At a glance

Also known as

Desialated transferrin; Asialotransferrin; CSF-specific transferrin; Tau protein

Why get tested?

To help identify cerebrospinal fluid (CSF) leaking from the skull.

When to get tested?

If there is a watery discharge from your nose or ear (rhinorrhoea or otorrhoea) after you have suffered a skull fracture or after brain surgery.

Sample required?

A sample of the suspicious watery discharge is collected into a plastic tube.

Test preparation needed?

None

What is being tested?

Cerebrospinal fluid (CSF) is normally found only within the brain and the spinal canal. If you suffer an injury which causes a tear in the membranes covering the brain and spine, CSF may leak out. This may sometimes cause watery fluid to drip from either the nose or the ear (rhinorrhoea or otorrhoea). Distinguishing CSF from other watery discharges involves looking for the presence of something which would normally only be found in CSF. Beta-2 transferrin is a form of the protein transferrin that is present in CSF but not usually found in blood, nasal secretions or other body fluids.

How is the sample collected for testing?

The suspicious watery discharge will be collected into a plain plastic tube.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

The Test

How is it used?

If you suffer an injury (e.g. skull fracture) which causes a tear in the membranes covering the brain and spine, or have had brain surgery, CSF may leak out. This may cause a watery discharge from your nose or ear (rhinorrhoea or otorrhoea). It may be necessary to distinguish CSF from other watery discharges in these circumstances. This involves looking for the presence of something which would normally only be found in CSF, such as beta-2 transferrin. This is a form of transferrin present in CSF but not usually found in blood, nasal secretions or other body fluids.

When is it requested?

Beta-2 transferrin would be requested when there is doubt over the origin of a watery ear or nose discharge, following a high risk event such as a head injury or brain surgery.

What does the test result mean?

If the fluid from the nose or ear is indeed CSF, beta-2 transferrin would be detected when the fluid sample was analysed. Sometimes the result is inconclusive and in such cases the laboratory may test for another protein known as beta trace protein. 

Is there anything else I should know?

CSF leaking from the nose or ear is very rare. Most nasal and ear discharges have an obvious straightforward explanation e.g. infection, and this type of analysis is only required in a very small number of cases where a doctor has a high level of suspicion about the source of discharge.

Common Questions

Can this be measured at my doctor's office?

No, a specialist laboratory using techniques such as immunofixation electrophoresis is required.

Last Review Date: April 5, 2017