Alzheimer’s diagnosis overhaul adopts cancer-like rating scale

(Reuters) – Alzheimer’s disease experts are revamping the way doctors diagnose patients with progressive brain disorders – the most common type of dementia – by designing a seven-point rating scale based on cognitive changes and biological in the patient.

The proposed guidelines, unveiled by experts in a report released at an Alzheimer’s Association conference in Amsterdam on Sunday, encompass a numerical staging system assessing disease progression similar to that used in cancer diagnostics. They also eliminate the use of terms like mild, moderate and severe.

The overhaul – replacing guidelines published in 2018 – was prompted by the increased availability of tests that detect key proteins linked to Alzheimer’s disease such as beta-amyloid in the blood and new treatments that require confirmation of pathology disease before use.

The new system is designed to be more accurate and better reflect a person’s underlying disease, according to Dr. Clifford Jack of the Mayo Clinic in Rochester, Minnesota, lead author of the report sponsored by the Alzheimer’s Association and the National Institute. of Aging, part of the US government’s National Institutes of Health.

The change comes as doctors prepare to identify and treat patients with Eisai and Biogen’s Leqembi drug, which won Food and Drug Administration approval this month, and experimental drug donanemab. from Eli Lilly, which is currently under review by the FDA.

“We are really entering an era of much more personalized medicine, where we are beginning to understand that there are certain biomarkers that are elevated to certain degrees in people at different stages,” said Dr. Maria Carrillo, scientific director of the Alzheimer’s Association. .

Under the new diagnostic approach, patients would be given a score of 1 to 7 based on the presence of abnormal disease biomarkers and the extent of cognitive changes. The system also includes four biological stages classified a, b, c and d. For example, stage 1a corresponds to a person who is completely asymptomatic but has abnormal biomarkers.

“Stage 1a is really the beginning of proof that someone has the disease,” Jack said.

In stage 2, an individual may have abnormal biomarkers and very subtle changes in cognition or behavior. Stage 3 is roughly equivalent to the current presymptomatic stage known as mild cognitive impairment, while stages 4, 5, and 6 are equivalent to mild, moderate, and severe dementia.

The new scale also includes a stage 0 for people who carry genes that guarantee they will develop Alzheimer’s disease. This category includes people with Down syndrome, 75% of whom develop Alzheimer’s disease in adulthood.

Noting the new system’s similarity to cancer stages, Jack said: “Mild breast cancer doesn’t exist. They’re digital stages.” Jack also noted that many other conditions can cause dementia, but not all dementia is Alzheimer’s disease.

The proposed guidelines are intended for use by physicians in clinical practice, as many are faced for the first time with the prospect of offering patients treatments that can slow the progression of the disease, rather than simply treating symptoms.

The draft guidelines are open for expert review and comment and will be revised later to reflect this input, according to a spokesperson for the Alzheimer’s Association.

Alzheimer’s disease, which progressively destroys memory and thinking skills, is characterized by changes in the brain, including beta-amyloid plaques and neurofibrillary tangles, or tau, which lead to the loss of neurons and their connections. .

The 2018 guidelines, which were intended for research, incorporated existing technologies to detect Alzheimer’s proteins based on brain PET scans and cerebrospinal fluid tests, which were only accessible through a lumbar puncture. . These tests were expensive and not generally used in standard medical practice.

(Reporting by Julie Steenhuysen in Chicago; Editing by Will Dunham)

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