Engineering Lymphangiogenesis-On-Chip: The Independent and Cooperative Regulation by Biochemical Factors, Gradients, and Interstitial Fluid Flow

Despite the crucial role of lymphangiogenesis during development and in several diseases with implications for tissue regeneration, immunity, and cancer, there are significantly fewer tools to understand this process relative to angiogenesis. While there has been a major surge in modeling angiogenesis with microphysiological systems, they have not been rigorously optimized or standardized to enable the recreation of the dynamics of lymphangiogenesis. Here, a Lymphangiogenesis-Chip (L-Chip) is engineered, within which new sprouts form and mature depending upon the imposition of interstitial flow, growth factor gradients, and pre-conditioning of endothelial cells with growth factors. The L-Chip reveals the independent and combinatorial effects of these mechanical and biochemical determinants of lymphangiogenesis, thus ultimately resulting in sprouts emerging from a parent vessel and maturing into tubular structures up to 1 mm in length within 4 days, exceeding prior art. Further, when the constitution of the pre-conditioning cocktail and the growth factor cocktail used to initiate and promote lymphangiogenesis are dissected, it is found that endocan (ESM-1) results in more dominant lymphangiogenesis relative to angiogenesis. Therefore, The L-Chip provides a foundation for standardizing the microfluidics assays specific to lymphangiogenesis and for accelerating its basic and translational science at par with angiogenesis.

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.

Roles of endothelial cell specific molecule‑1 in tumor angiogenesis (Review)

Angiogenesis plays a crucial role in tumor growth and metastasis, and is heavily influenced by the tumor microenvironment (TME). Endothelial cell dysfunction is a key factor in tumor angiogenesis and is characterized by the aberrant expression of pro-angiogenic factors. Endothelial cell specific molecule-1 (ESM1), also known as endocan, is a marker of endothelial cell dysfunction. Although ESM1 is primarily expressed in normal endothelial cells, dysregulated ESM1 expression has been observed in human tumors and animal tumor models, and implicated in tumor growth, metastasis and angiogenesis. The precise role of ESM1 in tumor angiogenesis and its potential regulatory mechanisms are not yet conclusively defined. However, the aim of the present review was to explore the involvement of ESM1 in the process of tumor angiogenesis in the TME and the characteristics of neovascularization. In addition, the present review discusses the interaction between ESM1 and angiogenic factors, as well as the mechanisms through which ESM1 contributes to tumor angiogenesis. Furthermore, the reciprocal regulation between ESM1 and the TME is explored. Finally, the potential of targeting ESM1 as a therapeutic strategy for tumor angiogenesis is presented.

Systematic Review of Endocan as a Potential Biomarker of COVID-19

Since the start of the coronavirus disease 2019 (COVID-19) pandemic, several biomarkers have been proposed to assess the diagnosis and prognosis of this disease. The present systematic review evaluated endocan (a marker of endothelial cell damage) as a potential diagnostic and prognostic biomarker for COVID-19. PubMed, Scopus, Web of Science, and Embase were searched for studies comparing circulating endocan levels between COVID-19 cases and controls, and/or different severities/complications of COVID-19. Eight studies (686 individuals) were included, from which four reported significantly higher levels of endocan in COVID-19 cases compared with healthy controls. More severe disease was also associated with higher endocan levels in some of the studies. Studies reported higher endocan levels in patients who died from COVID-19, were admitted to an intensive care unit, and had COVID-19-related complications. Endocan also acted as a diagnostic and prognostic biomarker with different cut-offs. In conclusion, endocan could be a novel diagnostic and prognostic biomarker for COVID-19. Further studies with larger sample sizes are warranted to evaluate this role of endocan.

The Relationship Between Endocan and Serum Inflammatory Markers in Patients with Senile Calcific Aortic Stenosis

BACKGROUND

Endocan is an indicator of many pathologies accompanied by inflammation, endothelial cell activation, and dysfunction. In this study, we examined the relationship between degenerative aortic sclerosis, which progresses in a similar pathophysiologic mechanism as atherosclerosis, and serum inflammatory markers and endocan levels.

METHODS

A total of 155 patients without known coronary artery disease, aged between 65 and 80 years, were consecutively included in the prospective cross-sectional study. The study population was analyzed in 4 different groups. The control group consisted of patients with normal aortic valve structure, while patients with aortic stenosis were classified as mild aortic stenosis (2-2.9 m/s), moderate aortic stenosis (3-3.9 m/s), and severe aortic stenosis (≥ 4 m/s) according to their aortic velocity. While there were 39 patients in the control group, there were 58, 24, and 34 patients in the mild, moderate, and severe aortic stenosis groups, respectively.

RESULTS

There was no statistically significant difference between the groups in terms of patient distribution and characteristics. History of dyspnea and angina was correlated with the severity of aortic stenosis (P <.001). In this study, no statistically significant correlation was found between serum endocan levels and the severity of aortic stenosis (control group: 17.3 ± 6.3 ng/mL, mild aortic stenosis: 17.6 ± 8.7 ng/mL, moderate aortic stenosis: 16.3 ± 3.8 ng/mL, severe aortic stenosis: 15.2 ± 5.9 ng/mL, P =.396). However, it was figured out that there was a positive correlation between endocan levels and hemoglobin (Hg) (r = 0.308, P =.001), platelet (PLT) (r = 0.320, P <.001), and albumin (Alb) (r = 0.206, P =.026).

CONCLUSION

In this study, no significant correlation was found between serum endocan levels and the severity of aortic stenosis. On the other hand, there was a positive correlation between endocan levels and Hg, PLT, and Alb.

Investigation of maternal serum endocan concentrations in pregnant women with gestational diabetes mellitus; a prospective case-control study

OBJECTIVE

We aimed to investigate the maternal serum endocan concentrations in pregnant women diagnosed with Gestational Diabetes Mellitus (GDM) and to investigate the usability of serum endocan in GDM screening.

METHODS

This prospective case-control study was conducted with 160 pregnant women. The GDM group consisted of 80 pregnant women who had 75 g OGTT between the 24th and 28th weeks of pregnancy and were diagnosed with GDM. The control group consisted of 80 healthy pregnant women who were matched with the GDM group in terms of age and body mass index (BMI) and had a normal 75 g OGTT result. Serum endocan concentrations were evaluated between 24 and 28 weeks of gestation in all participants and the groups were compared in terms of serum endocan concentrations.

RESULTS

The median maternal serum endocan concentration was found to be significantly higher in the GDM group than in the control group (498 ng/L, and 467 ng/L, respectively, p = 0.024). In the subgroup analysis according to the BMI of the participants, the highest median maternal serum endocan concentration (513 ng/L) was found in the overweight GDM group. ROC analysis was performed to determine the value of maternal serum endocan concentration in predicting GDM. AUC analysis of maternal serum endocan for estimation of GDM was 0.603 (p = 0.024, 95% CI = 0.515 - 0.691). The optimal threshold value for maternal serum endocan concentration was determined as 376 ng/L with 88.75% sensitivity and 32.5% specificity.

CONCLUSION

Although serum endocan does not have high enough specificity to be used as an alternative to OGTT in GDM screening between 24 and 28 weeks of gestation, we think that it is somehow involved in the pathogenesis of GDM. The contribution of placental endocan expression to the serum concentration and the effect of blood glucose regulation on serum endocan concentration in GDM remain to be investigated.

Association between elevated endocan levels and obstructive sleep apnea hypopnea syndrome in Turkey and China: A meta-analysis

BACKGROUND

Endothelial dysfunction has been implicated in the pathogenesis of obstructive sleep apnea-hypopnea syndrome (OSAHS). Previous research has linked endothelial dysfunction to the vascular pathology marker endothelial cell-specific molecule-1 (endocan). This meta-analysis compared endocan concentrations among adult patients with OSAS and controls, and ascertained whether any differences exist. This study aimed to highlight the association between high endocan levels and OSAHS.

METHODS

A comprehensive, systematic literature search of the PubMed, Cochrane Library, China National Knowledge Infrastructure, Web of Science, Embase, and Wan Fang databases for relevant studies, published between January 2000 and June 10, 2013, was performed. Additionally, standardized mean differences, correlation coefficients, and adjusted odds ratios were used to assess the effect size. Statistical analyses were performed using R version 4.13 (Copenhagen: The Cochrane Collaboration) and Stata version 10.0 (StataCorp LLC, College Station, TX).

RESULTS

Twelve studies fulfilled the inclusion criteria. Nine studies reported endocan levels in patients with OSAHS and controls, and 6 reported serum endocan levels in relation to polysomnography (PSG) indexes (apnea-hypopnea index, body mass index, minimum oxygen (O2) saturation, and flow-mediated dilatation [FMD]). Five studies reported that serum endocan levels functioned independently as risk factors for OSAHS. These levels were determined to be elevated in adults with OSAHS compared with controls (standardized mean difference 1.30 [95% confidence interval (CI) 1.06-1.54]) and increased more significantly with increasing disease severity in individuals with OSAHS. Subjects were divided into different subgroups based on race, geographical region, sample type, and study design. Results indicated increased endocan levels across all OSAHS subgroups compared with the control group. The data highlighted a positive association between serum endocan levels and apnea-hypopnea index, and a negative association with FMD and minimum O2 saturation. The overall adjusted odds ratio between serum endocan levels and OSAHS was 1.04 (95% CI 1.02-1.06).

CONCLUSION

Results of this meta-analysis provide further evidence supporting elevated endocan levels in adults with OSAHS. Serum endocan levels were correlated with various PSG indices and may be associated with OSAHS.

Relationship Between Serum Endocan Levels and Other Predictors of Endothelial Dysfunction in Obese Women

Endocan, or endothelial cell-specific molecule-1 (ESM-1), is a potential inflammatory marker implicated in endothelial dysfunction. The purpose of this study was to determine the correlation between serum endocan levels and the presence and severity of endothelial dysfunction, and the relationships with serum intracellular adhesion molecule-1 (ICAM-1), adiponectin (a marker of inflammation), high sensitivity C-reactive protein (hsCRP) levels, and carotid intima-media thickness (cIMT) in obese subjects. Serum endocan, ICAM-1, adiponectin, hsCRP levels, and cIMT were evaluated in 76 obese women (BMI > 30 kg/m2) and 53 controls (BMI < 25 kg/m2). ICAM-1 (P = .01), hs-CRP (p < 0.001), and cIMT (p < .001) were significantly higher, while adiponectin (P = .006) was significantly lower, in obese women compared with the controls. Serum endocan levels were similar between the obese (470.5 ± 171.3 pg/mL) and controls (471.9 ± 146.3 pg/mL) (P = .732). There was no correlation between serum endocan values and the endothelial dysfunction markers, hsCRP (r = -.021), ICAM-1 (r = -.054), adiponectin (r = .113), or cIMT (r = -.060) in obesity. Endocan is not a suitable marker of endothelial dysfunction in the context of obesity. More research is required to evaluate the role of endocan in the regulation of inflammatory processes in obesity.

The Evaluation of Serum Endocan, Interleukin-6, and CRP Levels Following Sleeve Gastrectomy

Background

The excessive accumulation of fat tissue in obesity is the source of chronic low-level inflammation and causes future dysmetabolic and cardiovascular disorders. Removal of this excessive fat tissue with the aid of bariatric surgery (BS) techniques, such as sleeve gastrectomy, may reverse adverse inflammatory outcomes. The aim of this study is to investigate the impact of sleeve gastrectomy on inflammatory markers, specifically endocan, IL-6, and CRP, in individuals with obesity.

Methods

Thirty-two patients with class 3 obesity and class 2 obesity + comorbidities were enrolled in the study. Clinical characteristics including age, comorbidity, body mass index (BMI), waist, and hip circumferences of the participants were noted before and 3 months after sleeve gastrectomy. Blood samples were collected during those periods to assess biochemical features such as serum endocan, interleukin-6 (IL-6), C-reactive peptide, fasting insulin, glycosylated hemoglobin A1c levels, and lipid panel. A statistical package program was used for the analysis of those parameters, and p<0.05 was accepted as significant at a 95.0% confidence interval.

Results

BMI reduced from 43.55±6.78 to 36.16±6.14 kg/m2 within 3 months following BS (p<0.001). Preoperative serum endocan, IL-6, and CRP levels were correlated with BMI, and in line with BMI reduction, their serum levels decreased after BS (p<0.05). HOMA-IR also reduced after BS, and both in the pre and post-BS periods correlated with BMI, IL-6, endocan, and CRP levels (p<0.05). The mean total body weight loss was 20.4% within 3 months post-BS.

Conclusion

BS techniques are effective in weight loss and reversing the inflammatory processes caused by obesity. Serum endocan, IL-6, and CRP levels are promising markers for describing obesity-related inflammation and objectively checking the alleviation of inflammation following BS.

Early Diagnostic Markers of Late-Onset Neonatal Sepsis

OBJECTIVE

Early diagnosis of nosocomial infections in newborns is a great challenge, because in the initial phase of systemic infection, clinical symptoms are often non-specific, and routinely used hematological markers are not sufficiently informative. The aim of this study was to determine the potential of early inflammatory markers to diagnose late-onset neonatal sepsis-procalcitonin (PCT), interleukin 6 (IL-6), interleukin 8 (IL-8) and endocan (ESM-1).

MATERIAL AND METHODS

A prospective clinical-epidemiological study was conducted in a third-level NICU in Pleven, Bulgaria. Patients with suspected late-onset sepsis and healthy controls were tested. A sandwich ELISA method was used to measure the serum concentrations of biomarkers.

RESULTS

Sixty newborns were included, of which 35% symptomatic and infected, 33.3% symptomatic but uninfected and 31.7% asymptomatic controls. The mean values of PCT, IL-6, I/T index and PLT differ significantly in the three groups. For ESM-1, IL-8 and CRP, the difference was statistically insignificant. The best sensitivity (78%) and negative predictive value (84%) was found for IL-6. The combinations of PCT + IL-6 and PCT + IL-6+ I/T+ PLT showed very good diagnostic potential.

CONCLUSION

The introduction into the routine practice of indicators such as PCT and IL-6 may provide an opportunity to promptly optimize the diagnostic and therapeutic approach to LOS.

Is maternal serum endocan level a novel marker in gestational diabetes mellitus?

AIM

To determine whether there was a significant difference between serum endocan levels of pregnant women with and without gestational diabetes mellitus (GDM).

METHODS

A total of 90 pregnant women, 45 with gestational diabetes and 45 healthy pregnant women, between 24 and 28 gestational weeks, were included in this prospective case-control study. The pregnant women were screened for gestational diabetes using a two-step protocol. Serum endocan levels were measured using a commercially available enzyme-linked immunosorbent assay (ELISA) kit. A p-value of <0.05 was considered statistically significant.

RESULTS

Serum endocan level was significantly higher in the GDM group than in healthy controls (168.46 ± 160.6 vs. 105.66 ± 26.52 pg/mL, respectively; p < 0.001). Serum endocan concentrations were positively correlated with the results of 50 g oral glucose challenge test (GCT) (p < 0.001). Receiver operating characteristic curve analysis showed that endocan with a cut-off point of 133.9 ng/dL indicated women with GDM with a sensitivity of 55.6% and specificity of 88.9% (area under the curve [AUC]: 0.737, 95% CI: 0.634-0.824). The overall differential performance of endocan according to the GDM groups was determined as 73.7% (p < 0.001). Maternal serum endocan level was positively correlated with fasting glucose, postprandial glucose, and glycated hemoglobin (HbA1c) (p < 0.001).

CONCLUSIONS

Elevated endocan levels in gestational diabetes were correlated with fasting glucose, postprandial glucose, HbA1c, and oral glucose tolerance test (OGTT) results. Despite the low sensitivity of 55.6% and the high specificity of 88.9%, we found a high differential performance rate indicating that serum endocan levels were important for the pathophysiology of GDM and should be investigated for the possibility of being a novel marker in larger populations.

Endocan is Related to Increased Cardiovascular Risk in Type 2 Diabetes Mellitus Patients

Aim: Type 2 diabetes mellitus (T2D) patients have an increased risk for cardiovascular disease (CVD). Different algorithms are used for the CVD risk quantification and United Kingdom Prospective Diabetes Study (UKPDS) score was among the most validated. Endocan is a novel endothelial dysfunction marker. The aim was to explore the potential relationship between serum endocan level and UKPDS risk engine score [which enables calculation of the 10-year risk of nonfatal and fatal coronary heart disease (eCHD) and stroke] in T2D patients. Materials and Methods: The study included a cohort of 104 patients with T2D (of them 52.8% men), with median age 66 years and body mass index (BMI) = 30.7 kg/m2. Patients were divided into: low (<15%), moderate (≥15% and <30%), and high-risk UKPDS category (≥30%). Results: In multivariable regression analysis (when adjusted for sex, BMI and/or hip circumference), endocan was the independent predictor for moderate and high estimated risks (nonfatal eCHD, fatal eCHD, and nonfatal stroke risk). In the Model for high nonfatal eCHD [areas under curve (AUC) = 0.895] and high fatal eCHD (AUC = 0.860) endocan indicated good clinical accuracy, and an excellent accuracy in discriminating patients with high risk for nonfatal stroke risk (AUC = 0.945). Conclusion: Endocan was the independent predictor for moderate and high estimated risks (i.e., nonfatal and fatal CHD and nonfatal stroke risk scores) in T2D patients. When included in models with sex and obesity indices endocan demonstrated good clinical accuracy in discriminating T2D patients with high risk for nonfatal and fatal eCHD and nonfatal stroke risk from those patients with low risk.

