Affordable Blood Test Detects Proteins for Early Alzheimer's Diagnosis

Researchers from the Keck School of Medicine at USC have developed a cost-effective blood test capable of detecting early signs of Alzheimer's disease by measuring specific proteins associated with the condition. The innovative test, called Penta-Plex Alzheimer's Disease Capture Sandwich Immunoassay (5ADCSI), simultaneously measures five biomarkers, including various forms of amyloid and tau proteins, which are known to accumulate in the brain during Alzheimer's progression. This new approach surpasses traditional blood tests that usually detect fewer biomarkers and rely on specialized, expensive equipment, by utilizing widely accessible xMAP technology often found in many laboratories.

A recent proof-of-concept study published in the Journal of Alzheimer's Disease demonstrated that 5ADCSI effectively distinguishes between healthy individuals, those with mild cognitive impairment, and Alzheimer's patients. The test showed particularly strong correlations with cerebrospinal fluid biomarkers, which are more invasive and costly to obtain, suggesting that blood-based testing could be a reliable early screening tool.

This development is significant because early detection allows for interventions that may delay or prevent cognitive decline. The affordability of 5ADCSI could enable widespread screening programs similar to cholesterol or blood sugar tests, making early diagnosis more accessible. Dr. Ebrahim Zandi emphasized that the test’s simplicity and low cost could facilitate regular screenings in clinics, potentially leading to earlier treatment and lifestyle modifications such as increased exercise.

The test's creation involved selecting key biomarkers linked to Alzheimer's, including Aβ40, Aβ42, phosphorylated tau, neurofilament light chain, and GFAP. Using antibody-coated beads, scientists could detect these proteins in blood samples through fluorescence imaging, allowing precise quantification. The study included 63 blood samples, revealing that Alzheimer’s patients had significantly higher levels of biomarkers, especially p217Tau, a promising indicator of disease.

Moving forward, the researchers aim to validate the test in larger patient populations and incorporate it into clinical practice. The goal is to combine 5ADCSI with genetic testing for APOE4 to provide a comprehensive risk assessment, ultimately facilitating early preventive measures.

This breakthrough signifies a major step toward accessible, early detection of Alzheimer’s, potentially transforming how the disease is diagnosed and managed in the future.

Source: https://medicalxpress.com/news/2025-05-blood-proteins-early-alzheimer.html