Identification of a 14kDa endocan fragment generated by cathepsin G, a novel circulating biomarker in patients with sepsis

Endothelitis profile in acute heart failure and cardiogenic shock patients: Endocan as a potential novel biomarker and putative therapeutic target

Aims: Inflammation-driven endothelitis seems to be a hallmark of acute heart failure (AHF) and cardiogenic shock (CS). Endocan, a soluble proteoglycan secreted by the activated endothelium, contributes to inflammation and endothelial dysfunction, but has been scarcely explored in human AHF. We aimed to evaluate serum (S-Endocan) and urinary endocan (U-Endocan) profiles in AHF and CS patients and to correlate them with biomarkers/parameters of inflammation, endothelial activation, cardiovascular dysfunction and prognosis.

Methods: Blood and spot urine were collected from patients with AHF (n = 23) or CS (n = 25) at days 1–2 (admission), 3-4 and 5-8 and from controls (blood donors, n = 22) at a single time point. S-Endocan, U-Endocan, serum IL-1β, IL-6, tumour necrosis factor-α (S-TNF-α), intercellular adhesion molecule-1 (S-ICAM-1), vascular cell adhesion molecule-1 (S-VCAM-1) and E-selectin were determined by ELISA or multiplex immunoassays. Serum C-reactive protein (S-CRP), plasma B-type natriuretic peptide (P-BNP) and high-sensitivity troponin I (P-hs-trop I), lactate, urea, creatinine and urinary proteins, as well as prognostic scores (APACHE II, SAPS II) and echocardiographic left ventricular ejection fraction (LVEF) were also evaluated.

Results: Admission S-Endocan was higher in both patient groups, with CS presenting greater values than AHF (AHF and CS vs. Controls, p < 0.001; CS vs. AHF, p < 0.01). Admission U-Endocan was only higher in CS patients (p < 0.01 vs. Controls). At admission, S-VCAM-1, S-IL-6 and S-TNF-α were also higher in both patient groups but there were no differences in S-E-selectin and S-IL-1β among the groups, nor in P-BNP, S-CRP or renal function between AHF and CS. Neither endocan nor other endothelial and inflammatory markers were reduced during hospitalization (p > 0.05). S-Endocan positively correlated with S-VCAM-1, S-IL-6, S-CRP, APACHE II and SAPS II scores and was positively associated with P-BNP in multivariate analyses. Admission S-Endocan raised in line with LVEF impairment (p = 0.008 for linear trend).

Conclusion: Admission endocan significantly increases across AHF spectrum. The lack of reduction in endothelial and inflammatory markers throughout hospitalization suggests a perpetuation of endothelial dysfunction and inflammation. S-Endocan appears to be a biomarker of endothelitis and a putative therapeutic target in AHF and CS, given its association with LVEF impairment and P-BNP and its positive correlation with prognostic scores.

Endocan in Acute Leukemia: Current Knowledge and Future Perspectives

Endocan is a soluble dermatan sulfate proteoglycan expressed by endothelial cells and detected in serum/plasma. Its expression is increased in tumors/tumor vessels in several human malignancies, and high expression (high serum/plasma levels or tumor levels) has an adverse prognostic impact in several malignancies. The p14 endocan degradation product can also be detected in serum/plasma, but previous clinical studies as well as previously unpublished results presented in this review suggest that endocan and p14 endocan fragment levels reflect different biological characteristics, and the endocan levels seem to reflect the disease heterogeneity in acute leukemia better than the p14 fragment levels. Furthermore, decreased systemic endocan levels in previously immunocompetent sepsis patients are associated with later severe respiratory complications, but it is not known whether this is true also for immunocompromised acute leukemia patients. Finally, endocan is associated with increased early nonrelapse mortality in (acute leukemia) patients receiving allogeneic stem cell transplantation, and this adverse prognostic impact seems to be independent of the adverse impact of excessive fluid overload. Systemic endocan levels may also become important to predict cytokine release syndrome after immunotherapy/haploidentical transplantation, and in the long-term follow-up of acute leukemia survivors with regard to cardiovascular risk. Therapeutic targeting of endocan is now possible, and the possible role of endocan in acute leukemia should be further investigated to clarify whether the therapeutic strategy should also be considered.

