Glycocalyx In Patients Research Articles

Four-month treatment with long-acting glucagon-like peptide-1 receptor agonists (GLP-1) or sodium-glucose co-trasporter-2 inhibitors (SGLT-2i) improves vascular function in type 2 diabetes mellitus

Abstract Background/Introduction Patients with type 2 diabetes mellitus (T2DM) and ischemic stroke present impaired markers of vascular and endothelial function. Glucagon-like peptide-1 receptor agonists (GLP-1) and sodium-glucose contrasporter-2 inhibitors (SGLT-2) are novel antidiabetic agents reducing the risk of cardiovascular complications. Purpose The aim of the study is to investigate the effect of treatment with GLP-1 or SGLT2 on arterial stiffness and endothelial glycocalyx in patients with T2DM and ischemic stroke. Methods We recruited in total 81 patients with T2DM and ischemic stroke who received dulaglutide (n=27), dapagliflozin (n=27) or insulin (n=27). We measured at baseline and at four months post-treatment the: a) Carotid-femoral pulse wave velocity (PWV-Complior; ALAM Medical), b) Augmentation index (Aix), c) Central systolic blood pressure (cSBP), and d) Perfused boundary region (PBR) of the sublingual arterial microvessels(marker of endothelial glycocalyx thickness), e) Left ventricular global longitudinal strain (GLS) using speckle-tracking echocardiography. Results At baseline, patients among the three groups had similar age, sex, HbA1c and markers of endothelial and cardiovascular function (p>0.05). Dapagliflozin and dulaglutide showed a greater reduction of PBR, PWV and central SBP than insulin, despite a similar HbA1c reduction (p<0.05). After four months treatment, patients on dapagliflozin and on dulaglutide displayed a greater reduction of PWV (−10% and −8% vs −1%), of cSBP (−9% and −8% vs +1%), of Aix (−65% and −13% vs −3%) and of GLS (+11% and +7% vs +5%) compared to patients on insulin (p<0.05 for all comparisons) (Table 1). PBR values were improved only in patients who received dulaglutide (−4% vs dapagliflozin: −2% vs insulin +1%). Conclusions Dulaglutide and dapagliflozin improve cardiovascular function, but only dulaglutide improves endothelial glycocalyx in patients with T2DM and ischemic stroke after four months treatment. Funding Acknowledgement Type of funding sources: None.

Disruption of endothelial glycocalyx in patients with rheumatoid arthritis

BACKGROUND: Endothelial glycocalyx has an important role in the regulation of endothelial functioning. It is the first to be damaged during the development of autoimmune inflammatory diseases. Thinning of endothelial glycocalyx leads to a violation of the barrier function of blood vessels, the development and maintenance of the inflammatory process. In this context, using endothelial glycocalyx assessment for diagnostic and monitoring of diseases is considered of great interest.
 AIM: To establish the relationship between endothelial glycocalyx thickness with activity, serological profile and risk factors for an unfavorable course of rheumatoid arthritis.
 MATERIALS AND METHODS: The study included 76 patients from 18 to 65 years of both sexes with rheumatoid arthritis. The perfusion boundary region of endothelial glycocalyx determined using a dark-field microscope has been used as the main indicator for assessing the state of endothelial glycocalyx.
 RESULTS: The obtained results have demonstrated a decrease in the initial endothelial glycocalyx thickness in females in the presence of risk factors for an unfavorable course of rheumatoid arthritis. At the same time, no relationship with the serological profile and endothelial glycocalyx thickness has been found. An inverse correlation between endothelial glycocalyx thickness and syndecan-1 level and erythrocyte sedimentation rate has been found. This confirms the fact that endothelial glycocalyxes are involved in the inflammatory process in rheumatoid arthritis. Endothelial glycocalyx assessment using dark-field microscopy made it possible to predict the subsequent appointment of pulse therapy with methylprednisolone in the hospital. On re-examination, endothelial glycocalyx thinning has been observed in the presence of unfavorable risk factors for the course of rheumatoid arthritis, in negative to anti-cyclic citrullinated peptide antibodies patients, or in the absence of response to treatment.
 CONCLUSIONS: The use of dark-field microscopy is unique in its capabilities for intravital and non-invasive assessment of endothelial glycocalyx thickness. It provides important fundamental information deepening knowledge in the pathological physiology of disease. From a clinical point of view, it allows to consider a decrease in endothelial glycocalyx thickness as an additional prognostically unfavorable marker in rheumatoid arthritis.

