- About 32 million people around the world are currently living with Alzheimer’s disease.
- Better outcomes are linked to early Alzheimer’s disease diagnosis.
- A workgroup from the Alzheimer’s Association has published revised criteria for the diagnosis and staging of the condition based on the biology of the disease and the latest research.
About 32 million people globally are currently living with a type of dementia called Alzheimer’s disease. That number is expected to triple by 2050.
As with any illness, an early diagnosis can potentially lead to a better outcome. This is especially true of Alzheimer’s disease — although there is currently no cure for the condition, there are medications that can help slow disease progression.
Additionally, previous research shows that current Food and Drug Administration (FDA)-approved medications for Alzheimer’s disease work best in people diagnosed in the early to middle stages of the condition.
In an effort to improve the early diagnosis of Alzheimer’s disease, a workgroup from the Alzheimer’s Association has published revised criteria for the diagnosis and staging of the condition that are based on the biology of the disease and the latest research.
One of the main focuses of the revised Alzheimer’s disease diagnosing criteria is the use of blood-based biomarkers.
There has been a lot of current research focused on identifying biomarkers for Alzheimer’s disease.
For example, a study published in May 2024 identified a new biomarker within the asymptomatic, or symptom-free, stages of Alzheimer’s disease, while research published in February 2024 focused on biomarkers in cerebrospinal fluid (CSF) and blood plasma believed to assist with early diagnosis of Alzheimer’s disease.
For the revised criteria, researchers grouped Alzheimer’s biomarkers into three categories:
- core biomarkers of Alzheimer’s disease neuropathologic change (ADNPC)
- nonspecific biomarkers that are important in Alzheimer’s but are also involved in other brain diseases
- biomarkers of diseases/conditions that commonly co-exist with Alzheimer’s.
“These updates to the diagnostic criteria are needed now because we know more about the underlying biology of Alzheimer’s and we are able to measure those changes,” said Clifford Jack, Jr., MD, professor of radiology at the Mayo Clinic in Rochester, Minn., and the lead author of this study in a press release.
He added that:
“Treatments that target one of these processes — buildup of amyloid-beta — have been approved by regulators, and biomarker proof that the underlying biology is present must be confirmed to be eligible for treatment. Plus, the accuracy of some of the emerging Alzheimer’s blood tests needs to be considered, and researchers and clinicians made aware and properly educated on their use.”
“The revised criteria, guided by the biology of Alzheimer’s disease and reflecting recent advances in biomarker detection, promise to significantly enhance diagnostic accuracy and patient care,” Verna Porter, MD, a board-certified neurologist and director of the Dementia, Alzheimer’s Disease, and Neurocognitive Disorders at Pacific Neuroscience Institute in Santa Monica, CA — who was not involved in the criteria revisions — told Medical News Today.
In her view, “[t]he inclusion of blood-based biomarkers is particularly exciting, offering a less invasive and more accessible diagnostic tool.”
In conjunction with the use of biomarkers, the revised criteria for the diagnosis and staging of Alzheimer’s disease also focus on defining the condition biologically rather than focusing just on symptoms.
“Defining diseases biologically, rather than based on syndromic presentation, has long been standard in many areas of medicine — including cancer, heart disease, and diabetes — and is becoming a unifying concept common to all neurodegenerative diseases,” Jack said in the press release. “An unchanging principle is that effective treatment will always rely on the ability to diagnose and stage the biology driving the disease process.”
“This new set of diagnostic guidelines is needed to educate all providers about the availability of biomarker tests to inform [the] diagnosis and general staging of Alzheimer’s disease,” Karen D. Sullivan, PhD, ABPP, a board-certified neuropsychologist, owner of I CARE FOR YOUR BRAIN, and Reid Healthcare Transformation Fellow at FirstHealth of the Carolinas in Pinehurst, NC — who was not involved in the criteria revision — told MNT.
“Specialists have known of these for some time now but with the massive rise in people impacted by Alzheimer’s disease in the next decade, we need all medical providers to know what these tests are, what they measure, how to order them, and, most importantly, how to interpret them,” she emphasized.
“What is still unclear is the one-to-one relationship between biological Alzheimer’s disease and clinical Alzheimer’s disease,” Sullivan continued. “That is, roughly 25% of people with the hallmark of Alzheimer’s disease, amyloid-beta, at the brain level do not have an amnestic memory disorder. As the authors acknowledge, even with this advancement, a biologically based diagnosis should assist and not eliminate the need for a clinical evaluation.”
– Karen D. Sullivan, PhD, ABPP
As this revised criteria is for medical professionals, what can individuals learn from these changes?
Porter noted that individuals “should understand that the revised criteria represent a significant shift towards a biological understanding of Alzheimer’s disease, emphasizing early detection through biomarkers even before clinical symptoms appear.”
“These criteria are designed to improve diagnostic accuracy, guide treatment, and bridge the gap between research and clinical practice, ultimately aiming to enhance patient outcomes,” she explained.
According to Sullivan, “[t]his was a needed contribution to the clinical management of Alzheimer’s disease, as well as research including clinical trials.”
“But, with brain diseases, we very much also need a clinical evaluation meaning folks still need to be assessed by an expert like a neuropsychologist or behavioral neurologist who can use a person-centered interview and testing approach to understand the clinical expression of biological changes,” she advised.
Following the publishing of the revised criteria, Porter said the next steps should include the development and dissemination of formal clinical practice guidelines based on these criteria.
“Additionally, further research to validate and refine blood-based biomarkers, and expanding educational efforts to ensure clinicians are well-informed about using these new diagnostic tools, will be crucial,” she continued. “Lastly, clinical trials targeting individuals in the earliest stages of the disease could help assess the effectiveness of new treatments based on these criteria.”
Sullivan said she looks forward to this group’s next paper, which will be on how clinicians can integrate biomarker studies to contribute to clinical management throughout the disease process.
“Science will get us very far, but we can never forget we are talking about unique human beings and the care of a brain health challenge requires us to always put scientific findings back into the human context of the person in front of us,” she added.
