HIV infection, antiretroviral therapy, and measures of endothelial function, inflammation, metabolism, and oxidative stress

Retinal Vessel Functional Responses in South Africans Living With and Without HIV: The EndoAfrica-NWU Study

OBJECTIVES

The effects of HIV and antiretroviral therapy (ART) on microvascular function are poorly explored. We compared retinal vessel functional responses to flicker light-induced provocation (FLIP) in people living with HIV (PLWH) and people living without HIV (PLWoutH).

METHODS

We included 115 PLWH and 51 PLWoutH with a median age of 41 years. Treated PLWH received similar first-line fixed-dose combination ART. Clinical characteristics and retinal vessels functional responses to FLIP were compared in (a) PLWH and PLWoutH; and (b) PLWH groups stratified by the median of (i) CD4-count (511 cells/mm3), (ii) viral load (50 copies/mL), and (iii) ART duration (57.6 months).

RESULTS

PLWH were older, smoked more, and had a lower prevalence of hypertension than PLWoutH (p < 0.05). Almost 64% of PLWH were infected for more than 5 years. Retinal vessel responses to FLIP were similar between PLWH and PLWoutH after taking confounders into account. In addition, PLWH subgroups stratified according to immuno-virological status by CD4-count, viral load, and ART duration showed no differences in retinal vessel responses to FLIP.

CONCLUSION

Living with HIV and receiving ART were not associated with altered microvascular function as assessed with dynamic retinal vessel analysis in a South African case-control study.

Immune checkpoints and pancreatic beta cell dysfunction in HIV

We explored the impact of immune dysregulation on pancreatic beta cell injury in HIV patients. Analyzing 105 participant samples, we observed lower IL-21 levels and elevated immune checkpoint levels (e.g. PD-1, CD27+, CD40+) in untreated HIV patients. Notably, soluble TIM-3 correlated positively with improved beta cell function and inversely with beta cell stress, suggesting its potential role in beta cell protection in untreated HIV.

Distinct profile of antiviral drugs effects in aortic and pulmonary endothelial cells revealed by high-content microscopy and cell painting assays

Antiretroviral therapy have significantly improved the treatment of viral infections and reduced the associated mortality and morbidity rates. However, highly effective antiretroviral therapy (HAART) may lead to an increased risk of cardiovascular diseases, which could be related to endothelial toxicity. Here, seven antiviral drugs (remdesivir, PF-00835231, ritonavir, lopinavir, efavirenz, zidovudine and abacavir) were characterized against aortic (HAEC) and pulmonary (hLMVEC) endothelial cells, using high-content microscopy. The colourimetric study (MTS test) revealed similar toxicity profiles of all antiviral drugs tested in the concentration range of 1 nM-50 μM in aortic and pulmonary endothelial cells. Conversely, the drugs' effects on morphological parameters were more pronounced in HAECs as compared with hLMVECs. Based on the antiviral drugs' effects on the cytoplasmic and nuclei architecture (analyzed by multiple pre-defined parameters including SER texture and STAR morphology), the studied compounds were classified into five distinct morphological subgroups, each linked to a specific cellular response profile. In relation to morphological subgroup classification, antiviral drugs induced a loss of mitochondrial membrane potential, elevated ROS, changed lipid droplets/lysosomal content, decreased von Willebrand factor expression and micronuclei formation or dysregulated cellular autophagy. In conclusion, based on specific changes in endothelial cytoplasm, nuclei and subcellular morphology, the distinct endothelial response was identified for remdesivir, ritonavir, lopinavir, efavirenz, zidovudine and abacavir treatments. The effects detected in aortic endothelial cells were not detected in pulmonary endothelial cells. Taken together, high-content microscopy has proven to be a robust and informative method for endothelial drug profiling that may prove useful in predicting the organ-specific endothelial toxicity of various drugs.

Connection Between HIV and Mitochondria in Cardiovascular Disease and Implications for Treatments

HIV infection and antiretroviral therapy alter mitochondrial function, which can progressively lead to mitochondrial damage and accelerated aging. The interaction between persistent HIV reservoirs and mitochondria may provide insight into the relatively high rates of cardiovascular disease and mortality in persons living with HIV. In this review, we explore the intricate relationship between HIV and mitochondrial function, highlighting the potential for novel therapeutic strategies in the context of cardiovascular diseases. We reflect on mitochondrial dynamics, mitochondrial DNA, and mitochondrial antiviral signaling protein in the context of HIV. Furthermore, we summarize how toxicities related to early antiretroviral therapy and current highly active antiretroviral therapy can contribute to mitochondrial dysregulation, chronic inflammation, and poor clinical outcomes. There is a need to understand the mechanisms and develop new targeted therapies. We further consider current and potential future therapies for HIV and their interplay with mitochondria. We reflect on the next-generation antiretroviral therapies and HIV cure due to the direct and indirect effects of HIV persistence, associated comorbidities, coinfections, and the advancement of interdisciplinary research fields. This includes exploring novel and creative approaches to target mitochondria for therapeutic intervention.

HIV Infection, Antiretroviral Drugs, and the Vascular Endothelium

Endothelial cell activation, injury, and dysfunction underlies the pathophysiology of vascular diseases and infections associated with vascular dysfunction, including human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome. Despite viral suppression with combination antiretroviral therapy (ART), people living with HIV (PLWH) are prone to many comorbidities, including neurological and neuropsychiatric complications, cardiovascular and metabolic diseases, premature aging, and malignancies. HIV and viral proteins can directly contribute to the development of these comorbidities. However, with the continued high prevalence of these comorbidities despite viral suppression, it is likely that ART or some antiretroviral (ARVs) drugs contribute to the development and persistence of comorbid diseases in PLWH. These comorbid diseases often involve vascular activation, injury, and dysfunction. The purpose of this manuscript is to review the current literature on ARVs and the vascular endothelium in PLWH, animal models, and in vitro studies. I also summarize evidence of an association or lack thereof between ARV drugs or drug classes and the protection or injury/dysfunction of the vascular endothelium and vascular diseases.

