International experts propose revised definition of Alzheimer's disease

Today, Professor Howard Feldman, on behalf of the International Working Group (IWG), presented revised diagnostic criteria for Alzheimer's disease at the Clinical Trials in Alzheimer's Disease (CTAD) conference in Madrid.

The IWG, led by Professor Bruno Dubois and Dr. Nicolas Villain (Pitié-Salpêtrière-Sorbonne University Hospital, Paris, France), Professor Howard Feldman (University of California, San Diego, USA), and Professor Giovanni Frisoni (Geneva University Hospital); The research team, made up of 46 international experts from 17 countries, including representatives from Alzheimer's Disease Europe (Geneva, Switzerland), reviewed the available evidence on the role and impact of biomarkers in the diagnosis and definition of Alzheimer's disease. Reviewed.

The IWG proposed a number of important recommendations, which were released today in parallel with this presentation. Journal of the American Medical Association – Neurology (JAMA Neurology):

• Alzheimer's disease should be defined as a clinicobiological entity in which the diagnosis is made considering both clinical disease and support for positive amyloid and tau biomarkers.
• This definition supports diagnosing Alzheimer's disease at an early prodromal stage, after the appearance of mild but distinct clinical features.
• For people with normal cognitive function who are only positive for amyloid-related biomarkers, the IWG proposes the term “at risk for subclinical Alzheimer's disease.” This is because these people have a higher lifetime risk of developing symptomatic Alzheimer's disease.
• The IWG is also proposing a category of “pre-symptomatic Alzheimer's disease” for people with autosomal dominant genetic mutations, Down syndrome, and other unique conditions. biomarker A profile with a very high lifetime risk of developing clinical disease (e.g. amyloid positivity combined with tau accumulation in neocortical areas).

In presenting these recommendations, Professor Feldman emphasized: “The IWG recommendations published today advocate that the diagnosis of Alzheimer's disease be a clinically established diagnosis with the support of biomarkers that reflect the pathology of the disease. We believe that biomarkers themselves are important, reflecting differences in the level of risk of developing the disease in people without clinical symptoms. ”

In its recommendations, the IWG also takes a position on the Alzheimer's Disease Association Workgroup's recently published Revised Criteria for Diagnosis and Staging of Alzheimer's Disease. The IWG believes that a purely biological definition of Alzheimer's disease, which uses one core biomarker to extend the diagnosis of Alzheimer's disease to cognitively normal individuals, can lead to false positives and prevent symptoms from developing. It highlights that it can cause people to live with the Alzheimer's disease label without (patients – waiting) having significant social consequences. Dr. Nicolas Villain said: “As our understanding of Alzheimer's disease continues to improve, advances in biomarkers are enabling early diagnosis, even before symptoms appear. However, our primary focus will be on It is important to emphasize that there should be a potential future risk of associated cognitive decline. using these biomarkers rather than just the biological changes themselves. ”

These recommendations are the result of a collaboration of 46 international experts who emphasize that the diagnosis of Alzheimer's disease should rely primarily on clinical assessment supported by biomarkers. Importantly, we distinguish between two groups. People who show typical Alzheimer's disease symptoms and have positive biomarkers are diagnosed with Alzheimer's disease, whereas people who have positive biomarkers but do not have typical Alzheimer's symptoms are considered at risk. This distinction is critical because it paves the way for more targeted research, risk assessment, and the development of personalized treatments for people at risk. ”

Professor Bruno Dubois

The IWG also emphasized the importance of continued research into asymptomatic people at risk for Alzheimer's disease to better understand and measure individual risk. Professor Frisoni said: “Further development of brain health services for dementia prevention could lead to improved risk assessment, risk communication and risk mitigation strategies targeting modifiable risk factors.” I commented.

Jean-Georges, Director General of Alzheimer's Europe and one of the co-authors, welcomed the recommendation and said: “The IWG's recommendations are an important step forward for Alzheimer's Europe on routine biomarker testing for diagnostic purposes in individuals without cognitive symptoms. Consistent with the current position of “If you test positive for amyloid because you have preclinical Alzheimer's disease, it can have a significant negative psychological impact,'' so instead, disclose your personal risk. We recommend that appropriate support, counseling and tailored risk mitigation plans are provided to assist in processing and managing this information.”