AkutePhaseReaktanten

Akute Phase Reaktanten (APR) are a group of proteins that are synthesized and released by the liver in response to inflammation or infection. They are part of the acute phase response, a physiological reaction to tissue injury or infection, which aims to restore homeostasis and protect the body from further damage. APRs are characterized by their ability to increase in concentration in the bloodstream during the acute phase of an inflammatory response.

The most well-known APRs include C-reactive protein (CRP), serum amyloid A (SAA), and fibrinogen. CRP is a pentameric protein that binds to phosphorylcholine, a component of bacterial cell walls, and is used as a marker of inflammation in clinical settings. SAA is a family of proteins that share structural similarities and are involved in various physiological processes, including immune response and lipid metabolism. Fibrinogen is a glycoprotein involved in blood clotting and is also elevated during inflammation.

The synthesis and release of APRs are regulated by cytokines, particularly interleukin-6 (IL-6), which is produced by immune cells in response to infection or tissue damage. IL-6 stimulates the liver to produce APRs, which in turn help to modulate the immune response and promote tissue repair.

APRs play a crucial role in the body's defense mechanisms by enhancing the immune response, promoting tissue repair, and aiding in the clearance of damaged cells and pathogens. However, chronic or excessive levels of APRs can be indicative of underlying inflammatory conditions or diseases, such as rheumatoid arthritis, inflammatory bowel disease, or certain types of cancer. Therefore, monitoring APR levels can be useful in diagnosing and managing these conditions.