Endothelial Glycocalyx Damage and Renal Dysfunction in HIV Patients Receiving Combined Antiretroviral Therapy

Angiopoietin-2 and endothelial damage associated with viral load in untreated people living with HIV

BackgroundHIV infection is associated with various types of endothelial damage. Early and accurate diagnosis of endothelial dysfunction may help prevent adverse outcomes. For the first time, this cross-sectional study aims to investigate the effects of increased viral load on endothelial damage and nephrinuria in untreated people living with HIV.MethodsPeople living with HIV not on treatment were included. Laboratory parameters, such as viral load and CD4 count were collected. Participants were divided into three groups according to the tertiles of viral load: low, moderate and high viral load groups. Urinary nephrin, vascular cell adhesion molecule 1 (VCAM-1), angiopoietin-2 and syndecan-1 were quantified by sandwich ELISA assays kits.ResultsA total of 49 patients were examined. The high viral load group (3rd tertile) exhibited a greater frequency of nephrinuria and significantly higher levels of syndecan-1 (58 [48-93] vs 43 [38-65] ng/mL, p = .049) and angiopoietin-2 (2.58 [1.5-3.06] vs 1.34 [0.89-1.76] ng/mL, p = .035). Syndecan-1 levels positively correlated with viral load (rho = 0.452, p = .006), while angiopoietin-2 was positively correlated with viral load (rho = 0.529, p = .001) and inversely correlated with CD4 count (rho = -0.493, p = .003). No significant associations were found for VCAM-1 levels.ConclusionUntreated people living with HIV with elevated viral loads exhibited more pronounced endothelial damage and vascular inflammation, emphasizing the critical importance of early initiation of antiretroviral treatment to mitigate these complications. However, the study's findings should be interpreted with caution due to the small sample size, which may limit the generalizability of the results. Future studies with larger cohorts are needed to confirm these findings.

Endothelial injury and decline in lung function in persons living with HIV: a prospective Danish cohort study including 698 adults

Objectives

Endothelial injury may promote declining lung function. We aimed to investigate in well-treated persons living with HIV (PLWH) whether elevated levels of thrombomodulin (TM) and syndecan-1 (SDC1) are associated with excess lung function decline and worsening dyspnea.

Methods

A prospective cohort study comprising patients from the Copenhagen municipality. We included 698 PLWH with undetectable viral load. Biomarkers and demographics were measured at baseline, spirometry [forced expiratory volume in one second (FEV1) and forced vital capacity (FVC)] and dyspnea score both at baseline and 2-year follow-up.Both biomarkers were dichotomized at the 3rd quartile. Decline in lung function was estimated using a linear mixed model with patient-specific random effect. Increase in dyspnea score was estimated using a general mixed logistic regression model.

Results

We did not find an association between elevated SDC1 or TM and an excess decline in neither FEV1: SDC1: 4.5 mL/year (95% CI: -3.9-12.9, p = 0.30), TM: 2.2 mL/year (95% CI: -6.0-10.4, p = 0.60) nor FVC: SDC1: 4.1 mL/year (95% CI: -6.0-14.2, p = 0.42), TM: 1.4 mL/year (95% CI: -8.3-11.1, p = 0.78). A subgroup analysis of never-smokers was consistent with the main analysis.Likewise, we did not find any association between elevated SDC1 and TM and increase in dyspnea score: SDC1: OR 1.43 (95% CI: 0.89-2.30, p = 0.14), TM: OR 1.05 (95% CI: 0.65-1.71, p = 0.26).

Conclusion

We did not find a significant association between elevated biomarkers of endothelial injury and decline in lung function nor dyspnea.

