Assessing nutritional status, especially in monitoring the response
Nephelometry
PAB (Prealbumin)
TBPA
Transthyretin
Serum
This is an immunologic protein measurement. For thyroxine-binding measurement of prealbumin, see TBPE / Thyroxine-Binding Protein Electrophoresis, Serum.
Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
0.5 mL
Gross hemolysis | OK |
Gross lipemia | Reject |
Gross icterus | OK |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 28 days | |
Frozen | 28 days | ||
Ambient | 14 days |
Assessing nutritional status, especially in monitoring the response
Prealbumin is synthesized in the liver and acts as a binding
The serum concentration of prealbumin reflects the synthesis
Due to its short half-life of approximately 2 days, prealbumin
< or =18 years: 12-32 mg/dL
>18 years: 19-38 mg/dL
Results below the reference intervals for adults and pediatric patients may suggest protein depletion.
Clinical correlation recommended with patient status and other nutritional markers.
No significant cautionary statements
1. Haider M, Haider SQ: Assessment of protein-calorie malnutrition. Clin Chem 1984;30:1286-1299
2. Grant JP, Custer PB, Thurlow J: Current techniques of nutritional assessment. Surg Clin North Am 1981;61:437-463
3. Bernstein LH, Leukhardt-Fairfield CJ, Pleban W, et al: Usefulness of data on albumin and prealbumin concentrations in determining effectiveness of nutritional support. Clin Chem 1989;35:271-274
4. Kanakoudi F, Drossou V, Tzimouli V, et al: Serum concentrations of 10 acute-phase proteins in healthy term and pre-term infants from birth to age 6 months. Clin Chem 1995;41:605-608
5. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Sixth edition. Edited by N Rafai, AR Horvath, CT Wittwer. Elsevier, 2018
In this Siemens Nephelometer II method, the light scattered onto the antigen-antibody complexes is measured. The intensity of the measured scattered light is proportional to the amount of antigen-antibody complexes in the sample under certain conditions. If the antibody volume is kept constant, the signal behaves proportionally to the antigen volume.
A reference curve is generated by a standard with a known antigen content on which the scattered light signals of the samples can be evaluated and calculated as an antigen concentration. Antigen-antibody complexes are formed when a sample containing antigen and the corresponding antiserum are put into a cuvette. A light beam is generated with a light emitting diode (LED), which is transmitted through the cuvette. The light is scattered onto the immuno-complexes that are present. Antigen and antibody are mixed in the initial measurement, but no complex is formed yet. An antigen-antibody complex is formed in the final measurement.
The result is calculated by subtracting value of the final measurement from the initial measurement. The distribution of intensity of the scattered light depends on the ratio of the particle size of the antigen-antibody complexes to the radiated wavelength.(Siemens Nephelometer II Operations Instruction Manual, Siemens, Inc., Newark, DE, Version 2.3, 2008; Addendum to the Instruction Manual 2.3, 08/2017)
Monday through Friday
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
84134
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
PALB | Prealbumin (PAB), S | 46130-1 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
PALB | Prealbumin (PAB), S | 46130-1 |