Currently the diagnosis of probable Alzheimer disease (AD) is made based on clinical symptoms, largely by the exclusion of other causes of dementia, with postmortem evidence of AD pathology required to confirm the diagnosis. Two common neuropathologic features found in the brains of patients with AD are the presence of plaques composed of beta-amyloid (Abeta) peptides and intracellular neurofibrillary tangles containing hyperphosphorylated Tau (tubulin-associated unit) proteins.

Pathological changes associated with AD are reflected by an increase in the CSF concentrations of t-Tau and p-Tau. Increases in CSF t-Tau reflect the intensity of the neuronal and axonal damage and degeneration and is associated with a faster progression from MCI to AD. Increases in CSF p-Tau concentrations are also associated with a faster progression from MCI to AD with more rapid cognitive decline in AD patients and in mild AD dementia cases.

Alicia Algeciras-Schimnich, Ph.D., gives an overview of this test available through Mayo Clinic Laboratories. She discusses when this testing should be ordered, how this testing compares to previous testing approaches, and what clinical action can be taken due to the results of this testing.

Testing

Useful for:

  • Assessment of adults with cognitive impairment being evaluated for Alzheimer disease (AD) and other causes of cognitive impairment.

Specimen Requirements

Specimen Type 

CSF

Specimen Required 

Patient Preparation: For 12 hours before specimen collection do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.

Supplies: Alzheimer’s Disease Evaluation (ADEVL) Collection Kit (T836)

Collection Container/Tube: CSF AD Biomarker Tube; specimens not collected in this tube will be rejected

Specimen Volume: 2 mL

Collection Instructions:

1. Perform lumbar puncture and discard the first 1 to 2 mL of cerebrospinal fluid (CSF).

2. Collect 2 mL of CSF directly into CSF AD Biomarker Tube. Do not aliquot. Analysis needs to be performed using collection tube

Performance Information

Day(s) and Time(s) Test Performed 

Tuesday, 6 pm

Analytic Time 

1 day

Alyssa Frank

Alyssa Frank

Alyssa Frank is a Marketing Segment Manager at Mayo Clinic Laboratories. She leads marketing strategies for product management and specialty testing. Alyssa has worked at Mayo Clinic since 2015.