Prealbumin

Sample for Prealbumin

1. The venous blood of the patient is needed to prepare the serum.
2. This can be estimated in the 24 hours of urine and CSF.

Indications for Prealbumin

1. Marker for the patient with nutritional status.
2. It is a sensitive indicator of protein synthesis and catabolism.

Precautions for Prealbumin

1. If there is co-existent inflammation, then test result interpretation is not possible.
2. Drugs increasing the level are anabolic steroids, androgens, estrogens, and prednisolone.
3. Drugs that may decrease the level are amiodarone, estrogens, and oral contraceptives.

Pathophysiology of Prealbumin

1. Prealbumin is also called transthyretin.
2. In 1995, the joint committee on Accreditation of health organizations first issued the main parameter to assess the patient’s nutritional status to identify all patients with malnutrition.
   1. For a long time, albumin was the parameter for nutritional status (malnutrition). Now it is found that prealbumin is the better choice because of the short half-life of 1.9 days.
3. Prealbumin is one of the major proteins.
4. Prealbumin has a shorter half-life of 2 days (1.9 days).
   1. The Prealbumin half-life of 2 days is much less than the albumin of 21 days.
   2. Because of its short half-life, prealbumin is a better indicator of synthesis and catabolism.
   3. This is usually indicated to monitor the effectiveness of parenteral nutrition therapy.
5. This is present in the serum and CSF.
   1. This is the main component of the CSF proteins. It can cross the blood-brain barrier, so it is secreted into the CSF by the choroid plexus.
   2. Prealbumin is the faster-migrating protein on serum electrophoresis. Because of the less amount, it is not seen in traditional serum electrophoresis.
   3. But this is seen in the CSF protein electrophoresis.
   4. CSF electrophoresis aims to diagnose multiple myelosclerosis by finding the oligoclonal band.

Functions of Prealbumin:

1. The pre-albumin binds and transports:
   1. Prealbumin binds retinol-binding protein (RBP), which binds vitamin A.
   2. It plays a role in the transport and metabolism of vitamin A. This protein-vitamin complex formation is necessary to transport the oil-soluble vitamin A through the body.
   3. Prealbumin is sometimes referred to as thyroxine-binding prealbumin (TPA). It does not play a major role in thyroid hormone functions.
   4. It binds T3 and T4, also called transthyretin and thyroxine-binding prealbumin (TBPA).
   5. Mainly there is the secretion of T4, and only about 7% is T3. In the blood,>99% of T4 and T3 are bound to serum proteins. About 80% to 85% of T4 is bound to T4-binding globulin (TBG) and α-1 globulin;  about 10% to 15% to prealbumin.