Evaluation of serum endothelial cell specific molecule-1 (endocan) levels as a biomarker in patients with pulmonary thromboembolism

IL-33/sST2 signaling pathway in pulmonary thromboembolism: A clinical observational study

BACKGROUND

Pulmonary thromboembolism (PTE) is a cardiovascular emergency that can result in mortality. In the interleukin-33 (IL-33) /soluble suppression of tumorigenicity 2 (sST2) signaling pathway, increased sST2 is a cardiovascular risk factor. This study aimed to investigate the effectiveness of biomarkers in the IL-33/sST2 signaling pathway in determining PTE diagnosis, clinical severity, and mortality.

METHOD

This study was conducted as a single-center, prospective, observational study. Patients admitted to the emergency department and diagnosed with PTE constituted the patient group (n = 112), and healthy volunteers with similar sociodemographic characteristics constituted the control group (n = 62). Biomarkers in the IL-33/sST2 signaling pathway were evaluated for diagnosis, clinical severity, and prognosis.

RESULTS

IL-33 was lower in the patient group than in the control group (275.89 versus 403.35 pg/mL), while sST2 levels were higher in the patient group than in the control group (53.16 versus 11.78 ng/mL) (p < 0.001 and p = 0.001; respectively). The AUC of IL-33 to diagnose PTE was 0.656 (95 % CI: 0.580-0.726). The optimal IL-33 cut-off point to diagnose PTE was ≤304.11 pg/mL (56.2 % sensitivity, 79 % specificity). The AUC of sST2 to diagnose PTE was 0.818 (95 % CI: 0.752-0.872). The optimal sST2 cut-off point to diagnose PTE was >14.48 ng/mL (83 % sensitivity, 71 % specificity). IL-33 levels were lower in patients with mortality (169.85 versus 332.04 pg/mL) compared to patients without mortality, whereas sST2 levels were higher in patients with mortality (118.32 versus 28.07 ng/mL) compared to patients without mortality (p > 0.001 for both). The AUC of IL-33 to predict the mortality of PTE was 0.801 (95 % CI: 0.715-0.870). The optimal IL-33 cut-off point to predict the mortality of PTE was ≤212.05 pg/mL (75 % sensitivity, 79.5 % specificity). The AUC of sST2 to predict the mortality of PTE was 0.824 (95 % CI: 0.740-0.889). The optimal sST2 cut-off point to predict the mortality of PTE was >81 ng/mL (95.8 % sensitivity, 78.4 % specificity).

CONCLUSION

In the IL-33/ST2 signaling pathway, decreased IL-33 and increased sST2 are valuable biomarkers for diagnosis and prediction of mortality in patients with PTE.

Investigation of Serum Endocan Levels in SARS-CoV-2 Patients

Endocan is an endothelial-cell-specific proteoglycan (ESM-1) and has emerged as an endothelial dysfunction and inflammatory marker in recent years. Endocan can be used as a marker of inflammatory endothelial dysfunction in endothelium-dependent disease: cardiovascular disease, sepsis, lung and kidney disease and malignancies. Recent data suggest that endothelial dysfunction is a key mechanism in COVID-19 pathogenesis. Endotheliitis and thrombo-inflammation are associated with severe forms of SARS-CoV-2 infection, and endocan is currently under investigation as a potential diagnostic and prognostic marker. The aim of this study was to determine serum endocan levels in patients with COVID-19 to evaluate the correlation between endocan levels and clinical disease diagnosis and prognosis. This study enrolled 56 patients, divided into three groups depending on disease severity: mild (15), moderate (25) and severe (16). The biochemical, demographic, clinical and imagistic data were collected and evaluated in correlation with the endocan levels. Serum endocan levels were significantly higher in the COVID-19 patients compared to the control group; also, endocan concentration correlated with vaccination status. The results revealed significantly elevated serum endocan levels in COVID-19 patients compared to the control group, with a correlation observed between endocan concentration and vaccination status. These findings suggest that endocan may serve as a novel biomarker for detecting inflammation and endothelial dysfunction risk in COVID-19 patients. There was no significant relationship between serum endocan levels and disease severity or the presence of cardiovascular diseases. Endocan can be considered a novel biomarker for the detection of inflammation and endothelial dysfunction risk in COVID-19 patients.

