Alzheimer Disease Evaluation, CSF

Label Mnemonic: ADEVL
Epic code: LAB9894
Downtime form: Doctor/Provider Orders - Pathology Core and Specialty Care Nursery
Commercial Mailout Laboratory
6240-8 RCP
356-8593
Specimen(s):
CSF

Discard first 1 to 2 mL of CSF. Collect 1.5 to 2.5 mL CSF directly into Sarstedt Polypropylene tube. Submit in original polypropylene tube, do not aliquot.

Collection Medium:
Individually Wrapped Sterile Polypropylene Transfer Tube
Minimum:

1.5 to 2.5 mL CSF.

 

Contact Core Laboratory at (356-3527) or Mailouts at (356-8593) for the Individually Wrapped Sterile Polypropylene Transfer Tube.

Rejection Criteria:

Tubes other than polypropylene are not acceptable.

Testing Schedule:

Tuesday, Thursday, Friday (TAT 1–4 days)

Reference Range:

Beta-amyloid (1-42) (Abeta42): >834 pg/mL

 

Total-Tau: < or =238 pg/mL

 

Phosphorylated-Tau 181: < or =21.6 pg/mL

 

p-Tau/Abeta42: < or =0.028

Comments:

A positive cerebrospinal fluid (CSF) beta-amyloid 42 (Abeta42), total Tau (t-Tau), or phosphorylated Tau (p-Tau181) result, or p-Tau181/Abeta42 ratio does not establish a diagnosis of Alzheimer disease (AD) or other cognitive disorder. These results should be interpreted in combination with other clinical diagnostic and radiologic evaluations.

 

An abnormal p-Tau181/Abeta42 ratio in the context of a normal Abeta42 may be observed in some individuals. In some situations, interindividual differences in overall concentration of Abeta peptide production and/or in p-Tau elevation stemming from other neurodegenerative disease may result in an abnormal p-Tau181/Abeta42 ratio.

 

Failure to adhere to the specimen collection instructions provided may result in falsely low Abeta42 concentrations and potential misdiagnosis of AD.

 

There is no high-dose hook effect at Abeta42 concentrations up to 6000 pg/mL, p-Tau181 concentrations up to 300 pg/mL, and t-Tau concentrations up to 4267 pg/mL.

 

CSF biotin concentrations up to 1200 ng/mL do not interfere with this assay.

 

Performing Laboratory:

Mayo Clinic Laboratories – Rochester Superior Drive (CLIA Number: 24D1040592)

 

References:

  1. Peyro Saint Paul L, Debruyne D, Bernard D, Mock DM, Defer GL. Pharmacokinetics and pharmacodynamics of MD1003 (high-dose biotin) in the treatment of progressive multiple sclerosis. Expert Opin Drug Metab Toxicol. 2016;12(3):327-344
  2. Grimsey P, Frey N, Bendig G, et al. Population pharmacokinetics of exogenous biotin and the relationship between biotin serum levels and in vitro immunoassay interference. J Pharmacokinet Pharmacodyn. 2017;2(4):247-256. doi:10.4155/ipk-2017-0013
  3. van Harten AC, Wiste HJ, Weigand SD, et al. Detection of Alzheimer's disease amyloid beta 1-42, p-tau, and t-tau assays. Alzheimers Dement. 2022;18(4):635-644. doi:10.1002/alz.12406
  4. Campbell MR, Ashrafzadeh-Kian S, Petersen RC, et al. P-tau/AB42 and AB42/40 ratios in CSF are equally predictive of amyloid PET status. Alzheimers Dement (Amst). 2021;13(1):e12190. doi:10.1002/dad2.12190
  5. Blennow K, Stomrud E, Zetterberg H, et al. Second-generation Elecsys cerebrospinal fluid immunoassays aid diagnosis of early Alzheimer's disease. Clin Chem Lab Med. 2022;61(2):234-244. doi:10.1515/cclm-2022-0516
  6. Leuzy A, Mattsson-Carlgren N, Cullen NC, et al. Robustness of CSF AB42/40 and AB42/P-tau181 measured using fully automated immunoassays to detect AD-related outcomes. Alzheimers Dement. 2023;19(7):2994-3004. doi:10.1002/alz.12897
  7. Jack CR Jr, Bennett DA, Blennow K, et al. NIA-AA Research Framework: Toward a biological definition of Alzheimer's disease. Alzheimers Dement. 2018;14(4):535-562
  8. Lifke V, Kollmorgen G, Manuilova E, et al. Elecsys Total-Tau and Phospho-Tau (181P) CSF assays: Analytical performance of the novel, fully automated immunoassays for quantification of tau proteins in human cerebrospinal fluid. Clin Biochem. 2019;72:30-38
  9. Hansson O, Seibyl J, Stomrud E et al. CSF biomarkers of Alzheimer's disease concord with amyloid-beta PET and predict clinical progression: A study of fully automated immunoassays in BioFINDER and ADNI cohorts. Alzheimers Dement. 2018;14(11):1470-1481
  10. Shaw LM, Arias J, Blennow K, et al. Appropriate use criteria for lumbar puncture and cerebrospinal fluid testing in the diagnosis of Alzheimer's disease. Alzheimers Dement. 2018;14(11):1505-1521
  11. Hansson O, Batrla R, Brix B, et al. The Alzheimer's Association international guidelines for handling of cerebrospinal fluid for routine clinical measurements of amyloid beta and tau. Alzheimers Dement. 2021;17(9):1575-1582. doi:10.1002/alz.12316
Methodology:

Electrochemiluminescent Immunoassay (ECLIA)

CPT Code:
82234
84393
84394