Lab Test

Creutzfeldt Jacob Disease (CJD) Immunoassay

CJD proteins: 14-3-3 gamma, RT-QuIC, Total tau

Test Codes

EPIC: LAB3153, Beaker: XCJD, National Prion

Department

Send Outs

Instructions

Testing requires the ordering physician to complete forms for the independent clinical laboratory performing the testing. For the forms, please go to: https://case.edu/medicine/pathology/sites/default/files/2024-02/Test%20Request%20Form.pdf

Specimen Collection Criteria

Collect: 2.0 mL Cerebrospinal Fluid (CSF) in a Sarstedt CSF false bottom tube. Avoid a bloody tap. (Minimum: 1.0 mL). Freeze sample immediately after collection, preferably within 30 minutes.

  • Collect CSF using standard lumbar puncture procedure.
  • Discard the first 2.0 mL of fluid or use it for other testing. 
  • Prior to freezing double-bag the specimen with biohazard lab specimen bags
  • Notify the lab processing area that a suspect CJD specimen is being sent. 

Physician Office/Draw Specimen Preparation

Freeze (-20°C/-4°F or below) double-bagged specimen immediately and maintain frozen prior to transport.

Preparation for Courier Transport

Transport: 2.0 mL CSF frozen (-20°C/-4°F or below). (Minimum: 1.0 mL)

Rejection Criteria

  • CSF samples of patients under 12 years are rejected.
  • Specimens not collected and processed as indicated.

In-Lab Processing

Label: specimen and specimen bag with “Suspect CJD patient” label before distributing to Send Outs Laboratory.

Freeze: (-20°C/-4°F or below) double-bagged specimen immediately prior to transport.

Transport: 2.0 mL CSF frozen (-20°C/-4°F or below). (Minimum: 1.0 mL) 

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): unacceptable
Refrigerated (2-8°C or 36-46°F): unacceptable
Frozen (-20°C/-4°F or below): Indefinite

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent directly to National Prion Laboratory, Cleveland, OH.

Performed

Results available within 8-14 days.

Reference Range

By report.

Test Methodology

Immunoassay and Real-Time Quaking-Inducing Conversion (RT-QuIC).

Interpretation

By report.

Clinical Utility

In patients with dementia, a positive RT-QuIC in cerebrospinal fluid strongly supports a diagnosis of Creutzfeldt-Jakob disease. This finding, however, does not support the use of the test in patients without clinical indications. Assumes that the patient has a history of a rapid neurodegenerative condition and does not have several conditions that might compromise the test results. Conditions include but are not limited to, subarachnoid hemorrhage, various encephalitis, stroke with acute infarction, multi-infarct dementia with acute infarction, brain neoplasm, and paraenoplastic neurological disorders. These conditions may yield false-positive results.

CPT Codes

86317 (x2), 0035U.

Contacts

Last Updated

2/5/2025

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