Plasmaproteiner

Plasma proteins are a diverse group of soluble proteins found in blood plasma. They are predominantly synthesized in the liver, with a subset produced by immune cells such as plasma cells. Together they make up a substantial portion of plasma and perform a wide range of essential functions, including transport, immune defense, blood clotting, and maintenance of blood volume and pH.

The major components of plasma proteins include albumin, globulins, and coagulation factors. Albumin is the most abundant plasma protein and helps maintain colloid osmotic pressure, carriers, and transports various substances such as fatty acids, hormones, and drugs. Globulins form a heterogeneous group that includes immunoglobulins (antibodies) providing specific immune defense, as well as transport proteins like transferrin and ceruloplasmin, and components of the complement system. Coagulation factors such as fibrinogen, prothrombin, and others participate in hemostasis and wound healing. Inflammation can raise the levels of certain plasma proteins, known as acute-phase reactants, while others may fall during disease.

Synthesis and regulation of plasma proteins are dynamic. The liver is the primary site of production for most plasma proteins, and the rate of synthesis can be influenced by nutritional status, hormones, and inflammatory signals. Plasma proteins have varying half-lives and can be measured clinically to assess health status. Total protein and albumin concentration are common laboratory tests, and electrophoresis or immunochemical methods can separate and quantify different protein fractions.

Clinical relevance of plasma proteins includes monitoring liver and kidney function, nutritional status, and immune competence. Abnormal levels can indicate malnutrition, liver disease, nephrotic syndrome, chronic infections, inflammatory conditions, or immunodeficiencies.