Akuttfasproteinerna

Akuttfasproteinerna, or acute-phase proteins, are a group of proteins whose levels in the blood change significantly in response to inflammation. These proteins are primarily synthesized in the liver and are part of the body's innate immune response to infection, injury, or other tissue damage. Their concentrations can increase or decrease during the acute phase, but the term most commonly refers to those that increase.

The elevation of acute-phase proteins is triggered by cytokines, signaling molecules released by immune cells at the site of inflammation. Key cytokines like interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interleukin-1 (IL-1) stimulate the liver to produce these proteins.

Common examples of positive acute-phase proteins include C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin, and fibrinogen. CRP and SAA are particularly useful as biomarkers for inflammation, as their levels can rise rapidly and substantially. These proteins play various roles in the inflammatory process, such as opsonization (marking pathogens for destruction by phagocytes), complement activation, and scavenging of free radicals.

Negative acute-phase proteins, conversely, decrease in concentration during inflammation. Examples include albumin, transferrin, and transthyretin. Their reduced levels are thought to divert amino acids for the synthesis of positive acute-phase proteins.

Measuring the levels of acute-phase proteins, especially CRP, is a common diagnostic tool in clinical medicine to detect and monitor inflammatory conditions, infections, and autoimmune diseases.