DECREASED SOLUBLE ADHESION MOLECULE L-SELECTIN PLASMA-CONCENTRATIONS AFTER MAJOR TRAUMA

Background: Binding of the leukocyte glycoprotein L-selectin to ligand s expressed by activated endothelium directs leukocyte recruitment to areas of acute inflammation. Sequestration by activated microvascular endothelium has been proposed to explain the tow plasma concentrations of soluble L-selectin (sCD62L) observed early in patients with acute respiratory distress syndrome. We hypothesized that inflammatory endot helial activation may occur in trauma patients, leading to decreased s CD62L plasma concentrations. Methods: This study was a prospective ana lysis of sCD62L plasma concentrations in patients with isolated head i njuries and multiple trauma patients without head injuries admitted to two tertiary-level intensive care units. sCD62L plasma concentrations were determined in 18 consecutive adult patients with isolated modera te and severe head injuries and in 13 multiple trauma patients without head injuries immediately upon admission to the intensive care unit a nd then daily for up to 10 days after trauma. Results: Compared with h ealthy adult controls (n = 22), patient sCD62L plasma concentrations w ere significantly decreased upon admission (5.7 +/- 1.6 vs. 11.0 +/- 1 .7 pmol/mL; p < 0.001). In all patients, sCD62L concentrations remaine d depressed throughout the study period. sCD62L concentrations did not differ significantly between patients with isolated head injuries and multiple trauma patients without head injuries, although repeated-mea sures analysis of variance showed significantly more depressed sCD62L concentrations associated with severe (n = 14) compared with moderate head injuries (n = 4) during the study period (p < 0.05). Conclusion: Patients with major trauma present with a significant reduction of sCD 62L plasma concentrations within the first 12 hours after trauma and d uring subsequent intensive care. This finding suggests widespread micr ovascular endothelial activation after trauma, which may be associated with increased neutrophil extravasation.