New Biomarkers (Endocan, Interleukin-17, and Thrombospondin-4) for the Diagnosis, Assessment of Severity, and Follow-Up of Peripheral Arterial Disease

The present study evaluated the use of endocan, interleukin-17 (IL-17), and thrombospondin-4 (TSP-4) blood levels as potential biomarkers for the diagnosis and follow-up of peripheral arterial disease (PAD). Patients with PAD (Rutherford categories I, II, and III) who were admitted between March 2020 and March 2022 for cardiovascular surgery or outpatient clinic follow-up were included. The patients (n = 60) were divided into 2 groups: medical treatment (n = 30) and surgical treatment (n = 30). In addition, a control group (n = 30) was created for comparison. Endocan, IL-17, and TSP-4 blood levels were measured at the time of diagnosis and at the first month after treatment. Endocan and IL-17 values were found to be significantly higher in both groups that underwent medical (259.7 ± 46 pg/mL, 63.7 ± 16.6 pg/mL) and surgical (290.3 ± 84.5 pg/mL, 66.4 ± 19.6 pg/mL) treatment than the control group (187.4 ± 34.5 pg/mL, 56.5 ± 7.2 pg/mL P < .001). Tsp-4 value was found to be significantly higher only in the surgical treatment group (15 ± 4.3 ng/mL) than the control group (12.9 ± 1.4 ng/mL P < .05). The decreases in endocan, IL-17, and TSP-4 levels at the first month of treatment in both groups were also significant (P < .001). A combination of classical and these new biomarkers could be included in PAD screening, early diagnosis, severity determination, and follow-up protocols in order to provide effective assessment in clinical practice.

New potential biomarkers for early chronic kidney disease diagnosis in patients with different glucose tolerance status

Background

The purpose of the present study was to investigate the role of oxidative stress, platelet activation, and endocan levels in renal dysfunction in normal glucose tolerance (NGT) patients with 1-h plasma glucose values ≥155 mg/dl (NGT ≥ 155), compared to NGT < 155, impaired glucose tolerance (IGT), and type 2 diabetes mellitus (T2DM) newly diagnosed subjects. We enlisted 233 patients subjected to an oral glucose tolerance test (OGTT).

Materials and methods

The serum levels of platelet activation (glycoprotein VI and sP-selectin), oxidative stress biomarkers (8-isoprostane and Nox-2), and endocan were evaluated using an ELISA test.

Results

Among NGT < 155 patients and the T2DM group, there was a statistically significant increase in 8-isoprostane (p < 0.0001), Nox-2 (p < 0.0001), glycoprotein VI (p < 0.0001), and sP-selectin (p < 0.0001) serum levels. Higher serum endocan levels were found with the worsening of metabolic profile (p < 0.0001); specifically, NGT ≥ 155 patients presented higher serum endocan values when compared to NGT < 155 patients (p < 0.0001). From the multivariate linear regression analysis, 1-h glucose resulted in the major predictor of estimated glomerular filtration rate (e-GFR) justifying 23.6% of its variation (p < 0.0001); 8-isoprostane and Nox-2 added respectively another 6.0% (p < 0.0001) and 3.2% (p = 0.001).

Conclusion

Our study confirmed the link between 1-h post-load glucose ≥155 mg/dl during OGTT and the possible increased risk for chronic kidney disease (CKD) in newly diagnosed patients. The novelty is that we demonstrated a progressive increase in oxidative stress, platelet activation, and serum endocan levels with the worsening of metabolic profile, which becomes evident early during the progression of CKD.

Investigation of Serum Endocan Levels and Age in Critical Inflammatory Conditions

Aging negatively affects the endothelium. Endocan (ESM-1), an endothelium-derived soluble proteoglycan, participates in fundamental biological processes of endothelial cells. We aimed to examine the role of endothelial dysfunction and age in poor outcomes in critical illness. ESM-1 levels were measured in the sera of mechanically ventilated critically ill patients, including COVID-19, non-septic, and septic patients. The 3 patient cohorts were divided based on age (≥65 and <65). Critically ill COVID-19 patients had statistically higher ESM-1 levels compared to critically ill septic and non-septic patients. Only in critically ill septic patients were ESM-1 levels higher in older compared to younger patients. Finally, the age-subgrouped patients were further subdivided based on intensive care unit (ICU) outcome. ESM-1 levels were similar in COVID-19 survivors and non-survivors, irrespective of age. Interestingly, only for the younger critically ill septic patients, non-survivors had higher ESM-1 levels compared to survivors. In the non-septic survivors and non-survivors, ESM-1 levels remained unaltered in the younger patients and tended to be higher in the elderly. Even though endocan has been recognized as an important prognostic biomarker in critically ill patients with sepsis, in our patient cohort, increased age, as well as the extent of endothelial dysfunction, seemed to affect its prognostic ability.

Diagnostic Role of Circulating Endocan Levels in Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

Endocan, as an endothelial cell damage marker, plays role in several cardiovascular and non-cardiovascular diseases. This systematic review and meta-analysis evaluates the role of endocan as a potential diagnostic or prognostic biomarker for obstructive sleep apnea (OSA). International databases including PubMed, Embase, Web of Science, and Scopus were searched for relevant studies assessing endocan levels in OSA patients compared with healthy controls or within different severities or comorbidities of OSA. Random-effect meta-analysis was performed in order to calculate the standardized mean difference (SMD) and 95% confidence interval (CI) of serum/plasma endocan in all comparisons. A total of 10 studies were included in our systematic review, among which seven were used in meta-analysis. Meta-analysis showed that endocan levels were significantly higher in patients with OSA compared with healthy controls (SMD 1.29, 95% CI 0.64-1.93, P < .001) and this was not different between serum and plasma subgroups. However, there was no statistical difference between severe and non-severe OSA patients (SMD .64, 95% CI -.22 to 1.50, P = .147). Considerably, higher endocan levels in patients with OSA in comparison with non-OSA individuals might have clinical implications. This association warrants further research due to its potential use as a diagnostic and prognostic biomarker.

Novel predictors of early atherosclerosis in nonalcoholic fatty liver disease

Aim of the study

Non-alcoholic fatty liver disease (NAFLD) is regarded as the most relevant liver disease of the twenty-first century, affecting at least one third of the general population. NAFLD is associated with increased mortality due to cardiovascular disease (CVD) and cancer. The carotid intimal media thickness (CIMT), mean platelet volume (MPV) and endocan level could be markers for generalised atherosclerotic burden and endothelial dysfunction. The aims of the study were to evaluate the association between non-alcoholic fatty liver disease and early atherosclerosis by measuring CIMT, MPV and endocan level, as markers of endothelial dysfunction, in NAFLD patients.

Material and methods

This cross-sectional study included 50 patients who were divided into two groups: group I included 25 subjects with NAFLD and group II included 25 healthy subjects. Complete blood count with MPV, liver profile, lipid profile, fasting blood glucose level, 2-hour postprandial kidney function test, and serum concentrations of endocan were measured for all patients. NAFLD fibrosis score (NFS) was calculated. Abdominal ultrasonography and carotid ultrasound scan for measurement of CIMT were performed.

Results

Serum endocan levels, MPV and CIMT were significantly higher (p < 0.005) in NAFLD patients (0.6, 9.3 ±1.2 and 0.9 ±0.3 respectively) than healthy subjects (0.1, 8.1 ±0.6 and 0.6 ±0.1 respectively). The analysis of diagnostic performance of these factors revealed that they have good sensitivity and specificity in prediction of endothelial dysfunction with AUC (0.950, 0.844 and 0.849 respectively).

Conclusions

Serum endocan levels, MPV and CIMT could be considered as good predictors of endothelial dysfunction and therefore early detection of subclinical atherosclerosis in NAFLD patients.

Endocan Knockdown Down-Regulates the Expression of Angiogenesis-Associated Genes in Il-1ß Activated Chondrocytes

Endocan is a small soluble proteoglycan (PG) known to be involved in inflammation and angiogenesis. Increased endocan expression was found in the synovia of arthritic patients and chondrocytes stimulated with IL-1ß. Considering these findings, we aimed to investigate the effects of endocan knockdown on the modulation of pro-angiogenic molecules expression in a model of IL-1ß-induced inflammation in human articular chondrocytes. Endocan, VEGF-A, MMP-9, MMP-13, and VEGFR-2 expression was measured in both normal and endocan knockdown chondrocytes stimulated with IL-1ß. VEGFR-2 and NF-kB activation were also measured. Results have shown that endocan, VEGF-A, VEGFR-2, MMP-9, and MMP-13 were significantly up-regulated during IL-1ß-induced inflammation; interestingly, the expression of such pro-angiogenic molecules and NF-kB activation were significantly reduced by endocan knockdown. These data support the hypothesis that endocan released by activated chondrocytes may be involved in the mechanisms that stimulate cell migration and invasion, as well as angiogenesis, in the pannus of arthritic joints.

