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Phosphorylated Tau 217/Amyloid-beta 42 Ratio

Order Code
2925042
CPT
83520×2
Test Details
Synonyms

p-Tau 217/AB 42 Ratio, p-Tau 217/AB 1-42 Ratio, Phosphorylated Tau 217/AB 1-42 Ratio

TAT

Up to 7 days

Methodology

Chemiluminescent enzyme immunoassay (CLEIA)

Reference Interval

Low probability of AD ≤0.00370

Remarks

Results are reported as high, intermediate, or low probability of amyloid pathology.

Plasma p-tau 217 cut-offs are based on large prospective and retrospective studies, and our validation has established this as a laboratory-developed test (LDT).Plasma p-tau 217 is a highly sensitive and specific biomarker for the early detection of Amyloid-beta pathology, making it a feasible test for Alzheimer’s disease (AD) screening in clinical practice. It correlates strongly with core AD pathology as determined by cerebrospinal fluid (CSF) biomarkers, positron emission tomography (PET), or post-mortem examination.

A positive plasma p-tau 217 result, or a positive plasma p-tau 217/Amyloid-beta 42 ratio, in a patient with cognitive symptoms is consistent with amyloid pathology with >90% certainty. However, such a finding does not in itself establish a diagnosis of Alzheimer’s disease but represents a measurement of Amyloid-beta and tau burden; results should always be interpreted in the context of MRI findings, clinical data, and patient history.

Performing Location

Accredited NRL Laboratory

Testing Frequency

Weekly

Test Overview

Plasma Phosphorylated Tau 217 (p-Tau 217) is a highly sensitive and specific biomarker for the early detection of Amyloid-beta pathology, making it a feasible test for Alzheimer’s disease (AD) screening in clinical practice. It correlates strongly with core AD pathology as determined by cerebrospinal fluid (CSF) biomarkers, positron emission tomography (PET), or post-mortem examination.

Specimen Type

K2-EDTA Plasma

Volume

2 mL

Specimen Container

K2-EDTA Plasma (Lavender Top)

Patient Preparation

Samples should be collected following overnight fasting. If patients are taking biotin (Vitamin B7), they should stop taking it 72 hours prior to sample collection.

Collection

Transport to the laboratory immediately following collection; samples must be centrifuged in a refrigerated centrifuge and separated within 24 hours. If this is not possible, centrifuge in a refrigerated centrifuge and aliquot samples, then store and transport samples refrigerated (2-8° C).

Specimen Stability
Temperature Period
Refrigerated 3 days
Frozen 2 weeks at -20° C
Order Code
2925042
CPT
83520×2
Test Details
Synonyms

p-Tau 217/AB 42 Ratio, p-Tau 217/AB 1-42 Ratio, Phosphorylated Tau 217/AB 1-42 Ratio

TAT

Up to 7 days

Methodology

Chemiluminescent enzyme immunoassay (CLEIA)

Reference Interval

Low probability of AD ≤0.00370

Remarks

Results are reported as high, intermediate, or low probability of amyloid pathology.

Plasma p-tau 217 cut-offs are based on large prospective and retrospective studies, and our validation has established this as a laboratory-developed test (LDT).Plasma p-tau 217 is a highly sensitive and specific biomarker for the early detection of Amyloid-beta pathology, making it a feasible test for Alzheimer’s disease (AD) screening in clinical practice. It correlates strongly with core AD pathology as determined by cerebrospinal fluid (CSF) biomarkers, positron emission tomography (PET), or post-mortem examination.

A positive plasma p-tau 217 result, or a positive plasma p-tau 217/Amyloid-beta 42 ratio, in a patient with cognitive symptoms is consistent with amyloid pathology with >90% certainty. However, such a finding does not in itself establish a diagnosis of Alzheimer’s disease but represents a measurement of Amyloid-beta and tau burden; results should always be interpreted in the context of MRI findings, clinical data, and patient history.

Performing Location

Accredited NRL Laboratory

Testing Frequency

Weekly

Test Overview

Plasma Phosphorylated Tau 217 (p-Tau 217) is a highly sensitive and specific biomarker for the early detection of Amyloid-beta pathology, making it a feasible test for Alzheimer’s disease (AD) screening in clinical practice. It correlates strongly with core AD pathology as determined by cerebrospinal fluid (CSF) biomarkers, positron emission tomography (PET), or post-mortem examination.

Specimen Type

K2-EDTA Plasma

Volume

2 mL

Specimen Container

K2-EDTA Plasma (Lavender Top)

Patient Preparation

Samples should be collected following overnight fasting. If patients are taking biotin (Vitamin B7), they should stop taking it 72 hours prior to sample collection.

Collection

Transport to the laboratory immediately following collection; samples must be centrifuged in a refrigerated centrifuge and separated within 24 hours. If this is not possible, centrifuge in a refrigerated centrifuge and aliquot samples, then store and transport samples refrigerated (2-8° C).

Specimen Stability
Temperature Period
Refrigerated 3 days
Frozen 2 weeks at -20° C