Specimen Collection:
2 tubes each with 2 mL CSF. Note: these are additional to any other tubes taken for other CSF tests (e.g. microbiology and chemistry).
A special request form must be completed and accompany the CSF specimens (click on link below).
On receipt at LabPLUS - the samples are to be placed in the Endocrinology box in freezer 36.
Laboratory Notes:
Any queries please contact Section Leader/Technical Specialist SCP - Endocrinology
Sample : 2 x 2 ml CSF tubes
ALSS staff Both tubes placed in ENDO box in freezer 36
Stability 4 months at 2-8 degrees Celsius
Endo staff Follow procedure regarding specimen suitability and comment reporting (LPCHPENDPR333)
If there is spare CSF sample, this is stored in a pot in the Bio -80˚C freezer and kept for 3 months post receipt of the results.
Sendaway staff: Send 1 tube of CSF (2 mL) by courier on a Monday, at 4 degrees Celsius to:
Dept. of Immunology, Churchill Hospital, Old Road, Headington, Oxford, OX3 7LJ, UK.
Turnaround time - between 4 and 6 weeks
Assay Method: Radioimmunoassay
The special request form must accompany the specimen.
Refer to https://www.ouh.nhs.uk/immunology/diagnostic-tests/tests-catalogue/orexin/
Diagnostic Use and Interpretation:
Orexin, also called hypocretin, is a neuropeptide that regulates arousal, wakefulness, and appetite. The most common form of narcolepsy, in which the sufferer briefly loses muscle tone (cataplexy), is caused by a lack of orexin in the brain.
Low CSF orexin / hypocretin levels can be useful for diagnosis of narcolepsy.
Reference: Mignot, E. et al. Arch. Neurol. 2002; 59(10):1553-62