Evaluation of subclinical atherosclerosis in obese patients with three noninvasive methods: Arterial stiffness, carotid intima-media thickness, and biomarkers of endothelial dysfunction

Objective

In this study, we aimed to evaluate subclinical atherosclerosis in patients with obesity who had cardiovascular disease risk indicators such as arterial stiffness, which is evaluated using pulse wave velocity (PWV), carotid intima-media thickness (CIMT), and biomarkers of endothelial dysfunction such as endocan, ADAMTS97, and ADAMTS9.

Subjects and methods

Sixty obese subjects, including 23 subjects with body mass index (BMI) ≥ 40, 37 subjects with BMI ≥ 30 but < 40, and 60 age-and sex-matched control subjects, were included in our study. Serum endocan, ADAMTS97, and ADAMTS9 levels as well as PWV and CIMT measurements of the subjects in the obese and control groups were performed.

Results

In the obesity group, PWV levels were significantly higher than they were in the control group and endocan levels were significantly lower than they were in the control group. When we compared the obese group with BMI ≥ 40 and the control group, the BMI ≥ 40 group had significantly higher PWV and CIMT levels than the control group had, whereas endocan, ADAMTS7, and ADAMTS9 levels were similar to those of the control group. When we compared the obese group with BMI ≥ 30 < 40 to the control group, endocan levels were lower in the group with BMI ≥30 < 40, and PWV and CIMT levels were similar to the control group.

Conclusion

We found that arterial stiffness and CIMT increased in obese patients with BMI ≥ 40 and that increased arterial stiffness was associated with age, systolic blood pressure, and HBA1C. In addition, we found that the endocan levels were lower in obese patients than they were in nonobese control individuals.

The Role of Endocan in Cardiometabolic Disorders

Discovered two decades ago, endocan still represents an intriguing biomarker related to inflammation. Endocan is a soluble dermatan sulphate proteoglycan secreted by endothelial cells. Its expression is observed in tissues related to the enhanced proliferation, especially hepatocytes, lungs, kidneys, etc. Endocan has been investigated in many cardiometabolic disorders that are tightly connected with inflammation, such as type 2 diabetes mellitus, hypertension, atherosclerotic cardiovascular disease, kidney disease, obesity, polycystic ovary syndrome, metabolic syndrome, non-alcoholic fatty liver disease, etc. In this narrative, comprehensive review of the currently available literature, special attention will be paid to the role of endocan in the broad spectrum of cardiometabolic disorders. Since endocan has emerged as a novel endothelial dysfunction marker, the discovery of potential therapeutic strategies for patients with certain cardiometabolic risk factors would be of great importance to delay or even prevent the onset and progression of related complications, mainly cardiovascular.

Serum endocan levels in patients with habitual abortion

AIM

The aim of this study was to investigate whether there is a new factor in the etiology of recurrent loss of pregnancy. For this purpose, serum malondialdehyde (MDA) and nitric oxide (NO) levels as indicators of oxidative stress, and endocan levels, a marker of vascular dysfunction, were investigated in patients diagnosed with habitual abortion.

MATERIALS AND METHODS

The research was conducted as a prospective case-control study. Patients aged 18-40 years with two or more consecutive pregnancy losses revealed by ultrasonographic or histopathological examination, and with no pathology capable of causing habitual abortion were included in the study group. Patients with no history of abortion, with at least one healthy pregnancy, who were planning pregnancies, and who presented to the outpatient clinic for routine prepregnancy tests were selected as the control group. Two groups were established-habitual abortion (n = 30) and control (n = 29). At the end of the menstrual cycle, blood samples were collected and centrifuged. Serum NO, MDA, and endocan levels were studied.

RESULTS

Serum endocan, NO, and MDA levels were higher in women with habitual abortion compared to healthy controls. Pearson's correlation analysis revealed a positive correlation between serum endocan levels and NO and MDA levels. A positive correlation was also observed between serum MDA and NO levels. Multiple regression was run to predict serum endocan levels from MDA and NO levels. These variables emerged as statistically significant predictors of endocan.

CONCLUSION

These findings suggest the presence of vascular endothelial dysfunction in patients with habitual abortion.

Endocan Promotes Pro-Tumorigenic Signaling in Lung Cancer Cells: Modulation of Cell Proliferation, Migration and lncRNAs H19 and HULC Expression

Endocan is a circulating proteoglycan secreted by several cell lines and identified as a potential biomarker of inflammation and angiogenesis. Endocan-increased expression has been found in a broad spectrum of human tumors, including lung cancer, and is associated with a poor prognosis. To elucidate the possible mechanism, this study aimed to investigate the role of endocan in non-small-cell lung carcinoma (NSCLC) using an in vitro model of cultured cells. Endocan expression was knocked down by using a specific small interfering RNA. The effects of endocan knockdown have been evaluated on VEGF-A, VEGFR-2, HIF-1α, the long non-coding RNAs H19 and HULC expression, and AKT and ERK 1/2 degree of activation. Cell migration and proliferation have been studied as well. VEGF-A, VEGFR-2, HIF-1α, and the long non-coding RNAs H19 and HULC expression were significantly affected by endocan knockdown. These effects correlated with a reduction of cell migration and proliferation and of AKT and ERK 1/2 activation. Our findings suggest that endocan promotes a more aggressive cancer cell phenotype in NSCLC.

Higher Serum Endothelial-Specific Molecule-1 (ESM-1/Endocan) Levels are Associated with Poor Pathological Outcomes in Primary Bladder Cancer: A Non-randomized, Prospective, Case-Control Study

AIM

To compare serum endothelial-specific molecule-1 (ESM-1 or endocan) levels between individuals with primary bladder cancer (BC) who have various pathological features of BC and healthy volunteers.

MATERIALS AND METHODS

154 consecutive patients with primary BC (Group-1) and 52 healthy volunteers (Group-2) were accepted into this prospective, non-randomized, observational research between January 2017 and December 2018. Peripheral blood samples were obtained from each participant to measure serum ESM-1/endocan levels. Group-1 was further divided into subgroups as Group-1A (pTa), Group-1B (pT1) and Group-1C (pT2) based on the transurethral resection of bladder tumour (TURBT) histopathological results. In addition Group-1 was divided into other subgroups based on pathological features of BC including tumor grade, tumor volume and muscle-invasive status. Groups were compared statistically regarding ESM-1/endocan levels.

RESULTS

Median age of the individuals was 63 (22) years in Group-1 and 66 (11) years in Group-2 (p = 0.051). There were 140 (90.9%) males and 14 (9.1%) females in Group-1 and 30 (57.7%) males and 22 (42.3%) females in Group-2 (p < 0.001). The serum ESM-1/endocan measurements were lower in Group-2 than in Group-1 (p = 0.018). Of the patients in Group-1, 62 (40.3%) had low-grade tumors and 92 (59.7%) had high-grade tumors. When Group-1 was further divided into other subgroups according to different pathological features of BC such as tumor stage, grade, muscle-invasive status and tumor volume it was detected that there was a statistically meaningful difference between all subgroups of Group-1 and Group-2 in terms of serum ESM-1/endocan levels (p < 0.05 for each). The serum ESM-1/endocan cut-off value (3.472 ng/mL) had a specificity of 57.7%, sensitivity of 59.1%, NPV (negative predictive value) of 32.3% and PPV (positive predictive value) of 80.5% for predicting the presence of BC with an AUC (Area Under the Curve) of 0.609 (95% confidence interval (CI) 0.524-0.694; p = 0.018).

CONCLUSIONS

The serum ESM-1/endocan levels can be considered a potentially useful predictor for BC. Higher serum ESM-1/endocan levels are related with poor pathological outcomes in BC.

Elevated Circulating Endocan Levels Are Associated with Increased Levels of Endothelial and Inflammation Factors in Postprandial Lipemia

BACKGROUND

Postprandial lipemia (PPL) causes endothelial dysfunction by causing endothelial damage to lipoproteins that remain rich in triglycerides. Endocan is a proteoglycan with increased tissue expression, endothelial activation, and neovascularization. The aim of the study was to examine circulating endocan levels in PPL subjects by considering the degree of PPL response according to a high-fat test meal. The other aim was to determine the association between endocan levels and endothelial and inflammatory factors.

METHOD

Fifty-four hyperlipidemic subjects and 28 normolipidemic subjects consumed the high-fat meal. Endocan, sICAM-1, sVCAM-1, and VEGFA as endothelial factors and IL-6 and LFA-1α as inflammatory factors were evaluated.