Microvascular dysfunction in COVID-19: the MYSTIC study

RationalePre-clinical and autopsy studies have fueled the hypothesis that a dysregulated vascular endothelium might play a central role in the pathogenesis of ARDS and multi-organ failure in COVID-19.ObjectivesTo comprehensively characterize and quantify microvascular alterations in patients with COVID-19.MethodsHospitalized adult patients with moderate-to-severe or critical COVID-19 (n = 23) were enrolled non-consecutively in this prospective, observational, cross-sectional, multi-center study. Fifteen healthy volunteers served as controls. All participants underwent intravital microscopy by sidestream dark field imaging to quantify vascular density, red blood cell velocity (VRBC), and glycocalyx dimensions (perfused boundary region, PBR) in sublingual microvessels. Circulating levels of endothelial and glycocalyx-associated markers were measured by multiplex proximity extension assay and enzyme-linked immunosorbent assay.Measurements and main resultsCOVID-19 patients showed an up to 90% reduction in vascular density, almost exclusively limited to small capillaries (diameter 4–6 µm), and also significant reductions of VRBC. Especially, patients on mechanical ventilation showed severe glycocalyx damage as indicated by higher PBR values (i.e., thinner glycocalyx) and increased blood levels of shed glycocalyx constituents. Several markers of endothelial dysfunction were increased and correlated with disease severity in COVID-19. PBR (AUC 0.75, p = 0.01), ADAMTS13 (von Willebrand factor-cleaving protease; AUC 0.74, p = 0.02), and vascular endothelial growth factor A (VEGF-A; AUC 0.73, p = 0.04) showed the best discriminatory ability to predict 60-day in-hospital mortality.ConclusionsOur data clearly show severe alterations of the microcirculation and the endothelial glycocalyx in patients with COVID-19. Future therapeutic approaches should consider the importance of systemic vascular involvement in COVID-19.

Preserving the endothelial glycocalyx in patients undergoing cardiopulmonary bypass: a prospective randomised interventional pilot study of lidocaine and doxycycline (LiDEG trial)

Background: During major surgery, particularly heart surgery, an element of the lining of blood vessels, known as the endothelial glycocalyx (EG), can be damaged. This can lead to swelling, low oxygen levels, kidney failure and other problems, which delay recovery. There are laboratory studies that show lidocaine (a local anaesthetic) and doxycycline (an antibiotic) may help protect this lining. The study agents are widely available, cheap and safe drugs. Trial design and objective: This is a phase IV, single centre, prospective, unblinded, randomised, parallel-group trial. The objectives of the trial are to investigate the role of doxycycline and lidocaine as potential agents to reduce EG shedding and correlate with early postoperative outcomes. Methods: 60 adult patients undergoing heart surgery requiring cardiopulmonary bypass (CPB) will be randomly assigned to one of three groups: doxycycline group (oral doxycycline, 200mg preoperatively); lidocaine group (perioperative intravenous lidocaine, 1.5mg/kg bolus at induction followed by 2mg/kg/hr infusion for the duration of surgery); and control group (standard care). The randomisation will be undertaken using a sealed opaque envelope method. The primary outcome will be the relative difference in the biochemical marker of EG injury, syndecan-1, at different timepoints in the intraoperative and early post-operative period. Secondary endpoints include vasopressor requirements, markers of organ dysfunction (lung, kidney, brain, arrhythmia), coagulation and inflammation. Discussion: EG injury is ubiquitous in patients undergoing CPB. Maintaining homeostasis of this delicate layer would appear to be a valuable therapeutic target. To date no agents have been shown to be effective in protecting the EG. Our study agents have shown some promise in the preclinical setting and would represent a novel therapeutic approach should they show a protective effect. Trial registration: Australian New Zealand Clinical Trials Registry, ACTRN12619000621112 (26th April 2019).

The Effect of Total Intravenous Anesthesia and Volatile Anesthesia on Shedding of the Endothelial Glycocalyx in Patients Undergoing Laparoscopic or Robotic Assisted Gastrectomy

The Effect of Total Intravenous Anesthesia and Volatile Anesthesia on Shedding of the Endothelial Glycocalyx in Patients Undergoing Laparoscopic or Robotic Assisted Gastrectomy

A Low Tacrolimus Concentration/Dose Ratio Increases the Risk for the Development of Acute Calcineurin Inhibitor-Induced Nephrotoxicity.

