USC scientists have unveiled a new blood test to detect Alzheimer’s disease early. This affordable and accessible test, which measures five biomarkers, could revolutionize how the disease is diagnosed and treated.
Researchers from the Keck School of Medicine at the University of Southern California (USC) have made a significant breakthrough in the early detection of Alzheimer’s disease with the development of a cost-effective blood test. Known as the Penta-Plex Alzheimer’s Disease Capture Sandwich Immunoassay (5ADCSI), this test measures five crucial biomarkers linked to Alzheimer’s, offering an economic and accessible solution for early diagnosis.
The new test can identify the presence of amyloid and tau, proteins that accumulate in the brain and blood as Alzheimer’s progresses. Unlike its expensive predecessors that require specialized equipment and can only detect a few biomarkers, 5ADCSI utilizes the widely available xMAP® technology from Luminex.
This advancement promises to bring annual Alzheimer’s screenings into routine medical practice.
“The biggest advantage is that our test is very cost-effective compared to other existing technologies, and it’s relatively easy to implement because many laboratories in universities, hospitals and clinics are already using this technology,” Ebrahim Zandi, an associate professor of molecular microbiology and immunology at the Keck School of Medicine who led the research, said in a news release.
Early Detection, Early Intervention
The importance of early detection in Alzheimer’s cannot be overstated. Current treatments are most effective when applied at the earliest stages, before significant cognitive decline.
The 5ADCSI test, with its affordability and ease of use, could make widespread early detection feasible. This timely identification enables interventions that might delay or even prevent the onset of severe symptoms.
“In the 10 to 20 years Alzheimer’s takes to develop, proteins such as amyloid and tau are slowly building up,” Zandi added. “If we have an affordable blood test that detects those proteins early on, we can start interventions long before symptoms begin.”
Development and Testing
The research team meticulously chose biomarkers known to accumulate with Alzheimer’s: amyloid-beta 40, amyloid-beta 42, phosphorylated tau (p217Tau), neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP).
Using xMAP® technology, they developed a custom assay for these biomarkers. The test involves color-coded beads coated with antibodies that bind to these proteins in a blood sample. The biomarkers are then identified using powerful imaging sensors.
In a proof-of-concept study, funded by the National Institutes of Health and published in the Journal of Alzheimer’s Disease, the researchers validated the test’s effectiveness by measuring biomarkers in 63 blood samples.
These samples came from three groups: patients with Alzheimer’s, individuals with mild cognitive impairment and healthy participants. The highest levels of biomarkers were found in those with Alzheimer’s.
Further tests compared blood biomarker levels to those in cerebrospinal fluid (CSF), the latter being more challenging and costly to collect. The strong correlations found validate the test’s sensitivity and capability for early detection.
Future Prospects
Christopher Beam, an associate professor of psychology at the USC Dornsife College of Letters, Arts and Sciences, highlighted how this innovation serves both research and clinical needs.
Initially developed for research purposes, the team aims to refine the test for clinical settings, planning larger studies to confirm its accuracy across a broader patient population.
Zandi and his colleagues envision the test becoming a standard component of annual check-ups, rivaling cholesterol and blood sugar tests. He aims to expand the test’s utility by integrating genetic testing for APOE4, a gene variant associated with Alzheimer’s, enabling comprehensive brain health risk assessments.
Source: Keck School of Medicine, University of Southern California