ASSOCIATION OF INTERLEUKIN-4 PLASMA-LEVELS WITH TRAUMATIC INJURY AND CLINICAL COURSE

Objectives: To determine if interleukin-4 (IL-4) could be detected in plasma of trauma patients and if IL-4 activity is associated with patt erns of clinical events, complications, or outcomes. Methods: A prospe ctive case series conducted in a tertiary care referral center with a level I trauma center. One hundred patients admitted to the trauma int ensive care unit for at least 3 days were included. Plasma concentrati ons of IL-4 and IgE were determined from admission to intensive care u nit discharge. Data on clinical outcome were collected, including deat h, sepsis, severe sepsis, adult respiratory distress syndrome, pneumon ia, and renal dysfunction. Results: Interleukin-4 was detected in the plasma of 87 patients. Patients with an Injury Severity Score of great er than 25 had higher admission IL-4 levels (P=.03) and greater maxima l IL-4 levels (P<.001). Admission hypotension (P=.04) and age 30 years or younger (P<.001) were also associated with higher admission IL-4 l evels. Increases in IL-4 levels were significantly greater for patient s in whom sepsis, severe sepsis, or pneumonia developed (P<.05). A low admission IL-4 level was associated with a greater incidence of nosoc omial pneumonia (P<.001). Additional indirect evidence of IL-4 activat ion included increased plasma IE levels. Conclusions: Anti-inflammator y cytokine mechanisms are activated after injury and are associated wi th the development of infectious complications (sepsis, severe sepsis, and pneumonia). Exogenous administration of interleukin-4 should be e valuated as an experimental therapeutic approach after trauma and asso ciated sepsis.