RESULTS

Fasting serum endocan, VEGFA, sICAM-1, sVCAM-1 IL-6, and LFA-1α levels were increased in the PPL group compared to the control group. The PPL group was divided into tertiles based on mean AUC levels. Endocan levels in tertile 3 were at the highest and were increased significantly compared to tertiles 1 and 2. AUC and endocan levels were positively correlated with other endothelial and inflammation factors. ROC analysis showed endocan levels to be one of the highest values.

CONCLUSIONS

Circulating endocan is seen at significantly higher levels and independently associated with endothelial and inflammatory factors in postprandial lipemia and dyslipidemia.

Evaluation of Endocan as a Treatment for Acute Inflammatory Respiratory Failure

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a life-threatening condition resulting from acute pulmonary inflammation. However, no specific treatment for ARDS has yet been developed. Previous findings suggest that lung injuries related to ARDS could be regulated by endocan (Esm-1). The aim of this study was to evaluate the potential efficiency of endocan in the treatment of ARDS.

METHODS

We first compared the features of acute pulmonary inflammation and the severity of hypoxemia in a tracheal LPS-induced acute lung injury (ALI) model performed in knockout (Esm1^-/-) and wild type (WT) littermate C57Bl/6 mice. Next, we assessed the effects of a continuous infusion of glycosylated murine endocan in our ALI model in Esm1^-/- mice.

RESULTS

In our ALI model, we report higher alveolar leukocytes (p < 0.001), neutrophils (p < 0.001), and MPO (p < 0.001), and lower blood oxygenation (p < 0.001) in Esm1^-/- mice compared to WT mice. Continuous delivery of glycosylated murine endocan after LPS-induced ALI resulted in decreased alveolar leukocytes (p = 0.012) and neutrophils (p = 0.012), higher blood oxygenation levels (p < 0.001), and reduced histological lung injury (p = 0.04), compared to mice treated with PBS.

CONCLUSIONS

Endocan appears to be an effective treatment in an ARDS-like model in C57Bl/6 mice.

The association of catestatin and endocan with the effects of cardiac shock wave therapy: Biomarker sub-study of the randomized, sham procedure-controlled trial

Introduction

Cardiac shock-wave therapy (CSWT) is a non-invasive regenerative treatment method based on low-frequency ultrasound waves, which stimulate angiogenesis. Current data about the effects of revascularization procedures on angiogenesis biomarkers is limited. Recently, an association of catestatin and endocan with coronary collateral development was shown in several trials. In this study, we aimed to evaluate the impact of CSWT on the dynamics of catestatin and endocan levels and to assess their correlation with parameters of myocardial perfusion and function.

Methods

Prospective, randomized, triple-blind, sham procedure-controlled study enrolled 72 adult subjects who complied with defined inclusion criteria (NCT02339454). We measured biomarkers in 48 patients with stable angina (24 patients of CSWT group, 24 patients of sham-procedure group). Additionally, patients were divided into responders and non-responders according to improvement in myocardial perfusion and/or contractility assessed by myocardial scintigraphy and dobutamine echocardiography (30 and 13 patients, respectively). The blood samples were collected at baseline, after the last treatment procedure (9th treatment week) and at 6-month follow-up to evaluate biomarkers concentration and stored at -80° until analysis. Serum catestatin and endocan levels were determined by commercially available ELISA kits.

Results

Serum catestatin concentration significantly increased in all patients. While endocan levels significantly decreased in the responders sub-group. The increase in catestatin levels at 9th week and 6 months was positively associated with improvement in summed difference score (rho = 0.356, p = 0.028) and wall motion score, WMS (rho = 0.397, p = 0.009) at 6 months in the whole study population. Meanwhile, the decrease in endocan levels over 6 months was positively correlated with improvement in WMS at 3- and 6- months (r = 0.378, p = 0.015 and r = 0.311, p = 0.045, respectively). ROC analysis revealed that a change at 6 months in catestatin and endocan levels significantly predicted improvement in myocardial perfusion and contractile function with 68.9% sensitivity and 75.0% specificity (p = 0.039) and 51.7% sensitivity, and 91.7% specificity (p = 0.017), respectively. Baseline endocan concentration and its change at 6 months predicted response to CSWT with 68.8% sensitivity and 83.3% specificity (p = 0.039) and 81.3% sensitivity and 100% specificity (p < 0.0001), respectively.

Conclusion

This study demonstrates the association of increase in catestatin and decrease in endocan levels with the improvement of myocardial perfusion and contractile function. The potential predictive value of catestatin and endocan dynamics for the response to regenerative therapy is shown.

Endothelial Cell-Specific Molecule-1 Inhibits Albuminuria in Diabetic Mice

Background

Diabetic kidney disease (DKD) is the most common cause of kidney failure in the world, and novel predictive biomarkers and molecular mechanisms of disease are needed. Endothelial cell-specific molecule-1 (Esm-1) is a secreted proteoglycan that attenuates inflammation. We previously identified that a glomerular deficiency of Esm-1 associates with more pronounced albuminuria and glomerular inflammation in DKD-susceptible relative to DKD-resistant mice, but its contribution to DKD remains unexplored.

Methods

Using hydrodynamic tail-vein injection, we overexpress Esm-1 in DKD-susceptible DBA/2 mice and delete Esm-1 in DKD-resistant C57BL/6 mice to study the contribution of Esm-1 to DKD. We analyze clinical indices of DKD, leukocyte infiltration, podocytopenia, and extracellular matrix production. We also study transcriptomic changes to assess potential mechanisms of Esm-1 in glomeruli.

Results

In DKD-susceptible mice, Esm-1 inversely correlates with albuminuria and glomerular leukocyte infiltration. We show that overexpression of Esm-1 reduces albuminuria and diabetes-induced podocyte injury, independent of changes in leukocyte infiltration. Using a complementary approach, we find that constitutive deletion of Esm-1 in DKD-resistant mice modestly increases the degree of diabetes-induced albuminuria versus wild-type controls. By glomerular RNAseq, we identify that Esm-1 attenuates expression of kidney disease-promoting and interferon (IFN)-related genes, including Ackr2 and Cxcl11.

Conclusions

We demonstrate that, in DKD-susceptible mice, Esm-1 protects against diabetes-induced albuminuria and podocytopathy, possibly through select IFN signaling. Companion studies in patients with diabetes suggest a role of Esm-1 in human DKD.

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.

Serum Endocan Levels and Subclinical Atherosclerosis in Behçet's Syndrome

Background and Aim

Behçet disease (BD) is a rare chronic relapsing-remitting inflammatory systemic vasculitis. BD patients were reported to have marked acceleration of subclinical atherosclerosis (SCA). Endocan is a soluble proteoglycan mainly secreted by the activated endothelium. The present study aimed to assess the relation between serum endocan levels and SCA in BD patients.

Subjects and Methods

The study included 40 adult BD patients in addition to twenty age- and sex-matched healthy controls. BD was diagnosed according to International Study Group criteria. Upon recruitment, all participants were subjected to careful history taking and thorough clinical examination. BD activity was assessed using Behçet Syndrome Activity Score. Measurement of serum endocan was performed using quantitative double-antibody sandwich ELISA kit. CIMT measurement was done using B-mode ultrasound.

Results

Comparison between patients and controls regarding serum endocan levels revealed significantly higher endocan levels in BD patients [median (IQR): 155.0 (69.3–610.0) versus 73.8 (51.9–94.6)]. Using ultrasound assessment, SCA was found in 14 BD patients (35.0%). Comparison between patients with SCA and patients without regarding the clinical and laboratory data revealed that the former group had significantly higher CRP [median (IQR): 36.5 (26.8–43.5) versus 21.0 (11.8–26.8) mg/dL, p < 0.001] and endocan [median (IQR): 622.0 (107.4–974.8) versus 104.5 (64.0–342.0) mg/dL, p = 0.004] levels. Logistic regression analysis recognized endocan [OR (95% CI): 1.0 (1.0–1.012), p0.035] levels as significant predictor of SCA in multivariate analysis.

Conclusion

The present study identified the clinical value of serum endocan levels as a possible early marker of vascular involvement in BD patients.

Biomarkers of Glycocalyx Injury and Endothelial Activation are Associated with Clinical Outcomes in Patients with Sepsis: A Systematic Review and Meta-Analysis

OBJECTIVE

Sepsis is one of the main causes of morbidity and mortality worldwide. Microcirculatory impairment, especially damage to the endothelium and glycocalyx, is often not assessed. The objective of this systematic review and meta-analysis was to summarize the available evidence of the risk of unsatisfactory outcomes in patients with sepsis and elevated glycocalyx injury and endothelial activation biomarkers.

DESIGN

A systematic search was carried out on PubMed/MEDLINE, Embase, Cochrane and Google Scholar up to December 31, 2021, including studies in adults and children with sepsis which measured glycocalyx injury and endothelial activation biomarkers within 48 hours of hospital admission. The primary outcome was the risk of mortality from all causes and the secondary outcomes were the risk of developing respiratory failure (RF) and multiple organ dysfunction syndrome (MODS) in patients with elevations of these biomarkers.