Endothelial dysfunction, a predictor of cardiovascular disease in HIV patients on antiretroviral therapy: A systematic review and meta-analysis

Aim Although antiretroviral therapy (ART) is available, the rate of new HIV infections is alarming. With this trend, it is anticipated that the use of ART will continue to rise, potentially resulting in associated vascular disorders. Therefore, we aimed to examine the impact of ART on endothelial function in people living with HIV (PLHIV), a predictor of cardiovascular diseases.

METHOD

A comprehensive search for evidence was made on PubMed and Scopus on May 06, 2023, following the Preferred Reporting Items for Systematic Review and Meta-analysis. Cochrane and Newcastle-Ottawa quality assessment scales were used to evaluate quality, while the metaHun web tool and Review Manager version 5.4.1 were used for analysis. Subgroup, sensitivity, and publication bias were conducted for each outcome measure.

RESULTS

We identified 37 studies, including a sample size of 3700 with 2265 individuals on ART. The analyzed evidence showed a large significant effect of ART on vascular cell adhesion molecule-1, with a standardized mean difference (SMD) of -1.23 (95 % CI: -1.72, -0.74; p = 0.0013). Similarly, a significant medium effect of ART was observed on intercellular cell adhesion molecule-1 in PLHIV, with an SMD of -1.28 (95 % CI: -2.00, -0.56; p = 0.0231) compared to the control group. Furthermore, ART exhibited a significant but small effect on flow-mediated dilation (FMD) with an SMD of -0.40 (95 % CI: -0.62, -0.19, p = 0.0159).

CONCLUSION

Our findings show an improved endothelial function in PLHIV on ART, as demonstrated by reduced adhesion molecules; however, ART exhibited a small effect on FMD, thus suggesting PLHIV on ART may still be at risk of endothelial dysfunction and further cardiovascular diseases.

Large lessons learned from small vessels: coronary microvascular dysfunction in HIV

PURPOSE OF REVIEW

Large cohort studies have consistently shown the presence of heart failure is approximately doubled among persons with HIV (PWH). Early studies of cardiovascular disease (CVD) in HIV were primarily focused on atherosclerotic burden, and we now have a greater understanding of large vessel disease in HIV. More recent studies have begun to inform us about small vessel disease, or coronary microvascular dysfunction (CMD), in HIV. CMD is recognized to be an important risk factor for adverse events related to heart failure, associated with cardiovascular mortality, and often presents without overt atherosclerotic disease.

RECENT FINDINGS

In this review, we highlight implications for CMD and relevant clinical studies in HIV. Inflammation and endothelial dysfunction, well known risk factors in HIV, may mediate the pathogenesis of CMD. Initial studies suggest that CMD worsens with ART initiation. Newer studies reveal CMD is present among well treated PWH without known CVD. In addition, myocardial flow reserve (MFR), a marker of CMD, is reduced in HIV similar to diabetes. There also appears to be sex differences, such that CMD is worse among women vs. men with HIV.

SUMMARY

Alterations in the coronary microvasculature may be an important mediator of subclinical myocardial dysfunction that deserves further clinical attention among PWH without known CVD.

The role of HIV as a risk modifier for coronary endothelial function in young adults

BACKGROUND

People living with HIV have an increased risk of cardiovascular disease (CVD). Although coronary endothelial function (CEF) is an early direct indicator of CVD, only a few studies have been able to interrogate CEF directly. Most studies have examined vascular endothelial function through indirect assessment of brachial flow-mediated dilatation (FMD). However, peripheral arteries are significantly larger and manifest atherogenesis differently from the coronary arteries, and so produce conflicting results. Additionally, none of these studies focused on young adults who acquired HIV perinatally or in early childhood.

OBJECTIVE

The present study investigates CEF in a unique population of young adults with lifelong HIV using direct magnetic resonance imaging (MRI) of coronary FMD (corFMD) with an in-house developed MRI-integrated isometric handgrip exercise system with continuous feedback and monitoring mechanisms (fmIHE).

METHODS

Young adults who acquired HIV perinatally or in early childhood (n = 23) and group-matched healthy participants (n = 12) completed corFMD-MRI with fmIHE. CorFMD was measured as the coronary cross-sectional area response to the fmIHE.

RESULTS

In univariable and multivariable regression analysis, HIV status was a significant risk modifier. CD8+ T-cell count and smoking pack-years and their interaction with HIV status were independently associated with impaired coronary artery response to fmIHE. In people living with HIV, corFMD was significantly inversely correlated with CD8+ T-cells and smoking pack-years. In a multivariable regression analysis adjusted for age and body mass index, CD8+ T-cells and smoking and their interaction with HIV status remained significant independent predictors of coronary endothelial dysfunction.

DISCUSSION

In this unique population of young adults, HIV status was a significant risk modifier, and immune activation and smoking were associated with decreased CEF, directly measured from the coronary vascular response to fmIHE.

CONCLUSIONS

Management of CVD risk factors such as smoking and developing strategies that target immune activation in people living with HIV are warranted.

Plasma levels of fibrinolytic and coagulation biomarkers in HIV-infected individuals on highly active antiretroviral therapy: A case-control study in a Northern Ghanaian population

Background and Aim

Impaired coagulation and fibrinolysis have been implicated in thromboembolism in human immunodeficiency virus (HIV)-infected individuals. This study evaluated the plasma levels of plasminogen activator inhibitor-1 (PAI-1) and coagulation biomarkers in HIV-infected individuals on highly active antiretroviral therapy (HAART).

Methods

This matched case-control study from March to December, 2020 comprised 76 participants: 38 HIV-positive individuals on HAART and 38 apparently healthy HIV-negative individuals as controls. Blood samples were collected for prothrombin time (PT), activated partial thromboplastin time (aPTT), D-dimers, PAI-1, and soluble fibrin monomer complex (SFMC) estimations. The data were analysed using SPSS version 22.0 and statistical significance was set at p < 0.05.

Results

Activated partial thromboplastin time was significantly lower in HIV seropositive individuals on HAART compared with HIV seronegative controls (25.90 s vs. 29.0 s, p = 0.030); however, PT, SFMC, D-dimers, and PAI-1 were significantly higher among the HIV-seropositive individuals compared with the controls: PT: (16.29 s ± 2.16 vs. 15.15 s ± 2.60, p = 0.010), SFMC: [8.53 ng/mL (8.03-9.12) vs. 7.84 ng/mL (7.32-8.58), p = 0.005]), D-Dimer: [463.37 ng/mL (402.70-526.33) vs. 421.11 ng/mL (341.11-462.52), p = 0.015], and PAI-1: [12.77 ng/mL (10.63-14.65) vs. 11.27 ng/mL (10.08-12.95), p = 0.039]. PAI-1 showed a moderate positive correlation with D-Dimer (r = 0.659, p < 0.001) and SFMC (r = 0.463, p = 0.003) among HIV-positive individuals on HAART. There was a strong positive correlation between the plasma PAI-1 concentration and the HIV viral load (r = 0.955, p < 0.001).

Conclusion

HIV-seropositive individuals on HAART have deranged coagulation and fibrinolytic markers. Higher HIV viral load correlates strongly with elevated plasma levels of PAI-1 antigens. Periodic assessment of markers of coagulation and fibrinolysis be included in the management of HIV/AIDS in Ghana.

HIV and race are independently associated with endothelial dysfunction

OBJECTIVE

Evaluating the vascular function in HIV-infected compared with HIV uninfected with assessment of body composition, inflammation, and gut integrity markers.

DESIGN

A noninvasive test that measures the endothelial function.

METHODS

We included participants at least 18 years old, with peripheral arterial tonometry testing (EndoPAT2000) between 2014 and 2022. Persons with HIV (PWH) had documented infection, a stable ART regimen, and a viral load less than 400 copies/ml. We measured the vessel's function with the reactive hyperemia index (RHI) (normal >1.67) and Augmentation Index. Lower Augmentation Index reflect better arterial elasticity. We assessed markers of systemic inflammation, immune activation, and gut integrity. We used linear mixed models to estimate endothelial dysfunction with a significant P value less than 0.05.

RESULTS

Overall, 511 participants (296 HIV-infected; 215 HIV-uninfected controls) were included. Estimated RHI among PWH was 13% lower (P = 0.01) compared with persons without HIV. In nonwhite race, the estimated RHI was 9% lower (P = 0.001) than white race. For every 1% increase in BMI, we would expect RHI to increase 0.17% (P = 0.01). At the time of EndoPAT, the estimated RHI was 8% lower (P = 0.04) among protease inhibitor users compared with PWH who were not taking protease inhibitors. The estimated odds of abnormal RHI ≤1.67) is 1.56 times greater [95% confidence interval (CI) 1.05-2.31] in nonwhite race compared with white race, independent of HIV status [OR = 1.4 (95% CI 0.94-2.13)]. There was not enough evidence to suggest that inflammation, gut, or monocyte markers, current or nadir CD4+ cell count, or duration of HIV were associated with endothelial dysfunction.

CONCLUSION

HIV, nonwhite race, and protease inhibitor use are independently associated with endothelial dysfunction.

Elevated inflammatory fecal immune factors in men who have sex with men with HIV associate with microbiome composition and gut barrier function

Introduction

People living with HIV infection (PLWH) exhibit elevated levels of gastrointestinal inflammation. Potential causes of this inflammation include HIV infection and associated immune dysfunction, sexual behaviors among men who have sex with men (MSM) and gut microbiome composition.

Methods

To better understand the etiology of gastrointestinal inflammation we examined levels of 28 fecal soluble immune factors (sIFs) and the fecal microbiome in well-defined cohorts of HIV seronegative MSM (MSM-SN), MSM with untreated HIV infection (MSM-HIV) and MSM with HIV on anti-retroviral treatment (MSMART). Additionally, fecal solutes from these participants were used to stimulate T-84 colonic epithelial cells to assess barrier function.

Results

Both MSM cohorts with HIV had elevated levels of fecal calprotectin, a clinically relevant marker of GI inflammation, and nine inflammatory fecal sIFs (GM-CSF, ICAM-1, IL-1β, IL-12/23, IL-15, IL-16, TNF-β, VCAM-1, and VEGF). Interestingly, four sIFs (GM-CSF, ICAM-1, IL-7 and IL-12/23) were significantly elevated in MSM-SN compared to seronegative male non-MSM. Conversely, IL-22 and IL-13, cytokines beneficial to gut health, were decreased in all MSM with HIV and MSM-SN respectively. Importantly, all of these sIFs significantly correlated with calprotectin, suggesting they play a role in GI inflammation. Principal coordinate analysis revealed clustering of fecal sIFs by MSM status and significant associations with microbiome composition. Additionally, fecal solutes from participants in the MSM-HIV cohort significantly decreased colonic transcellular fluid transport in vitro, compared to non-MSM-SN, and this decrease associated with overall sIF composition and increased concentrations of eight inflammatory sIFs in participants with HIV. Lastly, elevated levels of plasma, sCD14 and sCD163, directly correlated with decreased transcellular transport and microbiome composition respectively, indicating that sIFs and the gut microbiome are associated with, and potentially contribute to, bacterial translocation.

