as leading health issues in this population. In the present review article, we discuss HIV-associated cardiovascular disease, focusing on epidemiology, etiopathogenesis, diagnosis, prognosis, management and therapy. Cardiovascular involvement in treatment-naive patients is still important in situations such as non-adherence to treatment, late initiation of treatment, and/or limited access to HAART in developing countries. We therefore describe the cardiovascular consequences in treatment-naive patients and the potential effect of antiretroviral treatment on their regression, as well as the metabolic and cardiovascular implications of HAART regimens in HIV-infected individuals.

The effect of initiation of antiretroviral therapy on monocyte, endothelial and platelet function in HIV-1 infection

OBJECTIVES

Monocyte activation, endothelial dysfunction and platelet activation all potentially contribute to the increased risk of cardiovascular disease (CVD) reported in those with HIV-1 infection. To date, no study has examined how initiation of antiretroviral therapy (ART) affects markers of all three processes. We aimed to compare markers of monocyte, endothelial and platelet function between untreated HIV-positive subjects and HIV-negative controls and to examine the early effects of ART initiation on these markers.

METHODS

We measured monocyte [soluble CD14 (sCD14) and sCD163], endothelial [von Willebrand factor (vWF), intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1)] and platelet [soluble P-selectin (sP-selectin), soluble CD40 ligand (sCD40L) and soluble glycoprotein VI (sGPVI)] biomarkers before and at weeks 4 and 12 post ART initiation in HIV-positive and well-matched HIV-negative controls.

RESULTS

We examined 40 subjects, 25 HIV-positive subjects and 15 controls, with a median age of 34 years [interquartile range (IQR) 31, 40 years], of whom 60% were male and 47.5% Caucasian. Pre-ART, all biomarkers (monocyte, endothelial and platelet) were significantly higher in HIV-positive patients versus controls (all P < 0.05) and decreased with ART initiation, except for sCD14, which remained unchanged [median 1680 (IQR 1489, 1946) ng/mL at week 12 versus 1570 (IQR 1287, 2102) ng/mL at week 0; P = 0.7]. Although platelet activation markers reduced to levels comparable to those in controls, endothelial dysfunction markers remained elevated, as did sCD163 [at week 12, median 1005 (IQR 791, 1577) ng/mL in HIV-positive patients versus 621 (IQR 406, 700) ng/mL in controls; P < 0.0001].

CONCLUSIONS

ART initiation resulted in reductions in levels of CVD-associated biomarkers; however, although they improved, markers of endothelial dysfunction and monocyte activation remained elevated. How these persistent abnormalities affect CVD risk in HIV infection remains to be determined.

Platelet Activation in Human Immunodeficiency Virus Type-1 Patients Is Not Altered with Cocaine Abuse

Recent work has indicated that platelets, which are anucleate blood cells, significantly contribute to inflammatory disorders. Importantly, platelets also likely contribute to various inflammatory secondary disorders that are increasingly associated with Human Immunodeficiency Virus Type-1 (HIV) infection including neurological impairments and cardiovascular complications. Indeed, HIV infection is often associated with increased levels of platelet activators. Additionally, cocaine, a drug commonly abused by HIV-infected individuals, leads to increased platelet activation in humans. Considering that orchestrated signaling mechanisms are essential for platelet activation, and that nuclear factor-kappa B (NF-κB) inhibitors can alter platelet function, the role of NF-κB signaling in platelet activation during HIV infection warrants further investigation. Here we tested the hypothesis that inhibitory kappa B kinase complex (IKK) activation would be central for platelet activation induced by HIV and cocaine. Whole blood from HIV-positive and HIV-negative individuals, with or without cocaine abuse was used to assess platelet activation via flow cytometry whereas IKK activation was analyzed by performing immunoblotting and in vitro kinase assays. We demonstrate that increased platelet activation in HIV patients, as measured by CD62P expression, is not altered with reported cocaine use. Furthermore, cocaine and HIV do not activate platelets in whole blood when treated ex vivo. Finally, HIV-induced platelet activation does not involve the NF-κB signaling intermediate, IKKβ. Platelet activation in HIV patients is not altered with cocaine abuse. These results support the notion that non-IKK targeting approaches will be better suited for the treatment of HIV-associated inflammatory disorders.

Update on the key developments of the neurologic complications in children infected with HIV

PURPOSE OF REVIEW

To discuss recent research findings of neurologic complications in HIV-infected children, specifically addressing neuroinfections, cerebrovascular disease, epilepsy and neurocognitive complications. The range of neurologic childhood onset complications is diverse and often overlaps diseases previously considered only to manifest in adults. In the pediatric population, these complications frequently have their own unique disease identity, which may be related to maturational patterns evident in the developing brain.

