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Test Code LAB4816 Phospho-Tau 217, Plasma

Additional Codes

SQ CODE: PT217M

MAYO CODE: PT217


Ordering Guidance


This assay is useful for individuals presenting with mild cognitive impairment or early dementia. Results must be interpreted in conjunction with other diagnostic tools such as neurological examination, neurobehavioral tests, imaging, and routine laboratory tests.

 

This assay should not be ordered for individuals younger than 50 years or in cognitively unimpaired individuals regardless of age.

 

This assay should not be used to predict the development of dementia or other neurologic conditions.



Specimen Required


Collection Container/Tube: Lavender top (EDTA)

Submission Container/Tube: Plastic screw-top vial

Specimen Volume: 0.6 mL

Collection Information: Centrifuge and aliquot plasma into plastic vial. Do not submit in original tube.


Secondary ID

621635

Useful For

Evaluation of individuals, aged 50 years and older, presenting with cognitive impairment who are being assessed for Alzheimer disease and other causes of cognitive decline

 

This test is not intended as a screening test for Alzheimer disease in asymptomatic individuals.

Method Name

Chemiluminescent Enzyme Immunoassay

Reporting Name

Phospho-Tau(217), P

Specimen Type

EDTA Plasma

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
EDTA Plasma Refrigerated (preferred) 14 days
  Frozen  90 days
  Ambient  72 hours

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Gross icterus OK

Reference Values

Negative: ≤0.185 pg/mL

Intermediate: 0.186-0.324 pg/mL

Positive: ≥0.325 pg/mL

Method Description

Plasma calibrator or specimen are added to particle solution. Phosphorylated Tau217 (p-Tau217) in specimens or calibrators specifically binds to anti-p-Tau217 monoclonal antibody (mouse) on the particles and antigen-antibody immunocomplexes are formed. The particles are washed and rinsed to remove unbound materials. Alkaline phosphatase (ALP)-labeled anti-Tau monoclonal antibodies (mouse) are added and specifically bind to the prior formed immunocomplexes on the particles, and additional immunocomplexes are formed. The particles are washed and rinsed to remove unbound materials. Substrate solution is added and mixed with the particles and 3-(2'-spiroadamantane)-4-methoxy-4-(3"-phosphoryloxy) phenyl-1,2-dioxetane disodium salt (AMPPD) contained in the substrate solution is dephosphorylated by the catalysis of ALP indirectly conjugated to particles. Luminescence (at a maximum wavelength of 477 nm) is generated by the cleavage reaction of dephosphorylated AMPPD. The luminescent signal reflects the amount of p-Tau217 in the sample.(Unpublished Mayo method)

Day(s) Performed

Monday through Friday

Report Available

1 to 3 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

83520

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PT217 Phospho-Tau(217), P 104663-0

 

Result ID Test Result Name Result LOINC Value
217PT pTau217, P 104663-0
PTINT pTau217 Interpretation 69048-7