CJD

Diagnostic Use

14-3-3 protein in CSF, is a non-specific marker of neuronal injury or death in the central nervous system.
A positive CSF 14-3-3 protein result has approximately 90% sensitivity and specificity for sporadic CJD.

Department

Microbiology - Virology

Delphic Registration Code

CJDP

Laboratory Handling

Phlebotomy

CSF collection in Standard CSF collection tube. ( specialist tubes required for transportation purposes or for direct collection of CSF for Alzheimers disease)

Registration

CSF Samples requesting 14-3-3 protein for CJD should remain double bagged during the registration process then passed to the virology department directly.

Separating

2.5 ml minimum must be transfered to specialised blue sarstedt 63.614.625 tube in Virology for transportation to reference centre. Tubes availiable in Virology.

Synonyms

14-3-3 protein
Creutzfeldt-Jakob disease
Spongiform encephalopathy
RT-QUIC

Turnaround Time

2 weeks

Test Code

2327

Specimen Type

• CSF

Specimen Requirements

Tube/Container Type:

Minimum Sample Volume (ml)

2.5

Interferences

Haemolysis: CSF sample must be clear and non-haemolysed.

Pre-testing Requirements

Lab MUST be phoned and clinical information MUST be provided.
If PCR testing for viruses and bacteria is requested and CJD is also requested the 14-3-3 protein test will be performed first. This may delay the PCR testing for 1-2 weeks.
Note: Requestors are advised that referred specimens for 14-3-3 protein are sent on week 1 and week 3 of the month. TAT's advised below.
Further critical information: Refer Additional Specimen Information.

Additional Specimen Information

For all referred and locally collected CSF samples.

1) Minimum 2.5mL of CSF - undiluted (CSF must be clear and colourless) and must not be centrifuged.
2) CSF Collection date must be indicated.
3) Other results that must be provided: These are all needed for result interpretation.
Biochemistry CSF Protein g/L
Biochemistry Glucose mmol/L
Microbiology: CSF Red Cell count x 10^6 /L ( must be less than 500)
Microbiology: CSF White Cell count x 10^6/L (must be less than 10)

Note: 14-3-3 protein exists in erythrocytes, platelets and plasma. Lysis of these cells
releases the protein thus contaminating the CSF sample and leading to false
positive results.
4) CSF must not be centrifuged.

Aliquot Instructions

Minimum Volume (ml)

2.5

Transport to Lab

Ambient (8 - 24 degrees Celsius)
If overnight - Chilled (2 - 8 degrees Celsius)

Additional Referral/Aliquot Information

Strict adherence to requirements stated is required. Deviation from specific requirements will likely mean sample is rejected.
All requests for CJD 14-3-3 protein are assessed by our clinical microbiology specialists.

IMPORTANT: clinical information must be provided. Please indicate onset, history of dementia, any tests suggesting CJD i.e. MRI or EEG. Mention of other indicators - rigidity, myoclonus, ataxia. If the patient has none of these, an outline of what is indicated is needed.

A copy of the original doctors request slip is required to accompany the sample.

Interpretation

Application:
The 14-3-3 protein test is a non-specific marker of CNS system injury or death. In carefully selected patients, a positive result can have approximately 90% sensitivity and specificity for sporadic Creutzfeldt-Jakob disease.
Testing should only be performed in the appropriate clinical setting of the patient with dementia who has not had a cerebral infarct in the last month.
False positive results have been noted in encephalitis (especially Herpes simplex virus) and recent cerebral infarcts.

Test Method

14-3-3 protein is detected by a semi-quantitative western blotting procedure.

Non-Funded Test Cost

$1446.17 (Exclusive of GST)

Billing Code

2327

Additional Costing Information

Sent to Australian National CJD registry, The Florey Institute, University of Melbourne.

Specimens are sent on special shipments on dry ice. Where possible shipments are combined with other specimens however this is not usually achievable given required TATS.
Transportation costs form a significant portion of the overall testing. For this reason test costings may be reviewed more regularly.

Contact Information

Enquiry Form