RECENT FINDINGS

Developments regarding the pathogenesis of neuroAIDS, treatment of tuberculous meningitis and prevention of bacterial meningitis are described. With the advent of neuroimaging, there is greater insight into silent cerebrovascular events and the progression of vasculopathy in HIV-infected children. The role of surgical intervention for affected cases is a novel area that could alter the otherwise poor prognosis. Epilepsy, although common as a burden of disease, carries its own additional complications with regard to cross reactivity with various antiretroviral therapies. Increased risk of low bone mineral density supports a role for supplementation with vitamin D in people receiving antiretroviral therapy and antiepileptic drugs. Recognition of the early neurobiological, as well as spectrum of neurocognitive effects of the HIV on the developing brain, is evolving, as greater numbers of children are treated early. Developments in these critical areas are described.

SUMMARY

Recent research reflects the need for improved strategies to prevent neuroinfections, more effective screening and interventions for vasculopathy and better antiepileptic drugs for HIV-infected children. Furthermore, our understanding of the timing and spectrum of neurocognitive complications is evolving.

Platelet interactions with viruses and parasites

While the interactions between Gram-positive bacteria and platelets have been well characterized, there is a paucity of data on the interaction between other pathogens and platelets. However, thrombocytopenia is a common feature with many infections especially viral hemorrhagic fever. The little available data on these interactions indicate a similarity with bacteria-platelet interactions with receptors such as FcγRIIa and Toll-Like Receptors (TLR) playing key roles with many pathogens. This review summarizes the known interactions between platelets and pathogens such as viruses, fungi and parasites.

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.

Cardiovascular disease in HIV patients: from bench to bedside and backwards

HIV patients are exposed to a higher risk of adverse cardiovascular events, due to complex interactions between traditional risk factors and HIV infection itself in terms of ongoing endothelial dysfunctional immune activation/inflammation and increased risk of thrombosis. On the other hand, long-span antiretroviral therapy administration still raises questions on its long-term safety in an era in which life expectancy is becoming longer and longer while treatment of non-HIV-related serious events is increasingly raising concern. In this article, we will critically analyse the current knowledge of pathological and clinical aspects pertaining to the increased risk of cardiovascular events associated with HIV.

Neural effects of inflammation, cardiovascular disease, and HIV: Parallel, perpendicular, or progressive?

The pervasive reach of the inflammatory system is evidenced by its involvement in numerous disease states. Cardiovascular disease, marked by high levels of circulating inflammatory mediators, affects an estimated 83.6 million Americans. Similarly, human immunodeficiency virus (HIV) produces a paradoxical state of generalized immune activity despite widespread immunosuppression, and affects 35 million people worldwide. Patients living with HIV (PLWH) suffer from inflammatory conditions, including cardiovascular disease (CVD), at a rate exceeding the general population. In this combined disease state, immune mechanisms that are common to both CVD and HIV may interact to generate a progressive condition that contributes to the exacerbated pathogenesis of the other to the net effect of damage to the brain. In this review, we will outline inflammatory cell mediators that promote cardiovascular risk factors and disease initiation and detail how HIV-related proteins may accelerate this process. Finally, we examine the extent to which these comorbid conditions act as parallel, perpendicular, or progressive sequela of events to generate a neurodegenerative environment, and consider potential strategies that can be implemented to reduce the burden of CVD and inflammation in PLWH.

Dyslipidemia and cardiovascular risk in human immunodeficiency virus infection

The pathogenesis of atherosclerosis in human immunodeficiency virus (HIV)-infected individuals is incompletely understood and appears to be multifactorial. Proatherogenic changes in blood and tissue lipids are associated with an increased risk of cardiovascular disease among HIV-infected subjects, and these changes may be both quantitative (dyslipidemia) and qualitative. In view of the pivotal role of dyslipidemia in the process of atherosclerosis, the increased incidence of dyslipidemia in HIV-infected individuals, and the emerging role of lipid abnormalities in systemic pathophysiologic processes such as immune activation, we review the contributions of dyslipidemia to cardiovascular risk in HIV infection.

Post-transcriptional gene regulation by RNA-binding proteins in vascular endothelial dysfunction

Endothelial cell dysfunction is a term which implies the dysregulation of normal endothelial cell functions, including impairment of the barrier functions, control of vascular tone, disturbance of proliferative and migratory capacity of endothelial cells, as well as control of leukocyte trafficking. Endothelial dysfunction is an early step in vascular inflammatory diseases such as atherosclerosis, diabetic vascular complications, sepsis-induced or severe virus infection-induced organ injuries. The expressions of inflammatory cytokines and vascular adhesion molecules induced by various stimuli, such as modified lipids, smoking, advanced glycation end products and bacteria toxin, significantly contribute to the development of endothelial dysfunction. The transcriptional regulation of inflammatory cytokines and vascular adhesion molecules has been well-studied. However, the regulation of those gene expressions at post-transcriptional level is emerging. RNA-binding proteins have emerged as critical regulators of gene expression acting predominantly at the post-transcriptional level in microRNA-dependent or independent manners. This review summarizes the latest insights into the roles of RNA-binding proteins in controlling vascular endothelial cell functions and their contribution to the pathogenesis of vascular inflammatory diseases.