Conclusion

Taken together, these data demonstrate that inflammatory sIFs are elevated in MSM, regardless of HIV infection status, and are associated with the gut microbiome and intestinal barrier function.

HIV-associated thrombotic thrombocytopenic purpura (HIV-TTP): A practical guide and review of the literature

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP), a serious thrombotic microangiopathy (TMA), is prevalent in the South African HIV-infected population. The exact pathogenesis of HIV-associated TTP (HIV-TTP) is however still unclear with diagnostic and therapeutic inconsistancies.

METHODS

A systematic review of the published literature regarding HIV-TTP was performed.

RESULTS

HIV-TTP is still associated with significant morbidity and mortality in Africa despite the availability of anti-retroviral therpy (ART). Diagnosis of HIV-TTP requires the presence of a micro-angiopathic haemolytic anaemia with significant red blood cell schistocytes and thrombocytopenia in the absence of another TMA but background activation of the coagulation system and inflammation in HIV infected people can result in diagnostic anbiguity. Plasma therapy in the form of infusion or exchange is successful but expensive, associated with side-effects and not widely available. Adjuvant immunosuppression therapy may of benefit in patients with HIV-TTP and ART must always be optimised. Endothelial dysfunction caused by chronic inflammation and complement activation most likely contributes to the development of HIV-TTP.

CONCLUSION

The role of adjuvant immunomodulating therpy, the therapeutic targets and pathogenic contribution from endothelial dysfunction in HIV-TTP requires further investigation.

Distinguishing and overlapping laboratory results of thrombotic microangiopathies in HIV infection: Can scoring systems assist?

BACKGROUND

Patients with Human Immunodeficiency Virus (HIV) infection are at risk of thrombotic microangiopathies (TMAs) notably thrombotic thrombocytopenic purpura (TTP) and disseminated intravascular coagulation (DIC). Overlap between laboratory results exists resulting in diagnostic ambiguity.

METHODS

Routine laboratory results of 71 patients with HIV-associated TTP (HIV-TTP) and 81 with DIC with concomitant HIV infection (HIV-DIC) admitted between 2015 and 2021 to academic hospitals in Johannesburg, South Africa were retrospectively reviewed. Both the PLASMIC and the International Society of Thrombosis and Haemostasis (ISTH) DIC scores were calculated.

RESULTS

Patients with HIV-TTP had significantly (P < .001) increased schistocytes and features of hemolysis including elevated lactate dehydrogenase (LDH)/upper-limit-of-normal ratio (median of 9 (interquartile range [IQR] 5-12) vs 3 (IQR 2-5)) but unexpectedly lower fibrinogen (median 2.8 (IQR 2.2-3.4) vs 4 g/L (IQR 2.5-9.2)) and higher D-dimer (median 4.8 (IQR 2.4-8.1) vs 3.6 g/L (IQR 1.7-6.2)) levels vs the HIV-DIC cohort. Patients with HIV-DIC were more immunocompromised with frequent secondary infections, higher platelet and hemoglobin levels, more deranged coagulation parameters and less hemolysis. Overlap in scoring systems was however observed.

CONCLUSION

The laboratory parameter overlap between HIV-DIC and HIV-TTP might reflect a shared pathogenesis including endothelial dysfunction and inflammation and further research is required. Fibrinogen in DIC may be elevated as an acute phase reactant and D-dimers may reflect the extensive hemostatic activation in HIV-TTP. Inclusion of additional parameters in TMA scoring systems such the LDH/upper-limit-of-normal ratio, schistocytes count and wider access to ADAMTS-13 testing may enhance diagnostic accuracy and ensure appropriate utilization of plasma.

Hypertension and human immunodeficiency virus: A paradigm for epithelial sodium channels?

Hypertension is a risk factor for end organ damage and death and is more common in persons with HIV compared to the general population. Several mechanisms have been studied in the pathogenesis of hypertension. Current evidence suggests that the epithelial sodium channel (ENaC) plays a key role in regulating blood pressure through the transport of sodium and water across membranes in the kidney tubules, resulting in retention of sodium and water and an altered fluid balance. However, there is scarcity of information that elucidates the role of ENaC in HIV as it relates to increasing the risk for development or pathogenesis of hypertension. This review summarized the evidence to date implicating a potential role for altered ENaC activity in contributing to hypertension in patients with HIV.

HIV, Combination Antiretroviral Therapy, and Vascular Diseases in Men and Women

Thanks to the advent of combination antiretroviral therapy (cART), people living with human immunodeficiency virus (HIV) (PLWH) experienced a marked increase in life expectancy but are now at higher risk for cardiovascular disease (CVD), the current leading cause of death in PLWH on cART. Although HIV preponderantly affects men over women, manifestations of HIV-related CVD differ by sex with women experiencing greater risks than men. Despite extensive investigation, the etiopathology of CVD, notably the respective contribution of viral infection and cART, remain ill-defined. However, both viral infection and cART have been reported to contribute to endothelial dysfunction, the precursor and major cause of atherosclerosis-associated CVD, through mechanisms involving endothelial cell activation, inflammation, and oxidative stress, all leading to reduced nitric oxide bioavailability. Therefore, preserving endothelial function in PLWH on cART should be a main target to reduce CVD morbidity and mortality, notably in females.

Factors Associated With Being Overweight and Obesity in People Living With Human Immunodeficiency Virus on Antiretroviral Therapy: Socioclinical, Inflammation, and Metabolic Markers

BACKGROUND

We investigated the association between socioclinical, inflammatory, and metabolic markers and weight gain in people with human immunodeficiency virus (HIV) on combination antiretroviral therapy (cART).

