CHEARS

Researchers are close to finding early cancer with a blood test. They may soon do the same with Alzheimer's disease. A new blood test called p-tau217 has shown great promise in diagnosing people with the disease.

Alzheimer’s disease (AD) has been the leading cause of dementia, and many studies have focused on finding effective blood biomarkers for the accurate diagnosis of this disease.

Since its discovery, the disease has been a challenge to test for and predict in patients.

For much of the past century, a definitive Alzheimer’s diagnosis could only be made during an autopsy. Brain imaging and spinal fluid tests however make it possible to spot the disease in patients even before the initial symptoms appear.

But these invasive tests are expensive and generally limited to research settings that are not part of routine care for the millions of people suffering from the most common neurodegenerative disorder.

An era in which an Alzheimer’s diagnosis can begin in a doctor’s office is now arriving.

Research presented at the last Alzheimer’s Association International Conference, a blood test that may show a promising effect in detecting Alzheimer’s before symptoms appear, in an affordable and accessible manner.

The C2N test, called Precivity AD, uses an analytic technique known as mass spectrometry to detect specific types of beta-amyloid, a protein fragment that is a pathological hallmark of disease.

Beta-amyloid proteins accumulate and form plaques visible on brain scans two decades before a patient notices memory problems. As plaques build up in the brain, levels of beta-amyloid decline in the surrounding fluid. Such changes can be measured in spinal fluid samples—and now in blood, where beta-amyloid concentrations are significantly lower. PrecivityAD is the first blood test for Alzheimer’s to be cleared for widespread use and one of a new generation of such assays that could enable early detection of the leading neurodegenerative disease—perhaps decades before the onset of the first symptoms.

PrecivityAD is meant for 60- to 91-year-olds with early signs of cognitive impairment. The prescribing physician ships patient blood samples for analysis at C2N’s lab and receives results within 10 business days.

An accessible, affordable, and minimally invasive biomarker for Alzheimer's disease would revolutionize care of patients worldwide, as well as boost the development of novel drugs for this presently still incurable disease.

“The development of a blood-based test for Alzheimer’s disease is just phenomenal,” says Michelle Mielke, a neuroscientist and epidemiologist at the Mayo Clinic. “The field has been thinking about this for a very long time. It’s really been in the last couple of years that the possibility has come to fruition.”

Together, these studies represent a crucial step towards the widespread use of biomarkers in clinical routine, making effective blood biomarker testing for Alzheimer's disease a reality for most clinical settings, including primary care.