Endocan: A novel biomarker of endothelial dysfunction in depression?

Endocan is a proteoglycan secreted from endothelium upon endothelial damage. Since depression is associated with higher inflammation and oxidative stress to the vascular endothelium, endothelial dysfunction is prevalent and it is one of the responsible mechanisms for increased cardiovascular morbidity and mortality in depressive disorders. This study aimed to investigate endocan levels in patients with depression (either bipolar or unipolar) and healthy controls to evaluate the projected endothelial injury. We included nonsmoker patients without comorbid inflammatory conditions: 31 with Bipolar Disorder Depression (BDD), 30 with Major Depressive Disorder (MDD) and 25 healthy controls (HC). The severity of depression was assessed with the Hamilton Depression Rating Scale (HDRS). Ultimately, serum endocan levels were significantly higher in patients with BDD than in patients with MDD (p < .000) and HCs (p < .000). Also, patients with MDD had significantly higher endocan levels than HCs (p < .000). The AUC value for the endocan to differentiate patients with depression from controls was 0.990 (95% CI: 0.971-1.000; p < .001) with sensitivity and specificity of 98.4 and 100%, respectively, and an optimal cut-off value of 316.92 ng/L. Serum endocan levels showed a mild positive correlation with HDRS scores (r = 0.372, p = .039) in the BDD group but not in the MDD group (r = -0.242, p = .20). Patients with BDD had higher endocan levels than MDD; this finding, while preliminary, could be an implication of higher endothelial dysfunction in BDD.

Development of a Decision Support Tool for Anticoagulation in Critically Ill Patients Admitted for SARS-CoV-2 Infection: The CALT Protocol

Severe COVID-19 infections are at high risk of causing thromboembolic events (TEEs). However, the usual exams may be unavailable or unreliable in predicting the risk of TEEs at admission or during hospitalization. We performed a retrospective analysis of two centers (n = 124 patients) including severe COVID-19 patients to determine the specific risk factors of TEEs in SARS-CoV-2 infection at admission and during stays at the intensive care unit (ICU). We used stepwise regression to create two composite scores in order to predict TEEs in the first 48 h (H0-H48) and during the first 15 days (D1-D15) in ICU. We then evaluated the performance of our scores in our cohort. During the period H0-H48, patients with a TEE diagnosis had higher D-Dimers and ferritin values at day 1 (D1) and day 3 (D3) and a greater drop in fibrinogen between D1 and D3 compared with patients without TEEs. Over the period D1-D15, patients with a diagnosis of a TEE showed a more marked drop in fibrinogen and had higher D-Dimers and lactate dehydrogenase (LDH) values at D1 and D3. Based on ROC analysis, the COVID-related acute lung and deep vein thrombosis (CALT) 1 score, calculated at D1, had a diagnostic performance for TEEs at H0-H48, estimated using an area under the curve (AUC) of 0.85 (CI95%: 0.76-0.93, p < 10^-3). The CALT 2 score, calculated at D3, predicted the occurrence of TEEs over the period D1-D15 with an estimated AUC of 0.85 (CI95%: 0.77-0.93, p < 10^-3). These two scores were used as the basis for the development of the CALT protocol, a tool to assist in the decision to use anticoagulation during severe SARS-CoV-2 infections. The CALT scores showed good performances in predicting the risk of TEEs in severe COVID-19 patients at admission and during ICU stays. They could, therefore, be used as a decision support protocol on whether or not to initiate therapeutic anticoagulation.

Contemporary Biomarkers in Pulmonary Embolism Diagnosis: Moving beyond D-Dimers

Pulmonary embolism (PE) is a rather common cardiovascular disorder constituting one of the major manifestations of venous thromboembolism (VTE). It is associated with high mortality and substantial recurrence rates, and its diagnosis may be challenging, especially in patients with respiratory comorbidities. Therefore, providing a prompt and accurate diagnosis for PE through developing highly sensitive and specific diagnostic algorithms would be of paramount importance. There is sound evidence supporting the use of biomarkers to enhance the diagnosis and predict the recurrence risk in patients with PE. Therefore, several novel biomarkers, such as factor VIII, Ischemia Modified Albumin, and fibrinogen, as well as several MicroRNAs and microparticles, have been investigated for the diagnosis of this clinical entity. The present review targets to comprehensively present the literature regarding the novel diagnostic biomarkers for PE, as well as to discuss the evidence for their use in daily routine.

