Albumin, serum
Clinical Background:
Albumin is a carbohydrate-free protein, which constitutes 55-65% of total plasma protein. It maintains plasma oncotic pressure, and is also involved in the transport and storage of a wide variety o...
Albumin is a carbohydrate-free protein, which constitutes 55-65% of total plasma protein. It maintains plasma oncotic pressure, and is also involved in the transport and storage of a wide variety of ligands and is a source of endogenous amino acids. Albumin binds and solubilises various compounds, e.g. bilirubin, calcium and long-chain fatty acids. It is also capable of binding toxic heavy metal ions as well as numerous pharmaceuticals. About half the plasma calcium is bound to albumin and hypoalbuminaemia is accompanied by hypocalcaemia. As this involves only the protein bound (physiologically inactive) fraction, symptoms of tetany do not develop.
Test Details
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Discipline:
Biochemistry
Biochemistry
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Specimen Container Adult:
Serum
Serum
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Specimen Container Paediatric:
Serum
Serum
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Minimum Volume Adult:
1 mL blood
1 mL blood
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Minimum Volume Paediatric:
0.5 mL blood
0.5 mL blood
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Sample Stability:
Unseparated sample: 6 days
Separated sample:
- at 15-25C: 2.5 months
- at 4ºC: 5 months
- at -20C: 4 months
Unseparated sample: 6 days
Separated sample:
- at 15-25C: 2.5 months
- at 4ºC: 5 months
- at -20C: 4 months
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Interpretation:
An abnormally high albumin level is found only with dehydration, or artefactually, in a sample taken with prolonged venous stasis.
Generally, only low albumin levels are of clinical interest. Hypoa...Read MoreAn abnormally high albumin level is found only with dehydration, or artefactually, in a sample taken with prolonged venous stasis.
Generally, only low albumin levels are of clinical interest. Hypoalbuminaemia occurs during many illnesses and is caused by several factors:
1) Changes due to relative water excess. These are concentration changes only and do not indicate alterations in absolute amounts of protein.
a) Overhydration
b) Artefactual - blood taken from "drip" arm.
2) Excessive loss of protein (mainly albumin)
a) Through the kidney in Nephrotic Syndrome
b) From the skin after severe burns
c) Through the intestine in protein losing enteropathy.
3) Decreased synthesis
a) Severe dietary protein deficiency e.g. Kwashiorkor
b) Severe liver disease
c) Severe malabsorption -
Reference Ranges:
< 1 yr: 30 - 45 g/L
1 - 16 yr: 30 - 50 g/L
>16 yr: 35 - 50 g/L
< 1 yr: 30 - 45 g/L
1 - 16 yr: 30 - 50 g/L
>16 yr: 35 - 50 g/L
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Factors Affecting Result:
Plasma protein concentrations increase with excessive stasis during venepuncture; blood for albumin measurement should be collected with a minimum of stasis.
Plasma protein concentrations increase with excessive stasis during venepuncture; blood for albumin measurement should be collected with a minimum of stasis.
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Other Info:
Lithium heparin plasma sample also acceptable
Lithium heparin plasma sample also acceptable
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Routine Contact Name:
Duty Biochemist
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Routine Telephone:
Freeman: 0191 244 8889
RVI: 0191 282 9719Freeman: 0191 244 8889
RVI: 0191 282 9719 -
Routine Email: