Interleukin-6 in the injured patient. Marker of injury or mediator of inflammation?
OBJECTIVE
The effects of interleukin (IL)-6 in the injured patient are examined in an attempt to clarify the potential pathophysiologic role of IL-6 in the response to injury.


BACKGROUND
Interleukin-6 is an integral cytokine mediator of the acute phase response to injury and infection. However, prolonged and excessive elevations of circulating IL-6 levels in patients after trauma, burns, and elective surgery have been associated with complications and mortality. The mechanistic role of IL-6 in mediating these effects is unclear.


METHODS
A review of current literature is performed to summarize the origins, mechanisms of action, and biologic effects of IL-6 and to characterize the IL-6 response to injury.


RESULTS
Interleukin-6 is a multifunctional cytokine expressed by a variety of cells after a multitude of stimuli, under complex regulatory control mechanisms. The IL-6 response to injury is uniquely consistent and related to the magnitude of the insult. Moreover, the early postinjury IL-6 response correlates with complications as well as mortality.


CONCLUSIONS
Interleukin-6 appears to play an active role in the postinjury immune response, making it an attractive therapeutic target in attempts to control hyperinflammatory provoked organ injury.
Biffl
W L
WL
Department of Surgery, Denver General Hospital, Colorado 80204, USA.
Moore
E E
EE
Moore
F A
FA
Peterson
V M
VM
D015703:Antigens, CD / Q000502:physiology; D015415:Biomarkers; D002056:Burns / Q000276:immunology; D016207:Cytokines / Q000502:physiology; D006801:Humans; D007108:Immune Tolerance; D007249:Inflammation / Q000276:immunology; D015850:Interleukin-6 / Q000096:biosynthesis / Q000097:blood / Q000502:physiology*; D018123:Receptors, Interleukin / Q000502:physiology; D019947:Receptors, Interleukin-6; D015398:Signal Transduction; D013514:Surgical Procedures, Operative; D014947:Wounds and Injuries / Q000276:immunology* / Q000401:mortality
D015703:Antigens, CD; D015415:Biomarkers; D016207:Cytokines; D015850:Interleukin-6; D018123:Receptors, Interleukin; D019947:Receptors, Interleukin-6