Proteins that may signal dementia with Lewy bodies (DLB) are GFAP, alpha-synuclein, NfL and p-tau217 in plasma, plus alpha-synuclein in red blood cells. Plasma levels run higher in DLB, while red-cell alpha-synuclein runs lower than in healthy people and in Alzheimer's or Parkinson's disease. DLB affects mainly older adults and is hard to separate early because symptoms overlap other dementias. A simple blood test would help doctors choose care sooner and find the right trial.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- Why does low red-cell alpha-synuclein matter?
- What does the four-protein plasma panel add?
- Which changes show up first?
- What should families do now?
Why does low red-cell alpha-synuclein matter?
Toho University researchers found people with DLB carry far less alpha-synuclein in red blood cells than healthy controls and patients with Alzheimer's or Parkinson's disease, as described in the Toho University announcement. The team said the drop could form the basis of a simple blood test to tell DLB apart early.
That distinction matters because memory loss, slowed movement and hallucinations cross disease lines. A red-cell measure points directly at Lewy-related change rather than general decline.
What does the four-protein plasma panel add?
In 151 DLB patients versus 2010 controls, plasma GFAP, alpha-synuclein, NfL and p-tau217 were all higher in DLB. Researchers writing in npj Parkinson's Disease reported the four-protein panel plus polygenic risk scores reached AUC 0.927 for DLB diagnosis, in the Nature study report.
The result affects mainly older adults at risk for DLB. A combined score sorts risk better than any single protein alone.
Which changes show up first?
The NINDS PDBP summary of Diaz-Galvan and colleagues tracks timing across the DLB continuum, as detailed in the NINDS PDBP summary. Abnormal plasma GFAP appears at prodromal mild cognitive impairment with Lewy bodies with higher amyloid PET.
Abnormal p-tau181 and NfL appear later, at the dementia stage. Plasma p-tau181 showed the highest accuracy for detecting abnormal amyloid and tau PET in DLB. Doctors can use it to flag Alzheimer's co-pathology and select patients for close monitoring or trials.
What should families do now?
Lund University researchers found misfolded alpha-synuclein before symptoms in spinal fluid in about 10% of more than 1,100 healthy people. They cautioned that blood testing is harder because target levels are much lower than in spinal fluid, according to the Lund University report.
These tests are research tools, not clinic tests. If changes in memory, movement, sleep or alertness worry you: Bring that record to the visit and ask which follow-up fits your case.
- write down start dates, frequency and examples of hallucinations, fainting, stiffness and daytime sleepiness
- bring a full drug list, symptom diary and family history to the visit
- ask about referral to a memory clinic and about trials that use plasma markers
