What is being tested?

Beta-2-transferrin is a form of the protein transferrin that is present in cerebrospinal fluid (CSF), but not usually found in blood, nasal secretions or other body fluids. It is used to distinguish CSF from other watery discharge from the nose or ear after a traumatic injury to the brain and or spine.

How is it used?

Cerebrospinal fluid (CSF) is normally found only within the brain and the spinal canal. 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 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.

More information

RCPA Manual: Rhinorrhoea CSF Testing