The earlier Alzheimer’s disease can be diagnosed, the better the outcomes; however, it can be hard to diagnose the disease in its earliest stages.
Researchers estimate that about 32 million peopleTrusted Source globally live with a type of dementia called Alzheimer’s disease, with the number of dementia cases expected to triple by 2050Trusted Source.
Like all diseases, the sooner Alzheimer’s disease is diagnosed, the better the outcome. This is partially because medications available for the condition aim to treat symptoms and potentially slow the progression of the disease.
An Alzheimer’s diagnosisTrusted Source is currently made through an evaluation that includes a person’s medical history, cognitive assessment, PET or MRI brain imaging, and laboratory tests to check for the presence of the proteins amyloid-beta and tauTrusted Source in a sample of cerebrospinal fluid (CSF).
Despite all these tools, it can be hard to diagnose Alzheimer’s disease, especially at its earliest stageTrusted Source.
In an effort to help improve the early diagnosis of Alzheimer’s disease, the U.S. FDA has recently clearedTrusted Source the Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio made by Fujirebio Diagnostics, Inc., as the first blood test to help diagnose the condition.
How does the blood test for Alzheimer’s work?
According to the FDA’s press releaseTrusted Source, the Lumipulse blood test works by measuring the amount of pTau 217 and beta-amyloid 1-42Trusted Source in the plasma of the blood. The concentration ratio of the two proteins is used to determine the presence or absence of amyloid plaques in the brain, which is considered a hallmark of Alzheimer’s disease.
“Imagine your brain is like an organized library, with information neatly stored on shelves (neurons),” Manisha Parulekar, MD, FACP, AGSF, CMD, director of the Division of Geriatrics at Hackensack University Medical Center and co-director of the Center for Memory Loss and Brain Health at Hackensack University Medical Center in New Jersey explained to Medical News Today. “In Alzheimer’s disease, two troublesome proteins, beta-amyloid and tau, disrupt this organization, making it hard to access the information.”
“Think of beta-amyloid as sticky notes that clump together between the bookshelves (outside the neurons),” Parulekar continued.
“These clumps, called plaques, interfere with communication between the neurons, like blocking pathways in the library. Tau is normally like a librarian, helping to keep the bookshelves (internal neuron structure) stable and organized. In Alzheimer’s, tau becomes twisted and tangled. These tangles disrupt the transport of nutrients and other essential materials within the neurons, eventually leading to their death,” she said.
“In simple terms, this blood test helps identify the ‘culprits’ responsible for Alzheimer’s damage, allowing for earlier diagnosis, better disease management, and faster development of effective treatments.”
— Manisha Parulekar, MD, FACP, AGSF, CMD
CSF vs. blood tests for Alzheimer’s
Up until now, the main laboratory test to check levels of amyloid-beta and tau proteins was by examining a sample of a person’s cerebrospinal fluid (CSF). The sample is taken through a lumbar punctureTrusted Source — also known as a spinal tap — where a needle is inserted into a person’s lower spine.
Gediminas Gliebus, MD, director of cognitive and behavioral neurology at Marcus Neuroscience Institute, a part of Baptist Health South Florida, told MNT having a test requiring a blood sample instead of a CSF sample significantly simplifies the testing process, eliminating the need for invasive and costly procedures like lumbar punctures, which can deter some patients from seeking evaluation.
“By relying on a simple blood sample, this test makes it more accessible to a broader population, facilitating earlier diagnosis and enabling timely interventions that could help manage the progression of the disease. This new test has the potential to change how we diagnose Alzheimer’s disease by streamlining the process and reducing the need for more invasive procedures.”
— Gediminas Gliebus, MD
“Based on the scientific data provided by the company, only 20% of patients would require additional invasive and costly tests, such as lumbar punctures or PET scans, to confirm the diagnosis. This is a significant improvement, as it allows the majority of patients to receive a preliminary evaluation with minimal discomfort and expense, fostering early detection and intervention,” Gliebus explained.
