Albumin, fluid

Diagnostic Use

Albumin is a plasma protein produced by the liver. Albumin is important for the maintenance of plasma oncotic pressure, and is also a transport protein for many circulating molecules, including some drugs.

Measuring albumin in ascitic fluid enables calculation of the serum ascites albumin gradient (SAAG) which may assist in determining the underlying cause of the ascites.

Department

Core Biochemistry

Delphic Registration Code

FLUD

Synonyms

Fluid Alb

Turnaround Time

8 hours

Test Code

3684

Specimen Type

• Fluid

Specimen Requirements

Tube/Container Type:

Preferred

• Pottle

Preferred Sample Volume (ml)

5.0

Minimum Sample Volume (ml)

5000

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• Pottle

Preferred Sample Volume (ml)

0.5

Minimum Sample Volume (ml)

0.5

Additional Specimen Information

Viscous samples are unsuitable for analysis.
Blood-stained fluid samples may be compromised by contamination with plasma albumin, which may affect result interpretation.

Aliquot Instructions

Transport to Lab

Ambient (8 - 24 degrees Celsius)

Interpretation

Interpretation will depend on the nature of the fluid being analysed.

The serum ascites albumin gradient (SAAG) is calculated by subtracting the ascites albumin concentration from the serum/plasma albumin. High SAAG results are suggestive of underlying portal hypertension as the cause of the ascites, whereas low SAAG results are suggestive of an underlying inflammatory/infective process, or malignancy.

Albumin is not routinely measured in pleural/pericardial fluid – total protein is recommended as an alternative to differentiate between transudative and exudative effusions in these fluids.

Reference Intervals

Historically a cut-off of 11g/L has been used to differentiate between high-SAAG and low-SAAG ascites, although there is emerging evidence that this cut-off may be too high for modern albumin assays using the bromocresol purple (BCP) measurement principle.

Contact a chemical pathologist if more information is required.

Test Method

Performed on Beckman Coulter AU5822 analyser using Beckman Coulter reagents (bromocresol purple method).

Non-Funded Test Cost

$4.65 (Exclusive of GST)

Billing Code

3684

Contact Information

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