Revolutionary blood tests are allowing doctors to identify Alzheimer’s disease years before symptoms appear, offering hope for millions of aging Americans concerned about cognitive decline.
At a Glance
- Multiple new blood tests can detect Alzheimer’s biomarkers with up to 92% accuracy, potentially years before symptoms develop
- Researchers at UCLA identified placental growth factor (PlGF) as a blood biomarker that signals early brain changes linked to cognitive impairment
- Mount Sinai Health System is pioneering the clinical use of blood-based biomarkers for early Alzheimer’s detection in the Northeast U.S.
- These tests offer a cost-effective, less invasive alternative to traditional diagnostic methods like PET scans and spinal taps
- UK researchers aim to make blood tests for dementia available through their National Health Service within five years
The Dawn of Early Detection
Medical science has long struggled with Alzheimer’s disease diagnosis, typically confirming it only after significant damage has occurred. Now, researchers have developed blood tests that can detect the disease’s earliest biological markers, potentially years before memory problems begin. These tests measure specific proteins associated with Alzheimer’s, such as beta-amyloid and phosphorylated tau (p-tau217), which leak into the bloodstream when brain cells are damaged or die.
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Several companies now offer these groundbreaking tests, including Quest Diagnostics, ALZPath, Roche Diagnostics, LabCorp, and C2N Diagnostics. The PrecivityAD2 test from C2N Diagnostics has shown particularly impressive results, predicting Alzheimer’s in 88% to 92% of study participants. These tests represent a dramatic shift from traditional diagnostic methods that relied on expensive PET scans or invasive spinal taps, making early detection more accessible to the general population.
Promising New Biomarkers
UCLA researchers recently identified placental growth factor (PlGF) as a blood biomarker that could transform early detection. This protein appears to signal vascular brain injury before cognitive symptoms emerge. The discovery provides an opportunity for early intervention that was previously impossible with conventional diagnostic approaches.
Another promising approach comes from the University of Washington, where Dr. Valerie Daggett’s team developed the SOBA test to detect toxic amyloid-beta oligomers in blood. This test received FDA Breakthrough Device designation in 2022, accelerating its path to clinical use. Meanwhile, researchers at Gothenburg University created the p-tau217 immunoassay, considered a significant breakthrough in identifying Alzheimer’s before symptoms appear.
Clinical Implementation Beginning
Mount Sinai Health System recently became the first healthcare provider in the Northeast to implement blood-based biomarkers for Alzheimer’s detection in clinical settings. This pioneering program aims to rapidly identify at-risk patients and connect them with appropriate care options, including newly approved treatments.
In the United Kingdom, two major research initiatives are underway to bring Alzheimer’s blood tests to the National Health Service within five years. The READ-OUT study will evaluate multiple blood tests for various types of dementia, while the ADAPT study focuses specifically on p-tau217 testing. These programs recognize that timely, accurate diagnosis is crucial for accessing appropriate care and emerging treatments like lecanemab and donanemab.
Technological Breakthroughs
The revolution in blood-based testing has been made possible by significant advances in detection technology. The Simoa platform, developed by Quanterix, has transformed immunoassays by isolating single molecules, dramatically increasing sensitivity to detect even tiny amounts of brain proteins in blood samples.
Another important biomarker, neurofilament light chain (NfL), serves as a versatile indicator of neuronal damage across multiple conditions. Unlike some markers specific to Alzheimer’s, NfL can signal various types of brain injury, making it valuable for broader neurological screening. Researchers have found that blood NfL levels correlate strongly with measurements from cerebrospinal fluid, validating its use as a less invasive alternative.
The Path Forward
While these blood tests represent remarkable progress, medical experts caution that patients should consult healthcare providers before seeking testing. Understanding the results requires professional interpretation and planning for follow-up care. The tests currently serve primarily as screening tools, with positive results typically requiring confirmation through additional testing.
As these technologies continue to develop and reach more clinical settings, they promise to transform the Alzheimer’s treatment landscape. Early detection creates opportunities for lifestyle interventions, participation in clinical trials, and timely use of emerging therapies. For the millions of adults concerned about cognitive health, these blood tests offer something previously unavailable: the chance to know and prepare for what may lie ahead.
