Role of Serum Endocan Levels in Children with Bacterial and Viral Pneumonia: A Prospective, Case-Control Study

Introduction and Objective: Endocan has been used as a biomarker in the differential diagnosis of pulmonary diseases in adults. However, there are only a limited number of studies on its use in children. In this context, the objective of this study is to evaluate the relationship between serum endocan levels in children with bacterial and viral pneumonia. Materials and Methods: The population of this prospective case-control study consisted of hospitalized children aged 1 month to 15 years diagnosed with pneumonia between August 2020 and July 2021, whereas the control group consisted of randomly selected healthy children. The demographic and clinical characteristics of all participants were recorded. Participants' endocan levels, white blood cell (WBC) and neutrophil counts, and C-reactive protein (CRP) and procalcitonin (PCT) levels were measured within the scope of the laboratory tests. Results: The study sample consisted of 41 children, of whom 21 had bacterial pneumonia and 20 had viral pneumonia, whereas the control group consisted of 47 healthy children. Serum endocan levels, WBC and neutrophil counts, and PCT and CRP levels were significantly higher in children with bacterial pneumonia than in children with viral pneumonia and healthy children (P < 0.05). Additionally, serum endocan levels were significantly higher in children with viral pneumonia than in healthy children (P < 0.001). The endocan levels in children with bacterial pneumonia were significantly associated with the need for intensive care (P = 0.004) and correlated with the length of hospital stay (LoS) (r = 0.592, P = 0.005). Conclusion: The findings of this study indicated that serum endocan levels can be used in the differential diagnosis of bacterial and viral pneumonias. Additionally, it was found that the need for intensive care and LoS were significantly correlated with endocan levels in children with bacterial pneumonia.

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.

Is Serum Endocan Level an Indicator of the Severity of Childhood Community-Acquired Pneumonia?

Objective We aimed to investigate the relationship between serum endocan, procalcitonin (PCT), C-reactive protein (CRP), white blood cell count (WBC), neutrophil/lymphocyte ratios (NLR), and the severity of the disease in childhood community-acquired pneumonia (CAP) cases.

Methods This cross-sectional designed study included 30 pneumonia cases and 30 severe pneumonia cases aged between 3 months and 18 years who were hospitalized and treated in our hospital with the diagnosis of CAP. We also included 30 healthy controls in the same age range. Pearson's correlation and receiver operating characteristic (ROC) curve analyzes were performed.

Results PCT, endocan, NLR, and CRP levels were found to be significantly higher in patients with severe pneumonia. Sensitivity and specificity values in detecting pneumonia were 72.5 and 93% for PCT, 78.4 and 83.3% for CRP, 78.4 and 76.7% for endocan, and 64.7 and 63.3% for NLR. However, the area under the curve in ROC analysis were 0.821, 0.840, 0.842, and 0.670 for PCT, CRP, endocan, and NLR respectively.

Conclusion Endocan may be a marker of the diagnosis of pneumonia and not clinical severity, but studies are needed in large patient populations.

Endocan: A Novel Marker for Colchicine Resistance in Familial Mediterranean Fever Patients?

Introduction: Familial Mediterranean fever (FMF) patients had 5-10% colchicine resistance. Although FMF attacks are characterized by acute phase elevation, there are no biomarkers that can show colchicine resistance yet. The serum endocan levels may elevate in inflammatory and auto-inflammatory diseases. Objectives: This study aimed to evaluate serum endocan levels in FMF patients according to whether attack and colchicine resistance or not and also compare them with classical acute phase reactants. Methods: In this single-center and cross-sectional study, a total of 111 FMF patients and 60 healthy individuals were enrolled. All patients' basic demographic and clinical data were recorded and blood samples were collected. Results: A total of 46 (41.4%) FMF patients had colchicine resistance. In comparison to the FMF patients according to colchicine response, colchicine resistance patients had a significantly higher median (IQR) endocan levels than colchicine responsive patients [36.98 ng/ml (97.41) vs. 13.57 ng/ml (27.87), p = 0.007], but there were no differences between in terms of median ESR and CRP levels. Inversely, serum endocan levels were similar during an attack and attack-free period in FMF patients, although ESR and CRP levels were significantly different. Interestingly, the highest serum endocan levels were in the control group. Conclusion: In conclusion, serum endocan levels were higher in colchicine resistance than colchicine responsive patients, but attack state had no effect on serum endocan levels in our study. Unlike ESR and CRP, serum endocan may be a novel biomarker for detection of colchicine resistance and distinguish the FMF attacks.

