The Early Acute Phase Response After Burn Injury in Mice

In the hours immediately after burn injury, the body enters into an acute phase reaction characterized, in part, by the augmentation of cytokine and acute phase protein production. This reaction has been poorly characterized in the 24 hours immediately after injury. To better understand the early acute phase response, 8- to 10-week-old BALB/C female mice were subjected to a 15% total body surface area (TBSA). Hepatic levels of tumor necrosis factor-a, interleukin-1β, and interleukin-6 were monitored. In addition, the circulating level of serum amyloid A, an acute phase protein, also was measured at the same time points. Tumor necrosis factor-a levels peaked 2 hours after burn injury, whereas interleukin-1 had a biphasic response, increasing 2 hours after injury and again at 12 hours. Interleukin-6 and serum amyloid A were not increased until 12 hours after injury and began to decline at 24 hours. These results demonstrate that within the liver, the acute phase response after burn injury initially involves tumor necrosis factor-a and interleukin-1β, whereas interleukin-6 is not involved until later and that systemic serum amyloid A levels are not increased until interleukin-6 is also increased.