Plasma concentrations of syndecan-1 are dependent on kidney function

Urinary syndecan-1 in dogs anesthetized with isoflurane or sevoflurane: A randomized, prospective study

BACKGROUND

Syndecan-1 (SDC1) is an established marker of endothelial glycocalyx shedding. Most research on SDC1 has focused on plasma or serum concentrations, and little is known about urine concentrations.

OBJECTIVES

Measure urinary SDC1 concentrations in dogs undergoing anesthesia with either sevoflurane or isoflurane and assess the effects of anesthesia duration and IV crystalloids on urinary SDC1 concentrations.

ANIMALS

Thirty-one client-owned dogs undergoing anesthesia for magnetic resonance imaging (MRI) with or without surgery for suspected intervertebral disk disease (IVDD) were used.

METHODS

Dogs with suspected IVDD were randomized to undergo anesthesia with either sevoflurane or isoflurane. Urine was collected before and immediately after anesthesia for the analysis of SDC1. Urinary creatinine concentrations also were measured, and the ratio of urinary SDC1 to urinary creatinine (USCR) was used to account for dilution.

RESULTS

Median (range) USCR was significantly higher after anesthesia compared with baseline for all groups combined (P < .05). No significant difference was found between the groups for age, sex, weight, and type of anesthesia. Multiple regression analysis of the effect of the independent variables inhalant type, age, weight, sex, anesthesia time, surgery, and quantity of IV fluids on the dependent variable SDC1 found that only the quantity of IV fluids significantly predicted a change (P < .001).

CONCLUSIONS AND CLINICAL IMPORTANCE

The total volume of lactated Ringer's solution administered to anesthetized dogs may affect USCR. Further investigations are warranted to evaluate the relationship between IV fluids and SDC1.

Altered Serum Proteins Suggest Inflammation, Fibrogenesis and Angiogenesis in Adult Patients with a Fontan Circulation

Previous omics research in patients with complex congenital heart disease and single-ventricle circulation (irrespective of the stage of palliative repair) revealed alterations in cardiac and systemic metabolism, inter alia abnormalities in energy metabolism, and inflammation, oxidative stress or endothelial dysfunction. We employed an affinity-proteomics approach focused on cell surface markers, cytokines, and chemokines in the serum of 20 adult Fontan patients with a good functioning systemic left ventricle, and we 20 matched controls to reveal any specific processes on a cellular level. Analysis of 349 proteins revealed 4 altered protein levels related to chronic inflammation, with elevated levels of syndecan-1 and glycophorin-A, as well as decreased levels of leukemia inhibitory factor and nerve growth factor-ß in Fontan patients compared to controls. All in all, this means that Fontan circulation carries specific physiological and metabolic instabilities, including chronic inflammation, oxidative stress imbalance, and consequently, possible damage to cell structure and alterations in translational pathways. A combination of proteomics-based biomarkers and the traditional biomarkers (uric acid, γGT, and cholesterol) performed best in classification (patient vs. control). A metabolism- and signaling-based approach may be helpful for a better understanding of Fontan (patho-)physiology. Syndecan-1, glycophorin-A, leukemia inhibitory factor, and nerve growth factor-ß, especially in combination with uric acid, γGT, and cholesterol, might be interesting candidate parameters to complement traditional diagnostic imaging tools and the determination of traditional biomarkers, yielding a better understanding of the development of comorbidities in Fontan patients, and they may play a future role in the identification of targets to mitigate inflammation and comorbidities in Fontan patients.

Circulating Syndecan-1 Levels Are Associated with Chronological Coagulofibrinolytic Responses and the Development of Disseminated Intravascular Coagulation (DIC) after Trauma: A Retrospective Observational Study

BACKGROUND

The purpose of this study was to evaluate the association between endotheliopathy represented by high levels of circulating syndecan-1 (SDC-1) and coagulofibrinolytic responses due to trauma, which can lead to disseminated intravascular coagulation (DIC).

METHODS

We retrospectively evaluated 48 eligible trauma patients immediately admitted to our hospital and assessed SDC-1 and coagulofibrinolytic parameters for 7 days after admission. We compared the longitudinal changes of coagulofibrinolytic parameters and SDC-1 levels between two groups (high and low SDC-1) according to median SDC-1 value on admission.

RESULTS

The median circulating SDC-1 level was 99.6 (61.1-214.3) ng/mL on admission, and levels remained high until 7 days after admission. Coagulofibrinolytic responses assessed by biomarkers immediately after trauma were correlated with SDC-1 elevation (thrombin-antithrombin complex, TAT: r = 0.352, p = 0.001; antithrombin, AT: r = -0.301, p < 0.001; plasmin-α₂-plasmin inhibitor complex, PIC: r = 0.503, p = 0.035; tissue plasminogen activator, tPA: r = 0.630, p < 0.001). Sustained SDC-1 elevation was associated with intense and prolonged coagulation activation, impairment of anticoagulation, and fibrinolytic activation followed by inhibition of fibrinolysis, which are the primary responses associated with development of DIC in the acute phase of trauma. Elevation of circulating SDC-1 level was also associated with consumption coagulopathy and the need for transfusion, which revealed a significant association between high SDC-1 levels and the development of DIC after trauma (area under the curve, AUC = 0.845, cut-off value = 130.38 ng/mL, p = 0.001).