MEASUREMENTS AND MAIN RESULTS

A total of 17 studies (3,529 patients) were included: 11 evaluated syndecan-1 (n=2,397) and 6 endocan (n=1,132). Syndecan-1 was higher in the group of patients who died than in those who survived [255 ng/mL (IQR: 139-305) vs. 83 ng/mL (IQR:40-111); p=0.014]. Patients with elevated syndecan-1 had a greater risk of death (OR 2.32; 95% CI 1.89, 3.10: p<0.001), MODS (OR 3.3; 95% CI 1.51, 7.25: p=0.003;), or RF (OR 7.53; 95% CI 1.86-30.45: p=0.005). Endocan was higher in patients who died [3.1 ng/mL (IQR 2.3, 3.7) vs. 1.62 ng/mL (IQR 1.2, 5.7); OR 9.53; 95% CI 3.34, 27.3; p<0.001], who had MODS (OR 8.33; 95% CI 2.07, 33.58; p=0.003) and who had RF (OR 9.66; 95% CI 2.26, 43.95; p=0.002).

CONCLUSION

Patients with sepsis and abnormal glycocalyx injury and endothelial activation biomarkers have a greater risk of developing respiratory failure, multiple organ failure, and death. Microcirculatory impairment should be routinely evaluated in patients with sepsis, using biomarkers to stratify risk groups.

Endocan: A Key Player of Cardiovascular Disease

Endothelial dysfunction is considered to be an early change in atherosclerosis. Endocan, also known as endothelial cell specific molecule-1, is a soluble proteoglycan mainly secreted by endothelial cells. Inflammatory factors such as IL-1β and TNF-α can up regulate the expression of endocan and then affect the expression of cell adhesion molecules, such as ICAM-1 and VCAM-1, which play an important role in promoting leukocyte migration and inflammatory response. Elevated plasma levels of endocan may reflect endothelial activation and dysfunction, and is considered to be a potential immuno-inflammatory marker that may be related to cardiovascular disease. In the case of hypertension, diabetes, angina pectoris and acute myocardial infarction, the increase or decrease of serum endocan levels is of great significance. Here, we reviewed the current research on endocan, and emphasis its possible clinical value as a prognostic marker of cardiovascular disease. Endocan may be a useful biomarker for the prognosis of cardiovascular disease, but more research is needed on its mechanism of action.

Endocan as a potential marker in diagnosis and predicting disease severity in COVID-19 patients: a promising biomarker for patients with false-negative RT-PCR

BACKGROUND

Endothelial-specific molecule 1 (endocan) has emerged as an inflammatory biomarker in recent years. The purpose of this study was to investigate the diagnostic value of serum endocan levels in the prediction of COVID-19 disease among patients with a false-negative reverse transcription polymerase change reaction (RT-PCR) test, and also to determine its correlation with the clinical severity of the disease.

METHODS

Thirty patients with positive RT-PCR results and 30 with false-negative RT-PCR results, both with suspected COVID-19 in terms of clinical, radiological, and laboratory findings, were included in the study. Thirty healthy controls were also enrolled.

RESULTS

Serum endocan levels were estimated to be 821.8 ± 99.3 pg/mL in COVID-19 RT-PCR (+) patients, 803.9 ± 97.0 pg/mL in RT-PCR false (-) patients with suspected COVID-19, and 382.9 ± 37.5 pg/mL in the control group. No significant difference was observed between RT-PCR (+) and RT-PCR false (-) patients (P = 0.68). However, serum endocan levels differed significantly between patient groups and control group (P < 0.05). With a cut-off value of 444.2 pg/mL serum endocan levels differentiated COVID-19 cases from healthy individuals with 92% sensitivity and 80% specificity. Moreover, a significant positive correlation was observed between serum endocan levels and clinical severity (P < 0.01, r = 0.94).

CONCLUSIONS

There is a need for different laboratory markers capable of assisting diagnosis and showing COVID-19 infection in suspected COVID-19 RT-PCR false-negative patients. Endocan levels can be used as an assistant blood test for identifying COVID-19 patients with false-negative RT-PCR tests and in determining the clinical severity of the disease.

Arterial stiffness, carotid intima-media thickness, endocan and A disintegrin-like and metalloprotease with thrombospondin type I motif 9 levels and their relationship with disease activity in acromegaly patients with and without cardiovascular risk factors

OBJECTIVE

Cardiovascular complications such as cardiomyopathy and endothelial dysfunction, which are frequently seen in patients with acromegaly, are among the most important causes of morbidity and mortality. In this study, we aimed to investigate arterial stiffness, carotid intima-media thickness, endocan and A disintegrin-like and metalloprotease with thrombospondin type I motif 9 (ADAMTS9) levels and their relationship with disease activity in acromegaly patients with and without cardiovascular risk factors.

DESIGN

A total of 60 patients with acromegaly, 25 with active disease, 26 with well-controlled disease, and 9 newly diagnosed, and 60 age-, sex- and body mass index (BMI)-matched healthy control subjects were enrolled in this study. All subjects' height, weight, BMI, systolic blood pressure (SBP), distolic blood pressure (DBP), fasting plasma glucose (FPG), insulin, hemoglobin A1c (HbA1c), C-reactive protein (CRP), lipid, endocan, ADAMTS9, pulse wave velocity (PWV) and carotid intima-media thickness (CIMT) measurements were performed.

RESULTS

SBP, DBP, FPG, HbA1c and PWV levels of the acromegaly group were higher than the control group. In acromegaly patients with cardiovascular disease (CVD) risk factors, PWV was higher than the control group, and in acromegaly patients without CVD risk factor, PWV was similar to the control group. In the correlation analysis, a positive correlation was found between PWV and age, BMI, SBP, DBP, FPG and HbA1c levels in the acromegaly group.

CONCLUSIONS

In our study, we found that arterial stiffness increased in acromegaly patients with CVD risk factors, and that increased arterial stiffness was associated with hemodynamic (SBP, DBP) and metabolic (BMI, FPG, HBA1C) parameters.

Can Serum Endocan Levels be Used as an Early Prognostic Marker for Endothelial Dysfunction in COVID-19?

In this study, we aimed to investigate whether degree of pneumonia and COVID-19 prognosis are associated with serum endocan levels at the early stage, when vascular damage has started. Patients between the ages of 18–85 years who were hospitalized and followed up with a diagnosis of COVID-19 were included in the study. A total of 80 patients were divided into 2 groups as mild/moderate pneumonia and severe pneumonia. Serum endocan levels were measured on the 8th day from the onset of symptoms in all patients. Of the 80 patients included in the study, 56.3% were female and 43.8% were male. There was no significant relationship between serum endocan levels and degree of pneumonia (P = .220) and prognosis of the disease (P = .761). The correlation analysis indicated a weak positive correlation between serum endocan levels and lactate level in venous blood gas (r = .270; P = .037). During the 28-day follow-up, the mortality rate was 3.75%. It was determined that the serum endocan levels was not associated with the degree of pneumonia and was not an early prognostic marker for COVID-19.

Biomarkers Associated with Failure of Liberation from Oxygen Therapy in Severe COVID-19: A Pilot Study

This study aimed to investigate whether clinical and laboratory biomarkers can identify patients with COVID-19 who are less likely to be liberated from oxygen therapy. This was a retrospective study comparing 18 patients in the weaning failure group with 38 patients in the weaning success group. Weaning failure was defined as death or discharge with an oxygen device before day 28 after hospital admission or requiring oxygen support as of day 28. The median quick Sequential Organ Failure Assessment (qSOFA) score was significantly higher and the median SpO₂/FiO₂ was significantly lower in the weaning failure group. The laboratory biomarkers, procalcitonin (PCT) and D-dimer, were significantly higher in the weaning failure group, as were the biomarkers of endothelial injury, such as angiopoietin-2 (Ang-2) and Ang-2/Ang-1, and tumor necrosis factor-α (TNF-α). Patients’ qSOFA scores, SpO₂/FiO₂, and PCT, D-dimer, Ang-2, Ang-2/Ang-1, endocan (4-day and 7-day increases), and TNF-α levels predicted weaning failure; 7-day endocan levels were the best predictor of weaning failure with an AUC of 0.81 (95% CI, 0.67–0.94). We identified clinical and laboratory parameters, including plasma biomarkers of endothelial injury, that may be considered as biomarkers for predicting failure of liberation from oxygen therapy in patients with severe COVID-19.

