New Blood Test Shows 90% Accuracy in Diagnosing Alzheimer’s Disease

A recent study from Lund University in Sweden reveals that a blood test can determine whether memory loss is due to Alzheimer’s disease with over 90 percent accuracy. Published on July 28 in the Journal of the American Medical Association, the study highlights the potential of the p-tau217 blood test to outperform diagnoses from both primary care and specialist doctors.

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Study Findings

Researchers at Lund University discovered that the p-tau217 blood test can identify Alzheimer’s-related memory loss with 91 percent accuracy. In comparison, specialist doctors have an accuracy rate of 73 percent, and primary care doctors have an accuracy rate of 61 percent. This new test offers a more accessible and cost-effective alternative to the current gold-standard methods, which are expensive and often involve long wait times.

How the p-tau217 Test Works

The p-tau217 blood test measures levels of a specific blood peptide, a marker of neurological damage due to Alzheimer’s. By analyzing these levels, doctors can determine if cognitive decline is caused by Alzheimer’s or another form of dementia. Tau protein tangles, which are tracked by this test, indicate the buildup of amyloid in the brain—a key sign of Alzheimer’s. These tangles can appear decades before severe memory loss begins and are the target of new medications for the disease.

Research and Results

The study involved about 1,200 participants, with an average age of 74, who were being evaluated for potential Alzheimer’s. The blood test results were compared to diagnoses by doctors and full-accuracy spinal tap tests. Despite the high accuracy of the p-tau217 blood test, it is not infallible. Researchers hope it will reduce the burden on specialist care and improve access to diagnosis and treatment for those in need.

A similar study conducted in January showed even better results, with the p-tau217 blood test achieving a diagnosis accuracy of 96 percent.

Current Diagnostic Methods

According to the Mayo Clinic, brain imaging techniques like MRI, CT, or PET scans are commonly used to help diagnose Alzheimer’s. While laboratory blood tests can sometimes detect amyloid and tau levels, these tests are not widely available and may have limited coverage.

The Impact of Alzheimer’s Disease

The Centers for Disease Control and Prevention (CDC) state that Alzheimer’s is the most common form of dementia. It is a progressive disease that starts with mild memory loss and can lead to an inability to carry on a conversation or respond to the environment. In 2020, the CDC estimated that up to 5.8 million Americans were living with Alzheimer’s.

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The new p-tau217 blood test offers a promising advancement in the diagnosis of Alzheimer’s disease. With its high accuracy and potential for widespread use, it could significantly improve the detection and treatment of this debilitating condition.

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References:

• Lund University Study: Journal of the American Medical Association, July 28.
• Mayo Clinic: Diagnostic Methods for Alzheimer’s Disease.
• Centers for Disease Control and Prevention (CDC): Alzheimer’s Disease Overview.