High salt intake and HIV infection on endothelial glycocalyx shedding in salt-sensitive hypertension

The endothelial glycocalyx is closely associated with various physiological and pathophysiological events. Significant modification of the endothelial glycocalyx is an early process in the pathogenesis of cardiovascular disease. High dietary salt and HIV infection damages the endothelial glycocalyx causing endothelial dysfunction and increasing the risk for salt-sensitive hypertension and cardiovascular disease. The two factors, HIV infection and dietary salt are critical independent predictors of hypertension and cardiovascular disease and often synergize to exacerbate and accelerate disease pathogenesis. Salt-sensitive hypertension is more common among people living with HIV and is associated with risk for cardiovascular disease, stroke, heart attack and even death. However, the underlying mechanisms linking endothelial glycocalyx damage to dietary salt and HIV infection are lacking. Yet, both HIV infection/treatment and dietary salt are closely linked to endothelial glycocalyx damage and development of salt-sensitive hypertension. Moreover, the majority of individuals globally, consume more salt than is recommended and the burden of HIV especially in sub-Sahara Africa is disproportionately high. In this review, we have discussed the missing link between high salt and endothelial glycocalyx shedding in the pathogenesis of salt-sensitive hypertension. We have further elaborated the role played by HIV infection and treatment in modifying endothelial glycocalyx integrity to contribute to the development of hypertension and cardiovascular disease.

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.

Metabolic syndrome, soluble CD40L, and biomarkers of endothelial dysfunction in people living with HIV

In the present study, we aimed to investigate the association between soluble CD40 ligand (sCD40L, a marker of platelet activation), soluble thrombomodulin, and syndecan-1 (both well-described markers of endothelial dysfunction) and metabolic syndrome in a large cohort of well-treated people with HIV (PWH) and to elucidate their association with HIV-specific variables. We included 862 PWH with undetectable viral replication. Our hypotheses were tested using uni- and multivariable logistic regression models a priori adjusted for well-known confounders. While no association of soluble thrombomodulin and syndecan-1 with MetS was found, high levels of sCD40L (aOR 1.54 [1.07-2.22]) were associated with excess risk of MetS. Given the previously described association between sCD40L, vascular inflammation and endothelial damage, the results presented in our study may suggest a potential role for sCD40L in the well-known association between cardiometabolic comorbidity and HIV infection.

Monitoring Renal Function in HIV Patients Without Kidney Disease Using Endothelial Biomarkers: A Prospective Pilot Study

This study aimed to investigate the association between novel biomarkers and renal injury in people with HIV (PWH). A cohort study was carried out with PWH under chronic use of antiretroviral therapy (ART), followed at a public outpatient service. Clinical and laboratory parameters of the patients were evaluated year by year, from 2015 [at baseline (year 1, Y1)] to 2019 [year 5 (Y5)]. At baseline, biomarkers of renal damage (e.g., neutrophil gelatinase-associated lipocalin-NGAL, monocyte chemoattractant protein-1-MCP-1, and kidney injury molecule-1-KIM-1) and endothelial activation or glycocalyx damage [e.g., intercellular adhesion molecule 1 (ICAM-1), E-selectin, and syndecan-1] were quantified using enzyme-linked immunosorbent assays and their levels were used to classify patients into different groups. However, only syndecan-1 showed a significant correlation with serum creatinine (p < .001) and glomerular filtration rate (GFR) (p = .003) over the years. Moreover, both serum creatinine and GFR in almost 5 years were significantly associated with serum levels of syndecan-1 at baseline. The multivariate linear regression with confounders showed a significant and independent association between GFR and levels of syndecan-1 and CD4 cell count in the beginning of the study, as well as age in Y5. The data reinforce the screening for kidney diseases with novel biomarkers, especially syndecan-1, as an important strategy for a timely diagnostic and therapeutic approach.

Endothelial Glycocalyx Integrity in Treatment-Naïve People Living with HIV before and One Year after Antiretroviral Treatment Initiation

Endothelial glycocalyx (EG) derangement has been associated with cardiovascular disease (CVD). Studies on EG integrity among people living with HIV (PLWH), are lacking. We conducted a prospective cohort study among treatment-naïve PLWH who received emtricitabine/tenofovir alafenamide, combined with either an integrase strand transfer inhibitor (INSTI, dolutegravir, raltegravir or elvitegravir/cobicistat), or a protease inhibitor (PI, darunavir/cobicistat). We assessed EG at baseline, 24 (±4) and 48 (±4) weeks, by measuring the perfused boundary region (PBR, inversely proportional to EG thickness), in sublingual microvessels. In total, 66 consecutive PLWH (60 (90.9%) males) with a median age (interquartile range, IQR) of 37 (12) years, were enrolled. In total, 40(60.6%) received INSTI-based regimens. The mean (standard deviation) PBR decreased significantly from 2.17 (0.29) μm at baseline to 2.04 (0.26) μm (p = 0.019), and then to 1.93 (0.3) μm (p < 0.0001) at 24 (±4) and 48 (±4) weeks, respectively. PBR did not differ among treatment groups. PLWH on INSTIs had a significant PBR reduction at 48 (±4) weeks. Smokers and PLWH with low levels of viremia experienced the greatest PBR reduction. This study is the first to report the benefit of antiretroviral treatment on EG improvement in treatment-naïve PLWH and depicts a potential bedside biomarker and therapeutic target for CVD in PLWH.

