IS THE ACTIVITY OF SOLUBLE CD14 ENHANCED FOLLOWING MAJOR TRAUMA

Background: The molecule CD14 acts as a receptor for the protein-bound endotoxin (lipopolysaccharide [LPS]) complex and mediates the cellula r effects of LPS. The soluble formation, sCD14, is supposed to neutral ize circulating LPS (ie, LPS antagonist) or transfer LPS effects to en dothelial cells (ie, LPS agonist). Objective: To elucidate the release of sCD14 per se in patients with major trauma in the early posttrauma period. Our a priori hypothesis was that sCD14 release depends on the plasma LPS concentration simultaneously measured. Patients: In a pros pective study, 65 patients with multiple injuries (Injury Severity Sco re, 9-75) were enrolled. The patients were rescued by the medical heli copter service and directly admitted to our clinics. The plasma concen trations of sCD14 (enzyme immunoassay) and LPS (chromogenic limulus am ebocyte lysate test) were analyzed. The first blood sample was collect ed immediately at the accident site. The following samples were drawn at intervals from 2 hours to daily for 2 weeks. Results: Sixty-one pat ients survived the observation time. Immediately after trauma, their m ean sCD14 level was not different from that of healthy individuals. Tw o hours later, a pronounced increase of sCD14 was observed and sustain ed throughout the observation period. Even nonsurvivors showed an incr eased sCD14 release, but less pronounced. In all patients, plasma LPS levels were elevated during the first 12 hours. Conclusions: Major tra uma caused an increased release of sCD14. This elevation, however, was not correlated to LPS levels or to the severity of trauma (estimated by trauma scores). We found no evidence that sCD14 levels are of progn ostic value regarding survival. Furthermore, the release of sCD14 did not occur in an LPS-neutralizing manner, but rendered possible an LPS- independent mechanism.