14-3-3 CSF Protein Test

What is the 14-3-3 protein CSF test?

The 14-3-3 protein is an ante-mortem, non-specific marker of central nervous system neuronal injury or death. Based on international experience in carefully selected patients, a positive result has approximately 90% sensitivity and specificity for sporadic Creutzfeldt Jakob disease. False positives are recognized in various disease processes; for example encephalitis, encephalopathies and recent cerebral infarcts. Unselected sampling is consequently less reliable if the 14-3-3 protein CSF test is used to screen for a possible diagnosis of CJD.

In June 2005, evaluation of all 2002-2003 Australian CSF referrals where a known clinical outcome was provided to the ANCJDR after detailed followup, revealed a test sensitivity of 82% and specificity of 92%.

The sample

• No less than 1 ml of CSF – PLEASE DO NOT SPIN SAMPLE.
• CSF samples are to be packaged in polypropylene, sterile tubes with no additives.
• Double bag, freeze and transport frozen on dry ice. You are responsible for organizing your courier service to pick up and deliver the sample to The University of Melbourne.
• Please provide routine cell counts and protein levels. These results are needed for interpretation.
• A copy of the original request slip and a completed specimen data sheet should accompany the sample.
• PLEASE NOTIFY REGISTRY STAFF THAT THE SAMPLE IS BEING SENT.

Information about the test

• The test is run weekly.
• Samples received by 4pm Friday will have the result issued by the end of the following week.
• All salient clinical details are clarified with the requesting doctor. A researcher from the Registry will contact the clinician directly.
• Positive results will be verbally reported to the requesting clinician and a report issued to the referring laboratory.
• All results will be reported by post to the referring laboratory.
• Clinicians will be contacted approximately 9 months after a test result is reported for outcome advice. The ANCJDR performs follow-up on all referrals to evaluate sensitivity and specificity.

Unsuitable samples

Unsuitable samples will not be tested. All samples are screened on receipt and those considered unsuitable will be disposed of. The referring clinician will be contacted upon receipt of such a sample and advised. A report will be issued.

An unsuitable sample will include the following:

• Macroscopically haemorrhagic samples
• Xanthochromic samples
• Red blood cell counts >500 cells per µl
• White cell counts >10 cells per µl

Based on cumulative experience and published results, these samples are unsuitable to test due to the 14-3-3 protein existing in erythrocytes, platelets and plasma. Lysis of these cells releases the protein thus contaminating the CSF sample and giving a false positive result. (Day I.N.M and Thompson R.J. Clinica Chimica Acta 1984; 136: 219-228, Collins et al, J of Clin Neurosci 2000; 7:203-208).

Reporting Results

• Please directly contact your referring laboratory to check for results.
• Technical difficulties may cause delays in reporting. These delays cannot be predetermined and the test will be repeated until a satisfactory result is obtained.

Please notify samples being sent, and courier addressed to:

The Australian National CJD Registry
Level 5
The Medical Building
Department of Pathology
Faculty of Medicine
The University of Melbourne
Cnr Grattan St & Royal Pde
VIC 3010

Phone:	(03) 8344 1949
Fax:	(03) 9349 5105

Specimen Data Sheet

This form must accompany specimens sent for testing.

The 14-3-3 CSF test specimen data sheet is available for download from this page. The PDF document contains form fields allowing for completion of some or all fields prior to printing.

Download the specimen data sheet

Requires Acrobat Reader 5.0 or later

Diagnostic Testing Fees

Refer to Diagnostic pricing schedule