Plasma Endocan as a Biomarker of Thrombotic Events in COVID-19 Patients

(1) Background: Endocan is a marker of endothelial dysfunction that may be associated with thrombotic events. The aim of the study was to investigate the performance of endocan as a marker of thrombotic events in COVID-19 patients. (2) Methods: We measured endocan in plasma from 79 documented COVID-19 patients classified according to disease severity (from mild to critical). Thrombotic events were recorded. (3) Results: Endocan concentrations at admission were significantly increased according to COVID-19 severity. Levels of endocan were significantly increased in patients experiencing thrombotic events in comparison with those without (16.2 (5.5−26.7) vs. 1.81 (0.71−10.5) ng/mL, p < 0.001). However, endocan concentrations were not different between pulmonary embolism and other thrombotic events. The Receiver Operating Characteristic (ROC) analysis for the identification of thrombotic events showed an area under the ROC curve (AUC) of 0.776 with an optimal threshold at 2.83 ng/mL (93.8% sensitivity and 54.7% specificity). When combining an endocan measurement with D-dimers, the AUC increased to 0.853. When considering both biomarkers, the Kaplan−Meier survival curves showed that the combination of endocan and D-dimers better discriminated patients with thrombotic events than those without. The combination of D-dimers and endocan was independently associated with thrombotic events. (4) Conclusions: Endocan might be a useful and informative biomarker to better identify thrombotic events in COVID-19 patients.

Prognostic and Diagnostic Value of Endocan in Kidney Diseases

Endocan, previously called endothelial cell-specific molecule-1, is a soluble proteoglycan that is predominantly expressed in vascular endothelial cells of the lungs and kidneys. It is upregulated by proinflammatory cytokines and plays a critical role in inflammatory, proliferative, and neovascularization processes. The utility of endocan as a biomarker in a wide spectrum of diseases is being increasingly acknowledged. In this review, we summarize the current evidence concerning the role of endocan in kidney diseases, with emphasis on its prognostic and diagnostic value. It seems that the determination of plasma endocan levels may provide useful prognostic information in many types of renal failure such as chronic kidney disease, IgA nephropathy, and diabetic nephropathy. Endocan could additionally improve the early diagnostic evaluation of acute kidney disease, chronic renal allograft injury, and acute rejection after kidney transplantation, thus contributing to endothelial cell injury monitoring in a timely manner.

Endocan as a marker of disease severity in pulmonary thromboembolism

INTRODUCTION

The aim of this study is to determine the serum endocan levels in patients with pulmonary thromboembolism (PTE) and investigate whether a relationship exists between serum endocan levels and the disease severity.

MATERIALS AND METHODS

The study included 85 patients with acute PTE and 40 healthy control subjects. The patients with PTE were divided into three groups at admission as "high-risk", "intermediate-risk" and "low-risk", considering the guidelines of the European Society of Cardiology. Serum endocan levels in all participants' blood samples were measured.

RESULTS

The mean serum endocan levels were significantly higher in the PTE group, compared to the control subjects (P < 0.001). Serum endocan levels were significantly higher in the "high-risk" group when compared with patients in the "low-risk" and "intermediate-risk" groups (P < 0.001 and P < 0.01 respectively). Similarly, serum endocan levels were higher in the "intermediate-risk" group compared to those in the "low-risk" group (P < 0.001). There was a negative correlation between serum endocan levels and partial oxygen pressure (r = -0.262, P = 0.016), whereas a positive correlation was found between the serum endocan levels and systolic pulmonary arterial pressure (r = 0.296, P = 0.006). Additionally, endocan had an area under the curve in the receiver operating characteristic curve of 0.837 (0.768-0.907; 95% CI; P < 0.001) and cut-off value was 194.5 pg/mL (sensitivity 80%, specificity 72.5%).

