EFFECTS OF ACCIDENTAL TRAUMA ON CYTOKINE AND ENDOTOXIN PRODUCTION

Objective: To determine the effects of accidental injury of varying severity on interleukin (IL)-1alpha, IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), and endotoxin release. Design: Prospective, multi-unit, longitudinal study. Setting: Emergency Departments and intensive care units of two university hospitals. Patients: Trauma patients after mild, moderate, and severe injury (Injury Severity Score of less-than-or-equal-to 10, 11 to 24, and greater-than-or-equal-to 25, respectively). Interventions: None. Measurements and Main Results: Plasma cytokine and endotoxin concentrations were measured over a 5-day period, starting within 2 hrs of accidental injury. An enzyme-linked immunosorbent assay was used to determine plasma concentrations of IL-1alpha, EL-6, IL-8, and TNF-alpha. Plasma endotoxin concentrations were measured using a chromogenic limulus amebocyte assay. Preresuscitation samples obtained immediately on arrival in the Emergency Department, and within 2 hrs of injury, demonstrated significant increases of IL-6 and IL-8 concentrations in the severe injury group, in contrast to minimal increases seen after mild or moderate injury. Analysis of serial postresuscitation samples demonstrated rapid increases in IL-6 and IL-8 concentrations within 12 hrs of injury. IL-6 and IL-8 remained increased for 24 hrs after injury, then decreased markedly from their peak values during the next 24 hrs. Increased circulating concentrations of these cytokines continued to be present for >5 days in the severely injured patients. IL-6 and IL-8 concentrations were only minimally increased in patients 8 and 24 hrs after moderate injury. Endotoxin and IL-1alpha were not found in any samples, including those samples obtained serially from severely injured patients. No patient at any time point had TNF-alpha concentrations of >35 pg/mL. Conclusions: These results demonstrate that severe injury produces rapid, large increases in circulating concentrations of IL-6 and IL-8 that may contribute to the frequent development of the adult respiratory distress syndrome and multiple organ system failure in this clinical setting.