The Association Between Serum Endocan Level and Short-Term Prognosis of Patients With Acute Ischemic Stroke

This cohort study was designed to assess the association between serum endocan levels and the prognosis of acute ischemic stroke. A total of 227 patients were recruited consecutively. Study outcome data on death and major disability (modified Rankin Scale score ≥3) were collected at 3 months after stroke onset. After 3 months of follow-up, death and disability occurred in 48 and 85 patients, respectively, while the primary (death) and secondary (death or disability) outcome incident rate was 21.15% and 37.44%, respectively. The multivariable adjusted odds ratio (OR) (95% confidence interval, 95% CIs) of the highest endocan quartile for death or major disability was 1.21 (1.10, 4.13) compared with the lowest quartile. After adjusting for confounding factors, the increase in the risk of death was not significant. Receiver operating characteristic curve analysis showed that endocan predicted primary and secondary outcomes with C-statistical values (95% CIs) of 0.61 (0.55-0.67, P = .001) and 0.68 (0.59-0.76, P < .001), respectively. Elevated endocan levels were independently related to increased risk of poor outcome at 3 months after ischemic stroke onset. Endocan is a potential prognostic factor for ischemic stroke.

Diagnostic and Prognostic Value of Serum Endocan Levels in Patients With COVID-19

We aimed to evaluate whether there was a relationship between endocan (human endothelial cell-specific molecule-1) levels and disease prognosis in patients who presented to the emergency department with coronavirus disease 2019 (COVID-19). A total of 60 patients with COVID-19 who were hospitalized from the emergency department to clinical wards and a control group consisting of healthy adult individuals (n = 28), were included in the study. The majority (93.3%) of the patients were discharged after recovery; 6.7% died. The median endocan value was 243.5 ng/mL in the patient group versus 201.5 ng/mL in the control group (P = .002). The median endocan level was 240.5 ng/mL in those discharged with recovery and 558 ng/mL in those who died (P = .001). There was no significant relationship in hospitalization duration, sex, tomography findings, and clinical outcomes. A 202 ng/mL serum endocan level had 86.7% sensitivity and 50% specificity for COVID-19. Serum endocan levels may be a useful biomarker both for the diagnosis of COVID-19 and to predict mortality.

Dengue Virus Induces the Expression and Release of Endocan from Endothelial Cells by an NS1-TLR4-Dependent Mechanism

A common hallmark of dengue infections is the dysfunction of the vascular endothelium induced by different biological mechanisms. In this paper, we studied the role of recombinant NS1 proteins representing the four dengue serotypes, and their role in promoting the expression and release of endocan, which is a highly specific biomarker of endothelial cell activation. We evaluated mRNA expression and the levels of endocan protein in vitro following the stimulation of HUVEC and HMEC-1 cell lines with recombinant NS1 proteins. NS1 proteins increase endocan mRNA expression 48 h post-activation in both endothelial cell lines. Endocan mRNA expression levels were higher in HUVEC and HMEC-1 cells stimulated with NS1 proteins than in non-stimulated cells (p < 0.05). A two-fold to three-fold increase in endocan protein release was observed after the stimulation of HUVECs or HMEC-1 cells with NS1 proteins compared with that in non-stimulated cells (p < 0.05). The blockade of Toll-like receptor 4 (TLR-4) signaling on HMEC-1 cells with an antagonistic antibody prevented NS1-dependent endocan production. Dengue-infected patients showed elevated serum endocan levels (≥30 ng/mL) during early dengue infection. High endocan serum levels were associated with laboratory abnormalities, such as lymphopenia and thrombocytopenia, and are associated with the presence of NS1 in the serum.

Plasma Endocan Levels in Early and Late-Onset Preeclampsia

Preeclampsia (PE) may represent an inflammatory process. Endocan (ESM-1) is a marker of endothelial inflammation. We compared plasma endocan levels between PE and control groups and between early and late-onset PE. Study design: Maternal plasma endocan levels were measured in 41 preeclampsia (PE) pregnancies - 25 early-onset (<34 weeks); 16 late-onset (≥34 weeks), and 37 non-complicated pregnancies (22 matched with early-onset PE, 15 with late onset). Results: There was no significant differences between plasma endocan levels of patients with PE and control group (468.8(IQR: 169.7)ng/L vs 462.4(IQR: 321.1)ng/L, p > 0.05), between early and late-onset PE (458.8(221.8)ng/L vs 469.8(122.6)ng/L, p > 0.05), between early-onset PE and corresponding control group (458.8(221.8)ng/L vs 506.2(1481.9)ng/L, p > 0.05), or late-onset PE and corresponding control group (469.8(122.6)ng/L vs 451.0(85.1)ng/L, p > 0.05). Conclusion: There was no significant difference between endocan levels of early or late-onset PE compared with their corresponding control groups, nor between early and late-onset preeclampsia groups.

Serum endocan and endothelial dysfunction in childhood acute lymphoblastic leukemia survivors: a tertiary center experience

Background:

An increased risk of cardiovascular complications is reported in survivors of childhood acute lymphoblastic leukemia (ALL). Early identification of impaired vascular health may allow for early interventions to improve outcomes.

Aim:

The study was conducted to assess the endothelial dysfunction in ALL survivors using a new marker, serum endocan, and measurement of the mean common carotid arteries intima media thickness (cIMT).

Methods:

A case-control study was conducted on 100 childhood ALL survivors (aged 6–18 years), with 80 healthy age and sex-matched children as a control group. Lipid profile, hepatitis markers, and serum ferritin where measured, in addition to the measurement of serum endocan. and cIMT by B-mode high-resolution ultrasonography for all study participants.

Results:

Triglycerides, total cholesterol, post prandial glucose, and serum ferritin were significantly higher in ALL survivors than controls (p < 0.05). Dyslipidemia was detected in 6% of ALL survivors. ALL survivors showed statistically higher serum endocan levels (470.41 ± 556.1 ng/l, versus, 225.94 ± 185.2 ng/l, respectively) and increased cIMT levels compared with the control group (0.650 ± 0.129 mm versus 0.320 ± 0.095 mm, respectively) p < 0.05. Serum endocan was positively correlated with cIMT and blood cholesterol.

Conclusions:

The survivors of childhood ALL demonstrated an elevated level of serum endocan and increased cIMT. These can be used as predictors of endothelial dysfunction, and, as a consequence, the risk of developing premature atherosclerosis.

Targeting Endothelial Cell-Specific Molecule 1 Protein in Cancer: A Promising Therapeutic Approach

Despite the dramatic advances in cancer research in the past few years, effective therapeutic strategies are urgently needed. Endothelial cell-specific molecule 1 (ESM-1), a soluble dermatan sulfate proteoglycan, also known as endocan, serves as a diagnostic and prognostic indicator due to its aberrant expression under pathological conditions, including cancer, sepsis, kidney diseases, and cardiovascular disease. Significantly, ESM-1 can promote cancer progression and metastasis through the regulation of tumor cell proliferation, migration, invasion, and drug resistant. In addition, ESM-1 is involved in the tumor microenvironment, containing inflammation, angiogenesis, and lymph angiogenesis. This article reviews the molecular and biological characteristics of ESM-1 in cancer, the underlying mechanisms, the currently clinical and pre-clinical applications, and potential therapeutic strategies. Herein, we propose that ESM-1 is a new therapeutic target for cancer therapy.

Endocan and Circulating Progenitor Cells in Women with Systemic Sclerosis: Association with Inflammation and Pulmonary Hypertension

Background: Systemic sclerosis (SSc) is characterized by early vasculopathy and fibrosis in the skin, lungs, and other tissues. Vascular manifestations of SSc include Raynaud’s phenomenon, digital ulcers, and pulmonary artery hypertension (PAH). PAH is the second most common cause of mortality in SSc. Circulating CD34+ cells associated with cardiovascular health status in several conditions, including chronic immune-inflammatory disease. CD34+ cell numbers have been found inconstantly reduced in SSc. Endocan, a proteoglycan expressed by endothelial cells, was recently suggested as a marker of vascular stress. We tested the relationships among CD34+ cells, endocan, inflammatory markers, vitamin D levels, and clinical parameters in SSc patients with PAH. METHODS: Standard echocardiography was performed. Vitamin D levels, CD34+ cells, inflammatory markers, endocan plasma levels were determined in 36 female SSc patients (24 diffuse/12 limited) and 36 matched controls (HC). RESULTS: We found no difference in CD34+ and vitamin D levels in SSc as compared to controls; ESR, CRP, fibrinogen, endocan, sPAP were higher in SSc with respect to controls. We found a correlation between endocan and: CD34+ cells (r: −0.540, p = 0.002), pulmonary arterial pressure (sPAP) (r: 0.565, p < 0.001), tricuspid annular plane excursion (TAPSE) (r: −0.311, p < 0.01), and E/A ratio (r: −0.487, p < 0.001), but not with ejection fraction (r: −0.057, p = 0.785) in SSc. CD34+ cells correlate with fibrinogen (r: −0.619, p < 0.001), sPAP (r: −0.404, p = 0.011), E/A (r: 0.470, p < 0.005 in SSc. CONCLUSION: CD34+ cell number was significantly correlated with endocan levels and with sPAP in SSc; endocan and CD34+ progenitor cells might be suggested as a potential marker of disease status.

