Defining Alzheimer’s Disease (Again!)
The Face-off!
An Open Letter to the World’s Premier Alzheimer’s Researchers
An Explanation
In June 2024 the National Institute on Aging and the Alzheimer’s Association. [20 authors from 5 countries]1 dramatically re-defined Alzheimer’s disease (AD), as “a purely biological process”, to be diagnosed solely by AD biomarkers (brain imaging or biofluid tests revealing the presence of amyloid and/or tau proteins). Previously the diagnosis was largely a clinicaI one. The presence of Alzheimer’s disease was inferred from characteristic signs and symptoms, corroborating neurocognitive test results, and conformity with the disease’s classically described clinical course.(See https://ouragingbrains.com/defining-alzheimers-disease/ )
UNTIL 5 Months Later, when:
A second gathering of presumably equally eminent researchers (The “International Working Group” – IWG: 67 experts from 17 countries) published their review of the literature. They challenged the five-month-old definition of AD by the National Institute on Aging and the Alzheimer’s Association out of their concern for the “emerging movement to define Alzheimer’s disease as a purely biological entity based on biomarker findings”. The IWG concluded: “The approach of diagnosing AD without a clinical and biological construct would be unwarranted and potentially concerning without a clear knowledge of when or whether symptoms will ever develop.”2
The “Last Word”?
(at least for 2024)
was in an editorial published in the same JAMA Neurology issue as the second (IWG) piece. In spite of being seriously outnumbered by both opposing groups, Dr. Ronald. C. Petersen of the Mayo Clinic and his 2 co-authors concluded: “It is incumbent for the field to come together on the definition of AD. Neither the AA or IWG documents are appropriate to serve as a guide for how to apply biomarkers in a clinical setting.”
So,
Now What?
We’re back to the question that I asked in my September 4, 2024 blog post: (https://ouragingbrains.com/im-worried-about-alzheimers-should-i-undergo-biomarker-testing/)
“I’m Worried About Alzheimer’s. Should I Undergo Biomarker Testing?”
If 67 of the world’s experts can’t come together on a definition of Alzheimer’s disease or how it should be employed in practice, who exactly should you and I rely on? If these three groups can’t agree on how to define a disease that was first named in 1910, querying our neurologists or primary providers will be no different than flipping a coin.
Some of us, with varying degrees of of education, training, experience, or chutzpah (and no need to win friends or solicit grants), will try and sort the literature out for ourselves and our readers. That is what I tried to do with the whole Aging Or Alzheimer’s? question. (https://agingoralzheimers.com)
Topics from my September 4 post include:
1.Before signing on for one of these exams, ask yourself this question: “How would a positive result change my life?”
2. Now that we know we can know – should we know?
3. Practical Considerations for Biomarker Testing in Individuals Without Symptoms include:
Insurance: There is nothing to prevent those writing long-term care policies and life insurance from refusing to enroll someone positive for an AD biomarker.
Health equity
Quality of life
4. My Cautionery Bottom Line:
There is still no disease-modifying treatment for AD.
There is always “breaking news” surrounding this widespread and terrible disease. Remember the excitement around Aducanumab, the first anti-amyloid treatment: both approved, and then withdrawn in just 2 1/2 years.
As always: Focus on the GOOD NEWS!
Largely as a function of the long symptom-free periods after biomarkers become positive,
Nearly 75% Of Those Identified by Biomarkers Alone as Having Preclinical Disease Will Never Develop Clinical Alzheimer’s Disease In Their Lifetime.
References:
- Jack CR Jr, et al. Revised criteria for diagnosis and staging of Alzheimer’s disease: Alzheimer’s Association Workgroup. Alzheimers Dement. 2024 Jun 27. doi: 10.1002/alz.13859. Epub ahead of print. PMID: 38934362. https://alz-journals.onlinelibrary.wiley.com/doi/10.1002/alz.13859)
Dubois B, Villain N, Schneider L, Fox N, Campbell N, Galasko D, Kivipelto M, Jessen F, Hanseeuw B, Boada M, Barkhof F, Nordberg A, Froelich L, Waldemar G, Frederiksen KS, Padovani A, Planche V, Rowe C, Bejanin A, Ibanez A, Cappa S, Caramelli P, Nitrini R, Allegri R, Slachevsky A, de Souza LC, Bozoki A, Widera E, Blennow K, Ritchie C, Agronin M, Lopera F, Delano-Wood L, Bombois S, Levy R, Thambisetty M, Georges J, Jones DT, Lavretsky H, Schott J, Gatchel J, Swantek S, Newhouse P, Feldman HH, Frisoni GB. Alzheimer Disease as a Clinical-Biological Construct-An International Working Group Recommendation. JAMA Neurol. 2024 Nov 1. doi: 10.1001/jamaneurol.2024.3770. Epub ahead of print. PMID: 39483064.
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Originally Published on https://agingoralzheimers.com/
