A new path has opened for patients with neurological conditions to monitor their disease progression through a simple blood test, potentially eliminating the need for frequent and repetitive MRI scans.
A joint research team, led by Professor Lee Eun-jae of the Department of Neurology at Asan Medical Center, Dr. Kim Jin-hee of the Biomedical Research Institute, and Professor Shin Yong of the Department of Bioengineering at Yonsei University, announced the development of a novel biomarker technology. This technology tracks brain disease activity by selectively isolating signals from specific brain cells found in the bloodstream. The team's findings were recently published in the international nanoscience journal, Nano Today.
Addressing the Limitations of Traditional Imaging
Most brain diseases are degenerative, meaning they worsen over time as damaged nerve cells struggle to recover. This makes early diagnosis and continuous monitoring of recurrence vital. However, the brain is notoriously difficult to biopsy, and imaging tests like MRI have inherent limitations in tracking subtle, molecular-level changes. Furthermore, MRIs are expensive and require patients to remain perfectly still for extended periods, creating a significant physical and financial burden.
In response, the researchers developed a nanotechnology capable of isolating and analyzing signals from specific brain cells within the blood, successfully identifying molecular changes that reflect active disease.
The Breakthrough in Extracellular Vesicle Isolation
The team focused their research on extracellular vesicles (EVs)—tiny sacs secreted by cells that carry internal biological information, such as proteins and microRNAs. Because blood contains a mixture of EVs from cells throughout the entire body, isolating those specifically derived from the brain has historically been a major challenge.
To overcome this, the team engineered peptide-imprinted nanocomposites. These composites mimic the structure of specific proteins to precisely recognize target molecules. The technology is designed to identify surface proteins on astrocytes, allowing researchers to selectively isolate astrocyte-derived EVs from a standard blood sample. Remarkably, this isolation process is completed within just 40 minutes.
Clinical Validation via Neuromyelitis Optica
The researchers validated this technology using patients with Neuromyelitis Optica Spectrum Disorder (NMOSD). NMOSD is an autoimmune disease where the immune system attacks astrocytes, leading to relapses that cause cumulative neurological damage, including vision loss and paralysis. Quick and accurate detection of these relapses is essential for effective treatment.
The team analyzed 147 serum samples from the Asan Medical Center Biobank in two stages. The initial phase compared serum from 39 patients experiencing acute relapses, 49 stable patients, and 20 healthy controls. To ensure the test could differentiate between various conditions, they also conducted analyses on 39 patients with Multiple Sclerosis and Parkinson’s disease who were treated between 2024 and 2025.
New Molecular Patterns for Personalized Care
The results revealed that levels of Glial Fibrillary Acidic Protein (GFAP)—a key indicator of astrocyte damage—were significantly higher in patients undergoing a relapse compared to those in a stable phase. Conversely, levels of Aquaporin-4 Immunoglobulin G (AQP4), a primary diagnostic marker for NMOSD, tended to decrease during relapses. These levels accurately reflected the patient’s relapse status regardless of age or the severity of neurological impairment.
Furthermore, NMOSD exhibited distinct molecular patterns compared to Multiple Sclerosis and Parkinson’s, confirming the test's ability to differentiate between different central nervous system diseases. Characteristically shifting molecular signals were also observed in the microRNAs found within the isolated vesicles.
"This study presents the possibility of monitoring brain changes without repetitive imaging tests," said Professor Lee Eun-jae. "We expect this to be highly useful for predicting treatment responses and establishing personalized treatment strategies in the future."
Professor Shin Yong added, "Verifying the effectiveness of this technology through clinical patient serum is a substantial milestone. We expect this to become a foundational technology that can be expanded to various other brain diseases."