Endocan as a potential biomarker of disease severity and exacerbations in COPD

INTRODUCTION

Endocan is a proteoglycan that is regarded as a novel marker of endothelial dysfunction. Endothelial dysfunction in pulmonary vascular bed is known to play an important role for the pathogenesis of COPD.

OBJECTIVE

This study aimed to determine serum endocan levels in patients with stable COPD and acute exacerbation of COPD (AECOPD) and to test the relationship between serum endocan levels and exacerbations.

METHODS

This study enrolled a total of 55 COPD patients, 24 of which had AECOPD and 31 had stable COPD. All patients' basic demographic and clinical data were recorded and blood samples were collected.

RESULTS

Serum endocan levels were significantly higher in the AECOPD group compared to the stable COPD and control groups (for both p < 0.001) and stable COPD group had higher levels than the control group (p < 0.005). Additionally, serum endocan levels were negatively correlated with FVC, FEV1, partial oxygen pressure and oxygen saturation (r = -0.30, p = 0.03; r = -0.34, p = 0.01; r = -0.34, p = 0.01 and r = -0.36, p = 0.007 respectively), and positively correlated with disease duration and systolic pulmonary artery pressure (r = 0.47, p < 0.001; r = 0.31, p = 0.02 respectively). A cut-off value of 434.29 pg/ml for endocan predicted exacerbation with a sensitivity of 79% and a specificity of 84% (AUC: 0.778, 95% Cl 0.648-0.909; p < 0.001). Logistic regression analysis revealed that increased endocan levels was independent predictor of COPD exacerbation (OR = 9.32, 95%CI, 1.64-52.95; p = 0.01).

CONCLUSION

Endocan may be a novel biomarker for detection of endothelial dysfunction and prediction of exacerbations in patients with COPD.

Circulating Proteoglycan Endocan Mediates EGFR-Driven Progression of Non-Small Cell Lung Cancer

Although new generations of EGFR-tyrosine kinase inhibitors (EGFR-TKI) have been developed for the treatment of patients with non-small cell lung cancer (NSCLC) with EGFR-mutant tumors, TKI resistance often returns as a result of additional EGFR mutations. In addition to seeking for next-generation EGFR-TKI, developing novel EGFR-targeting strategies may hold the key to overcome the vicious cycle of TKI resistance. Endocan is known as a receptor tyrosine kinase ligand enhancer in tumorigenesis, but the impact of endocan on EGFR-driven NSCLC progression remains unknown. In this study, higher endocan levels were found in lung tumors compared with cancer-free tissues and correlated with poor prognosis in patients with NSCLC harboring mutant EGFR; circulating endocan levels were also significantly higher in patients with mutant EGFR. Endocan facilitated EGFR signaling via direct binding and enhancing of the EGF-EGFR interaction and supported the growth of tumors driven by mutated EGFR. Activated EGFR in turn upregulated expression of endocan via JAK/STAT3 and ERK/ELK cascades, thus forming a positive regulatory loop of endocan-EGFR signaling. On the basis of the binding region between endocan and EGFR, we designed therapeutic peptides and demonstrated promising therapeutic effects in xenografts harboring EGFR mutations including TKI-resistant T790M. Together, our findings highlight the novel interaction between endocan and EGFR and new opportunities to effectively target endocan-EGFR regulatory axis in patients with TKI-resistant NSCLC. SIGNIFICANCE: Endocan is a novel and critical regulator of EGF/EGFR signaling and serves as an alternative target of EGFR-TKI resistance in NSCLC.

Relationship between Serum Endocan Levels and Childhood Community-Acquired Pneumonia

OBJECTIVES

Community-acquired pneumonia (CAP) is a potentially lethal lower respiratory tract infection for children. For this reason, early recognition and appropriate treatment is essential. In addition, we need to determine which patient will be hospitalized or not hospitalized. Here, we aimed to evaluate the plasma endocan level to determine whether it is effective in making the decision on hospitalization and the assessment of the response to treatment in patients with CAP.

