First blood test for Alzheimer’s goes on sale in US

A US company has begun selling the first blood test to help diagnose Alzheimer’s disease.

St Louis based company, C2N Diagnostics, has started selling the test under general rules for commercial labs, as it has not yet been approved for use by the US Food and Drug Administration (FDA).

More than five million people in the US have Alzheimer’s, which is the most common form of dementia. To be diagnosed, people must have memory loss and a buildup of a protein called beta-amyloid in the brain.

Currently, the best way to test for the protein buildup is to undergo a PET brain scan, which can cost around $5,000 (£3,743) and is often not covered by medical insurance in the US.

C2N Diagnostics hopes that its blood test, which costs $1,250 (£936) with discounts offered based on income, can replace the scan as the most common way of identifying Alzheimer’s. However, it is also not covered by insurance or Medicare.

The test is currently being offered to people over the age of 60 who are undergoing assessments to determine whether they have Alzheimer’s.

Although it has not yet been approved for use by the FDA, the test is being sold in all but a few US states, and has just been cleared for sale in Europe.

C2N Diagnostics’ founders, Dr David Holtzman and Randall Bateman of Washington University School of Medicine, told the Associated Press that the test examined the same areas that the brain scan currently does.

Although the company has not yet released formal results on the accuracy of the test, the promotional materials claim it is comparable in accuracy with the brain scan currently offered.

The company’s chief executive, Dr Joel Braunstein, said that in trials the test missed eight per cent of cases that the brain scan found, while it ruled out Alzheimer’s 77 per cent of the time that the scan did.

Dr Braunstein said the company would seek FDA approval, and confirmed that the agency has designated it for a fast-tracked review.

He defended selling the tests before it has FDA approval, telling the Associated Press: “Should we be holding that technology back when it could have a big impact on patient care?”

However, Dr Eliezer Masliah, the neuroscience chief at the US National Institute on Aging, said: “I would be cautious about interpreting any of these things.”

He revealed the US government had helped fund the project, but added: “We’re encouraged, we’re interested, we’re funding this work but we want to see results.”

Heather Snyder of the Alzheimer’s Association said that the organisation will not endorse a test without FDA approval.

She added: “It’s not quite clear how accurate or generalisable the results are.”