PURPOSE: To investigate levels, associations between, and predictive value of plasma catecholamines and biomarkers of endothelial damage in patients with acute infectious illness stratified according to infection type and sepsis severity.

MATERIAL AND METHODS: This is a post hoc study of plasma samples collected in prospective studies conducted at a department of internal medicine. Plasma catecholamines, syndecan-1, and thrombomodulin were measured. Registration of biochemistry, physiology, and 28- and 90-day mortality was performed.

RESULTS: Patients (n = 321) were stratified into 5 groups: no infection (n = 50), local infection (n = 63), sepsis (n = 95), severe sepsis (n = 100), or septic shock (n = 13). Median Sequential Organ Failure Assessment (SOFA) score in all patients was 2, and 28- and 90-day mortality was 6% and 10%. Syndecan-1 and thrombomodulin increased progressively across groups with increasing disease severity (both P < .001), correlating with SOFA score in all groups (ρ = 0.24-0.87, all P < .05). Plasma noradrenaline, syndecan-1, and thrombomodulin were higher in nonsurvivors (P < .05) and by log-rank test, levels above median predicted increased 28-day (noradrenaline and syndecan-1, P < .05) and 90-day (thrombomodulin, P < .05) mortality.

CONCLUSIONS: Biomarkers of endothelial glycocalyx and cell damage increased with increasing acute infectious disease severity, correlated with SOFA score, and predicted mortality together with plasma noradrenaline. Sympathoadrenal activation and endothelial damage are linked to disease pathology also in less sick patients.