Consumers Can Now Buy a Blood Test to Evaluate Their Alzheimer Disease Risk, but Should They?

Consumers can order blood tests from the laboratory testing behemoth Quest Diagnostics to check their iron or vitamin D levels, learn whether they have a sexually transmitted disease, or determine whether their thyroid is functioning properly.

And now, for $399, plus a $13 “physician service fee,” they can order a blood test that promises to help assess their risk of Alzheimer disease.

In a press release, Quest Diagnostics noted that its AD-Detect Test for Alzheimer Disease is the first blood test available for consumers to purchase that measures a biomarker linked to the most common form of dementia. The test uses liquid chromatography–tandem mass spectrometry to assess the ratio of 2 amyloid-β peptides, 42 and 40, in plasma. Amyloid deposits in the brain are a hallmark of Alzheimer disease, although many people who have them don’t develop cognitive impairment.

Some neurologists and at least 1 bioethicist question the wisdom of marketing such a test to physicians, let alone to consumers. The test might not be ready for prime time, they say, expressing concern about the test’s accuracy as well as how consumers might interpret its results.

The problem is that individuals aren’t the best judge of their own cognition, S. Ahmad Sajjadi, MD, PhD, chief of the Memory Disorders Division at the University of California at Irving, told JAMA in an email. “In our field,” he wrote, “we have clear definitions and working criteria for defining the symptomatic stage of Alzheimer’s, which can only be determined by experts after careful history-taking and appropriate ancillary tests,” such as a neuropsychological assessment. Sajjadi recently coauthored a blog post that raised concerns about AD-Detect.

Read the article here.