CONCLUSION

Serum endocan levels were higher and related to the severity of the disease in PTE patients. Additionally, endocan could be an indicator to be used in the diagnosis of PTE and in the prediction of the disease severity.

The role of Endocan as a Prognostic Biomarker in community-acquired pneumonia

Objective:

The aim of this study was to determine the importance of using endocan as a biomarker in deciding the setting of treatment and predicting prognosis in patients with community-acquired pneumonia (CAP).

Methods:

This prospective, case-control study was conducted at Okmeydani Training and Research Hospital between November 20, 2016 to March 20^th 2017. Blood samples were obtained from 63 patients who were admitted to internal medicine clinic due to CAP and 25 volunteers without active infection. Serum samples were centrifuged at 1000G for 15 minutes and stored at -20ºC. Samples were analyzed using human ESM1 (endocan) (Lot No: AK0017MAR0830) (Elabscience, Texas, USA) kit with Robonik (Mumbai, India) ELISA Plate Reader and Washer. Demographic and clinical data of the patients were recorded. CURB-65, qSOFA and Pneumonia Severity Index (PSI) scores were calculated. Primary endpoint of the study was 30-days mortality.

Results:

Mean serum endocan levels of the study group and the control group were 30.99±3.3 pg/ml and 246.5±49.95pg/ml, respectively. The difference between groups was statistically significant (p<0.005). 30-days mortality rate was 12.7% with eight patients, three of which died subsequently in the ICU. When patients were classified according to PSI and CURB-65 scores, endocan levels of PSI class ≥4 and CURB-65 ≥2 individuals were found to be significantly different than the control group. ROC analysis showed that serum endocan levels less than 64.96pg/ml has 85.2% sensitivity and 83.3% specificity for PSI class ≥4 and 82.4% sensitivity and 55.6% specificity for CURB-65 score ≥2.

Conclusion:

Serum endocan levels are significantly lower in patients with community-acquired pneumonia than the control group.

Serum endocan levels in patients with stable COPD

Background

Endothelial cell specific molecule-1, also called as endocan, is a dermatan sulfate proteoglycan, which is expressed by endothelial cells in alveolar walls of the lung and kidney. High endocan levels are found associated with endothelial dysfunction and inflammation. We hypothesize that endocan level is also high in COPD due to systemic inflammation and endothelial dysfunction. We aimed to investigate the expression of endocan in patients with stable COPD.

Material and methods

The study included patients with COPD and control subjects. COPD patients were classified according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 criteria. Demographics, body mass index, smoking history, and comorbidities were recorded. Endocan levels of COPD patients and controls were compared.

Results

Totally, 88 subjects (47 stable COPD patients, 41 controls) were evaluated. Endocan levels were significantly higher in COPD patients than control group (860.1±259.8 vs 647.3±316.9 pg/mL, P=0.001). There was no relationship between GOLD COPD categories and endocan levels. Also endocan levels were similar between COPD patients with or without hypoxemia.

Conclusion

Serum endocan level was significantly higher in patients with stable COPD. Further studies should be performed to better understand the relationship between endocan and COPD.

Endocan Levels and Endothelial Dysfunction in Patients With Sarcoidosis

A systemic inflammatory reaction is a common feature of both sarcoidosis and atherosclerosis. Endothelial-cell specific molecule 1 (endocan) is a marker of vascular pathology which also shows a correlation with inflammation, endothelial dysfunction, and atherosclerosis. The objective of this study was to evaluate the vascular involvement in sarcoidosis using serum endocan levels and brachial artery flow–mediated dilation (FMD), a marker of endothelial dysfunction. We included 53 patients with sarcoidosis without conventional cardiovascular risk factors and 40 healthy controls. Endothelial function was assessed using FMD. Endocan concentrations were measured using a commercially available enzyme-linked immunoassay. Patients with sarcoidosis had significantly higher endocan levels (306 [68] ng/mL vs 269 [73] ng/mL; P = .039) and lower FMD (2.7% [2.3%-3.2%] vs 8% [5%-13%]; P < .001) compared with the healthy group. A negative correlation was found between endocan levels and FMD in the sarcoidosis group ( r = −.325, P < .007). We conclude that sarcoidosis is associated with high levels of endocan and lower FMD values, which may indicate endothelial dysfunction and an early stage of atherosclerosis.