Endocan: A Novel Predictor of Endothelial Dysfunction in Silent Brain Infarction

Silent brain infarction (SBI) has been considered as a subclinical risk factor for symptomatic possible future stroke. We investigated the association between serum inflammatory markers and SBI. Patients (n = 54) diagnosed with SBI as the study group and 52 individuals as the control group were included in this study. Silent brain infarction is defined as a hyperintense lesion that was ≥3 mm in 1 dimension on fluid-attenuated inversion recovery T2-weighted magnetic resonance image, if the patient had normal neurological examination or had an abnormality that was not consistent with the brain lesion locations, after being evaluated by a neurologist. Serum endocan levels (P = .036) and high-sensitivity C-reactive protein (hsCRP; P = .022) were significantly higher in patients with SBI than the controls. Pentraxin 3, erythrocyte sedimentation rate, white blood count, lymphocyte, monocyte, neutrophil, low-density lipoprotein, and triglyceride levels were not significantly different when comparing the groups with and without SBI. There was a significant correlation (r = -0.196; P = .16) between hsCRP and endocan levels in the SBI group. Endocan, a novel biomarker of endothelial pathology, was significantly increased in patients with SBI and may be useful to predict the future risk of stroke.

Can we use endocan level to determine severity of pancreatitis?

Background and study aims

Endothelial cell specific molecule-1 (ESM-1), also known as endocan, is a soluble proteoglycan secreted by human vascular endothelial cells. In some studies, it has been found that endocan have important effects on cell adhesion, inflammation and angiogenesis. In this study, we aimed to evaluate the endocan level in patients with pancreatitis and the availability of endocan level in determining the severity of the disease.

Patients and methods

A total of 42 patients with pancreatitis and 33 healthy individuals were included in the study. The serum endocan levels in patients were evaluated 1st and 3 th days after the symptom's onset. Current scoring systems and the relationship between the severity of the disease and endocan levels were evaluated.

Results

The endocan levels of the patients on day 1 are significantly correlated only with the APACHE II score (p=0.039 r=0.319), while the endocan values on day 3 are significantly correlated with the BISAP (bedside index of severity in acute pancreatitis) (p=0.013 r=0.380), APACHE II (Acute Physiology and Chronic Health Evaluation)(p<0.001; r=0.53) and Ranson (p=0.037 r=0.32) scores. The cutoff level of endocan (day 3) was calculated 92.2 pg/ml (83% sensitivity and 50% specificity; p=0.039 area under the curve 0.706) for severe pancreatitis when considering the patients with a score of 8 or higher in the APACHE II scoring system.

Conclusion

Serum endocan level can be used as a marker of prognosis in patients with pancreatitis. However, studies involving large populations are needed on this matter.

The significance of endocan immunohistochemical expression in chronic plaque psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory skin disease with immune-mediated mechanism. Endocan is a soluble dermatan sulfate proteoglycan expressed by endothelium of blood vessels.

AIMS

The present study aims to evaluate immunohistochemical localization of endocan in psoriatic skin in comparison with normal skin and to correlate its expression with the clinical and pathological data of psoriasis.

PATIENTS/METHODS

Skin biopsies from 36 psoriatic patients and 40 normal subjects were taken and processed for immunohistochemical staining of endocan.

RESULTS

Endocan was expressed in 63.9% and in 36.1% of epidermal keratinocytes and dermal endothelial and inflammatory cells of psoriatic skin, respectively, compared with its expression in 30% of epidermis of normal skin. Diffuse epidermal expression of endocan was in favor of cases with more angiogenesis and its intense expression was in favor of marked acanthosis and with cases affecting trunk as main presentation. Positive dermal endocan expression was significantly associated with marked parakeratosis and with more angiogenesis.

CONCLUSION

Endocan is over-expressed in psoriatic skin from epidermal keratinocytes and dermal endothelial and inflammatory cells. Endocan enhances angiogenesis and proliferation of psoriatic skin contributing to pathogenic mechanisms of psoriasis.

Increased Carotid Intima-Media Thickness and Endothelial Cell-Specific Molecule-1 (Endocan) Levels in Obese Children

Obesity in children appears to be associated with increased risk of cardiovascular and metabolic diseases later in life. Early development of insulin resistance (IR) may lead to endothelial dysfunction and increased carotid intima-media thickness (cIMT) even in childhood. We compared endothelial cell-specific molecule-1 (endocan) levels in pediatric obese patients with those in healthy controls to determine whether endocan could be used as a biological marker of complications caused by endothelial damage. In 80 obese pubertal children (44 males [M] and 36 females [F], mean age: 12.8 ± 2.5 years), anthropometric measurements, cIMT, endocan levels, and IR indices (homeostasis model assessment of insulin resistance [HOMA-IR]) were evaluated and compared with 80 healthy pubertal patients (42M/38F, mean age: 12.3 ± 3.2 years). High-resolution ultrasound was used to measure the cIMT. Obese children had higher levels of endocan compared with the controls (P < .001). Fasting insulin levels and HOMA-IR were also higher in obese children (P < .001 for both). In addition, obese children had an increased cIMT (P < .001). In obese children, there was a significant correlation between cIMT and HOMA-IR (β = -1.314, P = .002) and between cIMT and endocan (β = .483, P = .004). Measuring cIMT and endocan levels (noninvasive investigations) in obese children, together with early preventive measures, could significantly decrease morbidity and mortality in adulthood.

Endothelial Dysfunction and Atherosclerosis in Patients With Autosomal Dominant Polycystic Kidney Disease

Introduction

In this study, we aimed to determine the endothelial dysfunction (ED) and atherosclerosis in patients with autosomal dominant polycystic kidney disease (ADPKD).

Materials and methods

This study was conducted with 83 subjects (26 male, mean age: 46±11 years) consisted of three groups including ADPKD, hypertension (HT) and healthy control groups. The groups were evaluated in terms of serum endocan and asymmetric dimethylarginine (ADMA) levels, flow-mediated dilatation (FMD), nitroglycerin-mediated dilation (NMD) and carotid intima-media thickness (CIMT).

Results

Serum endocan and ADMA levels and CIMT were significantly higher while NMD was significantly lower in ADPKD group than control group. FMD and NMD were lower but serum ADMA level was higher in the ADPKD group than HT group; while serum endocan level and CIMT were not significantly different in ADPKD and HT groups. In ADPKD patients, CIMT value and serum endocan and ADMA levels were higher while NMD was lower in patients with eGFR≤60 mL/min/1.73 m² than patients with eGFR>60 mL/min/1.73 m². Serum ADMA level was higher and NMD was lower in hypertensive ADPKD patients than non-hypertensive ones. Serum endocan level was higher in ADPKD patients with nephrolithiasis and a negative correlation was detected between serum endocan level and 24-hour urine volume.

Conclusions

Endothelial dysfunction and atherosclerosis are common conditions in ADPKD patients and it was further reinforced in our study. In order to clarify the relationship between serum endocan level and 24-hour urine volume, which is a remarkable finding in our study, larger studies that including the measurement of urine endocan may be useful.

Serum endocan levels in relation to traditional and non-traditional anthropometric indices in adult population

Background

Association between endocan and nontraditional anthropometric indices, as distinct cardiovascular disease risk factors, has not been examined in previous studies. Endocan is a novel inflammation biomarker with its higher levels involved in cardiometabolic diseases development. Taking into consideration that obesity is an independent risk factor for many cardiometabolic diseases, we aimed to explore the relationship between endocan levels and novel anthropometric indices [i.e., body adiposity index (BAI), cardiometabolic index (CMI), a body shape index, body roundness index, conicity index, lipid accumulation product index and visceral adiposity index] and traditional ones [i.e., waist circumference, hip circumference, body mass index, waist-to-height ratio and waist-to-hip ratio] in adult population.

Methods

A total of 177 participants were included. Anthropometric indices and biochemical parametres were measured.

Results

Univariate regression analysis demonstrated positive correlations of endocan and almost all anthropometric data. To explore independent associations of endocan and anthropometric parameters, the Model which fulfilled criteria for ordinal regression testing was created. Adjusted odds for BAI given in the Model (OR=1.120, 95% CI 1.036-1.212, P=0.004), demonstrated that a rise in BAI by 1 unit increased the probability of higher endocan concentration by 12%. As well, a rise in CMI for 1 unit, increased the probability for higher endocan levels for 2.6 times (OR=2.599, 95% CI 1.006-6.712, P=0.049). A total of 20.1% of variation in endocan levels could be explained by this Model.

Conclusions

Non-traditional obesity indices, BAI and CMI independently correlated with higher serum endocan levels in adult population.

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.