A study published in Nature Communications found that RNA carried in tiny blood particles — including a newly characterized nanoparticle called a SECmere — may reveal Alzheimer’s-related brain changes earlier than current protein-based blood tests. According to Medical News Today, researchers identified brain-derived RNA signatures in circulating extracellular vesicles and particles (EVPs) from people with and without Alzheimer’s disease.
The Medical News Today report (Peter Morales-Brown, June 29, 2026) summarizes work in which investigators analyzed blood and brain tissue samples to isolate different EVP types and profile their RNA content. The team singled out SECmeres, described as sub-50-nanometer nanoparticles, as particularly enriched with markers of brain-cell origin.
Co-corresponding author Navneet Dogra, PhD, Assistant Professor of Pathology, Molecular and Cell-Based Medicine and member of the Icahn Genomics Institute at the Icahn School of Medicine at Mount Sinai, told Medical News Today that SECmeres “are significant because they are carrying RNA in blood from brain cell of origin.” The researchers report distinct RNA signatures in these particles that are linked with Alzheimer’s disease.
Most current blood tests for Alzheimer’s measure proteins such as amyloid-beta and phosphorylated tau. Medical News Today notes that the FDA cleared the protein-based Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio test in 2025. The study authors propose that RNA changes could arise earlier in the disease cascade than detectable protein accumulation, potentially widening the window for detection.
The investigators describe EVPs as a form of “liquid biopsy” of the brain and say RNA profiles in SECmeres might enable simpler, less invasive screening. Dogra and colleagues indicated plans for longitudinal studies to determine when these RNA changes appear during disease progression and suggested the potential development of a PCR-based assay to detect them in blood.
The research is preliminary. The authors and Medical News Today emphasize the need for larger, blinded clinical trials to validate the RNA biomarkers, determine diagnostic accuracy across diverse populations, and assess how well the signatures distinguish Alzheimer’s from other dementias and neurological disorders.
If validated, SECmere-based RNA assays could complement existing protein-based approaches and reduce reliance on costly imaging or invasive cerebrospinal fluid testing. For now, the findings point to a promising research direction rather than an available clinical test.
