Plea for Unity
In an accompanying editorial, Ronald C. Petersen, PhD, MD, director, Mayo Clinic Alzheimer’s Disease Research Center and Mayo Clinic Study of Aging, Rochester, Minnesota, and colleagues outline the difference between the IWG and Alzheimer’s Association positions.
As the IWG uses Alzheimer’s disease to define those with cognitive impairment and the Alzheimer’s Association group uses Alzheimer’s disease to define those with the pathology of the disease, the field is now at a crossroads. “Do we name the disease before clinical symptoms?” they asked.
They note that Alzheimer’s Association criteria distinguish between a disease and an illness, whereas the IWG does not. “As such, although the primary disagreement between the groups is semantic, the ramifications of the labeling can be significant.”
It is “incumbent” that the field “come together” on an Alzheimer’s disease definition, the editorial concluded. “Neither the Alzheimer’s Association or IWG documents are appropriate to serve as a guide for how to apply biomarkers in a clinical setting. Appropriate-use criteria are needed to form a bridge between biological frameworks and real-world clinical practice so we can all maximally help all of our patients with this disorder.”
In a comment, Reisa Sperling, MD, professor of neurology, Harvard Medical School, and director, Center for Alzheimer Research and Treatment, Brigham and Women’s Hospital and Massachusetts General Hospital, all in Boston, who is part of the Alzheimer’s Association work group that published the revised criteria for diagnosis and staging of Alzheimer’s disease, likened Alzheimer’s disease, which begins in the brain many years before dementia onset, to cardiovascular disease in that it involves multiple processes. She noted the World Health Organization classifies cardiovascular disease as a “disease” prior to clinical manifestations such as stroke and myocardial infarction.
“If someone has Alzheimer’s disease pathology in their brain, they are at risk for dementia or clinical manifestations of the disease — just like vascular disease quantifies the risk of stroke or heart attack, not risk of developing ‘vascular disease’ if the underlying vascular disease is already present,” said Sperling.
A large part of the controversy is related to terminology and the “stigma” of the “A” word in the same way there used to be fear around using the “C” word — cancer, said Sperling.
“Once people began talking about cancer publicly as a potentially treatable disease and began getting screened and diagnosed before symptoms of cancer were manifest, this has had a tremendous impact on public health.”
She clarified that her work group does not recommend screening asymptomatic people with Alzheimer’s disease biomarkers. “We actually need to prove that treating at the preclinical stage of the disease is able to prevent clinical impairment and dementia,” she said, adding “hopefully, we are getting closer to this.”
Dubois reported no relevant disclosures. Petersen reported receiving personal fees from Roche, Genentech, Eli Lilly and Company, Eisai, and Novo Nordisk outside the submitted work and royalties from Oxford University Press, UpToDate, and Medscape educational activities.
A version of this article appeared on Medscape.com.