CONCLUSIONS

High circulating levels of syndecan-1 were associated with intense and prolonged coagulation activation, impairment of anticoagulation, fibrinolytic activation, and consumption coagulopathy after trauma. Endotheliopathy represented by SDC-1 elevation was associated with trauma induced coagulopathy, which can lead to the development of DIC.

Major open abdominal surgery is associated with increased levels of endothelial damage and interleukin-6

OBJECTIVE

To examine changes in biomarkers of endothelial glycocalyx shedding, endothelial damage, and surgical stress following major open abdominal surgery and the correlation to postoperative morbidity.

INTRODUCTION

Major abdominal surgery is associated with high levels of postoperative morbidity. Two possible reasons are the surgical stress response and the impairment of the glycocalyx and endothelial cells. Further, the degree of these responses may correlate with postoperative morbidity and complications.

METHODS

A secondary data analysis of prospectively collected data from two cohorts of patients undergoing open liver surgery, gastrectomy, esophagectomy, or Whipple procedure (n = 112). Hemodynamics and blood samples were collected at predefined timestamps and analyzed for biomarkers of glycocalyx shedding (Syndecan-1), endothelial activation (sVEGFR1), endothelial damage (sThrombomodulin (sTM)), and surgical stress (IL6).

RESULTS

Major abdominal surgery led to increased levels of IL6 (0 to 85 pg/mL), Syndecan-1 (17.2 to 46.4 ng/mL), and sVEGFR1 (382.8 to 526.5 pg/mL), peaking at the end of the surgery. In contrast, sTM, did not increase during surgery, but increased significantly following surgery (5.9 to 6.9 ng/mL), peaking at 18 h following the end of surgery. Patients characterized with high postoperative morbidity had higher levels of IL6 (132 vs. 78 pg/mL, p = 0.007) and sVEGFR1 (563.1 vs. 509.4 pg/mL, p = 0.045) at the end of the surgery, and of sTM (8.2 vs. 6.4 ng/mL, p = 0.038) 18 h following surgery.

CONCLUSION

Major abdominal surgery leads to significantly increased levels of biomarkers of endothelial glycocalyx shedding, endothelial damage, and surgical stress, with the highest levels seen in patients developing high postoperative morbidity.

Reduction of Endothelial Glycocalyx on Peritubular Capillaries in Chronic Kidney Disease

In chronic kidney disease (CKD), peritubular capillaries undergo anatomic and functional alterations, such as rarefaction and increased permeability. The endothelial glycocalyx (EG) is a carbohydrate-rich gel-like mesh, which covers the luminal surface of endothelial cells. It is involved in many regulatory functions of the endothelium, including vascular permeability. Herein, we investigated ultrastructural alterations of the EG in different murine CKD models. Fluorescence staining using different lectins with high affinity to components of the renal glycocalyx revealed a reduced binding to the endothelium in CKD in the animal models, and there were similar finding in human kidney specimens. Lanthanum Dysprosium Glycosamino Glycan adhesion staining technique was used to visualize the ultrastructure of the glycocalyx in transmission electron microscopy. This also enabled quantitative analyses, showing a significant reduction of the EG thickness and density. In addition, mRNA expression of proteins involved in glycocalyx biology, synthesis, and turnover (ie, syndecan 1 and glypican 1), which are main components of the glycocalyx, and exostosin 2, involved in the synthesis of the glycocalyx, were significantly up-regulated in endothelial cells isolated from murine CKD models. Visualization of glycocalyx using specific transmission electron microscopy analyses allows qualitative and quantitative analyses and revealed significant pathologic alterations in peritubular capillaries in CKD.

Trajectory of plasma syndecan-1 and heparan sulphate during major surgery: A retrospective observational study

BACKGROUND

Surgical trauma-induced inflammation during major surgery may disrupt endothelial integrity and affect plasma concentrations of glycocalyx constituents, such as syndecan-1 and heparan sulphate. To date, no studies have focused on their perioperative temporal changes.

METHODS

As part of a trial, we obtained plasma and urine specimens sampled during the perioperative period in 72 patients undergoing major abdominal surgery. The plasma concentration of syndecan-1 and heparan sulphate was measured on five occasions, from baseline to the second postoperative day. Plasma and urinary creatinine and urinary syndecan-1 concentrations were measured before surgery and on the first postoperative morning.