MATERIALS AND METHODS

This prospective case-control study was conducted between November 2015 and May 2016 at Erciyes University School of Medicine. Fifty-three patients diagnosed as CAP with clinical and radiological findings were enrolled in the study. The patients were divided into various subgroups, such as inpatient, outpatient, complicated, non-complicated, dead patients, etc., and the levels of endocan were compared between the control group and those various groups.

RESULTS

A total of 53 children with a diagnosis of CAP and 55 healthy children were enrolled in the study. Patients were divided into two groups: hospitalized patients and outpatients. There was no statistically significant difference between these groups' serum endocan levels on the 1^st day and serum endocan levels on the 4^th day (p=0.783, p=0.419).

CONCLUSION

Serum endocan level had no significant value in predicting patients' hospitalization. On the other hand, high serum endocrine levels may be important in predicting the severity and prognosis of the disease.

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.

Endocan, a Risk Factor for Developing Acute Respiratory Distress Syndrome among Severe Pneumonia Patients

Background

Severe pneumonia (SP) has been widely accepted as a major cause for acute respiratory distress syndrome (ARDS), and the development of ARDS is significantly associated with increased mortality. This study aimed to identify potential predictors for ARDS development in patients with SP.

Methods

Eligible SP patients at admission from January 2013 to June 2017 were prospectively enrolled, and ARDS development within hospital stay was identified. Risk factors for ARDS development in SP patients were analyzed by univariate and multivariate logistic regression analysis. The receiver operating characteristic (ROC) curve analysis with the area under the curve (AUC) was performed for the predictive value of endocan for ARDS development.

Results

A total of 145 SP patients were eventually enrolled into the final analysis, of which 37 developed ARDS during the hospital stay. Our final multivariate logistic regression analysis suggested plasma endocan expression as the only independent risk factor for ARDS development in SP patients (OR: 1.57, 95% CI: 1.14–2.25, P=0.021). ROC curve analysis of plasma endocan resulted in an AUC of 0.754, 95% CI of 0.642–0.866, a cutoff value of 11.6 ng/mL, a sensitivity of 78.7%, and a specificity of 70.3%, respectively (P < 0.01).

Conclusions

Endocan expression at ICU admission is a reliable predictive factor in predicting ARDS in patients with SP.

Endocan, sepsis, pneumonia, and acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) and hospital-acquired pneumonia (HAP) are major problems of public health in intensive care units (ICUs), occurring in 15% of critically ill patients. Among the factors explaining ARDS development, sepsis is known as a frequent cause. Sepsis, ARDS, and HAP increase morbidity, mortality, length of stay in the ICU, and the overall costs of healthcare. The major challenge remains to identify accurately among critically ill patients those at risk of poor outcomes who could benefit from novel therapies. Endocan is released by the pulmonary endothelium in response to local or systemic injury. It inhibits mainly leukocyte diapedesis rather than leukocyte rolling or adhesion to the endothelial cells both in vitro and in vivo. Endocan was evaluated in 25 clinical reports, including 2454 critically ill patients and 452 healthy controls. The diagnostic value of endocan for sepsis or sepsis severity was equal to procalcitonin but its prognostic value was better. A predictive value for postoperative pneumonia was evidenced in two studies, and a predictive value for ARDS in four studies from three independent centers. This review presents an overview of the structure, expression, and functions of endocan. We also hereby summarize the potential applications of endocan in the prediction and prognosis of ARDS and HAP, as well as in the prognosis of sepsis.

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.

Endocan Concentration in Kidney Transplant Recipients

INTRODUCTION

Endocan is a novel soluble dermatan sulfate proteoglycan derived from endothelium. It has the capacity of binding to different biologically active molecules associated with cellular signaling, adhesion and regulating proliferation, differentiation, migration, and adhesion of different cell types in health and pathology. Elevated endocan levels are connected with endothelial activation/damage, neo-angiogenesis, and inflammation or carcinogenesis.

