‘Impossible’: Blood test accurately diagnosed Alzheimer’s in 90 per cent of cases

Groundbreaking blood test technology could be the key to diagnosing Alzheimer’s, new research has found.

A simple blood test could be the key to diagnosing Alzheimer’s disease quicker and more accurately, a new study has found.

The research, published on Sunday in the journal Journal of the American Medical Association and conducted by a team of scientists at Sweden’s Lund University, was based off 1213 patients there with the condition, which is the most common form of dementia in Australia.

According to the study, a blood test correctly identified whether patients with memory problems had Alzheimer’s 90 per cent of the time – making it “significantly” more accurate than cognitive tests and CAT scans in signalling the condition.

“Not too long ago measuring pathology in the brain of a living human was considered just impossible,” co-director at the University of Pennsylvania’s Penn Memory Centre who was not involved in the research, Dr Jason Karlawish, told The New York Times.

“This study adds to the revolution that has occurred in our ability to measure what’s going on in the brain of living humans.”

A scan of a healthy brain versus one with Alzheimer’s disease.

The test measures tau protein 217, the abnormal build-up of which in and around brain cells scientists believe could cause the disease.

“Increases in p tau-217 concentrations in the blood are quite profound in Alzheimer’s disease,” study co-author, Lund University associate professor and senior consultant neurologist, Dr Sebastian Palmqvist, told CNN.

“At the dementia stage of the disease, levels are more than eight times higher compared with elderly (people) without Alzheimer’s.”

As part of the study, the p tau-217 test was combined with one testing for another blood biomarker for Alzheimer’s called the amyloid 42/40 ratio.

The blood test measured two biomarkers for Alzheimer’s, tau protein 217 and amyloid.

Chief science officer of America’s Alzheimer’s Association, Dr Maria Carrillo, told CNN doctors would “love to have a blood test that can be used in a primary care physician’s office, functioning like a cholesterol test but for Alzheimer’s”.

“The p tau-217 blood test is turning out to be the most specific for Alzheimer’s and the one with the most validity. It seems to be the frontrunner,” she added.

Blood tests like this could “change the game in the speed in which we can conduct Alzheimer’s trials and get to the next new medication”.

“These are absolutely transformational times,” Dr Carrillo said.