RESULTS

We observed three different temporal patterns of plasma syndecan-1 concentration. Group 1 'low' (64% of patients) showed only minor changes from baseline despite a median heparan sulphate increase of 67% (p < .005). Group 2 'increase' (21% of patients) showed a marked increase in median plasma syndecan-1 from 27 μg/L to 118 μg/L during the first postoperative day (p < .001) with a substantial (+670%; p < .005) increase in median plasma heparan sulphate from 279 to 2196 μg/L. Group 3 'high' (14% of patients) showed a constant elevation of plasma syndecan-1 to >100 μg/L, but low heparan sulphate levels. The plasma C-reactive protein concentration did not differ across the three groups and 90% of colon surgeries occurred in Group 1. Treatment with dexamethasone was similar across the three groups. Surgical blood loss, duration of surgery and liver resection were greatest in Group 2.

CONCLUSION

Changes in syndecan-1 and heparan sulphate after surgery appear to show three different patterns, with the greatest increases in those patients with greater blood loss, more liver surgery and longer operations. These observations suggest that increases in syndecan-1 and heparan sulphate reflect the degree of surgical injury.

Serum Creatinine Levels and Nephrocheck® Values With and Without Correction for Urine Dilution-A Multicenter Observational Study

Background

The Nephrocheck® test is a single-use cartridge designed to measure the concentrations of two novel cell-cycle arrest biomarkers of acute kidney injury, namely tissue inhibitor of metalloproteinase 2 (TIMP-2) and insulin-like growth factor binding protein 7 (IGFBP7). Correlations of serum creatine values and TIMP-2 and IGFBP7 with and without correction for urine dilution have not been previously undertaken in patients undergoing major abdominal surgery. We hypothesized that the Nephrocheck® values would be significantly different with and without correction for urine dilution in patients with elevated creatinine values post major abdominal surgery.

Methods

We performed a post hoc analysis of serum and urine specimens sampled preoperatively and postoperatively in 72 patients undergoing major abdominal surgery. Thirty samples were measured from patients with the greatest decrease and the greatest increase in postoperative serum creatinine values. Urine was analyzed with the Nephrocheck to predict the risk of acute kidney injury (AKIRisk™). We then examined the relationship between serum creatinine and the urinary excretion of TIMP-2 and IGFBP7 as measured by the Nephrocheck test. The AKIRisk between the groups with and without correction for urine dilution was assessed.

Results

The median perioperative change in serum creatinine in the two groups was −19% and +57%, respectively. The uncorrected median baseline AKIRisk decreased from 0.70 (25th−75th percentiles, 0.09–1.98) to 0.35 (0.19–0.57) (mg/L)² in the first group and rose from 0.57 (0.22–1.53) to 0.85 (0.67–2.20) (mg/L)² in the second group. However, when corrected for the squared urine dilution, the AKIRisk™ in patients with postoperative increases in serum creatinine was not indicative of kidney injury; the corrected AKIRisk was 8.0 (3.2–11.7) μg²/mmol² before surgery vs.6.9 (5.3–11.0) μg²/mmol² after the surgery (P = 0.69).

Conclusion

In the setting of major abdominal surgery, after correction of TIMP-2 and IGFBP7 for urine dilution, the Nephrocheck AKIRisk scores were significantly different from the uncorrected values. These finding imply that the AKIRisk index is a function of urine flow in addition to an increased release of the biomarkers.

Circulating Syndecan-1 as a Predictor of Persistent Thrombocytopenia and Lethal Outcome: A Population Study of Patients With Suspected Sepsis Requiring Intensive Care

Background: Sepsis is defined as life-threatening organ dysfunction caused by dysregulated host responses to infection. Recent studies have suggested that endotheliopathy may be the common basis for multiple organ failure in sepsis. Under septic conditions, accumulation of proteases accelerates shedding of proteoglycans, such as syndecan-1, from the endothelial surface, resulting in augmented leukocyte adhesion to the vascular wall, enhanced vascular permeability, and intravascular coagulation. The purpose of this study was to determine the potential utility of syndecan-1 as a biomarker linking endotheliopathy to organ failure. Methods: One hundred patients with suspected infections who were admitted to the intensive care unit (ICU) at Kagoshima University Hospital were consecutively enrolled in the study. Serum syndecan-1 levels were measured using an in-house enzyme-linked immunosorbent assay. The difference between serum syndecan-1 levels in 28-day survivors and non-survivors was analyzed by the Mann-Whitney U-test. Receiver-operating characteristics curve analysis with area under the curve calculation was used to quantify the predictive performance of serum syndecan-1 for 28-day mortality. The correlations between serum syndecan-1 and coagulation markers were analyzed by Spearman's rank correlation test. Results: Serum syndecan-1 levels in non-survivors were significantly higher than those in survivors on Day 1 and Day 3 (P < 0.01). Among multiple organ failures, coagulation failure and renal failure were significantly correlated with serum syndecan-1. Spearman's rank correlation test indicated that serum syndecan-1 was weakly but significantly correlated with disseminated intravascular coagulation score (rho = 0.33, P < 0.01). Patients with serum syndecan-1 ≥21.4 ng/mL showed delayed recovery from thrombocytopenia relative to patients with serum syndecan-1 <21.4 ng/mL. Conclusions: Elevated circulating syndecan-1 on the first day of ICU admission was associated with persistent thrombocytopenia and lethal outcome in patients with suspected sepsis.