Frequently Asked Questions
Find Answers to the Questions that Matter Most
From those delivering care to those seeking it.
Clinician Questions
What is pTau217?
pTau217 is a specific form of the tau protein that has been modified by the addition of phosphate groups (phosphorylation). It is closely linked to Alzheimer’s disease pathology and is considered one of the most reliable blood biomarkers for detecting the disease. Elevated levels of pTau217 in the blood strongly correlate with the presence of amyloid plaques and tau tangles in the brain, which are hallmarks of Alzheimer’s disease.
What is the ALZpathDx test?
The ALZpathDx test is available from Neurocode and is a blood-based diagnostic tool designed to measure levels of pTau217. The test helps clinicians identify and monitor Alzheimer’s disease more accurately and at earlier stages than traditional methods. This enables earlier intervention and better tracking of disease progression and response to treatments.
Who is this test appropriate for?
The ALZPathDx test at Neurocode is recommended for individuals experiencing cognitive decline over the age of 55. Learn more at Neurocode’s website.
How do I order the test?
To order the blood collection kit, please visit the Neurocode website.
How do ALZpath antibody-powered assays compare to CSF and PET scans?
Recent research shows that pTau217 blood tests perform comparably to pTau217 measured in cerebrospinal fluid for the diagnosis of Alzheimer’s disease [1-2]. These assays also demonstrate exceptional accuracy in detecting amyloid and tau positivity, distinguishing the presence of tau tangles in amyloid-positive individuals, and tracks closely with PET imaging results in diverse cohorts [3].
For more information visit our publications.
How are ALZpath antibody-powered assays used in Alzheimer’s disease diagnosis?
ALZpath antibody-powered assays may be used to aid in the diagnosis of Alzheimer’s disease in individuals who are experiencing cognitive changes. Elevated levels of pTau217 in the blood may indicate the presence of Alzheimer’s disease pathology. While a definitive diagnosis of Alzheimer’s disease requires a combination of clinical assessments including cognitive testing, measuring pTau217 levels in the blood is emerging as a key tool for diagnosing Alzheimer’s disease-specific pathology in many patients. These assays may also aid in differentiating Alzheimer’s disease from other types of cognitive disorders [12].
Can ALZpath antibody-powered assays indicate the stage or severity of AD?
Currently, these assays are used to identify underlying Alzheimer’s disease pathology and do not offer a prognosis on disease severity or progression, although research in this area is active.
Do ALZpath antibody powered assays require special sample type?
A standard blood draw (EDTA plasma) can be performed in virtually any clinical setting, eliminating the need for specialized facilities or procedures. For more information on collection details contact Neurocode.
Does kidney disease interfere with pTau217 results?
Some studies have suggested that pTau217 can increase in patients with significant renal impairment (eGFR <45) [13].
For more information visit our publications.
What codes will I need to use and what reimbursement will I receive?
Currently, there is a PLA code, but no CPT code. This test is patient-pay only. Contact billing at customercare@neurocode.com for more details.
Patient Questions
How is the test administered?
The test requires a simple blood draw, typically conducted in a physician’s office, or certified laboratory, or at home.
How do I order the test?
The test must be ordered by your physician. Physicians can order the ALZpathDx pTau217 test from our partner laboratories, Neurocode or BC Neuroimmunology (Canada only), and the test will be shipped directly to their office.
Can I purchase the test without going through my medical provider?
Your doctor must order the test for you. We can provide your doctor with information to help them understand the test and how to order it.
Can I order the test for a loved one?
The test must be ordered for each patient individually, but you may support your loved one in receiving a requisition form from their doctor.
How will I receive my results?
Your results will be sent to your provider through a secure portal, and they will discuss the next steps with you.
Should I get tested if I have no symptoms?
pTau217 testing is currently intended for individuals experiencing cognitive symptoms or memory concerns. Ongoing research is exploring its potential use in people at risk but not yet symptomatic, with the goal of enabling earlier detection and intervention in the future.
Should I get tested if I have symptoms of cognitive decline?
If you are experiencing memory issues or other cognitive symptoms, a pTau217 blood test may help clarify whether Alzheimer’s disease could be contributing – providing guidance for the next steps.
How old must I be to receive ALZpathDx?
The test is intended for individuals 55 and older who are experiencing cognitive or memory concerns.
What does ALZpathDx show?
Elevated levels of pTau217 in the blood may indicate the presence of Alzheimer’s disease pathology.
What should I do if my blood biomarker levels are abnormal?
Follow up with your healthcare provider for further evaluation and guidance.
Is ALZpathDx offered outside of the US and Canada?
Yes, please contact Neurocode to learn more.
Will insurance cover the test?
Currently, the test is not covered by insurance.
How much does the test cost?
$349. See Neurocode (customercare@neurocode.com ) for additional details.
Is ALZpathDx approved by the FDA?
Currently, the test is not FDA-approved. ALZpathDx is available as a lab developed test at Neurocode, a CLIA certified laboratory.
Researcher Questions
How do I access the RUO version of the pTau217 test?
The RUO (Research Use Only) version of the test can be accessed by ordering through our partners by filling out the form on Our Science page.
What is the sensitivity/specificity of this test?
The pTau217 test has a PPV/NPV of 95% depending on the cut-off. Amyloid AUC: 0.957, Tau AUC: 0.952.
Alzheimer's Disease Questions
What is Alzheimer’s disease?
Alzheimer’s disease is a progressive neurodegenerative disorder that gradually damages brain cells, leading to worsening memory loss, confusion, and difficulties with thinking, problem-solving, and language. Over time, it affects a person’s ability to conduct daily activities and maintain independence. It is the most common cause of dementia in older adults.
What causes Alzheimer’s disease?
The exact cause of Alzheimer’s disease is not fully understood. However, it is believed to result from a combination of genetic, environmental, and lifestyle factors. Abnormal protein deposits in the brain—such as amyloid plaques and tau tangles—are hallmarks of the disease, and these changes disrupt communication between brain cells and eventually lead to cell death.
How is Alzheimer’s disease diagnosed?
Diagnosis of Alzheimer’s disease involves a comprehensive evaluation. This typically includes a review of the patient’s medical history, interviews with family members, cognitive and memory assessments, and neurological exams. Doctors may also use brain imaging (such as MRI or PET scans) and laboratory tests, including blood tests or spinal fluid analysis, to help rule out other conditions and support the diagnosis.
What is the difference between Alzheimer’s disease and dementia?
Dementia is a general term for a decline in cognitive function severe enough to interfere with daily life. Alzheimer’s disease is the most common cause of dementia, but there are other types as well, such as vascular dementia and Lewy body disease. In other words, all Alzheimer’s disease is dementia, but not all dementia is Alzheimer’s disease.
Biomarker Questions
What is a biomarker?
A biomarker is a measurable substance or characteristic in the body—such as a protein, gene, or molecule—that provides information about a biological process, disease state, or response to treatment. In Alzheimer’s disease, biomarkers help clinicians identify and monitor the presence and progression of the disease, often before symptoms appear.
What are blood biomarkers?
Blood biomarkers are specific indicators that can be detected through a simple blood test. In Alzheimer’s disease, these biomarkers—such as certain forms of amyloid and tau proteins—can reveal changes in the brain long before cognitive symptoms develop. Blood-based biomarkers are less invasive, more accessible, and more cost-effective than traditional methods like spinal fluid analysis or brain imaging, making early detection and monitoring easier for patients and clinicians
What is pTau217?
pTau217 is a specific form of the tau protein that has been modified by the addition of phosphate groups (phosphorylation). It is closely linked to Alzheimer’s disease pathology and is considered one of the most reliable blood biomarkers for detecting the disease. Elevated levels of pTau217 in the blood strongly correlate with the presence of amyloid plaques and tau tangles in the brain, which are hallmarks of Alzheimer’s disease.
What causes a build-up of pTau217?
A build-up of pTau217 occurs when tau proteins in the brain become abnormally phosphorylated, causing them to form tangles inside nerve cells. These tau tangles disrupt cell function and are a key feature of Alzheimer’s disease. The accumulation of pTau217 reflects underlying disease processes that contribute to memory loss and cognitive decline.
What is the ALZpathDx test?