Aortic aneurysms and markers of platelet activation, hemostasis, and endothelial disruption in people living with HIV

Introduction

People living with HIV (PLWH) are at twice the risk of developing cardiovascular diseases and have more than four times higher odds of aortic aneurysm (AA) than the uninfected population. However, biomarkers of AA in PLWH are yet to be discovered. We aimed to investigate whether circulating biomarkers reflecting platelet activation, hemostasis and endothelial disruption, i.e. sCD40L, D-dimer, syndecan-1, and thrombomodulin, were associated with AA in PLWH.

Methods

Five hundred seventy one PLWH from the Copenhagen Comorbidity in HIV Infection (COCOMO) study ≥40 years of age with an available contrast-enhanced CT scan as well as available biomarker analyses were included. The biomarkers were analyzed on thawed plasma. For each biomarker, we defined high level as a concentration in the upper quartile and low level as a concentration below the upper quartile. For D-dimer, the cut-off was defined as the lower limit of detection. Using unadjusted and adjusted logistic and linear regression models, we analyzed associations between AA and sCD40L, D-dimer, syndecan-1, and thrombomodulin, respectively in PLWH.

Results

PLWH had median (IQR) age 52 years (47-60), 88% were male, median (IQR) time since HIV diagnosis was 15 years (8-23), and 565 (99%) were currently on antiretroviral treatment. High level of sCD40L was associated with lower odds of AA in both unadjusted (odds ratio, OR, 0.23 (95% CI 0.07-0.77; P=0.017)) and adjusted models (adjusted OR, aOR, 0.23 (95% CI 0.07-0.78; P=0.019)). Detectable level of D-dimer was associated with higher odds of AA in both unadjusted (OR 2.76 (95% CI 1.34-5.67; P=0.006)) and adjusted models (aOR 2.22 (95% CI 1.02-4.85; P=0.045)).

Conclusions

SCD40L was associated with lower odds of AA whereas D-dimer was independently associated with higher odds of AA in PLWH. This calls for further investigations into specific biomarkers to aid early diagnosis of AA in PLWH.

Cardiovascular disease and risk assessment in people living with HIV: Current practices and novel perspectives

Human immunodeficiency virus (HIV) infection represents a major cardiovascular risk factor, and the cumulative cardiovascular disease (CVD) burden among aging people living with HIV (PLWH) constitutes a leading cause of morbidity and mortality. To date, CVD risk assessment in PLWH remains challenging. Therefore, it is necessary to evaluate and stratify the cardiovascular risk in PLWH with appropriate screening and risk assessment tools and protocols to correctly identify which patients are at a higher risk for CVD and will benefit most from prevention measures and timely management. This review aims to accumulate the current evidence on the association between HIV infection and CVD, as well as the risk factors contributing to CVD in PLWH. Furthermore, considering the need for cardiovascular risk assessment in daily clinical practice, the purpose of this review is also to report the current practices and novel perspectives in cardiovascular risk assessment of PLWH and provide further insights into the development and implementation of appropriate CVD risk stratification and treatment strategies, particularly in countries with high HIV burden and limited resources.

High levels of exfoliated fragments following glycocalyx destruction in hemorrhagic fever with the renal syndrome are associated with mortality risk

Background

The glycocalyx is a gel-like structure that covers the luminal side of vascular endothelial cells. It plays an important role in maintaining the integrity of the vascular endothelial barrier structure. However, the presence or absence of glycocalyx destruction in hemorrhagic fever with renal syndrome (HFRS) and its specific mechanism and role is still unclear.

