New Blood Test May Make Alzheimer’s Diagnosis Easier

Researchers at the University of California – UC San Francisco have analyzed the blood test in more than 300 patients and believe that they will see such a test available in doctor’s offices within five years, according to a press release from The University of California- San Francisco’s entitled “New Blood Test Could Make Alzheimer’s Diagnosis Easier Than Ever.”

“This test could eventually be deployed in a primary care setting for people with memory concerns to identify who should be referred to specialized centers to participate in clinical trials or to be treated with new Alzheimer’s therapies, once they are approved, ” said Adam Boxer, MD, PhD, neurologist at the UCSF Memory and Aging Center and senior author of the study published in Nature Medicine. Boxer also is affiliated with the UCSF Weill Institute for Neurosciences.

There is currently no blood test for either condition. Alzheimer’s diagnoses can only be confirmed by a PET scan of the brain, which can be expensive or an invasive lumbar puncture to test cerebrospinal fluid.

If approved, the new blood test could make screening easier and help increase the number of patients eligible for clinical trials—vital to the search for drugs to stop or slow dementia. Patients who know whether they have Alzheimer’s or FTD are also better able to manage their symptoms.

In the new study, scientists collected blood samples from 362 people aged 58 to 70, including 56 individuals who’d been diagnosed with Alzheimer’s, 190 diagnosed with FTD, 47 with mild cognitive impairment, plus 69 healthy controls.

Researchers checked the blood samples for proteins that could serve as signs of dementia. One protein, called pTau181, is known to aggregate in tangles in the brains of patients with Alzheimer’s. Blood levels of pTau181 were about 3½ times higher in people with Alzheimer’s as opposed to their healthy peers. People with FTD had normal levels of pTau181, and those with mild cognitive impairment due to underlying Alzheimer’s had an intermediate increase.

When researchers followed the patients for two years, they saw that higher levels of pTau181 predicted more rapid cognitive decline in those with Alzheimer’s or mild cognitive impairment.

The researchers note the new blood test has the same degree of accuracy as current PET scans and lumbar punctures in distinguishing Alzheimer’s from FTD. It would be less expensive and easier.

Alzheimer’s impacts nearly 6 million Americans and comprises two-thirds of dementia cases. FTD includes a broad group of brain disorders often linked with degeneration of the frontal and temporal lobes of the brain.

Reference: UCSF (March 2, 2020) “New Blood Test Could Make Alzheimer’s Diagnosis Easier Than Ever”