Clinical Information

Albumin is the most abundant protein in plasma, constituting about 55-65% of the total plasma protein. Albumin’s main purpose is to regulate the oncotic pressure of the plasma, but it is also involved in the transport of a variety of ligands including drugs, vitamins, hormones, calcium, and bilirubin. The abundance of charged amino acids on albumin’s surface leads to its high water-solubility, which makes it ideal as both a transporter and oncotic pressure regulator.

Hypoalbuminemia results from a variety of conditions involving either decreased synthesis or increased loss of albumin. Decreased synthesis can be caused by liver disease (since albumin is synthesized in the liver), reduced protein uptake, or Crohn’s (malabsorption of amino acids). Increased loss of albumin can occur due to proteinuria as a consequence of nephrotic syndrome, protein loss via the stool (neoplastic disease), or elevated catabolism due to inflammation or tissue damage (severe burns). Low plasma osmotic pressure from decreased levels of albumin causes water to shift from the capillaries to the tissues, resulting in edema. Hyperalbuminemia is usually the result of dehydration.