METHODS

Individuals from the COPANA cohort of normal weight (body mass index [BMI], 18.5-24.9 [ calculated as weight in kilograms divided by height in meters squared) at cART initiation who achieved virological suppression (viral load, <50 copies/mL) and maintained it through 36 months of treatment were selected. Clinical, immunovirological, and socioeconomic data and inflammation (high-sensitivity C-reactive protein, CXCL10, CXCL8, interleukin 6, soluble tumor necrosis factor receptors 1 and 2, soluble CD14, and soluble CD16) and serum metabolic (glucose, insulin, lipid profile, adiponectin, and leptin) markers were assessed. Factors associated with becoming overweight (BMI, 25-29.9) or obese (BMI, ≥30) at 36 months were assessed using multivariate logistic regression models.

RESULTS

After 36 months of cART, 32 of 158 people with HIV (20%) became overweight or obese (21% female; 65% born in France and 23% born in sub-Saharan Africa; median BMI at cART initiation, 22 [interquartile range, 21-23]). After adjustment, higher BMI, originating from sub-Saharan Africa, living in a couple, and higher soluble tumor necrosis factor receptor 2 and lower adiponectin concentrations at cART initiation were associated with becoming overweight or obese.

CONCLUSION

Weight gain on cART is multifactorial. Special attention should be given to migrants from sub-Saharan Africa. Monocyte activation and adipocyte dysfunction at cART initiation affect weight regulation.

Effect of HIV-1 Infection on Angiopoietin 1 and 2 Levels and Measures of Microvascular and Macrovascular Endothelial Dysfunction

Background Individuals infected with HIV have an increased risk of developing cardiovascular disease; yet, the underlying mechanisms remain unknown. Recent evidence has implicated the Tie-2 tyrosine kinase receptor system and its associated ligands ANG1 (angiopoietin 1) and ANG2 (angiopoietin 2) in maintaining vascular homeostasis. In the general population, lower ANG1 levels and higher ANG2 levels are strongly correlated with the development of cardiovascular disease. In this study, we aim to investigate the associations of HIV infection with angiopoietin levels and endothelial dysfunction. Methods and Results In this cross-sectional study, we compared measures of ANG1, ANG2, and endothelial dysfunction using flow-mediated vasodilation of the brachial artery in 39 untreated subjects infected with HIV, 47 treated subjects infected with HIV, and 46 uninfected subjects from the SCOPE (Observational Study of the Consequences of the Protease Inhibitor Era) cohort. Compared with uninfected controls, treated individuals infected with HIV had 53.1% lower mean ANG1 levels (P<0.01) and similar ANG2 levels. On the other hand, untreated individuals infected with HIV had similar ANG1 levels, and 29.2% had higher ANG2 levels (P<0.01) compared with uninfected controls. When compared with individuals with untreated HIV infection, those with treated HIV infection had 56% lower ANG1 levels (P<0.01) and 22% lower ANG2 levels (P<0.01).Both treated and untreated HIV infection were associated with significant impairment in hyperemic velocity, a key measure of microvascular dysfunction (median 61 versus 72 cm/s, P<0.01), compared with uninfected controls (median 73 cm/s). This difference persisted after adjustment for ANG1 and ANG2 levels. Interestingly, when compared with untreated individuals infected with HIV, treated individuals infected with HIV had worse hyperemic velocity (-12.35 cm/s, P=0.05). In contrast, HIV status, ANG1 levels, and ANG2 levels were not associated with macrovascular dysfunction as measured by flow-mediated dilatation and brachial artery diameter, 2 other measures of vascular homeostasis. Conclusions HIV infection affects the balance between levels of ANG1 and ANG2 and may disturb endothelial homeostasis through disruption of vascular homeostasis. Individuals with treated HIV had decreased ANG1 levels and similar ANG2 levels, whereas individuals with untreated HIV had similar ANG1 levels and increased ANG2 levels, suggesting that treatment status may alter the balance between ANG1 and ANG2. HIV also promotes endothelial dysfunction via impairment of microvascular dysfunction, independent of the Tie-2 receptor system; the finding of worse microvascular dysfunction in the setting of treated HIV infection may reflect the impact of viral persistence on the microvasculature or toxicities of specific antiretroviral regimens. Further research to clarify the mechanism of HIV-mediated endothelial dysfunction is necessary to advance treatment of cardiovascular complications of HIV infection.

Cytomegalovirus may influence vascular endothelial health in Indonesian HIV-infected patients after 5 years on ART

Objectives

Accelerated atherosclerosis in older HIV-infected patients has been attributed to persistent immune activation and high burden cytomegalovirus (CMV), as demonstrated in transplant recipients and the general population. Here we assess CMV and inflammatory markers linked with vascular health in young adult patients treated in Indonesia.

Study design

HIV-infected adults (n = 32) were examined when they began antiretroviral therapy (ART) with < 200 CD4 T-cells/µl (V0) and after 60 months (V60). Age-matched healthy controls (HC, n = 32) were assessed once.

Methods

Flow Mediated Dilatation (FMD) was assessed by ultrasound on brachial arteries at V60 and in HC. Plasma markers of immune activation and endothelial activation, and CMV antibodies (lysate, gB, IE-1) were assessed in all samples. Results were assessed using bivariate (non-parametric) and multivariable analyses.

Results

Levels of inflammatory biomarkers and CMV antibodies declined on ART, but the antibodies remained higher than in HC. FMD values were similar in patients and HC at V60. In HIV patients, levels of CMV lysate antibody correlated inversely (r = − 0.37) with FMD. The optimal model predicting lower FMD values (adjusted R² = 0.214, p = 0.012) included CMV lysate antibodies and chondroitin sulphate. In HC, levels of sTNFR correlated inversely with FMD (r = − 0.41) and remained as a risk factor in the optimal multivariable model, with CMV glycoprotein-B (gB) antibody predicting a healthier FMD (adjusted R² = 0.248, p = 0.013).

