A High Admission Syndecan-1 Level, A Marker of Endothelial Glycocalyx Degradation, Is Associated With Inflammation, Protein C Depletion, Fibrinolysis, and Increased Mortality in Trauma Patients

Objective: To investigate the association between markers of acute endothelial glycocalyx degradation, inflammation, coagulopathy, and mortality after trauma. Background: Hyperinflammation and acute coagulopathy of trauma predict increased mortality. High catecholamine levels can directly damage the endothelium and may be associated with enhanced endothelial glycocalyx degradation, evidenced by high circulating syndecan-1. Methods: Prospective cohort study of trauma patients admitted to a Level 1 Trauma Centre in 2003 to 2005. Seventy-five patients were selected blindly post hoc from 3 predefined injury severity score (ISS) groups (< 16, 16-27, > 27). In all patients, we measured 17 markers of glycocalyx degradation, inflammation, tissue and endothelial damage, natural anticoagulation, and fibrinolysis (syndecan-1, IL-6, IL-10, histone-complexed DNA fragments, high-mobility group box 1 (HMGB1), thrombomodulin, von Willebrand factor, intercellular adhesion molecule-1, E-selectin, protein C, tissue factor pathway inhibitor (TFPI), antithrombin, D-dimer, tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA), soluble uPA receptor, and plasminogen activator inhibitor-1), hematology, coagulation, catecholamines, and assessed 30-day mortality. Variables were compared in patients stratified according to syndecan-1 median. Results: Patients with high circulating syndecan-1 had higher catecholamines, IL-6, IL-10, histone-complexed DNA fragments, HMGB1, thrombomodulin, D-dimer, tPA, uPA (all P < 0.05), and 3-fold increased mortality (42% vs. 14%, P = 0.006) despite comparable ISS (P = 0.351). Only in patients with high glycocalyx degradation was higher ISS correlated with higher adrenaline, IL-6, histone-complexed DNA fragments, HMGB1, thrombomodulin, and APTT, lower protein C (all P < 0.05), unchanged TFPI and blunted D-dimer response (P < 0.001) because D-dimer was profoundly increased even at low ISS. After adjusting for age and ISS, syndecan-1 was an independent predictor of mortality (OR: 1.01 [95% CI, 1.00-1.02]; P = 0.043). Conclusions: In trauma patients, high circulating syndecan-1, a marker of endothelial glycocalyx degradation, is associated with inflammation, coagulopathy and increased mortality.