Health Spotlight: New blood test to diagnose Alzheimer’s

INDIANAPOLIS (WISH) — More than 6 million Americans are living with Alzheimer’s today. Half a million more people will be diagnosed this year, but thousands of cases will go undiagnosed, as well.

These undiagnosed cases go unnoticed because changes in the brain can begin at least 10 years or more before symptoms start. Now, researchers are working on new ways to detect the disease long before then.

For John and Lynn Struckhoff, retirement was a never-ending adventure that all changed when John started seeing his wife change. After several cognitive tests, doctors believed it was Alzheimer’s.

“I said, ‘Well, how do we know for sure?’ They said, ‘Well, the only way we really know is an autopsy and that’s not a practical thing right now,’” John said.

John then enrolled Lynn in a clinical trial by the Washington University School of Medicine that tests a person’s blood for changes in the brain.

The test measures two separate amyloid beta proteins, A-Beta 42 and A-Beta 40, in the blood. The less A-Beta 42 in the blood, the more likely someone is to have Alzheimer’s.

Dr. Suzanne Schindler with Washington University says that the A-Beta 42 is likely to get stuck in plaque, so it is unable to end up in the spinal fluid or in the blood.

When combined with genetic risk factors, the test is up to 93% accurate in identifying a person’s risk for Alzheimer’s. An earlier diagnosis could lead to new treatments to stop the progression.

“That’s what we’re aiming for — that you’ll get these tests and then get treated before you ever get symptoms,” Schindler said.

While this treatment is not an option for Lynn, the test gave John peace of mind. “She and I have been on a journey for 50-some-odd years and for whatever reason, she’s going on her own journey and I can’t come along,” he said.

The only other ways to test for Alzheimer’s are very costly. PET scans are the gold standard and cost up to $7,000, which is usually not covered by insurance. A spinal tap can cost up to $2,000. But, this blood test costs about $1,200 per patient.

The Washington University test is called Precivity-AD. While it’s available for use by doctors, the test is not yet covered by health insurance.

This story was created from a script aired on WISH-TV. Health Spotlight is presented by Community Health Network.