The Role of Endocan in Selected Kidney Diseases

Endocan, previously referred to as an endothelial-cell-specific molecule-1 (ESM-1) is a member of a proteoglycan family that is secreted by vascular endothelial cells of different organs, mainly lungs and kidneys. It is assumed to participate in endothelial activation and the triggering of inflammatory reactions, especially in microvasculatures. Thanks to its solubility in human fluids, i.e., urine and blood plasma, its stability and its low concentrations in physiological conditions, endocan has been proposed as an easily available, non-invasive biomarker for identifying and predicting the course of many diseases. Recently, endocan has been studied in relation to kidney diseases. In general, endocan levels have been linked to worse clinical outcomes of renal dysfunction; however, results are conflicting and require further evaluation. In this review, authors summarize available knowledge regarding the role of endocan in pathogenesis and progression of selected kidney diseases.

Cleaved endocan acts as a biologic competitor of endocan in the control of ICAM-1-dependent leukocyte diapedesis

Dysregulated leukocyte diapedesis is a major contributor to acute severe inflammatory states like sepsis and acute respiratory distress syndrome, which are common conditions in critically ill subjects. Endocan is a circulating proteoglycan that binds to the leukocyte integrin LFA-1 and blocks its interaction with its endothelial ligand ICAM-1, subsequently leading to the inhibition of leukocyte recruitment. Recent data have highlighted the hypothetic role of p14, endocan's major catabolite found in the bloodstream of septic patients, as a potential antagonist of endocan, thus participating in the regulation of acute inflammation. We hereby characterize the role of p14 as a biologic competitor of endocan, through assessment of its molecular interactions with LFA-1, endocan, and ICAM-1, as well as its effects on human leukocyte trafficking. Using immunodetection assay, we report that p14 can bind to LFA-1, thus inhibiting the interaction between LFA-1 and endocan, which in turn leads to the restoration of the ICAM-1/LFA-1 interaction. In primary human T cells trafficking assays, we underline the absence of effect of p14 on ICAM-1-dependent adhesion and migration, as well as on transendothelial migration. However, in those models, p14 reverses the antimigratory effect of endocan. To conclude, our study supports the hypothesis of an antagonistic role of p14 versus endocan in its effect on the LFA-1/ICAM-1-dependent human leukocyte recruitment.

Endothelial Cell-Specific Molecule-1 in Critically Ill Patients With Hematologic Malignancy

OBJECTIVES

To assess whether serum concentration of endothelial cell-specific molecule-1 (Endocan) at ICU admission is associated with the use of ICU resources and outcomes in critically ill hematology patients.

DESIGN

Prospective multicenter cohort study.

SETTING

Seventeen ICUs in France and Belgium.

PATIENTS

Seven hundred forty-four consecutive critically ill hematology patients; 72 critically ill septic patients without hematologic malignancy; 276 healthy subjects.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Median total endocan concentrations were 4.46 (2.7-7.8) ng/mL. Endocan concentrations were higher in patients who had received chemotherapy before ICU admission (4.7 [2.8-8.1] ng/mL vs. 3.7 [2.5-6.3] ng/mL [p = 0.002]). In patients with acute respiratory failure, endocan levels were increased in patients with drug-induced pulmonary toxicity compared with other etiologies (p = 0.038). Total endocan levels higher than 4.46 ng/mL were associated with a higher cumulative probability of renal replacement therapy requirement (p = 0.006), a higher requirement of mechanical ventilation (p = 0.01) and a higher requirement of vasopressors throughout ICU stay (p < 0.0001). By multivariate analysis, total endocan levels at admission were independently associated with ICU mortality (odds ratios, 1.39; 95% CI, 1.06-1.83; p = 0.018). The predictive value of endocan peptide fragments of 14 kDa in terms of mortality and life-sustaining therapies requirement was inferior to that of total endocan. Endocan levels were higher in critically ill hematology patients compared with healthy subjects (p < 0.0001) but lower than endocan values in critically ill septic patients without hematologic malignancy (p = 0.005) CONCLUSIONS:: Serum concentrations of endocan at admission are associated with the use of ICU resources and mortality in critically ill hematology patients. Studies to risk-stratify patients in the emergency department or in the hematology wards based on endocan concentrations to identify those likely to benefit from early ICU management are warranted.