Conclusions

Higher levels CMV antibodies optimally predict vascular health measured by FMD in HIV patients. However in healthy controls, sTNFR marks risk and CMV gB antibody may be protective.

Time Course of Redox Biomarkers in COVID-19 Pneumonia: Relation with Inflammatory, Multiorgan Impairment Biomarkers and CT Findings

Although the original data on systemic oxidative stress in COVID-19 patients have recently started to emerge, we are still far from a complete profile of changes in patients' redox homeostasis. We aimed to assess the extent of oxidative damage of proteins, lipids and DNA during the course of acute disease, as well as their association with CT pulmonary patterns. In order to obtain more insight into the origin of the systemic oxidative stress, the observed parameters were correlated with inflammatory biomarkers and biomarkers of multiorgan impairment. In this prospective study, we included 58 patients admitted between July and October 2020 with COVID-19 pneumonia. Significant changes in malondialdehyde, 8-hydroxy-2'-deoxyguanosine and advanced oxidation protein products levels exist during the course of COVID-19. Special emphasis should be placed on the fact that the pattern of changes differs between non-hospitalized and hospitalized individuals. Our results point to the time-dependent relation of oxidative stress parameters with inflammatory and multiorgan impairment biomarkers, as well as pulmonary patterns in COVID-19 pneumonia patients. Correlation between redox biomarkers and immunological or multiorgan impairment biomarkers, as well as pulmonary CT pattern, confirms the suggested involvement of neutrophils networks, IL-6 production, along with different organ/tissue involvement in systemic oxidative stress in COVID-19.

Susceptibility of the patients infected with Sars-Cov2 to oxidative stress and possible interplay with severity of the disease

Several recent reviews have suggested a role of oxidative stress in the pathophysiology of COVID-19, but its interplay with disease severity has not been revealed yet. In the present study, we aimed to investigate the association between the severity of COVID-19 and oxidative stress parameters. Clinical data of 77 patients with COVID-19 admitted to the hospital were analyzed and divided into moderate (n = 44) and severe (n = 33) groups based on their clinical condition. Production of oxidant (hydrogen peroxide) and defense antioxidants (total antioxidant capacity, reduced and oxidized glutathione, glutathione s-transferase), and oxidative damage (malondialdehyde, carbonyl, and sulfhydryl) were assessed using the serum samples. The results revealed that severe patients who presented high serum leukocyte count and CRP level stayed for a longer period in the hospital. However, there was no correlation observed between the oxidative stress parameters and degree of COVID-19 severity in the present study. In conclusion, these results indicate that the disease severity may not be a detrimental factor contributing to the changes in the redox profile of hospitalized patients with COVID-19.

Relationship between Endothelial Function, Antiretroviral Treatment and Cardiovascular Risk Factors in HIV Patients of African Descent in South Africa: A Cross-Sectional Study

Limited information on the effect of antiretroviral treatment (ART) on vascular function in South Africans of African descent living with human immunodeficiency virus (HIV) is available. The relationship between ART, vascular function and cardiovascular risk factors in South Africans of African ancestry with HIV was therefore studied. This cross-sectional study recruited 146 HIV-positive individuals on ART (HIV⁺ART⁺), 163 HIV-positive individuals not on ART (HIV⁺ART⁻) and 171 individuals without HIV (HIV⁻) in Mthatha, Eastern Cape Province of South Africa. Flow-mediated dilation (FMD) test was performed to assess endothelial function. Anthropometry and blood pressure parameters were measured. Lipid profile, glycaemic indices, serum creatinine as well as CD4 count and viral load were assayed in blood. Urinary albumin to creatinine ratio (ACR) was determined as a marker of cardiovascular risk. Obesity and albuminuria were positively associated with HIV, and HIV⁺ART⁺ participants had significantly higher HDL cholesterol. Dyslipidaemia markers were significantly higher in hypertensive HIV⁺ART⁺ participants compared with the controls (HIV⁺ART⁻ and HIV⁻ participants). FMD was not different between HIV⁺ART⁺ participants and the controls. Moreover, HIV⁺ART⁺ participants with higher FMD showed lower total cholesterol and LDL cholesterol comparable to that of HIV⁻ and HIV⁺ART⁻ participants. A positive relationship between FMD and CD4 count was observed in HIV⁺ART⁺ participants. In conclusion, antiretroviral treatment was associated with cardiovascular risk factors, particularly dyslipidaemia, in hypertensive South Africans of African ancestry with HIV. Although, ART was not associated with endothelial dysfunction, flow-mediated dilatation was positively associated with CD4 count in HIV-positive participants on ART.

Short-term aerobic training improves heart rate variability in men living with HIV: a pre-post pilot study

BACKGROUND

Heart rate variability (HRV) a feasible predictor of prognosis in cardiovascular outcomes shown to be reduced in people living with HIV (PLWH).

OBJECTIVE

This study sought to understand the effects of short-term aerobic training (AT) on the resting HRV and endothelial function in this population.

METHODS

PLWH performed 24 sessions of AT protocol. The protocol consists of 40 min of treadmill (60 to 80% of the VO_2max), 3 times per week, for 8 weeks. HRV (standard deviation of all normal RR intervals - SDNN; root mean square of the successive differences - rMSSD; low frequency - LF; high frequency - HF; LF:HF ratio) and endothelial function parameters were evaluated by EndoPAT system pre and post intervention.

RESULTS

7 men, the median age of the sample was 49 years (range, 38-68 years), completed the protocol. AT improved resting HRV parameters: SDNN (p = 0.02, power analysis (PA) 0.54), rMSSD (p = 0.02, PA = 0.99), LF (p = 0.02, PA = 0.85). HF, LF:HF ratio and endothelial function parameters showed no changes.

