Researchers develop blood test to detect early-stage Alzheimer's

FILE - In this Feb. 6, 2012, file photo, Alexis McKenzie, right, executive director of The Methodist Home of the District of Columbia Forest Side, an Alzheimer's assisted-living facility in Washington, puts her hand on the arm of a resident. (AP Photo)

Researchers say they’ve developed a blood test that detects an early stage of Alzheimer’s disease with “unparalleled accuracy.” The test, developed by researchers at the Rowan University School of Osteopathic Medicine and Durin Technologies, Inc., was recently demonstrated in a proof of concept study involving more than 200 subjects and returned a 100 percent rate of overall accuracy, sensitivity and specificity.

“About 60 percent of all MCI (mild cognitive impairment) patients have MCI caused by an early stage of Alzheimer’s disease,” Cassandra DeMarshall, lead study author and Ph.D. candidate at the Rowan University Graduate School of Biomedical Sciences, said in a news release. “The remaining 40 percent of cases are caused by other factors, including vascular issues, drug side-effects and depression. To provide proper care, physicians need to know which cases of MCI are due to early Alzheimer’s and which are not.”

For the study, researchers analyzed blood samples from 236 subjects, including 50 MCI patients with low levels of amyloid beta 42 peptide in their cerebrospinal fluid, which is an indicator of ongoing Alzheimer’s pathology in the brain. They then identified the top 50 autoantibody biomarkers capable of detecting early-stage Alzheimer’s pathology in MCI patients by using human protein microarrays, which contain human proteins that are used as bait to attract blood-borne autoantibodies.

According to the news release, the 50 biomarkers were 100 percent accurate in distinguishing patients with MCI due to Alzheimer’s in multiple tests.

“Our results show that it is possible to use a small number of blood-borne autoantibodies to accurately diagnose early-stage Alzheimer’s. These findings could eventually lead to the development of a simple, inexpensive and relatively noninvasive way to diagnose this devastating disease in its earliest stages,” she said.

The results were published in Alzheimer’s & Dementia: Diagnosis Assessment & Disease Monitoring, where researchers also reported the test’s ability to distinguish early-stage Alzheimer’s from more advanced stages. According to the news release, researchers also noted the test’s capability to distinguish Alzheimer’s at the MCI stage from other diseases such as Parkinson’s disease, multiple sclerosis and early stage breast cancer.

“It is now generally believed that Alzheimer’s-related changes begin in the brain at least a decade before the emergence of telltale symptoms,” Dr. Robert Nagele, lead researcher from Rowan University School of Osteopathic Medicine, said in the news release. “To the best of our knowledge, this is the first blood test using autoantibody biomarkers that can accurately detect Alzheimer’s at an early point in the course of the disease when treatments are more likely to be beneficial— that is, before too much brain devastation has occurred.”

The researchers noted the MCI biomarker test will have to be replicated in a larger study to determine whether it can be used in a patient setting. If successful, researchers predict the test will help patients possibly delay disease progression through lifestyle changes and earlier treatment.