Endocan regulates acute lung inflammation through control of leukocyte diapedesis

Acute respiratory distress syndrome is a severe form of respiratory failure, occurring in up to 20% of patients admitted to the intensive care unit with sepsis. Dysregulated leukocyte diapedesis is a major contributor to acute respiratory distress syndrome. Endocan is a circulating proteoglycan that binds to the leukocyte integrin leukocyte functional antigen-1 and blocks its interaction with its endothelial ligand, ICAM-1. The objective of this study was to evaluate the role of endocan in the control of acute lung inflammation. In vitro, endocan inhibited human leukocyte transendothelial migration as well as ICAM-1-dependent migration but had a very mild effect on ICAM-1-dependent adhesion. Endocan also acted as an inhibitor of transendothelial migration of mouse leukocytes. The effect of systemic administration of recombinant human endocan was assessed in a model of acute lung inflammation in BALB/c mice. Treatment with endocan 1 h after intratracheal LPS challenge reduced the alveolar inflammatory response, diminished histological features of acute lung injury, and improved respiratory function. These results highlight the anti-inflammatory role of human endocan and its protective effect against acute lung injury.NEW & NOTEWORTHY We show here that endocan inhibits ICAM-1-dependent human leukocyte transendothelial migration and ICAM-1-dependent adhesion. We also found that in BALB/c mice with tracheal LPS-induced acute lung injury treatment with recombinant human endocan reduces lung inflammation, notably through reduction of neutrophilic recruitment, and restores normal lung function. These results confirm the hypothesis that human endocan may have a protective effect against acute lung inflammation.

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.

Protective Effects of Chymostatin on Paraquat-Induced Acute Lung Injury in Mice

This study aims to evaluate the role of chymostatin in paraquat-induced acute lung injury. Institute of Cancer Research mice were randomly distributed into the NS, DMSO, chymostatin, paraquat or chymostatin treatment groups. Six mice from each group were intraperitoneally injected with chloral hydrate at 0, 1, 2, 4, 8, 12, 24 and 48 h after treatment administration. Blood samples were collected through cardiac puncture. Lung tissues were stained with haematoxylin and eosin for the observation of lung histology. The degree of pulmonary oedema was determined on the basis of lung wet-to-dry ratio (W/D). The serum activity of cathepsin G was determined through substrate fluorescence assay. The serum levels of endothelial cell-specific molecule-1 (endocan), tumour necrosis factor-a (TNF-a), interleukin-1β (IL-1β), IL-6 and high-mobility group box protein 1 (HMGB1) were determined through enzyme-linked immunosorbent assay. The expression levels of endocan and nuclear NF-κBp65 in the lung were quantified through Western blot. Chymostatin alleviated the pathological changes associated with acute alveolitis in mice; decreased the lung W/D ratio, the activity of cathepsin G and the serum concentrations of TNF-a, IL-1β, IL-6 and HMGB1; and increased the serum concentration of endocan. Western blot results revealed that chymostatin up-regulated endocan expression and down-regulated nuclear NF-κBp65 expression in the lung. Chymostatin reversed the inflammatory effects of paraquat-induced lung injury by inhibiting cathepsin G activity to up-regulate endocan expression and indirectly inhibit NF-κBp65 activity.

Low endocan levels are predictive of Acute Respiratory Distress Syndrome in severe sepsis and septic shock

PURPOSE

Endocan is a circulating proteoglycan measured at high blood levels during severe sepsis, with a likely lung anti-inflammatory function. The aim of this study was to assess whether paradoxically low endocan levels at Intensive Care Unit (ICU) admission could predict Acute Respiratory Distress Syndrome (ARDS) within 72 h in severe septic patients.

MATERIALS AND METHODS

Patients admitted for severe sepsis in the ICU of a French University Hospital were included in a prospective single-center observational study between October 2014 and March 2016.

RESULTS

72 patients admitted in ICU for severe sepsis were included. Endocan blood values at inclusion were significantly lower in patients who developed an ARDS at 72 h (p < 0.001). For endocan blood values > 5.36 ng/mL, the adjusted OR for development of ARDS at 72 h was of 0.001 (95% CI 0-0.215; p = 0.011). In our cohort, an endocan value < 2.54 ng/mL predicted ARDS at 72 h with a positive predictive value of 1 (Sp = 1 (95% CI 0.94-1)).

CONCLUSIONS

In a cohort of severe septic patients, we observed that low blood levels of endocan at ICU admission were predictive of ARDS at 72 h.

