Lumipulse, a new biomarker blood test to help clinicians diagnose Alzheimer’s, recently received FDA approval. This is progress for sure, but to many providers it’s a confusing development. As Dr. Jason Karlawish of Penn Memory Center cautioned, “Used right, this is a test that could really help to improve the diagnostic experience. But the outcome can be inappropriate prescribing of the tests because a lot of people have a desire to get it, but not a lot of clinicians know how to properly use it.”
There’s a real need for clarity around where and when to leverage this advancement alongside other tools in a cognitive health workflow.
In autopsy studies, researchers have found that as many as 30% of individuals with the plaques and tangles characteristic of Alzheimer’s had no cognitive symptoms in their lifetimes, which is thought to be an indication of cognitive resilience. In fact, as the updated International Working Group recommendations state, “...recent literature shows that the majority of biomarker-positive cognitively normal individuals will not become symptomatic along a proximate timeline.” The blood biomarkers that Lumipulse detects reflect the presence of amyloid plaques, but in a person without symptoms, there’s no certainty these plaques will ever lead to cognitive impairment.
Dr. Clifford Jack, Mayo Clinic neurologist and author of the Alzheimer’s Association biomarker-focused diagnostic criteria, has stressed that these blood tests should only be used in symptomatic individuals. For example, those previously flagged by cognitive screening platforms like Neurotrack.
Further, if a patient has no cognitive symptoms, the current crop of medications are not a clear match. More research is underway, but for now, the new amyloid-targeting, disease-modifying drugs have only shown efficacy in patients with mild cognitive impairment (MCI) or mild-stage dementia, and their side effects (including brain bleeds) can be serious.
Neurotrack is excited about the potential of new Alzheimer’s blood tests, but they’re not a substitute for routine cognitive screening. These tools are actually used in different parts of a cognitive health workflow.
Cognitive screening should be done routinely, and at scale. Detecting cognitive impairment with an objective, digital tool like Neurotrack, is an inexpensive, easily accessible, and essential first step to a dementia diagnosis. Once results are evaluated along with other important indicators, other causes are ruled out, and an MCI or dementia diagnosis is made, then clinicians can determine the type of dementia present, and the stage of disease, which steers intervention and care planning. This is where new biomarker blood tests could be used selectively, as an alternative to more expensive or invasive PET scans or lumbar punctures, to make a differential diagnosis for Alzheimer’s disease.
Research is ongoing and both biomarker blood tests and medications will continue to evolve, but efficient and routine checks of cognitive function remain an efficient way to catch cognitive changes across populations and flag those who would benefit most from new breakthrough tests and drugs.