α-synuclein antibodies recognize a protein present at lower levels in the CSF of patients with dementia with Lewy bodies

Background: Dementia with Lewy bodies (DLB) accounts for 15-20%, of the millions of people worldwide with dementia. Accurate diagnosis is essential to avoid harm and optimize clinical management. There is therefore an urgent need to identify reliable biomarkers. Methods: Mass spectrometry was used to determine the specificity of antibody alpha-synuclein (211) for alpha-synuclein. Using gel electrophoresis we measured protein levels detected by alpha-synuclein specific antibodies in the cerebrospinal fluid (CSF) of DLB patients and compared them to age matched controls. Results: A 24 kDa band was detected using alpha-synuclein specific antibodies which was significantly reduced in the CSF of DLB patients compared to age matched controls (p < 0.05). Further analysis confirmed that even DLB patients with mild dementia showed significant reductions in this protein in comparison to controls. Conclusions: The current study emphasizes the necessity for further studies of CSF alpha-synuclein as a biomarker of DLB and extends our previous knowledge by establishing a potential relationship between alpha-synuclein and the severity of cognitive impairment. The identification of this 24 kDa protein is the next important step in these studies.