Kinetics of endocan in patients undergoing cardiac surgery with and without cardiopulmonary bypass

BACKGROUND

Endocan plays an important role in the processes of inflammation and infection. The use of cardiopulmonary bypass (CPB) during cardiac surgery can induce an inflammatory response. We aimed to describe the kinetics of endocan in patients undergoing cardiac surgery with and without the use of CPB.

METHODS

Single-centre, observational study with retrospective analysis of prospectively collected data, to compare the kinetics of endocan in patients undergoing isolated coronary artery bypass graft (CABG) surgery. Endocan was measured at induction of general anesthesia (baseline), and at 6, 24, 48 and 72 h after the end of surgery. Patients were classified into two groups, namely those undergoing CPB (CPB group) and those without CPB (off-pump group).

RESULTS

In total, 91 patients were included in this analysis: 61 patients in the CPB group and 30 in the off-pump group. There were no major significant differences between groups. Patients with CPB had a significantly higher level of endocan at 6 h (9.7 ± 6.7 ng/ml vs 6.9 ± 3.3 ng/ml, p = 0.03), but the difference was no longer statistically significant at subsequent timepoints. Endocan values were not significantly correlated with the duration of CPB (p = 0.53).

CONCLUSION

Endocan levels in patients undergoing isolated CABG surgery with CPB are significantly higher at 6 h than in patients with off-pump surgery, and peaks earlier in those with CPB (6 h) than in those undergoing off-pump surgery (24 h).

Modeling the effect of platelet concentrate supernatants on endothelial cells: focus on endocan/ESM-1

BACKGROUND

Platelets (PLTs) are prone to activation and the release of biologic response modifiers (BRMs) under storage conditions. The transfusion inflammatory reaction in the vascular compartment involves endothelial cell activation due to cell-cell interactions and BRMs infused with the blood products. Endocan/ESM-1 is a proteoglycan secreted by endothelial cells under the control of proinflammatory cytokines. We aimed to measure endocan activity in supernatants of PLT components (PCs), implicated in serious adverse reactions (SARs) or not (no.AR), sampled at different stages during storage.

STUDY DESIGN AND METHODS

PLT function, by quantification of soluble CD62P, and their ability to produce endocan were assessed. Functional testing of PC supernatants was performed on EA.hy926 endothelial cells in vitro by exposing them to PC supernatants from each group (no.AR or SARs); EA.hy926 activation was evaluated by their production of interleukin (IL)-6 and endocan.

RESULTS

PLT endocan secretion was not induced in response to PLT surface molecule agonists, and no significant correlation was observed between sCD62P and endocan concentration after PLT activation. However, we observed a significant increase in the secretion of IL-6 and endocan after EA.hy926 activation by all PC supernatants. IL-6 and endocan secretion were significantly higher for cells stimulated with SAR than those stimulated with no.AR PC supernatants, as well as cell apoptosis.

CONCLUSION

The correlation between the secretion of endocan and that of IL-6 by endothelial cells suggests that endocan can be used as a predictive marker of inflammation for the quality assessment of transfusion grade PLTs.

Angiopoietin-2 Levels as Predictors of Outcome in Mechanically Ventilated Patients with Acute Respiratory Distress Syndrome

Pulmonary endothelium dysfunction is a key characteristic of ARDS. The aim of this study was to investigate endothelium-derived markers, such as angiopoietin-2 (Ang-2) and endothelial cell-specific molecule-1 (endocan), at the vascular and alveolar compartments as outcome predictors in ARDS. Fifty-three consecutive ARDS patients were studied. The primary outcome was 28-day mortality. Secondary endpoints were days of unassisted ventilation and days with organ failure other than ARDS, during the 28-day study period. Nonsurvivors presented higher lung injury scores and epithelial lining fluid (ELF) Ang-2 levels compared to survivors, with no significant differences in plasma Ang-2, endocan, and protein C concentrations between the two groups. In logistic regression analysis, ELF Ang-2 levels > 705 pg/ml were the only independent variable for 28-day mortality among the previous four. Plasma endocan values > 13 ng/pg were the only parameter predictive against days of unassisted ventilation during the 28-day study period. Finally, lung injury score > 2.25 and ELF Ang-2 levels > 705 pg/ml were associated with increased number of days with organ failure, other than ARDS. Our findings suggest that Ang-2 levels are increased in the alveolar compartment of ARDS patients, and this may be associated both with increased mortality and organ failure besides lung.