The ALZpathDx test is available from Neurocode and is a blood-based diagnostic tool designed to measure levels of pTau217. The test helps clinicians identify and monitor Alzheimer’s disease more accurately and at earlier stages than traditional methods. This enables earlier intervention and better tracking of disease progression and response to treatments.
Do ALZpath antibody powered assays require special sample type?
A standard blood draw (EDTA plasma) can be performed in virtually any clinical setting, eliminating the need for specialized facilities or procedures. For more information on collection details contact Neurocode [Source link: www.neurocode.com].
References
- Barthélemy NR, et al. Blood plasma phosphorylated-tau isoforms track CNS Alzheimer’s disease pathophysiology. J Exp Med. 2020;217(11). doi:10.1084/jem.20200861
- Janelidze S, Berron D, Smith R, et al. Associations of Plasma Phospho-Tau217 Levels With Tau Positron Emission Tomography in Early Alzheimer Disease. JAMA Neurol. 2021;78(2):149-156.
doi:10.1001/jamaneurol.2020.4201 - Ashton NJ, Brum WS, Di Molfetta G, et al. Diagnostic Accuracy of a Plasma Phosphorylated Tau 217 Immunoassay for Alzheimer Disease Pathology. JAMA Neurol. 2024;81(3):255-263. doi:10.1001/jamaneurol.2023.5319
- Pandey N, Yang Z, Cieza B, et al. Plasma phospho-tau217 as a predictive biomarker for Alzheimer’s disease in a large South American cohort. Alzheimer’s Research & Therapy. 2025;17:1. doi:10.1186/s13195-024-01655-w
- Zhong X, Wang Q, Yang M, Lin G, Yao K, Wu Z, et al. Plasma p-tau217 and p-tau217/Aβ1-42 are effective biomarkers for identifying CSF- and PET imaging-diagnosed Alzheimer’s disease: Insights for research and clinical practice. Alzheimer’s & Dementia. 2025;21(2):e14536. doi:10.1002/alz.14536
- Palmqvist S, Janelidze S, Quiroz YT, et al. Discriminative Accuracy of Plasma Phospho-tau217 for Alzheimer Disease vs Other Neurodegenerative Disorders. JAMA. 2020;324(8):772-781. doi:10.1001/jama.2020.12134
- Ennis GE, Cambronero FE, Hunt JFV, et al. The performance of plasma p-tau217 in Black middle-aged and older adults. Alzheimer’s & Dementia. 2025;21(9):e70288. DOI: 10.1002/alz.70288
- Wang Q, Zhong X, Yang M, et al. Assessing diagnostic performance of plasma biomarkers…: P-tau217 emerges as the optimal marker in Chinese cohorts. Alzheimer’s & Dementia. 2025;21(7):e70158. DOI: 10.3389/fnagi.2025.1554805
- Angioni D, Delrieu J, Hansson O, et al.; EU/US CTAD Task Force. Blood Biomarkers from Research Use to Clinical Practice: What Must Be Done? J Prev Alzheimers Dis. 2022;9(4):569–579. doi:10.14283/jpad.2022.85.
- Chang H-I, Ma M-C, Huang K-L, et al. Optimizing timing and cost-effective use of plasma biomarkers in Alzheimer’s disease. Alzheimer’s Research & Therapy. 2025;17:194. doi:10.1186/s13195-025-01851-2.
- Mattke S, Chen J, Hanson M, et al. Estimation of the value-based price of a blood test for Alzheimer’s disease pathology in primary and specialty care in the U.S. J Prev Alzheimers Dis. 2025;12(7):100219. doi:10.1016/j.tjpad.2025.100219.
- Sewell KR, Oberlin LE, Karikari TK, et al. Blood biomarkers differentiate AD-related versus non-AD-related cognitive deficits. Alzheimer’s & Dementia. 2025;21(3):e14619. doi:10.1002/alz.14619. PMCID: PMC11923558.
- Arslan B, Brum WS, Pola I, Therriault J, Rahmouni N, Stevenson J, et al. The impact of kidney function on Alzheimer’s disease blood biomarkers: implications for predicting amyloid-β positivity. Alzheimer’s Research & Therapy. 2025;17:48. doi:10.1186/s13195-025-01692-z
More Questions?
Connect With Us
If you want to learn more about ALZpath or our work, we’re here to talk.