Maternal Serum Endocan Concentration in Pregnancies Complicated by Intrauterine Growth Restriction

OBJECTIVES

Endocan plays a role in the development of vascular tissue in health and disease and is an indicator of endothelial cells activation and angiogenesis. Therefore, this study aimed to investigate the relationship between maternal endocan serum level and intrauterine growth restriction (IUGR) as well as ultrasound Doppler flow measurements indicating placental insufficiency.

METHODS

This study included a group of women with IUGR (n = 37) and a group of healthy pregnant women (controls, n = 37). The endocan serum concentrations were assessed using commercially available enzyme-linked immunosorbent assay kit. Every woman underwent an ultrasound examination with Doppler flow measurements of the uterine arteries, umbilical vessels, and fetal middle cerebral artery. We used the cerebroplacental ratio (CPR) to determine placental insufficiency.

RESULTS

We found significant differences in median (interquartile) endocan serum level (pg/mL) between study and control groups (464 [374-532] vs 339 [189-496], respectively; P < .001). The endocan serum level correlated neither with umbilical cord blood gases nor with Apgar score. Ultrasound Doppler findings revealed significant differences in middle cerebral artery pulsatility index (PI), umbilical artery PI, CPR, as well as mean uterine arteries PI between IUGR group and controls. In the study group, we found significant correlations between the serum endocan and CPR ( R = 0.56, P < .001) as well as between serum endocan and mean uterine arteries PI ( R = 0.46, P = .006).

CONCLUSION

Endocan is likely involved in the pathogenesis of IUGR in pregnant women and possibly is a useful marker of endothelial dysfunction in these cases.

Relevance of Endothelial Cell-Specific Molecule 1 (Endocan) Plasma Levels for Predicting Pulmonary Infection after Cardiac Surgery in Chronic Kidney Disease Patients: The Endolung Pilot Study

Objectives

This pilot study aimed to evaluate the relevance of endocan plasma levels for predicting pulmonary infection after cardiac surgery in patients with chronic kidney disease (CKD).

Methods

Serum collected in a previous prospective cohort study (from 166 patients with preoperative CKD who underwent cardiac surgery) was used. Five patients with postoperative pulmonary infection were compared with 15 randomly selected CKD patients with an uneventful outcome. Blood samples were tested at 4 time points (preoperatively and 6, 12, and 24 h after the end of surgery). Endocan, procalcitonin, and C-reactive protein plasma levels were compared between the two groups.

Results

At 6 h, the patients with pulmonary infection had significantly higher levels of endocan than the patients without pulmonary infection (24.2 ± 15.6 vs. 6.4 ± 3.2 ng/mL; p = 0.03). A receiver operating characteristic curve analysis showed 80% sensitivity and 100% specificity for endocan to predict pulmonary infection (area under the curve 0.84), with a cutoff value of 15.9 ng/mL. The time saved by assessment of the endocan dosage compared to a clinical diagnosis of pulmonary infection was 47 h.

Conclusion

This pilot study showed that a specific study to assess the link between endocan plasma levels and pulmonary infection after cardiac surgery in CKD patients is of potential utility.

Subclinical Atherosclerosis in Patients with Prior Pulmonary Thromboembolism

OBJECTIVE

Recent studies have indicated that endothelial dysfunction is common in patients with a prior history of pulmonary thromboembolism (PTE). Based on the established relationship between endothelial dysfunction and atherosclerosis, we aimed to investigate carotid intima-media thickness (cIMT) as a marker of subclinical atherosclerosis in patients who have a prior history of PTE.

SUBJECTS AND METHODS

Medical records belonging to patients with a history of PTE and age- and gender-matched control subjects among those who underwent transthoracic echocardiography in Konya Training and Research Hospital were reviewed. Echocardiographic findings and cIMT measurements were recorded. cIMT measurements were compared between patient and control groups, and then independent correlates of cIMT were investigated using appropriate statistical methods.

