CSF Protein Immunoassay Panel - Guide to Services

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Accredited by the Standards Council of Canada to Laboratory no. 594 - CAN-P-4E (ISO/IEC 17025)

Requisition Forms

Prion Diseases Program Requisition - CSF
06-PDP-CSF-requisition-ENG.pdf

Reference Details

Description:

14-3-3 protein testing of cerebrospinal fluid (CSF).

S100 protein ELISA

Tau protein ELISA

Test Category:

Host Marker

Pathogen:

Creutzfeldt-Jakob Disease (CJD) - sporadic, genetic and variant forms

Laboratory:

Prion Laboratory Section

Illnesses and Diseases:

Creutzfeldt-Jakob Disease (CJD)

Specimen:

CSF. Minimum volume of sample required is 2.0 mL.

Collection Method:

N/A

Specimen Processing, Storage and Shipping:

Freeze sample as soon as possible after collection. Ship frozen on dry ice.

Transportation of Dangerous Goods:

Shipping of specimens shall be done by a TDG certified individual in accordance with TDG regulations. For additional information regarding classification of specimens for the purposes of shipping, consult either Part 2 Appendix 3 of the TDG Regulations or section 3.6.2 of the IATA Dangerous Goods Regulations as applicable.

Patient Criteria:

Inclusion of CJD in the differential diagnosis of the patient.

Accompanying Documentation:

Completed Prion Laboratory Services requisition. Please include patient name, or unique identifier; DOB; gender; referring physician; sample date; mailing address for results.

Comments:

Local laboratory forms are accepted as long as the appropriate information is listed.

Methods and Interpretation of Results:

14-3- 3 Protein:

Proteins from human cerebrospinal fluid are separated by size on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and electrotransferred onto nitrocellulose membranes. A primary antibody reacts with a specific epitope found in 14-3-3 proteins. The immunoreactive bands are detected by a secondary antibody. The test result is scored as "positive" or "negative" by comparing sample reaction intensities to a threshold cutoff set by intensities of internal standards containing 14-3-3 protein.

Tau Protein ELISA:

The tau protein assay is conducted by sandwich enzyme-linked immunosorbent assay (ELISA), using a commercial kit, Innotest® hTAU Ag (Innogenetics) and colorimetric signal detection. Results are reported quantitatively in units of pg/mL. Consensus standards to support interpretation of CSF tau protein levels in the diagnosis of CJD have not yet been established. However, a prospective study of test performance characteristics conducted in Canadian patients with suspected sporadic CJD between 2004 and 2010 yielded the following estimates at an intermediate optimum cutoff of 976 pg/mL: Sensitivity 0.91 (95% CI: 0.84–0.95); Specificity 0.88 (95% CI: 0.85–0.90); Positive Likelihood Ratio 7.4 (95% CI: 6.9–7.8); Negative Likelihood Ratio 0.10 (95% CI: 0.06–0.20). ¹ Further detail on the validation study, performance characteristics and interpretive scenarios may be found in the supporting documentation.

S100 Protein ELISA:

The S100 protein assay is conducted by sandwich enzyme-linked immunosorbent assay (ELISA), using a commercial kit, S100 ELISA (Diasorin) and colorimetric signal detection. Results are reported quantitatively in units of ng/mL. Consensus standards to support interpretation of CSF S100 protein levels in the diagnosis of CJD have not yet been established. However, a prospective study of test performance characteristics conducted in Canadian patients with suspected sporadic CJD between 2004 and 2010 yielded the following estimates at an intermediate optimum cutoff of 2.5 ng/mL: Sensitivity 0.87 (95% CI: 0.80–0.90); Specificity 0.87 (95% CI: 0.84–0.91); Positive Likelihood Ratio 6.6 (95% CI: 6.1–7.1); Negative Likelihood Ratio 0.15 (95% CI: 0.09–0.20). ¹ Further detail on the validation study, performance characteristics and interpretive scenarios may be found in the supporting documentation.

Turnaround Time:

20 calendar days

Contact:

Phone #: (204) 789-6078 or 1-888-489-2999

Fax: (204) 789-5009

Email: NML.CJD@phac-aspc.gc.ca

References: