CJD

Diagnostic Use

Creutzfeldt-Jakob disease (CJD) is one of the human forms of the transmissible spongiform encephalopathies (TSEs), also referred to as prion diseases. Prion diseases mostly occur as a chance event but can be, in rare cases, attributed to a genetic mutation or acquired through a transmission event.

Those considered at high risk for the condition include patients who report neurological symptoms and display neurological signs of prion disease or have been diagnosed with suspected CJD/prion disease. Symptomatic patients with a recognised health care associated risk factor are also considered to be high risk.

Testing performed at the Florey Institute in Melbourne include the CJD Biomarker Panel 14-3-3 protein ELISA and RT-QuIC assay (Real-time quaking induced conversion; currently not National Association of Testing Authorities (NATA) accredited) and the total-tau protein (NATA accredited).

Department

Microbiology - Virology

Delphic Registration Code

CJDP

Laboratory Handling

Phlebotomy

CSF collection in standard CSF collection tube. (Specialist tubes required for collection of CSF for Alzheimer's disease)

Registration

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

Separating

2.5 mL minimum must be received by Virology for transportation to reference centre.

Laboratory

Testing is performed by the Florey Institute in Melbourne, Australia

Test Adds

Add-ons can be made if an appropriate sample has already been received for other bacterial or PCR testing and sufficient volume of sample remains. Please call Virology to discuss.

Synonyms

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

Turnaround Time

3 weeks

Test Code

2327

Specimen Type

• CSF

Specimen Requirements

Tube/Container Type:

Preferred Sample Volume (ml)

3.0

Minimum Sample Volume (ml)

2.5

Interferences

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

Pre-testing Requirements

Clinical information MUST be provided. Sample will not be referred without supporting clinical details, biochemistry and cell count information. Please indicate onset, history of dementia, any tests suggesting CJD i.e. MRI or EEG. Mention of other indicators - rigidity, myoclonus, ataxia.

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.

Note: Requestors are advised that referred specimens for 14-3-3 protein are sent on week 1 and week 3 of the month. Result expected within 7 days of receipt by the Florey Institute.

Additional Specimen Information

For all CSF samples the following criteria must be met:

Clear, non-haemolysed CSF

A minimum of 2.5ml is requested

No further sample processing – DO NOT SPIN

Store and send specimens, refrigerated at 2-8 degrees within 2 days, otherwise freeze

Provide routine microbiology and biochemistry results (red and white blood cell counts plus protein and glucose concentration). Please note the tube that cell count was performed on.
CSF Protein g/L
Glucose mmol/L
CSF Red Cell count x 10^6 /L (must be less than 500)
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.

Aliquot Instructions

Minimum Volume (ml)

2.5

Transport to Lab

If overnight - Chilled (2 - 8 degrees Celsius)

Interpretation

RT-QuIC (as determined by Real Time Quaking Induced Conversion; “RT-QuIC”
assay) has sensitivity and specificity of 93% and (approx.) 99% respectively.

The 14-3-3 (as determined by Roche Elecsys Immunoassay) proteins are
non-specific markers of central nervous system neuronal injury or death. In
the correct clinical context, sensitivity and specificity are 88% and 76%
(14-3-3) and 88% and 90% (Total-tau), respectively.

“False” (non prion disease specific) positive results may be recognised in
other diseases, including – encephalitis (especially Herpes simplex), invasive
CNS malignancy and recent cerebral infarcts.

Based on analysis of 165 pathologically proven sporadic CJD cases; total CSF
protein <1.0g/L is rarely seen in uncomplicated CJD (<2%) and total CSF while
cell count is never >10 cells/uL in uncomplicated cases

Non-Funded Test Cost

$1532.95 (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.

Prion disease is transmissible from one person to another only through invasive medical procedures involving high infective tissue (ie. brain, spinal cord, posterior eye chamber, olfactory epithelium, cranial and dorsal root ganglia) by the transfer of misfolded prion protein. Transmission can occur from anyone with prion disease, irrespective of whether their prion disease is sporadic, inherited or iatrogenic.

Contact Information

Enquiry Form