New protein discovery may contribute to improving the diagnosis of Dementia with Lewy Bodies

A research team led by Associate Professor Ayako Okado-Matsumoto from the Department of Biology at Toho University has made a significant finding that sheds new light on Dementia with Lewy Bodies (DLB). This study was conducted in collaboration with Professor Ryuji Sakakibara from the Department of Neurology at Sakura Medical Center, and Professors Hitoshi Nukada and Soroku Yagihashi from the Department of Exploratory Medicine on Nature, Life and Man at Toho University.

The team discovered a notable change in a specific protein found in the blood of patients with DLB. Their research revealed that individuals with DLB have significantly lower levels of α-synuclein in their red blood cells, compared to healthy individuals and patients with other neurological conditions such as Alzheimer's and Parkinson's diseases. α-synuclein is a protein known to play a role in the development of several neurodegenerative disorders when it accumulates abnormally in brain cells.

This finding may contribute to improving the diagnosis of DLB, which is often difficult to detect at an early stage. The possibility of developing a simple blood-based biomarker for early detection could offer meaningful benefits for both patients and their families.

The research findings were published online in The Journal of Biochemistry on April 16, 2025.

Key research findings

• Lower α-synuclein levels in DLB patients:
  The study revealed that individuals with Dementia with Lewy Bodies (DLB) have notably lower levels of α-synuclein in their red blood cells compared to healthy individuals or patients with Alzheimer's or Parkinson's disease.

• Elevated α-synuclein in plasma extracellular vesicles:
  The researchers also found that α-synuclein levels are elevated in small membrane-bound particles called extracellular vesicles-released by cells and present in the plasma-in patients with Alzheimer's disease, Parkinson's disease, and DLB, compared to healthy individuals.

• Implications for early diagnosis:
  These findings may contribute to the development of a blood-based test that could enable earlier and more accurate diagnosis of DLB, potentially leading to improved treatment outcomes and better patient care.