The receptor for advanced glycation endproducts (RAGE) recognizes a variety of ligands that play an important role in the posttraumatic inflammatory response. However, whether soluble RAGE (sRAGE) is released early after trauma-hemorrhage in humans and whether such a release is associated with the development of an inflammatory response and coagulopathy is not known and therefore constitutes the aim of the present study.
One hundred sixty eight patients were studied as part of a prospective cohort study of severe trauma patients admitted to a single Level 1 Trauma center. Blood was drawn within 10 minutes of arrival to the Emergency Department (ED) before the administration of any fluid resuscitation. sRAGE, TNF-a, IL-6, von Willebrand Factor (vWF), Angiopoietin-2 (Ang-2), Prothrombin time, (PT), prothrombin fragments 1+2 (PF1+2), soluble thrombomodulin (sTM), protein C (PC), plasminogen activator inhibitor-1 (PAI-1), and D-Dimers (fibrin degradation products) were measured using standard techniques. Base deficit was used as a measure of tissue hypoperfusion. Measurements were compared to outcome measures obtained from the electronic medical record and trauma registry.
Plasma levels of sRAGE were increased within 30 minutes after severe trauma in humans and correlated with the severity of injury, early posttraumatic coagulopathy and hyperfibrinolysis as well as with endothelial cell activation (angiopoietin-1 and complement). Furthermore, we found that there was a significant relationship between plasma levels of sRAGE and the development of acute renal failure. This relationship was not quite significant for patients who developed acute lung injury (p=.11), although patients with less than 26 ventilator-free days had significantly higher plasma levels of sRAGE than those with more than 26 ventilator-free days. Finally, there was no relationship between plasma levels of sRAGE and mortality rate in trauma patients.
The results of this study demonstrate that the release of sRAGE in the bloodstream of trauma patients requires severe injury and is associated with coagulation abnormalities and endothelial cell and complement activation.