July 17, 2021 – International experts propose diagnosing Alzheimer's disease using biomarkers – characteristics of an individual's health obtained by taking blood, fluid and tissue samples – slightly than testing memory and observing symptoms.
Under the proposed guidelines, healthcare providers would use a numerical staging system, giving patients a rating from 0 to six reflecting the stage of their disease, much like the staging system utilized in cancer diagnosis. Reuters reported. The rating could be based on the detection of biomarkers and cognitive changes.
“Care must evolve with science,” said Dr. Maria C. Carrillo, chief scientific officer of the Alzheimer’s Association, in a Press release“Our understanding of Alzheimer's disease has evolved, particularly our understanding of biomarkers, and this needs to be reflected in the way we describe and diagnose the disease.”
One of the core principles of the project is that “Alzheimer’s disease (AD) should be defined biologically and not based on clinical syndromes.”
The latest diagnostic procedures are expected to hurry up Alzheimer's diagnosis and enable patients to make informed decisions sooner, the press release states. Doctors could also determine earlier whether a patient is affected by Alzheimer's or one other disease with similar symptoms.
The latest guidelines would replace those adopted in 2018. The change is prompted by major advances within the testing of biomarkers, sometimes called molecular markers and signature molecules.
Biomarkers could be obtained in some ways, including blood tests and brain scans. Blood tests may also help doctors higher detect the buildup of beta-amyloid and tau proteins within the brain, which is an indication that an individual has or is developing Alzheimer's disease.
A Draft The latest guidelines were presented on Sunday on the Alzheimer's Association's international conference in Amsterdam. The draft guidelines are open to expert review and comment and could be revised after the comment period.
According to Reuters, the staging system includes 4 biological stages, classified as A, B, C and D.
For example, an individual in stage 1a would show no symptoms of Alzheimer's but would have abnormal biomarkers. In stage 2, a patient would have abnormal biomarkers and subtle changes in behavior and cognition. Stage 3 could be very much like the present presymptomatic stage, which known as mild cognitive impairment. Stages 4, 5, and 6 correspond to mild, moderate, and severe dementia.
Stage 0 could be for people whose genes indicate that they're more likely to develop Alzheimer's, equivalent to individuals with Down syndrome.
One of the potential complications of the brand new staging system is that an individual might be diagnosed as having Stage 1 Alzheimer’s disease based on a blood test alone, despite the fact that they show no signs of memory loss, CNN reported.
Clifford Jack, a neuroradiologist on the Mayo Clinic and co-author of the rules, said some Alzheimer's experts aren't comfortable with that possibility. “It's a big point of contention in the field,” he told CNN.