MATERIALS AND METHODS

The level of serum endocan among 63 kidney transplant recipients on three immunosuppressives (calcineurin inhibitors, mycophenolate mofetil, steroids) in correlation with other markers of endothelial damage was estimated. Additionally, 22 healthy volunteers were studied. Using a cross-sectional study design, the markers of endothelial damage like endocan, von Willebrand factor (vWF), intracellular adhesion molecule (ICAM), vascular cell adhesion molecule (VCAM); markers of inflammation high-sensitivity C-reactive protein (hsCRP) and IL-6; and marker of kidney function cystatin C were measured using commercially available assays.

RESULTS

Endocan, vWF, IL-6, hsCRP, ICAM, and VCAM levels were significantly higher in kidney transplant recipients comparing to healthy volunteers. In kidney transplant recipients, endocan levels correlated with renal function (estimated glomerular filtration rate by Modification of Diet in Renal Disease, r = -0.24, P < .05, creatinine r = 0.26, P < .05), time after transplantation r = -0.24, P < .05, activity of aspartate aminotransferase r = -0.46, P < .001, alanine aminotransferase r = 0.34, P < .01), ICAM r = -0.53, P < .001, VCAM r = -0.34, P < .01, hsCRP r = 0.35, P < .01, IL-6 r = 0.28, P < .05, vWF r = 0.26, P < .05. In a multifactorial analysis, the predictors of endocan levels were creatinine, ICAM, and VCAM predicting 59% of variability.

CONCLUSION

Endocan concentration among kidney transplant recipients is potentially connected with endothelial damage dependent upon graft function and time after transplantation.

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.

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.

Endocan Concentration and Chronic Inflammatory Process Among Heart Transplant Recipients

BACKGROUND

Endocan is a novel soluble dermatan sulfate proteoglycan derived from endothelium. It has the capacity of binding to different biologically active molecules associated with cellular signaling, adhesion, and regulating proliferation, differentiation, migration, and adhesion of different cell types in health and pathology. Its elevated level is connected with endothelial activation, neovascularization, and inflammation or carcinogenesis.

METHODS

The level of serum endocan among 131 heart transplant recipients on 3-drug immunosuppression (calcineurin inhibitor, mycophenolate mofetil/mycophenolic acid, steroid) in correlation with other markers of endothelial damage was determined. In addition, 22 healthy volunteers were studied. In cross-sectional study, markers were measured with the use of commercially available assays of endothelial damage-endocan and von Willebrand factor (VWF)-inflammation-high-sensitivity C-reactive protein (hsCRP), interleukin (IL) 6-and kidney function-cystatin C.

RESULTS

The endocan, VWF, IL-6, hsCRP, and cystatin C levels were significantly higher in heart transplant recipients compared with healthy volunteers. In our cohort, endocan level was correlated with renal function (estimated glomerular filtration rate: r = -0.21; P < .05), creatinine (r = 0.21; P < .05), erythrocyte count (r = -0.24; P < .01), hemoglobin (r = -0.33; P < .01), N-terminal pro-B-type natriuretic peptide (r = 0.25; P < .01), cholesterol (r = -0.22; P < .05), LDL (r = -0.21; P < .05), New York Heart Association functional class (r = 0.21; P < .05), hsCRP (r = 0.32; P < .01), IL-6 (r = 0.31; P < .01), and VWF (r = 0.27; P < .01). In multifactorial analysis, the predictors of endocan levels were cholesterol level, cystatin C, and IL-6, predicting 54% of variability.

CONCLUSIONS

Endocan concentration among heart transplant recipients is potentially connected with endothelial damage caused by subclinical inflammation resulting from hyperlipidemia.

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.

