[Liberation of soluble CD14 (sCD 14) in plasma of trauma patients]

Membrane-fixed CD14 acts as a receptor for the protein-bound endotoxin (LPS) complex and mediates the cellular effects of endotoxin. Soluble CD14 (sCD14) is suggested to neutralize circulating LPS, i.e., acting as an endotoxin antagonist. The aim of this study was to elucidate the release of both sCD14 and endotoxin in traumatized patients, starting from the earliest phase after trauma. A total of 15 patients (O ISS = 19, 9-75) suffering major trauma were enrolled in this prospective study. Blood samples were collected as early as immediately at the site of accident, on hospital admission, and thereafter hourly, then daily. For patients (O ISS = 47) died within 24 h because of their severe injuries. Immediately after the accident as well as during the first 2 h after hospital admission, the mean sCD14 levels of surviving patients did not differ from those of healthy volunteers (n = 53). Thereafter, however, sCD14 increased continuously in the trauma group. The concentrations remained elevated throughout the entire observation period. There was, however, no relation between the sCD14 release and the pattern or the severity of injury. In contrast, endotoxin levels revealed a pattern-specific release. The highest plasma concentrations of LPS were observed in patients suffering from (additional) thoracic injury. On the basis of these results we conclude that the release of sCD14 after trauma does not reflect a strict principle such as action/reaction caused by the appearance of endotoxin immediately after the injury. Soluble CD14 is more likely release by an endotoxin-independent mechanism.