Methods

In this study, we detected the levels of exfoliated glycocalyx fragments, namely, heparan sulfate (HS), hyaluronic acid (HA), and chondroitin sulfate (CS), in HFRS patients and investigated their clinical application value on the evaluation of disease severity and prognosis prediction.

Results

The expression of exfoliated glycocalyx fragments in plasma was significantly increased during the acute stage of HFRS. The levels of HS, HA, and CS in HFRS patients during the acute stage were significantly higher than in healthy controls and convalescent stages of the same type. HS and CS during the acute stage gradually increased with the aggravation of HFRS, and both fragments showed a significant association with disease severity. In addition, exfoliated glycocalyx fragments (especially HS and CS) showed a significant correlation with conventional laboratory parameters and hospitalization days. High levels of HS and CS during the acute phase were significantly associated with patient mortality and demonstrated an obvious predictive value for the mortality risk of HFRS.

Conclusion

Glycocalyx destruction and shedding may be closely associated with endothelial hyperpermeability and microvascular leakage in HFRS. The dynamic detection of the exfoliated glycocalyx fragments may be beneficial for the evaluation of disease severity and prognosis prediction in HFRS.

Intraoperative systemic biomarkers predict post-liver transplantation acute kidney injury

OBJECTIVE

Liver transplant (LT) is a definitive therapeutic option for patients with chronic liver disease. However, acute kidney injury after LT (post-LT AKI) is a frequent complication that may lead to graft dysfunction and decrease life expectancy. Delay in AKI detection by traditional biomarkers boosted research with new biomarkers for post-LT AKI as neutrophil gelatinase-associated lipocalin (NGAL) and syndecan-1. We aim to evaluate associations of intraoperative systemic NGAL and syndecan-1 levels with post-LT AKI.

METHODS

This is a prospective study conducted in 46 patients selected for LT. Patients were evaluated preoperatively and blood samples were collected intraoperatively: T1 (after induction of anesthesia), T2 (anhepatic phase) and T3 (2 h after reperfusion of the graft).

RESULTS

The mean age was 54 ± 12 years and 60% were male. Post-LT AKI was observed in 24 (52%) patients of which 12% needed dialysis. Serum NGAL and syndecan-1 increased along surgical phases. Mostly, increment values of serum NGAL of T2 to T3 and syndecan-1 at T3 were importantly associated with post-LT AKI. Into a multivariate model with model for end-stage liver disease score, age, gender, warm ischemia, cold ischemia and surgery time, syndecan-1 levels at T3 remains capable to predict post-LT AKI. Serum NGAL had significance only with increment values calculated by the ratio of 'T3/T2'. Finally, serum syndecan-1 at T3 had a better diagnostic performance in receiver operating characteristic curve analysis.

CONCLUSION

Serum syndecan-1 levels in 2 h after reperfusion were most useful in early post-LT AKI diagnosis and may be used to construct new risk groups in this context.

Endothelial activation is associated with albuminuria in multibacillary leprosy

Leprosy may present kidney and endothelial abnormalities, being a risk factor for complications. However, the involvement of renal and vascular endothelia has been poorly investigated. We aimed to investigate if the levels of systemic endothelial biomarkers are associated with kidney abnormalities and the clinical forms of leprosy. This is a cross-sectional study with leprosy patients enrolled in January 2017 to December 2018, before the initiation of the multidrug therapy. Leprosy-associated clinical and epidemiological data were collected. Two groups were investigated: Paucibacillary (PB) and Multibacillary (MB) infections, for the comparisons. Serum and urine samples were obtained for laboratory analysis. In serum samples, were evaluated the endothelial biomarkers VCAM-1 and ICAM-1. In total, 101 leprosy patients were included, the mean age was 48±١٥ years and 71 (70%) were male. The multibacillary form occurred in 81 cases (80%), among which 22 had the Virchowian form. Serum creatinine was more elevated in the MB group than in PB patients. In addition, VCAM-1 was elevated in the MB group and was correlated with the bacteriological index (rho = 0.372, p <0.01), the duration of disease symptoms (rho = 0.234, p = 0.04), and the number of skin lesions (rho = 0.468, p <0.001). Moreover, in MB patients who presented albuminuria >15 mg/g of creatinine, VCAM-1 showed a significant correlation with increased albuminuria and improved the correlation with the number of skin lesions (rho= 0.563, p=0.010). In conclusion, higher systemic VCAM-1 levels were associated with the multibacillary clinical form of leprosy and with increased albuminuria. Prospective studies are necessary to establish a cause-effect and evaluate the preventive role of these biomarkers to improve the clinical care.

