Plasmaeiwitten

Plasmaeiwitten are a diverse group of soluble proteins present in blood plasma. They play essential roles in maintaining colloid osmotic pressure, transporting hormones, lipids and metal ions, and defending the body against disease. In healthy adults, the total concentration of plasma proteins typically ranges from about 6 to 8 g per deciliter.

The proteins are traditionally classified into three broad groups: albumins (about 60% of plasma proteins, produced by the liver), globulins (about 35%, including alpha, beta and gamma globulins), and fibrinogen (about 0.2%, a clotting factor). Albumin maintains oncotic pressure and serves as a carrier protein for various substances. Globulins include transport proteins such as transferrin and hormone-binding proteins, as well as immunoglobulins produced by plasma cells that provide antibody-mediated immunity. Fibrinogen is converted by thrombin into fibrin during blood coagulation.

Most plasma proteins are synthesized in the liver, with gamma globulins produced by activated lymphocytes. Regulation of plasma protein levels is influenced by nutrition, liver function, kidney losses, and inflammatory states. During inflammation, the liver increases production of acute-phase proteins such as C-reactive protein, while other proteins may decrease.

Clinical assessment of plasma proteins involves measurement of total protein and albumin, to evaluate liver, kidney, and nutritional status. Abnormal levels can indicate liver disease, nephrotic syndrome, malnutrition, inflammation, or coagulation disorders. Hypoalbuminemia reduces oncotic pressure and can contribute to edema, while aberrant fibrinogen levels affect clotting or thrombosis risk.