CONCLUSIONS

The results suggest the short-term AT may improve HRV in men living with HIV.

Modulation of Monocyte Activation and Function during Direct Antiviral Agent Treatment in Patients Coinfected with HIV and Hepatitis C Virus

The activation phenotypes and functional changes in monocyte subsets during hepatitis C virus (HCV) elimination in HIV/HCV-coinfected patients were evaluated. Twenty-two HIV/HCV-coinfected patients on suppressive combination antiretroviral treatment (cART) achieving HCV elimination after direct-acting antiviral (DAA) therapy and 10 HIV-monoinfected patients were included. The activation phenotype (10 markers) and polyfunctionality (intracellular interleukin-1α [IL-1α], IL-1β, IL-6, IL-8, tumor necrosis factor alpha [TNF-α], and IL-10 production) in three monocyte subsets (classical, intermediate, and nonclassical) were evaluated by flow cytometry before and at the end of treatment. Cell-associated HIV DNA levels were assayed by droplet digital PCR. After HCV clearance, there was a significant increase in classical monocyte and decreases in intermediate and nonclassical monocyte levels. The levels of the activation markers CD49d, CD40, and CX3CR1 were decreased after treatment in the monocyte subsets, reaching the levels in HIV-monoinfected patients. After lipopolysaccharide (LPS) stimulation, although polyfunctionality significantly decreased in intermediate and nonclassical monocytes, some combinations, such as the IL-1α- (IL-1α-negative) IL-1β- IL-6+ (IL-6-producing) IL-8- TNF-α- IL-10- combination, were remarkably increased at the end of treatment compared to the control group. Cell-associated HIV DNA levels correlated with activation markers before but not after treatment. HCV clearance after DAA treatment in patients on cART exerts an anti-inflammatory profile on monocyte subsets, activation phenotypes, and polyfunctionality. However, there is not a complete normalization compared with HIV-monoinfected patients.

The association of nadir CD4-T cell count and endothelial dysfunction in a healthy HIV cohort without major cardiovascular risk factors

Objectives:

HIV-infected population may have increased risk of cardiovascular disease. The prevalence of traditional cardiovascular disease risk factors such as hypertension, diabetes and dyslipidemia in HIV-infected individuals has made it difficult to assess the direct effects of HIV and immune factors on endothelial dysfunction and associated increased risk of atherosclerosis. The purpose of this study was to investigate indicators of endothelial dysfunction in an HIV cohort without hypertension and diabetes.

Methods:

We studied 19 HIV-infected patients between the ages of 25–76 years old with effectively suppressed viral load and without diagnosis of hypertension or diabetes. Endothelial function was measured by digital thermal monitoring of vascular reactivity using the VENDYS technique. Endothelial function was reported as vascular reactivity index. Systolic blood pressure and diastolic blood pressure at the time of VENDYS test were measured and latest lipid panels were recorded. The association between vascular reactivity index and CD4-T cells count, different antiretroviral therapy types (non-nucleoside reverse transcriptase, nucleoside reverse transcriptase, protease inhibitors, integrase inhibitors), vitamins use, systolic blood pressure, diastolic blood pressure, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol was investigated.

Results:

Mean vascular reactivity index was 1.87 ± 0.53. Vascular reactivity index, marker of endothelial dysfunction, showed a significant correlation with lower nadir CD4 count (p = 0.003) as well as low-density lipoprotein cholesterol (p = 0.02). No additional significant correlation between vascular reactivity index and the rest of the investigated variables was found.

Conclusion:

Vascular reactivity index, a clinical predictor of endothelial dysfunction, is associated with lower nadir CD4-T cell and low-density lipoprotein cholesterol in HIV-infected men with no history of hypertension or diabetes and before clinical evidence of cardiovascular disease.

Near-infrared spectroscopy-derived muscle oxygen saturation during exercise recovery and flow-mediated dilation are impaired in HIV-infected patients

Highly active antiretroviral therapy has been associated with the presence of endothelial dysfunction in HIV-infected patients, which may impair oxygen delivery to muscles during exercise and exercise recovery. Near-infrared spectroscopy (NIRS) has been used to assess muscle oxygen saturation (SmO₂) kinetics during exercise in different clinical populations in order to evaluate the balance between oxygen delivery and utilization by muscles. However, studies assessing SmO₂ in HIV-infected patients have not been conducted. Therefore, the aim of the study was to evaluate NIRS-derived SmO₂ during rhythmic handgrip exercise and flow-mediated dilation (FMD) in HIV-infected patients (HIV) compared to non-HIV-infected controls (N-HIV). Eighteen HIV and 17 N-HIV individuals underwent FMD assessment by ultrasound. The subjects then performed one set of rhythmic handgrip exercise until fatigue at 30% maximal isometric voluntary contraction. SmO₂ was measured during entire exercise and 2-min exercise 3recovery. Muscle oxygen resaturation rate (upslope of the SmO₂ over 10 s of recovery) was calculated. A significant lower FMD (3.5 ± 1.7 vs 5.9 ± 1.5%, P < 0.001) and slower oxygen resaturation rate (0.78 ± 0.4 vs 1.14 ± 0.4%·s^-1, P = 0.020) in HIV as compared to N-HIV group were observed. In conclusion, our findings demonstrated that HIV-infected patients had reduced FMD and impaired muscle oxygenation during exercise recovery compared to non-HIV individuals.

