Alzheimer's Association Workgroup Publishes Biology-Based Criteria for Diagnosis and Staging of Alzheimer's Disease

Original from: Alzheimer's Association

A workgroup convened by the Alzheimer’s Association has published revised criteria for the diagnosis and staging of Alzheimer’s disease that are based on the biology of the disease and reflect recent advancements in Alzheimer’s research, diagnostics and treatment. The 2024 update includes an updated biomarker classification system that includes blood-based biomarkers (BBM) and a revised disease staging system.

“Revised Criteria for Diagnosis and Staging of Alzheimer’s Disease: Alzheimer’s Association Workgroup” was published online by Alzheimer’s & Dementia®: The Journal of the Alzheimer’s Association. DOI: 10.1002/alz.13859.

“These updated criteria for diagnosis and staging of Alzheimer’s are driven by the latest developments and discoveries in Alzheimer’s science,” said Maria C. Carrillo, Ph.D., Alzheimer’s Association chief science officer and medical affairs lead, and senior author on the newly published paper. “Our goal in sharing them now — even as the field and our knowledge continues to evolve — is to advance diagnosis, treatment and prevention in order to improve individual care and reduce the societal impact of Alzheimer’s.”

“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,” said Clifford Jack, Jr., M.D., Mayo Clinic, Rochester, Minn., and the lead author on the paper. “An unchanging principle is that effective treatment will always rely on the ability to diagnose and stage the biology driving the disease process.”

“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. 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,” Jack added. “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 define Alzheimer’s disease as a biological process that begins with the appearance of Alzheimer’s-related changes that happen in the brain before people exhibit memory and thinking problems. The authors state that progression, growth and expansion of these changes lead to the later appearance and progression of clinical symptoms, such as memory loss, disorientation, trouble with planning or organizing, and mental confusion.

According to the authors, symptoms and clinical syndromes commonly seen in people living with Alzheimer’s may also be caused by other disorders, so clinical presentation alone is not diagnostic of Alzheimer’s.

The Revised Criteria are not intended to provide step-by-step clinical practice guidelines for clinicians or specific treatment protocols. Rather, they contain general principles to inform diagnosis and staging of Alzheimer’s that reflect current science.

“Our intent is to present objective criteria for diagnosis and staging of Alzheimer’s, incorporating recent advances in biomarkers, to serve as a bridge between research and clinical care,” Jack said. “Formal clinical practice guidelines will appear in a subsequent publication.”

The newly published article acknowledges the vital role of clinicians — and clinical judgment — in Alzheimer’s diagnosis: “The biologically based diagnosis of Alzheimer’s disease is meant to assist rather than supplant the clinical evaluation of individuals with cognitive impairment. … Clinical judgment must always be used in the practice of medicine, and the application of diagnostic tests for [Alzheimer’s] is no exception.”

The Alzheimer’s Association has initiated a collaboration with clinical and subject-matter experts, a variety of interested organizations, and patient representatives to develop guidelines for the clinical implementation of Alzheimer’s diagnosis and staging criteria.

According to the workgroup, “[T]he clinical use of [Alzheimer’s] biomarkers is presently intended for the evaluation of symptomatic individuals, not cognitively unimpaired individuals. … At the present time disease-targeted therapies have not been approved for cognitively unimpaired individuals with [Alzheimer’s]. For this reason, we currently recommend against diagnostic testing in cognitively unimpaired individuals outside the context of … research studies.”​

Source: Alzheimer's Association Workgroup Publishes Biology-Based Criteria for Diagnosis and Staging of Alzheimer's Disease