Increased endocan expression in lesional skin and decreased endocan expression in sera in atopic dermatitis

Endocan is a novel human endothelial cell-specific molecule and is mainly expressed in endothelial cells in various tissues. Endocan has the capacity to inhibit leukocytes binding to the vascular endothelium. It also can promote the angiogenesis alongside vascular endothelial growth factor A. Through these functions, endocan has been implicated in the pathogenesis of various inflammatory diseases. To investigate the possible roles of endocan in atopic dermatitis (AD), we examined endocan expression in lesional skin and sera in patients with AD. Endocan mRNA and protein levels were increased in lesional skin of AD compared with healthy skin and endocan was expressed on epidermal keratinocytes and dermal endothelial cells. On the other hand, serum endocan levels in patients with AD were significantly lower than those in healthy controls. Our results suggest that elevated endocan expression in lesional skin may be associated with development of AD through angiogenesis and that decreased endocan expression in sera may be associated with increased leukocyte recruitment in AD.

Increased Extravascular Lung Water and Plasma Biomarkers of Acute Lung Injury Precede Oxygenation Impairment in Primary Graft Dysfunction After Lung Transplantation

BACKGROUND

After lung transplantation (LT), early prediction of grade 3 pulmonary graft dysfunction (PGD) remains a research gap for clinicians. We hypothesized that it could be improved using extravascular lung water (EVLWi) and plasma biomarkers of acute lung injury.

METHODS

After institutional review board approval and informed consent, consecutive LT recipients were included. Transpulmonary thermodilution-based EVLWi, plasma concentrations of epithelial (soluble receptor for advanced glycation endproducts [sRAGE]) and endothelial biomarkers (soluble intercellular adhesion molecule-1 and endocan [full-length and cleaved p14 fragment]) were obtained before and after LT (0 [H0], 6, 12, 24, 48 and 72 hours after pulmonary artery unclamping). Grade 3 PGD was defined according to the International Society for Lung and Heart Transplantation definition, combining arterial oxygen partial pressure (PaO2)/inspired fraction of oxygen (FiO2) ratio and chest X-rays. Association of clinical risk factors, EVLWi and biomarkers with grade 3 PGD was analyzed under the Bayesian paradigm, using logistic model and areas under the receiver operating characteristic curves (AUCs).

RESULTS

In 47 LT recipients, 10 developed grade 3 PGD, which was obvious at H6 in 8 cases. Clinical risk factors, soluble intercellular adhesion molecule-1 and endocan (both forms) were not associated with grade 3 PGD. Significant predictors of grade 3 PGD included (1) EVLWi (optimal cutoff, 13.7 mL/kg; AUC, 0.74; 95% confidence interval [CI], 0.48-0.99), (2) PaO2/FiO2 ratio (optimal cutoff, 236; AUC, 0.68; 95% CI, 0.52-0.84), and (3) sRAGE (optimal cutoff, 11 760 pg/mL; AUC, 0.66; 95% CI, 0.41-0.91) measured at H0.

CONCLUSIONS

Immediate postreperfusion increases in EVLWi and sRAGE along with impaired PaO2/FiO2 ratios were early predictors of grade 3 PGD at or beyond 6 hours and may trigger early therapeutic interventions.

Increase of circulating endocan over sepsis follow-up is associated with progression into organ dysfunction

How circulating inflammatory mediators change upon sepsis progression has not been studied. We studied the follow-up changes of circulating vasoactive peptides and cytokines until the improvement or the worsening of a patient and progression into specific organ dysfunctions. In a prospective study, concentrations of tumor necrosis factor-alpha (TNFα), interleukin (IL)-6, IL-8, IL-10, interferon-gamma (IFNγ), endocan and angiopoietin-2 (Ang-2) were measured in serum by an enzyme immunoassay in 175 patients at baseline; this was repeated within 24 h upon progression into new organ dysfunction (n = 141) or improvement (n = 34). Endocan and Ang-2 were the only parameters that were significantly increased among patients who worsened. Any increase of endocan was associated with worsening with odds ratio 16.65 (p < 0.0001). This increase was independently associated with progression into acute respiratory distress syndrome (ARDS) as shown after logistic regression analysis (odds ratio 2.91, p: 0.002). Changes of circulating cytokines do not mediate worsening of the critically ill patients. Instead endocan and Ang2 are increased and this may be interpreted as a key-playing role in the pathogenesis of ARDS and septic shock. Any increase of endocan is a surrogate of worsening of the clinical course.