Fast tacrolimus metabolism is linked to inferior outcomes such as rejection and lower renal function after kidney transplantation. Renal calcineurin-inhibitor toxicity is a common adverse effect of tacrolimus therapy. The present contribution hypothesized that tacrolimus-induced nephrotoxicity is related to a low concentration/dose (C/D) ratio. We analyzed renal tubular epithelial cell cultures and 55 consecutive kidney transplant biopsy samples with tacrolimus-induced toxicity, the C/D ratio, C0, C2, and C4 Tac levels, pulse wave velocity analyses, and sublingual endothelial glycocalyx dimensions in the selected kidney transplant patients. A low C/D ratio (C/D ratio < 1.05 ng/mL×1/mg) was linked with higher C2 tacrolimus blood concentrations (19.2 ± 8.7 µg/L vs. 12.2 ± 5.2 µg/L respectively; p = 0.001) and higher degrees of nephrotoxicity despite comparable trough levels (6.3 ± 2.4 µg/L vs. 6.6 ± 2.2 µg/L respectively; p = 0.669). However, the tacrolimus metabolism rate did not affect the pulse wave velocity or glycocalyx in patients. In renal tubular epithelial cells exposed to tacrolimus according to a fast metabolism pharmacokinetic profile it led to reduced viability and increased Fn14 expression. We conclude from our data that the C/D ratio may be an appropriate tool for identifying patients at risk of developing calcineurin-inhibitor toxicity.

P5741Impaired arterial elastic properties and endothelial glycocalyx in patients with embolic stroke of undetermined source

Abstract Background and purpose Cardioembolism is a postulated mechanism of embolic stroke of undetermined source (ESUS). We investigated endothelial glycocalyx, aortic elastic properties, oxidative stress, and their association left atrial (LA) function in ESUS and healthy individuals. Methods In 90 ESUS patients (age 50.4±13.2) and 90 controls with similar risk factors, we measured: a) perfused boundary region (PBR) of the sublingual arterial microvessels (range 5–25 micrometers), a marker inversely related with glycocalyx thickness, b) pulse wave velocity (PWV), central systolic blood pressure (cSBP) and augmentation index (AIx), c) LA volume and strain using speckle-tracking imaging, d) Malondialdehyde (MDA) and protein carbonyls (PC), as oxidative stress markers. Results Compared to controls, ESUS had higher PWV, PBR MDA, and PC levels as well as higher LA volume and reduced reservoir LA strain (p&lt;0.05). PBR&gt;1.18 μm of microvessel ranging from 5–9μm and PWV&gt;10.2m/s were associated with ESUS on multivariable analysis (odds ratio: 2.374 and 5.429, p&lt;0.05 respectively) and increased the c-statistic of the initial model from 0.54 to 0.71. In ESUS, glycocalyx damage (increased PBR) was related with increased PWV (p&lt;0.01) which was linked with LA reservoir strain after controlling for age, sex, and risk factors [p=0.03]. Increased MDA and PC were related with glycocalyx damage, increased PWV (r=0.67 and r=0.52) AIx, central SBP and aortic atheroma (p&lt;0.01). Conclusions Arterial function and endothelial glycocalyx are severely impaired in ESUS and are linked to LA dysfunction suggesting their contribution to ESUS pathogenesis.

Impaired Arterial Elastic Properties and Endothelial Glycocalyx in Patients with Embolic Stroke of Undetermined Source.

Cardioembolism is a postulated mechanism of embolic stroke of undetermined source (ESUS). We investigated endothelial glycocalyx, aortic elastic properties, oxidative stress, and their association with left atrial (LA) function in ESUS and healthy individuals. In 90 ESUS patients (age 50.4 ± 13.2) and 90 controls with similar risk factors, we measured: (1) perfused boundary region (PBR) of the sublingual arterial microvessels (range 5-25 µm), a marker inversely related with glycocalyx thickness, (2) pulse wave velocity (PWV), central systolic blood pressure (cSBP), and augmentation index (AIx), (3) LA volume and strain using speckle-tracking imaging, and (4) malondialdehyde (MDA) and protein carbonyls (PCs), as oxidative stress markers. Compared with controls, ESUS had higher PWV, PBR, MDA, and PC levels as well as higher LA volume and reduced reservoir LA strain (p < 0.05). PBR > 1.2 μm of microvessel ranging from 5 to 9 μm and PWV > 10.2 m/s were associated with ESUS on multivariable analysis (odds ratio: 2.374 and 5.429, p < 0.05, respectively) and increased the c-statistic of the initial model from 0.54 to 0.71. In ESUS, glycocalyx damage (increased PBR) was related with increased PWV (p < 0.01) which was linked with LA reservoir strain after controlling for age, sex, and risk factors (p = 0.03). Increased MDA and PC were related with glycocalyx damage, increased PWV (r = 0.67 and r = 0.52), AIx, cSBP, and aortic atheroma (p < 0.01). Arterial function and endothelial glycocalyx are severely impaired in ESUS and are linked to LA dysfunction suggesting their contribution to ESUS pathogenesis. URL-http://www.clinicaltrials.gov. Unique identifier: NCT03609437.

