Syndecan-1: A Quantitative Marker for the Endotheliopathy of Trauma

BACKGROUND: Endothelial glycocalyx breakdown elicits syndecan-1 shedding and endotheliopathy of trauma (EoT). We hypothesized that a cutoff syndecan-1 level can identify patients with endothelial dysfunction who would have poorer outcomes. STUDY DESIGN: We conducted a prospective observational study. Trauma patients with the highest level of activation admitted from July 2011 through September 2013 were eligible. We recorded demographics, injury type/severity (Injury Severity Score), physiology and outcomes data, and quantified syndecan-1 and soluble thrombomodulin from plasma with ELISAs. With receiver operating characteristic curve analysis, we defined EoT+ as the syndecan-1 cutoff level that maximized the sum of sensitivity and specificity (Youden index) in predicting 24-hour in-hospital mortality. We stratified by this cutoff and compared both groups. Factors associated with 30-day in-hospital mortality were assessed with multivariable logistic regression (adjusted odds ratios and 95% CIs reported). RESULTS: From receiver operating characteristic curve analysis (area under the curve = 0.71; 95% CI 0.58 to 0.84), we defined EoT+ as syndecan-1 level >= 40 ng/mL (sensitivity = 0.62, specificity = 0.73). Of the 410 patients evaluated, 34% (n = 138) were EoT+ patients, who presented with higher Injury Severity Scores (p < 0.001) and blunt trauma frequency (p = 0.016) than EoT- patients. Although EoT+ patients had lower systolic blood pressure (median 119 vs 128 mmHg; p < 0.001), base excess and hemoglobin were similar between groups. The proportion of transfused (EoT+ 71.7% vs EoT- 36.4%; p < 0.001) and deceased EoT+ patients (EoT+ 24.6% vs EoT- 12.1%; p < 0.001) was higher. EoT+ was significantly associated with 30-day in-hospital mortality (adjusted odds ratio = 2.23; 95% CI 1.22 to 4.04). CONCLUSIONS: A syndecan-1 level >= 40 ng/mL identified patients with significantly worse outcomes, despite admission physiology similar to those without the condition. (C) 2017 The Authors. Published by Elsevier Inc. on behalf of the American College of Surgeons.