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.

Perioperative kinetics of endocan in patients undergoing cardiac surgery with and without cardiopulmonary bypass

INTRODUCTION

Endothelial Specific Molecule-1 or endocan is a novel biomarker associated with the development of acute lung injury (ALI) in response to a systemic inflammatory state such as trauma. Acute Respiratory Distress syndrome (ARDS), a severe form of ALI is a devastating complication that can occur following cardiac surgery due to risk factors such as the use of cardiopulmonary bypass (CPB) during surgery. In this study we examine the kinetics of endocan in the perioperative period in cardiac surgical patients.

METHODS

After ethics approval, we obtained informed consent from 21 patients undergoing elective cardiac surgery (3 groups with seven patients in each group: coronary artery bypass grafting (CABG) with the use of CPB, off-pump CABG and complex cardiac surgery). Serial blood samples for endocan levels were taken in the perioperative period (T0: baseline prior to induction, T1: at the time of heparin administration, T2: at the time of protamine, T2, T3, T4 and T5 at 1, 2, 4 and 6h following protamine administration respectively). Endocan samples were analysed using the enzyme-linked immunosorbent assay (ELISA) method. Statistical analysis incorporated the use of test for normality.

RESULTS

Our results reveal that an initial rise in the levels of serum endocan from baseline in all patients after induction of anaesthesia. Patients undergoing off-pump surgery have lower endocan concentrations in the perioperative period than those undergoing CPB. Endocan levels decrease following separation from CPB, which may be attributed to haemodilution following CPB. Following administration of protamine, endocan concentrations steadily increased in all patients, reaching a steady state between 2 and 6h. The baseline endocan concentrations were elevated in patients with hypertension and severe coronary artery disease.

CONCLUSION

Baseline endocan concentrations are higher in hypertensive patients with critical coronary artery stenosis. Endocan concentrations increased after induction of anaesthesia and decreased four hours after separation from CPB. Systemic inflammation may be responsible for the rise in endocan levels following CPB.

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.

Host response biomarkers in the diagnosis of sepsis: a general overview

Critically ill patients who display a systemic inflammatory response syndrome (SIRS) are prone to develop nosocomial infections. The challenge remains to distinguish as early as possible among SIRS patients those who are developing sepsis. Following a sterile insult, damage-associated molecular patterns (DAMPs) released by damaged tissues and necrotic cells initiate an inflammatory response close to that observed during sepsis. During sepsis, pathogen-associated molecular patterns (PAMPs) trigger the release of host mediators involved in innate immunity and inflammation through identical receptors as DAMPs. In both clinical settings, a compensatory anti-inflammatory response syndrome (CARS) is concomitantly initiated. The exacerbated production of pro- or anti-inflammatory mediators allows their detection in biological fluids and particularly within the bloodstream. Some of these mediators can be used as biomarkers to decipher among the patients those who developed sepsis, and eventually they can be used as prognosis markers. In addition to plasma biomarkers, the analysis of some surface markers on circulating leukocytes or the study of mRNA and miRNA can be helpful. While there is no magic marker, a combination of few biomarkers might offer a high accuracy for diagnosis.

Evaluation of endothelial biomarkers as predictors of organ failures in septic shock patients

BACKGROUND

Endothelial injury is recognized to trigger organ failures during the first 48h of septic shock. We evaluate endothelial biomarkers at ICU admission in their ability to predict severity, outcome, and organ failures in septic shock patients.

METHODS

This prospective observational pilot study was conducted in a medical intensive care unit of a university hospital. Plasma levels of endothelial biomarkers as angiopoietin-2, sE-selectin or endocan were measured at ICU admission of 20 patients presenting with septic shock. Clinical and biological data were recorded at inclusion and each day during the first week.