279Inhibition of Interleukin-6 activity by tocilizumab improves arterial stiffness, LV myocardial deformation and endothelial glycocalyx in patients with rheumatoid arthritis

279Inhibition of Interleukin-6 activity by tocilizumab improves arterial stiffness, LV myocardial deformation and endothelial glycocalyx in patients with rheumatoid arthritis

Endothelial dysfunction mediated by interleukin-18 in patients with ischemic heart disease undergoing coronary artery bypass grafting surgery

When medication management or percutaneous coronary intervention is not successful in patients with advanced ischemic heart disease, surgical revascularisation—predominantly coronary artery bypass grafting (CABG)—is considered the gold standard. However, CABG surgery can lead to ischemia/reperfusion injury, which is characterized by a strong inflammatory response. Interleukin (IL)-18, is a strong inflammatory mediator, that is released from cardiomyocytes and can be found in the systemic circulation of patients during and immediately after CABG surgery. The existing damage of endothelial glycocalyx in patients with ischemic heart disease is further impaired concurrently during the surgery due to the anaesthesia-surgical technique used and intravascular fluid loading. This results in the increased incidence of adverse events, including myocardial infarction. IL-18 leads to the activation of lymphocyte cytotoxicity via cytotoxic mediators (Fas ligand, Tumour necrosis factor (TNF)-related apoptosis-inducing ligand, perforin, and granulysin). We hypothesize that IL-18 is released locally in the heart and the systemic circulation in patients undergoing CABG surgery and may be correlated with the level of activity of circulating lymphocytes. In turn, this may lead to lymphocyte-mediated cytotoxicity directed toward damaged and activated endothelial cells. Shear stress glycocalyx, as well as damaged and activated endothelial cells then become the main the source of pro-inflammatory cytokines, chemokines, and adhesion molecules. These attract activated lymphocytes to adhere to the endothelium or enter the subintimal layer, increasing existing or initiating the formation of new plaques, which leads to the development of myocardial infarction during or shortly after surgery. To evaluate our hypothesis, we will measure the local concentration of IL-18 in the sinus coronarius and systemic circulation. These values will then be correlated with immunological and biochemical parameters, predominantly with the concentration of degradation products of glycocalyx and cytotoxic mediators in activated lymphocytes. If our hypothesis is correct, measuring the IL-18 concentration that is responsible for glycocalyx deterioration, may become a useful tool for predicting myocardial infarction occurrence in patients undergoing CABG surgery.

PP.13.05

Objective: Aortic stiffness is considered valuable index of subclinical damage in hypertensive patients offering to cardiovascular risk estimation. The integrity of endothelial glycocalyx plays a vital role in vascular permeability, inflammation and elasticity. We aimed to explore any changes in aortic stiffness as well as in endothelial glycocalyx in patients with well controlled essential hypertension under treatment. Design and method: We studied 48 patients with newly diagnosed and never treated essential hypertension (mean age 48 + 10 years, 31 males). We performed carotid-femoral artery pulse wave velocity (PWV) in order to evaluate aortic stiffness. Increased perfusion boundary region (PBR) of the sublingual arterial microvessels (ranged from 5–25 micrometers) using Sideview Darkfield imaging (Microscan, Glycocheck) was measured as a non-invasive accurate index of reduced endothelial glycocalyx thickness. All patients started antihypertensive treatment and they re-evaluated in a period 16 + 8 months later. Results: Regarding total population, 30 patients (63%, group A) were well controlled regarding their blood pressure (<140/90 mmHg), 11 patients (22%, group B) were uncontrolled while 7 patients (15%, group C) stopped medication. We found that in group A: a. 17 patients (57%) significantly reduced their PWV (p < 0.001) in a period of 14 + 8 months and their therapy was based in RAAS antagonists (72%), b. 15 patients (50%) improved their endothelial glycocalyx (PBR5–9) (p = 0.002) after 15 + 8 months based in RAAS antagonists (73%) and c. 11 patients (37%) both PWV (p < 0.001) and endothelial glycocalyx (PBR5–9) (p = 0.006) were improved after 14 + 9 months based in RAAS antagonists (73%). Conclusions: Cardiovascular risk reduction in hypertensives is based not only in blood pressure decrease but also in target organ damage improvement. This is the first study showing the parallel improvement of aortic stiffness and endothelial dysfunction in well controlled hypertensives after at least one year antihypertensive treatment based on RAAS antagonists. Further studies are needed to confirm our results and establish endothelial glycocalyx measurement as a valuable tool in cardiovascular risk estimation

