International Working Group Discusses Diagnosing Alzheimer’s Disease

The International Working Group discussed diagnosing Alzheimer’s disease among cognitively unimpaired individuals in a presentation at the Clinical Trials on Alzheimer’s Disease annual meeting in Madrid and a paper published in JAMA Neurology.

In this MedPage Today video, Nicolas Villain, MD, PhD, of Sorbonne University and Pitié-Salpêtrière Hospital in Paris, explains the group’s position.

Following is a transcript of his remarks:

In 2021, we held our last update where we considered that asymptomatic individuals who had a positive biomarker for the Alzheimer pathology were only at risk. And since then, we have gathered new evidence, especially from a longitudinal cohort in cognitively unimpaired individuals who underwent both amyloid and tau PETs.

And this data have shown us that we have two subgroups with very different lifetime risk of developing symptoms, which are, on the one hand, the amyloid-positive and tau-negative cognitively unimpaired individuals who have a significantly increased but low risk to develop symptoms. They have approximately 15-20% risk of developing symptoms in the following 6 years. And we have, on the other hand, individuals who are amyloid-positive and tau-positive. And these individuals have a very high risk of developing symptoms in the upcoming years, within 80-85%.

So we have new evidence for risk in these individuals, and the International Working Group has always defined Alzheimer’s disease as a clinical biological disease concept, meaning that either you need symptoms and biomarkers to have Alzheimer’s disease or a very high risk of developing Alzheimer’s symptoms together with specific biomarkers of Alzheimer’s disease to be called presymptomatic Alzheimer’s disease.

And now we propose expanding this group to individuals who are amyloid-positive and tau-positive cognitively unimpaired. In clinical practice, it’s very simple. Only individuals who have symptoms should be labeled Alzheimer’s disease. So that’s completely aligned with clinical biological disease concept. And for those who are asymptomatic at the moment, there is no need for screening because there is no specific treatment or monitoring that is necessary for these individuals.

But things will likely change in the upcoming years. So there will be two clinical paths for individuals. Those who have memory complaint, but no cognitive impairment, they will go to brain health services. They will have a tailored risk assessment, tailored risk communication, and tailored management. And on the other hand, you will have a classical memory clinic population, those with memory complaints, who have memory impairment, and who will be labeled as having Alzheimer’s disease.

So this framework, the International Working Group framework, is totally aligned with the current clinical practice and with the future evolution of clinical practice that will involve the brain health services.