Inflammation-induced increases in plasma endocan levels are associated with endothelial dysfunction in humans in vivo

Although endothelial dysfunction is central to the pathogenesis of sepsis, no specific and clinically applicable marker for endothelial dysfunction is currently available. Endocan, a proteoglycan excreted by endothelial cells in response to inflammatory cytokines, may serve as such a marker. Our objective was to investigate the kinetics of endocan and its relationship with inflammation-induced endothelial dysfunction during experimental human endotoxemia. Endothelial function was assessed in 17 healthy male volunteers before and 4 h after the administration of 2 ng/kg lipopolysaccharide (LPS) by determination of the vasodilatory response of forearm blood vessels to intra-arterial infusion of endothelium-dependent (acetylcholine) or endothelium-independent (nitroglycerin/sodium nitroprusside) vasodilators using venous occlusion plethysmography. Plasma levels of endocan, inflammatory cytokines, intercellular adhesion molecule (ICAM), and vascular cell adhesion molecule (VCAM) were measured, and correlations with endothelial dysfunction were explored. Plasma levels of all measured cytokines, endocan, ICAM, and VCAM concentrations significantly increased after LPS administration. Furthermore, LPS administration resulted in a significantly blunted response to acetylcholine (mean ± SD increase in forearm blood flow [FBF] of 383% ± 320% before LPS vs. 173% ± 134% after LPS, P = 0.03), whereas the response to nitroglycerin/sodium nitroprusside was not affected (mean ± SD increase in FBF of 174% ± 120% before LPS vs. 110% ± 82% after LPS, P = 0.11). Furthermore, there was a significant correlation between the increase in plasma endocan levels and the attenuation of vasodilatory responses to acetylcholine (r = -0.48, P < 0.05). No correlation existed between plasma levels of ICAM or VCAM and the attenuation of the acetylcholine-induced vasodilatory response. Endocan levels are related to endothelial dysfunction in humans in vivo during systemic inflammation evoked by experimental endotoxemia. Therefore, this study suggests that endocan could be a novel marker of endothelial dysfunction in inflammatory conditions.

Protein profiling reveals consequences of lifestyle choices on predicted biological aging

Ageing is linked to a number of changes in how the body and its organs function. On a molecular level, ageing is associated with a reduction of telomere length, changes in metabolic and gene-transcription profiles and an altered DNA-methylation pattern. Lifestyle factors such as smoking or stress can impact some of these molecular processes and thereby affect the ageing of an individual. Here we demonstrate by analysis of 77 plasma proteins in 976 individuals, that the abundance of circulating proteins accurately predicts chronological age, as well as anthropometrical measurements such as weight, height and hip circumference. The plasma protein profile can also be used to identify lifestyle factors that accelerate and decelerate ageing. We found smoking, high BMI and consumption of sugar-sweetened beverages to increase the predicted chronological age by 2–6 years, while consumption of fatty fish, drinking moderate amounts of coffee and exercising reduced the predicted age by approximately the same amount. This method can be applied to dried blood spots and may thus be useful in forensic medicine to provide basic anthropometrical measures for an individual based on a biological evidence sample.

Endocan, Novel Potential Biomarker for Systemic Sclerosis: Results of a Pilot Study

BACKGROUND

Systemic sclerosis (Ssc) is an autoimmune disease characterized by vascular alterations of small arteries and microvessels with subsequent tissue fibrosis. Endocan is expressed by endothelial cells and associated with endothelial dysfunction; therefore it could be a potential biomarker for Ssc patients.

METHODS

Twenty-one Ssc patients and 20 sex- and age-matched healthy controls were recruited for the study. Serum endocan levels were determined using ELISA method in all patients and controls.

RESULTS

Serum endocan levels were superior in Ssc patients (median 2.53 (1.10-7 ng/ml)) compared with controls (0.79 (0-2 ng/ml), P < 0.05). Higher serum endocan expression was seen in diffuse Ssc subset and associated with the presence of digital ulcers and daily Raynaud's phenomenon (P < 0.05). Higher serum endocan levels were associated with a modified Rodnan skin score >14 and longer disease duration (P < 0.05). Values of areas under the receiver operating curves showed that serum endocan had good discriminative power for Ssc diagnosis, differentiating diffuse from limited subset type and differentiating patients with modified Rodnan skin score above and under 14 (area under curve: 0.94, 0.81, 0.75, respectively).

CONCLUSION

The results of this pilot study suggest endocan as a potential biomarker for microvascular manifestations and complications in Ssc patients. These encouraging results could promote future prospective studies in order to determine the exact role played by endocan as a biomarker for Ssc.

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.