Shedding of the endothelial glycocalyx during cardiac surgery: On-pump versus off-pump coronary artery bypass graft surgery

A healthy vascular endothelium is coated by the endothelial glycocalyx. Its main constituents are transmembrane syndecans and bound heparan sulfates. In vivo the glycocalyx binds plasma proteins, forming the endothelial surface layer, which has a thickness of 500 to 1000 nm in microvessels. This large structure maintains the physiologic permeability barrier and prevents leukocyte and platelet adhesion, thereby mitigating inflammation and tissue edema. Very recently, we provided the first evidence for an acute destruction of the endothelial glycocalyx in patients undergoing aortic surgery associated with ischemia reperfusion injury. Avoiding cardiopulmonary bypass (CPB) and cardioplegic arrest, including ischemia and reperfusion, should presumably reduce shedding of the endothelial glycocalyx. In the present study shedding of components of the endothelial glycocalyx (heparan sulfate and syndecan-1) was investigated in patients undergoing coronary artery bypass surgery with and without CPB.

Shedding of the Endothelial Glycocalyx in Patients Undergoing Major Vascular Surgery With Global and Regional Ischemia

The astonishing thickness of the endothelial glycocalyx, which rivals that of endothelial cells in the microvasculature, was disclosed in the last 15 years. As already demonstrated, this structure plays a key role in the regulation of inflammation and vascular permeability. Two components of the glycocalyx, syndecan-1 and heparan sulfate, were measured in arterial blood of 18 patients undergoing surgery of the ascending aorta with cardiopulmonary bypass (n=12 with and n=6 without deep hypothermic circulatory arrest) and of 14 patients undergoing surgery for infrarenal aortic aneurysm. Basal values of syndecan-1 (1.2 microg/dL) and heparan sulfate (590 microg/dL) of patients were similar to those of control subjects. Anesthesia and initiation of surgery caused no changes. Global ischemia with circulatory arrest (n=12) was followed by transient 42- and 10-fold increases in syndecan-1 and heparan sulfate, respectively, during early reperfusion (0 to 15 minutes). After regional ischemia of heart and lungs (cardiopulmonary bypass; n=6), syndecan-1 increased 65-fold, and heparan sulfate increased 19-fold. Infrarenal ischemia was followed by 15- and 3-fold increases, respectively (n=14). The early postischemic rises were positively correlated (r=0.76, P<0.001). Plasma concentrations of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 did not change. Circulating polymorphonuclear granulocytes and the level of postischemic heparan sulfate corresponded negatively. Immunohistochemical imaging and immunoassay of isolated hearts (guinea pig) substantiated syndecan-1 and heparan sulfate as components of the endothelial glycocalyx released into the coronary venous effluent. Electron microscopy revealed shedding of the glycocalyx after ischemia/reperfusion. This study provides the first evidence in humans for shedding of the endothelial glycocalyx during ischemia/reperfusion procedures.

Electron Microscopic Investigation of the Bladder Urothelium and Glycocalyx in Patients with Interstitial Cystitis

The electron microscopic appearance of the bladder urothelium and glycocalyx was investigated in ten patients with well defined interstitial cystitis and compared to the findings in ten control patients with stress incontinence as the only symptom. Ruthenium red, a polycationic dye which binds specifically to cell surface acid polysaccharides, was used to demonstrate the glycocalyx. In cases of interstitial cystitis two types of luminal cell were observed, each possessing a distinct surface glycocalyx. One type of cell possessed numerous plaques of asymmetric unit membrane associated with a relatively thin glycocalyx. The second type of cell was characterised by numerous microvilli and a relatively thick glycocalyx. In control material each type of cell and its associated glycocalyx was identified with similar frequency.Our study concludes that there are no differences in the morphologic appearances of the glycocalyx and of urothelial cells in patients with interstitial cystitis when compared with controls. Hence, the hypothesis that an important pathogenic factor in interstitial cystitis is a defective glycocalyx associated with a permeable urothelium, has not been supported.