Human glycocalyx shedding: Systematic review and critical appraisal

BACKGROUND

The number of studies measuring breakdown products of the glycocalyx in plasma has increased rapidly during the past decade. The purpose of the present systematic review was to assess the current knowledge concerning the association between plasma concentrations of glycocalyx components and structural assessment of the endothelium.

METHODS

We performed a literature review of Pubmed to determine which glycocalyx components change in a wide variety of human diseases and conditions. We also searched for evidence of a relationship between plasma concentrations and the thickness of the endothelial glycocalyx layer as obtained by imaging methods.

RESULTS

Out of 3,454 publications, we identified 228 that met our inclusion criteria. The vast majority demonstrate an increase in plasma glycocalyx products. Sepsis and trauma are most frequently studied, and comprise approximately 40 publications. They usually report 3-4-foldt increased levels of glycocalyx degradation products, most commonly of syndecan-1. Surgery shows a variable picture. Cardiac surgery and transplantations are most likely to involve elevations of glycocalyx degradation products. Structural assessment using imaging methods show thinning of the endothelial glycocalyx layer in cardiovascular conditions and during major surgery, but thinning does not always correlate with the plasma concentrations of glycocalyx products. The few structural assessments performed do not currently support that capillary permeability is increased when the plasma levels of glycocalyx fragments in plasma are increased.

CONCLUSIONS

Shedding of glycocalyx components is a ubiquitous process that occurs during both acute and chronic inflammation with no sensitivity or specificity for a specific disease or condition.

Nucleoside/nucleotide reverse transcriptase inhibitors attenuate angiogenesis and lymphangiogenesis by impairing receptor tyrosine kinases signalling in endothelial cells

BACKGROUND AND PURPOSE

Cardiovascular disease associated with antiretroviral therapy (ART) has become a major clinical challenge for HIV-positive patients. However, the role of ART in blood vessel growth is largely unknown. Here, we examined an integral component of ART, nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) and investigated their effects on key microvascular functions, including angiogenesis and lymphangiogenesis.

EXPERIMENTAL APPROACH

The angiogenesis/lymphangiogenesis capability of endothelial cells (ECs) was evaluated using migration, proliferation and tube formation assays in vitro, and mouse ear and Matrigel plug assays in vivo. Expressions of signalling molecules and mitochondrial antioxidant catalases were determined using Western blotting. Receptor tyrosine kinase (RTK) internalization and endocytosis were examined using flow cytometry and confocal immunofluorescence microscopy respectively. Mitochondrial DNA copy number and ROS were determined using quantitative real-time PCR and MitoSOX staining respectively.

KEY RESULTS

Pharmaceutical doses of NRTIs [azidothymidine (AZT), tenofovir disoproxil fumarate (TDF) and lamivudine (3TC)] inhibited angiogenesis and lymphangiogenesis both in vivo and in vitro by affecting the proliferation and migration of ECs. Correspondingly, NRTIs selectively attenuated the activation and transduction of endothelial RTK signals, VEGFR2 and FGFR1 pathways, in vascular ECs and the VEGFR3 pathway in lymphatic ECs. Both TDF and 3TC restrained RTKs' endocytosis into early endosomes but not internalization, while AZT blocked the protein maturation of RTKs. Excessive ROS levels were detected in NRTI-treated ECs, and the MnSOD mimic MnTMPyP alleviated the angiogenic/lymphangiogenic defects induced by NRTIs.

CONCLUSIONS AND IMPLICATIONS

NRTIs negatively regulate angiogenesis and lymphangiogenesis by inducing mitochondrial oxidative stress and subsequently impairing RTK signalling in ECs.

LINKED ARTICLES

This article is part of a themed section on Spotlight on Small Molecules in Cardiovascular Diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.8/issuetoc.