RESULTS

Significant correlations were found between angiopoietin-2 and severity scores at Day 1: SAPS2 (r(2)=0.620; p=0.004) and LOD score (r(2)=0.681; p=0.001). The angiopoietin-2 level was significantly higher in patients presenting with organ failure such as hemodynamic, renal or hepatic failure. It correlated with catecholamine infusion dose and was higher in non survivors compared with survivors (33.5 [28.9-51.4] vs. 12.4 [6.4-14.7]ng/ml; p=0.001). In contrast, in that population presenting with septic shock, endocan level at inclusion was not related to any organ failure at inclusion or Day 1 but appeared lower in patients presenting with respiratory failure at Day 3 compared to those who do not (1.9 [0.99-3.1] vs 5.2 [3.1-17.2]ng/ml; p=0.032). The endocan level at inclusion was correlated with the decrease in PaO2/FiO2 ratio at Day 2 (r(2)=0.628; p=0.0004) and Day 3 (r(2)=0.645; p=0.005). Endocan level <2.54ng/ml at admission is predictive of a respiratory failure presence at Day 3.

CONCLUSION

In septic shock patients, angiopoietine-2 is related with clinical severity during the first 24h but only endocan is able to predict the presence of respiratory failure at Day 3.

Endocan, a putative endothelial cell marker, is elevated in preeclampsia, decreased in acute pyelonephritis, and unchanged in other obstetrical syndromes

Objective: Endocan, a dermatan sulphate proteoglycan produced by endothelial cells, is considered a biomarker for endothelial cell activation/dysfunction. Preeclampsia is characterized by systemic vascular inflammation, and endothelial cell activation/dysfunction. Therefore, the objectives of this study were to determine whether: (1) plasma endocan concentrations in preeclampsia differ from those in uncomplicated pregnancies; (2) changes in plasma endocan concentration relate to the severity of preeclampsia, and whether these changes are specific or observed in other obstetrical syndromes such as small-for-gestational age (SGA), fetal death (FD), preterm labor (PTL) or preterm prelabor rupture of membranes (PROM); (3) a correlation exists between plasma concentration of endocan and angiogenic (placental growth factor or PlGF)/anti-angiogenic factors (soluble vascular endothelial growth factor receptor or sVEGFR-1, and soluble endoglin or sEng) among pregnancies complicated by preeclampsia; and (4) plasma endocan concentrations in patients with preeclampsia and acute pyelonephritis (both conditions in which there is endothelial cell activation) differ.

Method: This cross-sectional study included the following groups: (1) uncomplicated pregnancy (n = 130); (2) preeclampsia (n = 102); (3) pregnant women without preeclampsia who delivered an SGA neonate (n = 51); (4) FD (n = 49); (5) acute pyelonephritis (AP; n = 35); (6) spontaneous PTL (n = 75); and (7) preterm PROM (n = 64). Plasma endocan concentrations were determined in all groups, and PIGF, sEng and VEGFR-1 plasma concentrations were measured by ELISA in the preeclampsia group.

Results: (1) Women with preeclampsia had a significantly higher median plasma endocan concentration than those with uncomplicated pregnancies (p = 0.004); (2) among women with preeclampsia, the median plasma endocan concentration did not differ significantly according to disease severity (p = 0.1), abnormal uterine artery Doppler velocimetry (p = 0.7) or whether diagnosis was made before or after 34 weeks gestational age (p = 0.3); (3) plasma endocan concentration in women with preeclampsia correlated positively with plasma anti-angiogenic factor concentrations [sVEGFR-1: Spearman rho 0.34, p = 0.001 and sEng: Spearman rho 0.30, p = 0.003]; (4) pregnancies complicated by acute pyelonephritis with bacteremia had a lower median plasma endocan concentration than pregnancies complicated by acute pyelonephritis without bacteremia (p = 0.004), as well as uncomplicated pregnancies (p = 0.001); and (5) there was no significant difference in the median plasma endocan concentration between uncomplicated pregnancies and those complicated by FD, delivery of an SGA neonate, PTL or preterm PROM (other members of the “great obstetrical syndromes”; each p > 0.05).

Conclusion: Median maternal plasma endocan concentrations were higher preeclampsia and lower in acute pyelonephritis with bacteremia than in uncomplicated pregnancy. No significant difference was observed in the median plasma endocan concentration between other great obstetrical syndromes and uncomplicated pregnancies. The difference in the direction of change of endocan in preeclampsia and acute pyelonephritis with bacteremia may be consistent with the view that both disease entities differ in pathogenic mechanisms, despite their associations with systemic vascular inflammation and endothelial cell activation/dysfunction.