Acute Phase Proteins (APPs) refer to a group of proteins synthesized by the liver in response to inflammation, infection, or tissue damage. These proteins serve important roles in the body's immune response and help regulate the acute phase reaction.
During an acute phase reaction, the body undergoes systematic changes in response to injury or infection. One of these changes includes the increased production of APPs by hepatocytes (liver cells). The production of APPs is predominantly triggered by circulating cytokines, such as interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha), which are released in response to tissue injury or infections.
The functions of APPs are diverse and can vary among different proteins. Some of the key roles of APPs include enhancing the immune response, acting as opsonins (promoting phagocytosis), modulating inflammatory reactions, and promoting tissue repair and remodelling. Additionally, APPs can also serve as markers for diagnosing and monitoring various diseases, including infections, inflammations, and cancers.
Examples of well-known acute phase proteins include C-reactive protein (CRP), serum amyloid A (SAA), fibrinogen, haptoglobin, and ferritin. Their levels in the blood can be measured through laboratory tests, providing valuable information about the presence and severity of an acute phase reaction or an underlying disease.
In conclusion, acute phase proteins are a group of proteins synthesized by the liver in response to inflammation, infection, or tissue damage. They play crucial roles in the immune response, inflammation regulation, and tissue repair. Measurement of acute phase proteins can be used as diagnostic and monitoring tools for various diseases.
