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Systemic Manifestations of Inflammation

One of the essential military actions is called “damage control.” This response to an assault is commonly seen in the naval branch of the service. It is essential because sailors do not seem to want to lose their ship in the middle of the Atlantic Ocean. Now this may superficially appear to have something to do with survival in the middle of the ocean with no vessel, but we believe it is because of the sailorsvery fond attachment to their staterooms and the recreational activities aboard the cruise (pool, dance bands, etc… ). In any case, with the defensive system under consideration here, it is definitely clear that “damage control” is a biologic response for preserving the vessel.

Injury often results in a systemic reaction known as the acute phase response (APR). This response consists of a rapid physiologic reaction generated to deal with tissue damage. It is a nonspecific reaction that is triggered by injury associated with infection, ischemic necrosis, tumor growth, surgery, chemical irritants, and other injurious agents. It is designed to control injury, promote the removal of debris, and start repair. Let’s all grab a bucket and bail, bail, bail!

Very early in inflammation, monocytes and macrophages release interleukin-1 (IL-1), tumor necrosis factor (TNF), and IL-6 (hepatocyte stimulating factor). The latter binds to liver cells and causes them to increase protein synthesis. IL-1 and IL-6 are both needed to stimulate the synthesis and release of acute phase proteins.

Clinically there is fever, increase in the plasma level of acute phase proteins (many of which are synthesized by the stimulated hepatocytes), decreased appetite, and altered sleep patterns.

These may not sound like defensive activities that would naturally be very beneficial to survival and damage control, but take into account what is happening, and things start to look very different. Naturally, we would not appreciate having a fever, decreased appetite, />