Prealbumin

What sample is needed for Prealbumin?

1. This is done on the patient’s fresh serum.
2. Twenty-four hours of the urine sample can also be tested.

What are the indications for Prealbumin?

1. It is used to assess nutritional status.
2. As workup in patients with kidney diseases.
3. Advised in subclinical deficit and assessing the response to restorative therapy.

What are the precautions for Prealbumin estimation?

1. In the case of inflammation, the result is not representative of the disease.
2. Drugs like anabolic steroids, androgens, and prednisolone increase the level.
3. Drugs like estrogens and oral contraceptives decrease the level.

What is the pathophysiology of Prealbumin?

1. Prealbumin is synthesized mainly in the liver.
   1. This was also called transthyretin because of its binding with thyroid hormones.
2. This is the fastest-moving protein on serum electrophoresis.
3. This has the same concentration in the serum and CSF. Due to the low level of other proteins in the CSF, prealbumin is the major protein in the CSF.
   1. This can be used to differentiate CSF leakage from nasal secretions in cases of fractures of the skull’s base.
4. A very faint band is normally not seen on traditional electrophoresis.

Prealbumin shows a very faint band on serum Electrophoresis

5. It can cross the blood-brain barrier and actively secrete into the cerebrospinal fluid and choroid plexus.

What is the function of Prealbumin as a carrier protein?

1. It binds to T3 and T4, so-called Transthyretin or thyroxine-binding prealbumin.
   1. This is also referred to as thyroxine-binding prealbumin (TBPA).

T4 binding proteins and share of prealbumin

2. It also binds and carries retinol as a retinol-binding protein, which binds Vitamin A.
   1. This protein-vitamin complex is essential for transporting oil-soluble Vitamin A in the body.
3. Zinc is required to synthesize prealbumin; low levels occur in Zinc deficiency.

Prealbumin as a transport carrier

Prealbumin synthesis in the liver and is a carrier protein

What are the functions of prealbumin?

1. This is also the amyloid precursor protein found in cardiac amyloidosis.
2. Its half-life is 48 hours (1.9 days), which makes it more important than Albumin and transferrin.
   1. Albumin’s half-life is 21 days.
   2. Prealbumin is a good indicator of any change affecting protein synthesis and catabolism.
   3. Because of its short half-life (2 days), prealbumin responds quickly to nutritional intake and nutritional restoration.
   4. It gives the current nutritional status of the body, not the status from 3 weeks ago.
3. Prealbumin is important in the nasal secretions to differentiate fluid coming from the skull fracture versus nasal secretion.
4. Negative acute-phase protein:
   1. Prealbumin is a negative acute-phase protein, and serum level decreases in inflammation, malignancy, and protein-losing diseases of the kidneys and intestine.

How will you classify malnutrition based on prealbumin?

What is the normal level of prealbumin?

Source 2

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Prealbumin

• 19 to 38 mg/dL  (190 to 380 mg/L) by nephelometry

How will you Interpret nutritional status based on Prealbumin?

•  In severe protein deficiency, =  Level is 0 to 5 mg/dl.
• In moderate protein deficiency, = Level is 5 to 10 mg/dl.
• In mild protein deficiency, = Level is 10 to 15 mg/dl.

• (Normal value may vary from lab to lab.)

What are the causes of increased levels of prealbumin?

1. Chronic Alcoholics.
2. Patients with corticosteroid therapy.
3. Hodgkin’s lymphoma.
4. Kidney diseases.
5. Pregnancy.

What are the causes of decreased levels of prealbumin?

1. In cases of malnutrition.
2. Hypothyroidism
3. Liver diseases.
4. Inflammatory conditions.
5. In cases of trauma like burns.
6. In chronic diseases.
7. In some digestive diseases.
8. In Cancers.
9. Salicylate poisoning.

Questions and answers: