Association of interleukin-4 plasma levels with traumatic injury and clinical course.
OBJECTIVE
To determine if interleukin-4 (IL-4) could be detected in plasma of trauma patients and if IL-4 activity is associated with patterns of clinical events, complications, or outcomes.


METHODS
A prospective case series conducted in a tertiary care referral center with a level I trauma center. One hundred patients admitted to the trauma intensive care unit for at least 3 days were included. Plasma concentrations of IL-4 and IgE were determined from admission to intensive care unit discharge. Data on clinical outcome were collected, including death, sepsis, severe sepsis, adult respiratory distress syndrome, pneumonia, and renal dysfunction.


RESULTS
Interleukin-4 was detected in the plasma of 87 patients. Patients with an Injury Severity Score of greater than 25 had higher admission IL-4 levels (P = .03) and greater maximal 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 levels. Increases in IL-4 levels were significantly greater for patients in whom sepsis, severe sepsis, or pneumonia developed (P < .05). A low admission IL-4 level was associated with a greater incidence of nosocomial pneumonia (P < .001). Additional indirect evidence of IL-4 activation included increased plasma IgE levels.


CONCLUSIONS
Anti-inflammatory cytokine mechanisms are activated after injury and are associated with the development of infectious complications (sepsis, severe sepsis, and pneumonia). Exogenous administration of interleukin-4 should be evaluated as an experimental therapeutic approach after trauma and associated sepsis.
D000328:Adult; D015415:Biomarkers / Q000097:blood*; D005260:Female; D006801:Humans; D015847:Interleukin-4 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014947:Wounds and Injuries / Q000097:blood* / Q000150:complications
D015415:Biomarkers; D015847:Interleukin-4