RESULTS

A total of 110 patients (64.02 ± 12.67 years, males: n = 79 [71.81%]; females: n = 31 [28.19%]) were found to be eligible for assessment. Of these patients, 55 (50.00%) had a history of PTE. Patients with a history of PTE had significantly greater cIMT (p = 0.040). In this group of patients, cIMT positively and significantly correlated with basal right ventricular (RV) diameter (r = 0.271, p = 0.022), RV diastolic area (r = 0.376, p = 0.002), and systolic pulmonary artery pressure (r = 0.248, p = 0.037). In the multivariate linear regression analysis, only RV diastolic area was independently associated with cIMT in patients with PTE (p = 0.010).

CONCLUSION

Patients with a history of PTE have increased cIMT when compared to healthy subjects, and cIMT, which is a marker of subclinical atherosclerosis, is independently associated with RV diameter in these patients.

Endocan and the respiratory system: a review

Endocan, formerly called endothelial cell-specific molecule 1, is an endothelial cell-associated proteoglycan that is preferentially expressed by renal and pulmonary endothelium. It is upregulated by proangiogenic molecules as well as by pro-inflammatory cytokines, and since it reflects endothelial activation and dysfunction, it is regarded as a novel tissue and blood-based relevant biomarker. As such, it is increasingly being researched and evaluated in a wide spectrum of healthy and disease pathophysiological processes. Here, we review the present scientific knowledge on endocan, with emphasis on the evidence that underlines its possible clinical value as a prognostic marker in several malignant, inflammatory and obstructive disorders of the respiratory system.

Serum endothelial cell specific molecule-1 (endocan) levels in patients with obstructive sleep apnea

Objective: To investigate the level of endothelial cell specific molecule-1 (endocan) in obstructive sleep apnea (OSA). Methods: Study group included subjects with OSA. Control group included subjects who had no OSA on polysomnography and nonobese healthy subjects from population who had no OSA symptoms. Endocan levels of OSA and non-OSA subjects were compared. Results: Totally 106 individuals (63 OSA, 43 non-OSA) were included. Endocan levels were higher in OSA subjects than controls (1.25 ± 0.4 ng/ml vs 0.93 ± 0.3 ng/ml, p < 0.001). Endocan levels were correlated with BMI (r = 0.456, p < 0.001) and daytime PaO2 (r = -0.266, p < 0.042). In linear regression analysis there was no factor related to endocan level. Conclusion: Serum endocan is significantly higher in OSA. Further studies should be performed to better understand the relationship between endocan and OSA.

Endocan: a novel circulating proteoglycan

Endocan is a novel endothelium derived soluble dermatan sulfate proteoglycan. It has the property of binding to a wide range of bioactive molecules associated with cellular signaling and adhesion and thus regulating proliferation, differentiation, migration, and adhesion of different cell types in health and disease. An increase in tissue expression or serum level of endocan reflects endothelial activation and neovascularization which are prominent pathophysiological changes associated with inflammation and tumor progression. Consequently, endocan has been used as a blood-based and tissue-based biomarker for various cancers and inflammation and has shown promising results.

Systemic levels of the endothelium-derived soluble adhesion molecules endocan and E-selectin in patients with suspected deep vein thrombosis

The initial evaluation of patients with suspected deep vein thrombosis includes the use of biomarkers reflecting activation of the coagulation system. However, the thromboembolic process and neighboring inflammatory responses also affect endothelial cells, and endothelial cell markers may therefore be altered by the disease. In the present population-based single-center study, we investigated the plasma levels of the endothelium-specific biomarkers soluble E-selectin and endocan in a consecutive and unselected group of 120 patients admitted to hospital for suspected deep vein thrombosis. Blood samples were collected when patients arrived at the hospital. DVT patients showed evidence for an acute phase reaction with increased serum C-reactive protein levels, but this was similar to many other patients admitted with suspected but not verified thrombosis. Plasma endocan and E-selectin levels did not differ between patients with thrombosis, healthy controls and the patients without verified thrombosis (i.e. patients with other causes of their symptoms, including various inflammatory and non-inflammatory conditions). However, the combined use of endothelial biomarkers, C-reactive protein and D-dimer could be used to identify patient subsets with different frequencies of venous thrombosis. Thus, analysis of plasma biomarker profiles including endothelial cell markers may be helpful in the initial evaluation of patients with deep vein thrombosis.