Alzheimer’s disease (AD) is a diffcult condition on sufferrers, their carers and family. It has devastating effects on one’s ability to navigate life. It also places a serious burden on the majority of full time carers. Alzheimer’s has long been a challenge to diagnose accurately and affordably. Traditional methods are relying heavily on invasive lumbar punctures or expensive positron emission tomography (PET) scans.
In recent years, however, innovative diagnostic tests such as blood-based biomarkers have emerged. They are offering the potential to revolutionize the way we detect Alzheimer’s disease. The PrecivityAD2 blood test stands out for its clinical accuracy and patient accessibility.
The PrecivityAD2 test represents a significant leap in Alzheimer’s diagnostics. It is designed to measure biomarkers in the blood and it achieves a diagnostic accuracy of about 90% compared with PET scans, often considered the gold standard for identifying amyloid plaques in the brain. This is a notable improvement on traditional clinical assessments by general practitioners. They have historically achieved only around 61% accuracy in identifying Alzheimer’s.
The test uses a combination of two biomarkers to detect Alzheimer’s-related pathology:
- Tau Protein (%p-tau217). This biomarker measures the ratio of phosphorylated tau protein to its non-phosphorylated counterpart, reflecting tau pathology, which is a hallmark of Alzheimer’s disease.
- Amyloid-Beta (Aβ) Plaques (Aβ42/40 Ratio). This assesses the ratio of amyloid-beta 42 to amyloid-beta 40 peptides, a critical indicator of amyloid plaque build-up in the brain.
The test output, known as the Amyloid Probability Score 2 (APS2) demonstrated an impressive Area Under the Curve – Receiver Operating Characteristic (AUC-ROC) of 0.94 in studies, underlining its ability to differentiate patients with brain amyloid pathology from those without.
The PrecivityAD2 test offers a range of benefits that could address long-standing issues in Alzheimer’s diagnosis.
Unlike cerebrospinal fluid (CSF) testing, which requires a lumbar puncture, or PET imaging, which involves radiation exposure, the PrecivityAD2 test only requires a simple blood draw. This makes it far less invasive for patients and much more feasible to implement in primary care settings. As a result, it greatly increases accessibility for patients in areas lacking access to specialists or advanced imaging technology could receive an earlier and more accurate diagnosis.
A quicker diagnosis can enable patients to access new treatments, such as disease-modifying therapies like lecanemab. They require confirmation of amyloid pathology before administration. Early diagnosis also opens the door for timely lifestyle interventions and support for patients and their families.
At an estimated price of $1,495 (approximately £1,200), the test may initially seem very expensive. However, when compared with the costs of PET scans or the long-term financial and health impacts of misdiagnosis or delayed treatment, it might not be such a costly option. By improving diagnostic accuracy and reducing delays, the test could ultimately lower the burden on healthcare systems.
The PrecivityAD2 test holds great promise for Alzheimer’s research. Particularly in clinical trials. By streamlining the identification of eligible participants with amyloid pathology, the test could accelerate the development of new treatments. Its non-invasive, which makes it more appealing to everyone.
Despite its promise, there are still some challenges to overcome.
- Regulatory Approval. While the test is available in the U.S., it has yet to receive FDA approval.
- Insurance Coverage. The lack of insurance reimbursement is a cost barrier for many patients.
- Diverse Validation. Further validation is needed to ensure its effectiveness across different demographic groups. Genetic and environmental factors may influence test performance.
The Future of Alzheimer’s Diagnostics
The PrecivityAD2 test is not the only blood-based Alzheimer’s diagnostic tool being developed. Similar advancements, such as Quanterix’s Simoa technology and C2N Diagnostics’ PrecivityAD test, show that blood biomarkers are getting very popular. Dr Susan DeSanti, a leading researcher in Alzheimer’s diagnostics, highlighted this.
The shift to blood-based biomarkers for Alzheimer’s is one of the most exciting changes in neurodegenerative disease care. It holds the potential to make early detection accessible to millions. – Dr Susan DeSanti
Companies like C2N Diagnostics, Quanterix, and other biotech firms are spearheading the commercialisation of such tests. Investment in this field continues to grow fast. As regulatory approval progresses and validation studies expand, access to these tests is expected to improve.
This is a turning point in the diagnosis of Alzheimer’s disease. More accessible, more affordable and very accurate. With its non-invasive nature and capacity for early detection, this new test creates a new path for better patient outcomes. Companies continue to innovate and governments prioritise funding for new diagnostic technologies, with so far limited results.
However the future of Alzheimer’s care is one of hope and progress. Simply because we cannot do any worse.