New research by the Alzheimer’s Association suggests that diagnosis for this neurological condition may soon be detected through a quick blood test before the manifestation of fany symptoms.
Determining whether someone has the disease usually requires an extended diagnostic process, in which a doctor gathers a patient’s medical history, discusses symptoms, and administers verbal and visual cognitive tests.
The patient may then undergo a PET scan, an M.R.I., or a spinal tap, which are tests that identify the presence of two proteins in the brain, amyloid plaques and tau tangles, both associated with Alzheimer’s.
However, the draft guidelines, Revised Criteria for Diagnosis and Staging of Alzheimer’s Disease, display a much simpler approach in which a blood test could indicate the presence of amyloid. Tests such as these are already available in some clinics and doctor’s offices.
“Someone who has biomarker evidence of amyloid in the brain has the disease, whether they’re symptomatic or not,” reported Dr. Clifford R. Jack Jr. the chair of the working group and an Alzheimer’s researcher at the Mayo Clinic.
The final recommendations of the new criteria proposed by the association, which are expected later this year, will push a shift that is currently in action: from defining the disease by symptoms and behavioral patterns to defining it purely biologically using biomarkers, substances in the body that indicate the disease.
“The pathology exists for years before the inset of symptoms,” Dr. Jack said. “That’s the science. It’s irrefutable.”
Dr. Jack and his colleagues on the association’s panel still do not recommend testing people who have no symptoms of cognitive decline, but skeptics predict that it’s likely to occur regardless. In this case, a considerable percentage would test positive for amyloid and in turn be diagnosed with Alzheimer’s.
Yet, a number of experts and invested parties remain unconvinced by the proposition of turning to biomarkers alone. The American Geriatrics Society has called the new criteria “premature,” and has noted the significant proportion of panel members with ties to the pharmaceutical and biotechnology industries, which create potential conflicts of interest.
In addition to the amyloid blood tests, aducanumab (brand name: Aduhelm) and lecanemab (Leqembi), two drugs that remove amyloid from the brain, received regulatory approval, but not without controversy and waves of backlash from areas of the medical community.
Professionals on the other side of the matter argue that these shifts could help prevent Alzheimer’s from growing severe in patients before it’s too late, while others maintain that the monetary profits may outweigh the proposed medical gain.