Good Fences Make Good Neighbors: Human Immunodeficiency Virus and Vascular Disease

Cardiovascular disease, venous thrombosis, and microvascular disease in people with HIV (PWH) is predicted to increase in an aging HIV-infected population. Endothelial damage and dysfunction is a risk factor for cardiovascular events in PWH and is characterized by impaired vascular relaxation and decreased nitric oxide availability. Vascular disease has been attributed to direct viral effects, opportunistic infections, chronic inflammation, effects of antiretroviral therapy, and underlying comorbid conditions, like hypertension and use of tobacco. Although biomarkers have been examined to predict and prognosticate thrombotic and cardiovascular disease in this population, more comprehensive validation of risk factors is necessary to ensure patients are managed appropriately. This review examines the pathogenesis of vascular disease in PWH and summarizes the biomarkers used to predict vascular disease in this population.

Monotypic low-level HIV viremias during antiretroviral therapy are associated with disproportionate production of X4 virions and systemic immune activation

OBJECTIVE

During effective antiretroviral therapy (ART), low-level plasma viremias (LLV) (HIV RNA >30-1000 copies/ml) can be detected intermittently. We hypothesized that systemic inflammation is associated with LLV either as the cause or result of the production of virions from clonally expanded cells.

METHODS

Prospective cohort study of HIV-infected ART-naive Peruvians enrolled prior to ART and followed for 2 years. Plasma HIV RNA and peripheral blood mononuclear cell (PBMC) HIV DNA concentrations were quantified pre-ART from individuals whose plasma HIV RNA was ART-suppressed. Inflammatory biomarker concentrations were measured pre and during ART. Single-genome amplification (SGA) derived HIV env and pol genotypes from pre-ART and LLV specimens. Antiretroviral levels during ART assessed adherence. Statistical associations and phylogenetic relationships were examined.

RESULTS

Among 82 participants with median plasma HIV RNA less than 30 copies/ml, LLV were detected in 33 of 82 (40%), with a LLV median HIV RNA of 73 copies/ml. Participants with vs. without LLV had significantly higher pre-ART plasma HIV RNA (P < 0.001) and PBMC HIV DNA (P < 0.007); but, during ART, their antiretroviral drug levels were similar. LLV env sequences were monotypic in 17 of 28 (61%) and diverse in 11 of 28 (39%) participants. Those with the monotypic vs. diverse LLV pattern had elevated hsCRP and sCD163 (P = 0.004) and LLV with more X4 variants (P = 0.02).

CONCLUSION

In individuals with monotypic LLV sequences, higher levels of pre-ART HIV DNA and RNA, systemic inflammation and X4 viruses suggest an interaction between inflammation and the production of virions from proliferating infected cells, and that naïve T cells may be a source of LLV.

Immune reconstitution in ART treated, but not untreated HIV infection, is associated with abnormal beta cell function

HIV infection has been associated with increased diabetes risk, but prior work has mostly focused on insulin resistance, as opposed to beta cell effects, or included patients on antiretroviral therapies (ART) directly linked to metabolic toxicity. In this analysis, we measured markers of glucose homeostasis and beta cell function, stress, and death in fasting sera from a cross section of HIV+ individuals off ART (n = 43), HIV+ individuals on ART (n = 23), and HIV- controls (n = 39). Markers included glucose, HOMA%S, HOMA%B, proinsulin:C-peptide ratio (PI:C ratio), and circulating preproinsulin (INS) DNA. We performed multiple linear regressions with adjustments for age, sex, race, BMI, and smoking status. Compared to HIV- controls, HIV+ participants off ART exhibited similar beta cell function and insulin sensitivity, without increases in markers of beta cell stress or death. Specifically, in HIV+ participants with CD4 counts <350 cells/μL, PI:C ratios were lower than in HIV- controls (p<0.01), suggesting a reduction in intrinsic beta cell stress among this group. By contrast, HIV+ participants on ART had higher fasting glucose (p<0.0001) and lower HOMA%B (p<0.001) compared to HIV- controls. Among the entire HIV+ population, higher HIV RNA correlated with lower fasting glucose (r = -0.57, p<0.001), higher HOMA%B (r = 0.40, p = 0.001), and lower PI:C ratios (r = -0.42, p<0.001), whereas higher CD4 counts correlated with higher PI:C ratios (r = 0.2, p = 0.00499). Our results suggest that HIV seropositivity in the absence of ART does not worsen beta cell function or glucose homeostasis, but immune reconstitution with ART may be associated with worsened beta cell function.

A baseline metabolomic signature is associated with immunological CD4+ T-cell recovery after 36 months of antiretroviral therapy in HIV-infected patients

Objectives:

Poor immunological recovery in treated HIV-infected patients is associated with greater morbidity and mortality. To date, predictive biomarkers of this incomplete immune reconstitution have not been established. We aimed to identify a baseline metabolomic signature associated with a poor immunological recovery after antiretroviral therapy (ART) to envisage the underlying mechanistic pathways that influence the treatment response.

Design:

This was a multicentre, prospective cohort study in ART-naive and a pre-ART low nadir (<200 cells/μl) HIV-infected patients (n = 64).

Methods:

We obtained clinical data and metabolomic profiles for each individual, in which low molecular weight metabolites, lipids and lipoproteins (including particle concentrations and sizes) were measured by NMR spectroscopy. Immunological recovery was defined as reaching CD4⁺ T-cell count at least 250 cells/μl after 36 months of virologically successful ART. We used univariate comparisons, Random Forest test and receiver-operating characteristic curves to identify and evaluate the predictive factors of immunological recovery after treatment.

Results:

HIV-infected patients with a baseline metabolic pattern characterized by high levels of large high density lipoprotein (HDL) particles, HDL cholesterol and larger sizes of low density lipoprotein particles had a better immunological recovery after treatment. Conversely, patients with high ratios of non-HDL lipoprotein particles did not experience this full recovery. Medium very-low-density lipoprotein particles and glucose increased the classification power of the multivariate model despite not showing any significant differences between the two groups.

Conclusion:

In HIV-infected patients, a baseline healthier metabolomic profile is related to a better response to ART where the lipoprotein profile, mainly large HDL particles, may play a key role.