Elevated systemic IL-18 and neopterin levels are associated with posttraumatic complications among patients with multiple injuries: a prospective cohort study.

INTRODUCTION: Posttraumatic systemic inflammatory response syndrome (SIRS), sepsis and their subsequent complication, the multiple-organ dysfunction syndrome (MODS), remain major complications following polytrauma. This prospective clinical study aimed at evaluating the association between these and plasma interleukin-18 (IL-18) and neopterin levels.

METHODS: Inclusion in the series required an Injury Severity Score (ISS) >16, age 16-65 years, admission within 6 h of the accident and survival >48 h; 55 patients were enrolled. Over 14 days, plasma neopterin and IL-18 levels and the clinical course regarding MODS, SIRS and sepsis were recorded daily using the Marshall Score for MODS and the ACCP/SCCM criteria for SIRS and sepsis.

RESULTS: Neopterin and IL-18 plasma levels were increased in +MODS cases as compared with -MODS cases over almost the entire observation period. IL-18 concentrations over days 3-6 were significantly increased among participants with sepsis. These increases were all apparent 2-3 days before the clinical diagnosis of sepsis or MODS was made. In contrast, no significant differences in neopterin and IL-18 plasma levels were observed between participants with and without SIRS.

CONCLUSIONS: Determinations of neopterin and IL-18 concentrations might represent early markers for posttraumatic complications such as MODS and sepsis. They might help to differentiate between SIRS and sepsis and thereby guide the timing of the surgery for polytrauma. Neopterin and IL-18 levels should be used together with the clinical status and other inflammatory markers (IL-6, IL-8, etc.) for prediction of posttraumatic complications.