Phospho-Tau 217 (p217) NEW

This blood test is available to TDL, and referred to the National Hospital for Neurology, Queens Square, London. A patient needs to present with some form of cognitive impairment that is under assessment for Alzheimer disease and other causes of cognitive decline. This test should not be considered as a predictive test – there is not enough data to demonstrate that a result could show risk of an asymptomatic individual developing symptoms related to Alzheimer disease in the future. This test is not intended as a screening test for Alzheimer disease in asymptomatic individuals. p-Tau217 has been shown to increase over time in people with brain atrophy and cognitive decline.

• This is a test for the evaluation of individuals, aged 50 years and older, already presenting with cognitive impairment who are being assessed for Alzheimer disease and other causes of cognitive decline.
• Results from the p-Tau217 test must be interpreted in conjunction with other diagnostic tools, such as neurological examination, neurobehavioral tests, imaging, and routine laboratory tests.
• Elevations of p-Tau217 may be seen in individuals with impaired renal function associated with chronic kidney disease and this should be interpreted with caution in these situations – false-positive or false-negative test results may occur.
• There is no multiethnicity data for this test performance and studies have been done on a white US population.
• This assay should not be used for cognitively unimpaired (asymptomatic) individuals to predict the development of dementia or other neurological conditions.
• The safety and effectiveness of this test have not been established for monitoring the effect of disease monitoring therapies or for predicting development of dementia or other neurologic conditions.
• p-Tau217 concentrations have not been established to correlate with disease severity.
• The test is accredited and performed on Fujirebio Lumipulse analysers. Results obtained with different assay methods or kits may be different and cannot be used interchangeably. There are other p-Tau assays (181 and 231) using plasma. The increases in p-Tau217 levels have been shown to be superior at detecting Alzheimer’s Disease. P-Tau217 has also been show to increase in patients when correlated with brain atrophy and cognitive decline.

Results are reported as:

Negative: A normal (negative) phosphorylated Tau217 (p-Tau217) result is consistent with a negative (normal) amyloid-positron emission tomography (PET) scan result. This result indicates a reduced likelihood that an individual has neuropathological changes associated with Alzheimer disease.

Intermediate: An intermediate p-Tau217 result cannot accurately differentiate between the presence or absence of neuropathological changes associated with Alzheimer disease. Further testing, with PET scanning or cerebrospinal fluid Abeta42 and tau biomarkers, is needed to determine the likelihood of neuropathological changes associated with Alzheimer disease being present.

Positive: An elevated (positive) p-Tau217 result is consistent with a positive (abnormal) amyloid-positron emission tomography (PET) scan result. This result is consistent with the presence of neuropathological changes associated with Alzheimer disease. In the proper clinical context this test is supportive of Alzheimer disease being related to current clinical symptoms. This test has not been demonstrated to provide information on the risk of an asymptomatic individual developing symptoms related to Alzheimer disease in the future.